Abstracts

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GENERAL ANALYTICAL CHEMISTRY

1.1

Fundamentals, methods, apparatus, reagents, automation, data processing

Signal fluctuations due to individual droplets in inductively coupled plasma atomic emission spectrometry. J.W. Olesik, L.J. Smith and E.J. Williamsen.

Large emission intensity fluctuations are observed from analyte species in inductively coupled plasmas. Relative standard deviations are as large as 71% when emission is viewed with time resolution of ]0 gs. Low in the plasma, peaks in atom emission intensity are accompanied by depressions in ion emission. This behavior appears to be due to local cooling by aerosol droplets. High in the plasma, peaks in atom emission are followed by peaks in ion emission. These emission spikes result from atomization and ionization of analyte from vaporizing particles. Laser light scattering experiments show that droplets or particles exist in a conventional 1.0-kW plasma up to 20 mm above the load coil. Emission signals detected high in the plasma correlate with laser light scattering signals below. - Anal. Chem. 61, 2002-2008 (1989). Dept. Chem., Venable Kenan Labs., Univ. N. Carolina, Chapel Hill, NC (USA) Matrix effects of acids in inductively coupled plasma atomic emission spectrometry. Comparison of different instruments. E.G. Chudinov and G.V. Varvanina. Es wurde der Einflul3 von Minerals/iuren (HC1, HNOa, HC104, HzSO4, HaPO~) auf das analytische Signal (AS) yon 15 Elementen (Be, Cd, Cu, Co, Ga, Li, Mn, Mo, Ni, Sr, Te, T1, V, Y, Zn) bei der ICP-AESAnalyse untersucht; gearbeitet wurde mit 9 verschiedenen kommerziellen Spektroanalysatoren mit geeigneten Plasmageneratoren und automatischen Zerst/iubern mit freier oder Zwangsdosierung der zu analysierenden L6sung. Zur Durchf/ihrung der Messung unter analogen Bedingungen benutzte man das Plasma yon konstantem Strom. Die Beschreibung der getesteten Spektrometer und genaue Bedingungen der Analysendurchffihrung s. Original. Die S/iuren erniedrigen allgemein die durchschnittlichen AS-Werte, wobei ihre Unterdrfickungswirkung in der Reihe HC1 < HNO3 ~ HC104 ~ H3PO4 ~ H2SO~ steigt. 1 tool/1 HC1 erniedrigt z.B. AS um etwa 2%, dagegen 1 tool/1 H2SO4 um 12%. Je gr6Ber die Unterdrfickungswirkung der Sfiure ist, desto gr613er ist die Streuung der erreichten Ergebnisse in Anbetracht des durchschnittlichen Wertes. Die AS-Erniedrigung in saurem Medium ist der Dichte der L6sung sowie der Atomisierungsenergie der S/iuremolekel proportional; eine Ausnahme bildet HaSO4, wahrscheinlich infolge ihrer Trocknungseigenschaften. Die Abhfingigkeit des AS yon der verwendeten S/lure wird auch durch die Konstruktionseigenschaften und durch die Einstellung des Generators, weniger schon durch den pneumatischen Zerst/iuber, die Zerst/iubungskammer und das Verfahren der L6sungsdosierung in den Zerst~iuber, bedingt. Der beschriebene Effekt macht sich zumeist bei den Ger~iten mit Autogeneratoren mit der Frequenz um 50 MHz bemerkbar; bei einigen Ger/iten (z. B. Jobin-Yvon 48, SpectraSpan Beckman) bewirken die beschriebenen S/iuren eine Signalerh6hung. Die AS-Intensitfit von verschiedenen Elementen in Anwesenheit von den angeffihrten S/lurch unterscheidet sich je nach der benutzten Sfiure; die Differenzwirkung der S~iuren nimmt in der Reihe HC1 < HNO3 < HC104 ~ H2SO~ H3PO4 zu und hS.ngt nicht von einem einzigen Faktor der Analysendurchfi.ihrung ab. - Zh. Anal. Khim. 44, 814-826 (1989) (Russisch, mit engl. Zus.fass.). Kurchatov Inst. f. Atomenergie, Moskau (SU) F. Jancik Transient infrared emission spectroscopy by pulsed laser excitation. R.W. Jones and J.F. McCleliand. Transient infrared emission spectroscopy (TIRES) produces analytically useful emission spectra from optically thick samples by reducing

self-absorption of the emitted radiation. Use of a pulsed laser in the TIRES technique allows the observed emission from samples to be limited to a sufficiently thin surface layer of the material that self'absorption is nearly eliminated and the resulting spectra are close to being saturation free. Pulsed-laser TIRES emittance spectra are presented for various plastics and inorganic materials, and these spectra are compared to conventional emittance spectra and photoacoustic absorbance spectra. - Anal. Chem. 61, 1810-1815 (1989). Cent. Adv. Technol. Dev., Iowa State Univ., Ames, IA (USA) Approximation in calibration procedures for atomic absorption analysis. V.L. Makarov, N.G. Fattakhova and S.F. Gorbachev. Die Approximation der Eichkurven (EK), die unter Anwendung von verschiedenen Atomabsorptions-Spektrophotometern aufgestellt wurden, beruht iiblicherweise auf der durch die Beziehung A = klc + k2sin (C/Cm~x)TC(A = Absorbanz; c = Konzentration des zu bestimmenden Elements, k~,k2 = Koeffizienten) charakterisierten Modelleichkurve. Es werden die von verschiedenen Firmen, z. B. Perkin-Elmer (USA), Janaco (J), Baird Atomic (GB), Baird-Alpha (GB) und C. Zeiss, Jena (DDR) benutzten Approximationsverfahren sowie die lineare Approximation vorgelegt. Am besten bew/ihrte sich das Verfahren der Firma PerkinElmer, das auf der Beziehung c = klA + k3AZ/(k2A-1) beruht; bei diesem Verfahren verwendet man drei Vergleichsl6sungen in einem breiten Bereich der charakteristischen reellen EK; die Anderungen k6nnen im beschr~inkten Bereich durch die Beziehung A/c = a + bA + dA z ausgedrfickt werden. Einzelheiten der theoretischen Begrfindung des vorgeschlagenen Verfahrens der EK-Approximation s. Original, - Zh. Anal. Khim. 44, 810-813 (1989) (Russisch, mit engl. Zus.fass.). F. Jancik Theoretical calculation of measurement sensitivity in atomic absorption spectrometry using a temperature-stabilized furnace with a platform. B.V. L'vov, V.G. Nikolaev, E.A. Norman, N.V. Kocharova and N.P. Romanova. Es werden die berechneten und experimentellen Werte der charakteristischen Massen m ° ffir 35 Elemente verglichen; die Proben wurden zu diesem Zweck unter Bedingungen des temperaturstabilisierten Graphitrohrofens mit der Plattform bzw. Folie atomisiert. Zur theoretischen Berechnung dieser Werte benutzte man ein vereinfachtes Modell der Dampfdiffusion der Probe yon der Rohrmitte zu den Seiten6ffnungen des isothermisch erhitzten Ofens mit Hinsicht auf die Rohrlfinge und Atomisierungsdauer. Es werden auch einige physikalische Parameter (namentlich f u n d a) vereinfacht und der Einflul3 von naheliegenden analytischen Linien und der Doppler-Breite der analytischen Linie im Spektrum der Lichtquelle berficksichtigt. Die durchschnittlichen Werte yon m0ber/m0oxp entsprechen 0,86 + 0,13 mit Ausnahme von Li und Cs, deren Atomisierung durch Atomionisierung begleitet wird, so dab das erw/ihnte m°-Verhfiltnis 1,5-2mal h6her ist. Beim Durchmessen der angefiihrten Werte bemerkte man keinen Einflug der Raumnichtisothermie des Ofens aufdie Empfindlichkeit der Elementbestimmung. Gearbeitet wurde mit den AA-Spektrometern Perkin-Elmer, Modell 603 und 5000 mit den Atomisatoren HGA-76B und HGA-500 mit Ta-Folie bzw. Plattform. Die erzielten berechneten sowie experimentellen Resultate sind in einer Tabelle zusammengefaBt. - Zh. Anal. Khim. 44, 802 - 809 (1989) (Russisch, mit engl. Zus.fass.). Polytechn. Inst., Leningrad (SU) F. Jancik Gaseous-phase transfer of metals during low-temperature reduction of oxides by carbon in graphite furnace atomic absorption analysis. B.V. Uvov, L.K. Polzik and A.I. Yuzefovsky. Der Mechanismus der carbothermischen Reduktion yon Metalloxiden, der bei der Atomabsorptionsanalyse im Graphitrohrofen (GRO) verl/iuft, wird experimentell bestfitigt. Es wurde das Ph/inomen der Gasphasenfibertragung der Metalle aus der Sonde auf die GRO-Wfinde

426 w~ihrend der AnaIyse der Oxide von Bi, Pb, Cu, In, Mn, Ni, Co und Cr bei verh/iltnismfiBig niedrigen Temperaturen (470--920 K) nachgewiesen. Diese Feststellung bestfitigte v611igdie Theorie des Gascarbid-Mechanismus der carbothermischen Reduktion yon Metalloxiden, wobei das prim/ire Stadium der Reduktion des Oxids mit dem Kohlenstoff unter Bildung der Gasform des Metalls unabh/ingig vonder Metalldampftension verl~iuft. Man bestimmte die Ausgangstemperaturen der carbothermischen Reduktion der erwfihnten Metalloxide, die mit den berechneten Werten (Tabelle) gut tibereinstimmen. Mittels der Theorie des Mechanismus der carbothermischen Reduktion der Metalloxide kann man einige ungewohnte Ph/inomene bei der AAS unter Anwendung von GRO er1/iutern. - Zh. Anal. Khim. 44, 794-801 (1989) (Russisch, mit engl. Zus.fass.). Polytechn. Inst., Leningrad (SU) F. Jancik Cycloazachroms as reagents for spectrophotometric determination of elements. T.V. Petrova, A.V. Sultanov and S.B. Savvin. Man synthetisierte ] 7 neue zur Cycloazachrom-Gruppe (CAC) geh6rende Verbindungen durch Kupplung yon bis-diazotierten Bis(2-aminophenyl)oligopolyoxa(thia)alkanen mit Chromotrops/iure sowie auch yon zugeh6rigen Podanden und untersuehte ihre Farbreaktion mit 31 Metaliionen (MI). Die Reaktion mit MI wurde mit 0,025- 0,050%igen w/iBrigen L6sungen der genannten Verbindungen (StrukturformeI s. Original) bzw. unter Zusatz yon Aceton, n-Propanol, Dimethylformamid und Essigs/iure durchgeffihrt. Aufgrund des spektralphotometrischen Verhaltens sind CAC mit 2,7-bisazo-substituierten Chromotrops/iure-Derivaten vergleichbar. Von den untersuchten Reaktionen waren fiir eine Bestimmung am geeignetsten die Reaktion Hexaoxa-CAC (HO-CAC) mit Pb(II) und Tetraoxa-CAC (TO-CAC) mit Mo(VI), wobei auch andere CAC verwendbar sind. HO-CAC reagiert mit Pb(II) bei pH ~<3 unter Bildung des Farbkomplexes Pb: R = 1:2 (~max = 6 8 0 - - 720 nm; = 1,5 x ]0s), der erlaubt Pb neben Hg (1:6000), Ag (/:500), As(V) (/:2200), Sb(III) (1:700), In (1:600), Ge (1:400) und Cd (1:280) zu bestimmen. TO-CAC reagiert mit Mo(VI) in 0,05-0,1 M HC1, HNO3 oder H2SO4 unter Bildung eines Farbkomplexes @m,x = 620 und 680 rim; s = 5,2 x 104), der erm6glicht Mo in Anwesenheit von Hg und As(V) (1 : 5000), U(VI) und In (1 : 2500); Mg (1 : 700), Pb (1 : 500), Ni, Ca und Fe(III) (1 : ] 50), Zn (1 : 250), A1, Cr(III) und Bi (1 : 50) zu bestimmen. Ein 150facher Oberschul3 von Wein- und Phosphors~iure und ]0Sfacher UberschuB von Essigsfiure st6ren nicht. - Zh. Anal. Khim. 44, 6 0 3 614 (]989) (Russisch, mit engl. Zus.fass.). Vernadskii Inst. Geochem. u. Anal. Chem., Akad. Wiss., Moskau (SU) F. Jancik Masking agents in the spectrophotometric determination of metal ions with 2-(5-hromo-2-pyridylazo)-5-diethylaminophenol and non-ionic surfactant. J. Miura. Efficient masking methods were found for the selective spectrophotometric determination of metal ions with 2-(5-bromo-2-pyridylazo)-5diethylaminophenol in a miceliar solution of a non-ionic surfactant. N(Dithiocarboxy)sareosine (DTCS) and nitrilotriacetic acid were good choices for the determination of iron(II). Triethylenetetraamine and DTCS (or dimercaptosuccinic acid and diethylenetriamine) were an excellent combination for the specific determination of manganese(II). A combination of pyrophosphate and ethylene glycol bis(2-aminoethyl ether)-N,N,N',N'-tetraacetic acid was useful for the determination of cobalt(II). Hence, iron, manganese and cobalt were determined with high selectivity in various samples such as natural waters, metal samples and soil. - Analyst 114, 1323-1329 (1989). Fac. Engin., Fukui Univ., Bunkyo Fukui (J) Global optimization by simulated annealing with wavelength selection for ultraviolet-visible spectrophotometry. J.H. Kalivas, N. Roberts and J.M. Sutter. The problem of process optimization is routinely encountered by chemists. One favored technique for determination of a best or optimal set of operating conditions for a given system has been the simplex algorithm. The major defect of simplex lies in its inability to guarantee that the global optimum of a system has been located. This assurance is gained only by the convergence of repetitive trials with widely spaced starting points to the same globaI optimum. The generalized simulated annealing (GSA) method is promoted as a global optimum location technique, due to the ability of the algorithm to walk out of local optima

1 General analytical chemistry and converge upon the global optimum. Mathematical models with multiple optima are used to compare the convergence of simplex with GSA, and successful global optimum location by GSA is demonstrated. GSA locates the global optimum regardless of the starting position. GSA is also demonstrated as a viable route for wavelength selection. Anal. Chem. 61, 2024-2030 (1989). Dept. Chem., State Univ., Pocatello, ID (USA) Quantitative approximation for the selectivity of analytical spectrophotometric procedures with system which do not obey Beer's law. V. Peris Martinez, J.V. Gimeno Adelantado, A. Pastor Garcia and F. Bosch Reig. Verff. schlagen einen Selektivit/itsindex zur Definition der Selektivit/it eines spektralphotometrischen Verfahrens vor, das St6rungen durch Species ausgesetzt ist, die nicht dem Beerschen Gesetz innerhalb dieses Systems unterliegen. Die Wechselwirkungen zwischen Analyt und St6rsubstanzen, die die Absorption eines analytischen Systems beeinflussen, werden durch ein einfaches mathematisches Modell beschrieben. Es werden theoretische Ableitungen gegeben, die die Selektivitfit als Funktion der Analyt- oder St6rsubstanzkonzentration darstellen. Die Methodik wird am Beispiel des Zr(IV)-Chloranilsfiure-Systems in Gegenwart yon Thorium als St6rsubstanz erlfiutert. - Talanta 36, 909-917 (1989). Anal. Chem. Dept., Fac. Chem., Univ. Valencia, Burjassot (Valencia) (E) W. Czysz Quantitative analysis in the presence of spectral interferents using secondorder nonbilinear data. B.E. Wilson and B.R. Kowalski. One of the most serious problems that can occur when a model is being used to predict the concentration of an analyte in an unknown sample is the presence of one or more chemical species that are unaccounted for in the calibration samples. With very few exceptions, the model being used to predict analyte concentration is invalidated by the presence of these spectral interferents, and in some cases it is not even possible to detect the invalidation of the model except when nonsensical predictions are obtained. One group of methods that have been used successfully for prediction in the presence of spectral interferents are the rank annihilation methods. This paper compares nonbilinear rank annihilation with three curve resolution methods on three data sets (simulated spectra, two-dimensional nuclear magnetic resonance, and tandem mass spectrometry) for their abilities to accurately predict the concentration of an analyte in the presence of one ore more spectral interferents. Multiple linear regression is used as a referee method. It is shown that nonbilinear rank annihilation is the only one of the methods tested which has any potential for solving real chemical problems, in as much as the curve resolution methods are not consistently able to correctly solve even idealized cases (with no noise present). - Anal. Chem. 61, 2277-2284 (1989). Lab. Chemometr., Dept. Chem., Univ., Seattle, WA (USA) Chromatographic and luminescence properties of a 7-aminocoumarin derivative with peroxyoxalate chemiexcitation. M. Tod, M. Prevot, M. Poulou, R. Farinotti, J. Chalom and G. Mahuzier. Verff. beschreiben ein neues Derivatisierungsreagens f/ir Amine: Luminarin 1. Es wird in Form seines Pentylaminderivats eingesetzt. Gleichzeitig wird das chromatographische Verhalten im Normalphasen-RPSystem registriert. Bei Detektion durch Fluorescenzspektrometrie liegt die Nachweisgrenze im Subpikomolbereich. Bei optimierter Chemiluminescenzdetektion und Abtrennung im Normalphasen-System (unter Verwendung yon Bis(2,4-Dinitrophenyl)-oxalat und H202) k6nnen noch 1 Femtomol nachgewiesen werden, im RP-System (mit Bis(2,4,6-trichlorphenyl)-oxalat und H202) 6 Femtomol; die zugeh6rigen Variationskoeffizienten sind 3,4 bzw. 5,8%. - Anal. Chim. Acta 223, 3 0 9 - 3 / 7 (/989). Service Pharmacie, H6pital Avicenne, Bobigny (F) W. Czysz Quantitative estimation of component amplitudes in multiexponential data: Application to time-resolved fluorescence spectroscopy. A.L. Wong and J.M. Harris. Qnantitativer information about individual component contributions to multiexponential data is obtained by a reiterative, regression algorithm that employs a linear least-squares determination of component amplitudes within a nonlinear least-squares search for the exponential

1.1

Fundamentals, methods, apparatus, reagents, automation, data processing

decay times. Uncertainty in the parameter estimates, arising from uncertainty in the data and overlap in the response, is predicted from first principles. The analysis method includes weighting to account for the Poisson error distribution arising from shot-noise-limited signals, which increases the accuracy of the amplitude estimates. While the algorithm is applicable to a variety of kinetic methods, it is applied in the present work to the analysis of time-resolved fluorescence decay curves. A fluorescence decay curve, written as a row vector, D, is decomposed into two factors: A, a column vector containing the amplitude contribution of each component, and [C], a matrix which contains temporal behavior of each component in its rows. The analysis uses linear least squares to obtain estimates of A, which increases the efficiency by reducing the number of parameters that are searched. The theory of error in linear least squares allows the uncertainty of the component amplitudes to be determined from the [C] matrix, derived from best estimates of the temporal behavior of the sample. - Anal. Chem. 61, 2310 - 2315 (1989). Dept. Chem., Univ., Salt Lake City, UT (USA) Visible semiconductor laser fluorometry. T. [masaka, A. Tsukamoto and N. Ishibashi. A visible semiconductor laser oscillating at 670 nm is used as a light source for fluorescence spectrometry. The detection limit of rhodamine 800 is 4 x 10-12 M, which is slightly better than that obtained by nearinfrared semiconductor laser fluorometry. Several dyes with reactive sites, available in the deep-red region, are used as labeling reagents. Nile blue with a primary amine group is most efficiently bound to albumin with water-soluble carbodiimede, but the absorption maximum is located at 640 nm and is less efficiently detected. Oxazine 750 is less reactive to protein due to its attached ethyl group but gives the largest signal. This is ascribed to good coincidence between the absorption maximum (670 nm) and the laser wavelength. Methylene blue with a tertiary amino group is also used for labeling protein by electrostativ adsorption. Anal. Chem. 61, 2285-2288 (1989). Fac. Engin., Kyushu Univ., Hakozaki, Fukuoka (J) Excitation of K X-rays for a wide range of elements (25 ~< Z ~< 82) by direct interaction of beta particles from phosphorus-32. J.J. La Brecque and P.A. Rosales. The relative sensitivities of low-medium and high-Z elements from manganese to lead were investigated via their Kcz x-rays employing 75 gCi of 32p. This was accomplished by preparing various synthetic mixtures of elements in the range 25 ~< Z ~ 82, then simply introducing 32p solution to form source-samples. The advantages of excitation with 32p, are pure !3-emitter with a 13m,xenergy at 1709 keV, include the following: excitation of all the Kct x-rays from manganese to lead; the relative sensitivities of the K x-rays are all within one order of magnitude; the source itself does not produce any spectral lines; and the background can be greatly reduced by filtering. Excitation with 3zp is compared with that of a conventional 1°9Cd source and some possible applications are discussed. - X-Ray Spectrom. 18, 133-137 (1989). Inst. Venezolano Invest. Cien. IVIC, Caracas (YV) Enhancement between layers in multiple-layer thin-film samples. J.E. Willis. Secondary fluorescence effects are calculated and compared with the total fluorescence for multiple-layer thin-film samples of Fe, Ni and Fe, Ni, Cu, Cr. The ratio of secondary to total fluorescence for a given analyte is found to be greater in the system where the enhancer is in a layer which is closer to the surface. Secondary fluorescence effects are calculated for a Ni thin film on an Sn sample. Unusual acquisition conditions cause the intensity from the Ni thin film layer to exceed the intensity from a bulk sample of Ni. - X-Ray Spectrom. 18, 143-149 (1989). Data Acquisition and Control, Inc., Roswell, GA (USA) Heterogeneity effects and the reliability of X-ray fluorescence analytical results: Study on A1203 matrix with calcium, yttrium, gadolinium and thorium as probe elements. R.M. Agrawal and S.K. Kapoor. Synthetic standards obtained by dry mixing of the components in appropriate proportions, when used as calibration standards in XRF analysis can be a major source of error in the analytical results, owing to the differences in the degree of their homogeneity compared with that

427

of the sample. In an earlier study U3Os was used as the matrix and Ca, Y, Gd and Th in the low concentration range (0-1500 ppm) as probe impurity elements. The study has now been extended to the low-Z matrix A1203 using the same impurity elements as probe elements and the same concentrations range. This study also clearly illustrates the incompatibility of truely homogeneous standards with standards obtained by dry mixing and grinding and corroborates the results obtained in the earlier study. However, some of the general inferences drawn earlier required modification in order to explain the results for the two matrices. The effect of binding material, which is often required for briquetting the sample into pellet form and must be mixed with the sample by dry mixing, is discussed. - X-Ray Spectrom. 18,151 - 155 (1989). Spectrosc. Div., Bhabha Atomic Res. Centre, Trombay, Bombay (IND) Quantitative elemental analysis of thick samples by XRF and PIXE. F.B. Gil, G. Barreira, M.F. Guerra and L.C. Alves. An absolute quantitative analytical method without external standards has been developed for thick sample analysis by XRF and PIXE and has been applied to bronze and brass alloys. Comparisons between the results obtained and the chemical results were made and the detection limits for the determined elements were evaluated. In an Appendix a rapid calculation of the efficiency of the Ge(Hp) detector is presented. X-Ray Spectrom. 18, 157-164 (1989). Centro Fisica Nuclear Univ., Lisboa (P) Method for the determination of the phase fractions in solid systems by Xray microanalysis. R. Stoyanchev. A method is proposed for the quantitative evaluation of area fractions of phases with different chemical compositions in solid systems, e.g. alloys, mixtures of solid solutions and phases with defined stoichiometry, ceramics and minerals. The method is based on the scanning of the surface of the sample by an electron beam and applying an energydispersive x-ray spectrometer. By using the net integral intensities of the characteristic x-ray lines of the elements in the different phases, equations have been derived for the are fractions of an n-phase system composed o fro elements. Assuming that the phases are uniformly distributed within the sample, the practically important volume and weight fractious of the phases are expressed by the area fractions. A technique for the assessment of the elemental content in a complex sample using an electron probe is given, by using the phase fractions determined by the proposed method and the concentration data for the elements in the separate phases. The method has been tested experimentally for the determination of the area fractions in cases where the number of phases is less than or equal to the number of constituent elements. - X-Ray Spectrom. 18, 165-171 (1989). Inst. Phys. Chem., Acad. Sci., Sofia (BG) Influence of non-flat sample surface on e-coefficients. A. Kuczumow and J.A. Helsen. The application of the Lachance-Trail s-correction algorithm assumes homogeneous samples with fiat surfaces. In this paper a mathematical approach is presented describing the influence of non-flatness of sample surfaces on the value of a m-coefficient. The calculation is performed on a surface consisting of regular prismatic or pyramidal grooves. The ~coefficient is found to have a hyperbolic dependence on the slope of the solid with respect to the macroscopic surface. - X-Ray Spectrom. 18, 173-175 (1989). Dept. Metallurgy Materials Engin., Catholic Univ., Leuven (B) Factors affecting precision and accuracy in quantitative analysis by secondary ion mass spectrometry. R.C. Deng and P. Williams. In quantitative analysis by secondary ion mass spectrometry (SIMS) using external standards, precision and accuracy are affected by sample misaligmnent and different secondary ion energy distributions. To investigate this, depth profiles of four pieces of a B-implanted silicon wafer were obtained with samples mounted flat, or intentionally misaligned. The B ÷ signal was referenced to 3°Si+ and 28Si3+. In comparative analyses of four nominally identical samples, the relative standard deviation (RSD) was 5.9% for nominally flat samples compared to 13% for misaligned samples for the 3°Si + reference ion. When 28Si3÷ was used as the reference species, internal agreement was much worse (150% for misaligned samples compared to 13% for flat samples). The best results

428 (RSD 1.9%) were obtained for analyses from the center of one large sample with 3°Si+ as a reference. This study has shown that random sample misalignments lead to discrimination between analyte and reference ion species with differing energy distributions, which cause significant errors in the comparison of two samples. - Anal. Chem. 61, 1946 1948 (1989). Dept. Chem., State Univ., Tempe, AZ (USA) Separation of experiments in time and space using dual-cell Fourier transform ion cyclotron resonance mass spectrometry. J.R. Gord and B.S. Freiser. Verff. beschreiben eine neue Analysentechnik, Fourier-TransformIonencyclotronresonanz-Massenspektrometrie (FTICRMS), bei der die FT-Technologie zun/ichst auf ICR-Experimente iibertragen und die dabei ausgel6sten spezifischen Impulse in der Ionenfalle eines Massenspektrometers welter ausgewertet werden. Diese Technik bewfihrt sich besonders bei der Darstellung und Untersuchung bestimmter Ionenspecies in der Gasphase. Durch die Entwicklung yon Doppelzellen-FTICRMassenspektrometern k6nnen Experimente durchgeffihrt werden, die entweder r/iumlich aufgeteilt werden oder nach der Zeit hin differenzierbar sind. Beispiele (Schwefel-Eisen-Species) werden ausf/ihrlich beschrieben und anhand yon Massenspektren interpretiert. - Anal. Chim. Acta 225, 1 1 - 2 4 (1989). Dept. Chem., Purdue Univ., West Lafayette, IN (USA) W. Czysz Tandem quadrupol Fourier transform mass spectrometry. D.F. Hunt, J. Shabanowitz, J.R. Yates, III, P.R. Griffin and N.-Z. Zhu. Verff. zeigen, dag Tandem-Quadrupol-FT-MS eine fiir die Bestimmung yon Molekulargewichten geeignete Methode ist. Mit ihr k6nnen Proben im Massenbereich bis 6000 Dalton routinem/iBig im 0,1-1,0 pmol-Bereich analysiert werden. Fiir das Molekulargewicht indikative Ionen werden durch Partikelbeschug erzeugt, in ein supraleitendes Magnetfeld fiberf/ihrt, angereichert und massenanalysiert. Zus/itzliche strukturelle Informationen erh/ilt man durch Bestrahlen der angereicherten Ionen im Magnetfetd durch Photonen aus einem Argon-FluoridExcimer-Laser. M6glichkeiten der Sequenzanalyse yon Oligopeptiden, die durch Fliissigkeits-Chromatographie fraktioniert wurden, werden er6rtert. SchlieBlich wird die praktische Anwendung des Verfahrens am Beispiel der strukturellen Charakterisierung yon Proteinen, die mit zweidimensionaler Gel-Elektrophorese isoliert wurden, demonstriert. Anal. Chim. Acta 225, 1 - 10 (1989). Dept. Chem., State Univ., Charlottesville, VA (USA) W. Czysz Coupling of an atmospheric-sampling ion source with an ion-trap mass spectrometer. S.A. McLuckey, G.L. Glish and K,G. Asano. Eine an die Atmosph~ire angeschlossene Glfihentladungs-Ionisationsquelle wird direkt mit der Ionenfalle eines Massenspektrometers kombiniert. Diese Anordnung, deren genaue Konstruktion anhand einer Schemaskizze erlfiutert wird, erzielt unter optimalen Bedingungen eine Effizienz der Ioneninjektion yon 1 - 5 % . Faktoren, die die Effizienz beeinflussen, z. B. die Spannung des Linsensystems zwischen Ionenquellenausgang und Ionenfalleneingang, der Druck des Badgases, das im Geh/iuse des Ionenfallen-Vakuums vorhanden ist, die Art des Badgases und die Amplitude der Radiofrequenzspannung an der Ringelektrode wfihrend der Ioneninjektion. Die wichtigsten experimentellen Variablen fi.ir das AusmaB, in dem Dissoziation stattfindet, sind die Natur des Badgases, dessen Druck und die erw/ihnte Radiofrequenzspannung an der Ringelektrode wfihrend der Injektion. Beispiele von vielatomigen Anionen (z. B. DNT- und PropionsS.ure-Anion) sind angegeben. -- Anal. Chim. Acta 225, 25--35 (1989). Anal. Chem. Die., Nat. Lab., Oak Ridge, TN (USA) W. Czysz A method for correction of matrix effects in activation analysis based on characteristic X-ray measurements. A.M. Barouni, L. Bakos and E. Papp Zempl6n. The empirical coefficient method represents the absorption and enhancement effect of each eIement on each other by parameters independent of mass concentrations. This method is used together with the internal standard method for the determination of cadmium, bromine and selenium by 14 MeV neutron activation followed by X-ray spectrometry. The results of analysis show a relative error not more than

l

General analytical chemistry

_+5%. - J. Radioanal. Nucl. Chem., Art. 131, 445-455 (1989). Cent. Res. Inst., Phys., Budapest (H) Reactor neutron activation analysis followed by characteristic X-ray spectrometry. A.M. Barouni, L. Bakos, E. Papp Zempl~n and G. Ke6mley. The possibility of applications of characteristic X-rays from radioactive products of reactor neutron activation was investigated with particular emphasis on (n, 3'), (n, n'), (n, 2n), (n, p) and (n, c~) products with long half-lives. The sensitivity and detection limits of silver, cerium, gadolinium, selenium, cadmium and europium have been investigated. The elements were studied both in a pure and a matrix form, in both cases the samples were diluted with graphite ( ~ 90%) to minimize matrix effects (absorption and enhancement). - J. Radioanal. Nucl. Chem., Art. 131,457-466 (1989). Cent. Res. Inst. Phys., Budapest (H) Long-term stability of solid standards for radiochemical analysis. C.W. Sill. The long-term stability of - 2 0 0 mesh solid standards for use in radiochemical analysis has been questioned because of possible fractionation of the different sized particles on standing. Several such standards prepared by spiking - 200 to + 325 mesh soils with known quantities of various radionuclides were available in this laboratory that, because of some unique circumstance, were known to have been undisturbed for 5 to 15 years. Some standards prepared from naturally occuring uranium ores and mill tailings and then analyzed carefully and repeatedly for Z3°Th were also available. Small quantities of each standard were carefully removed from a thin layer at the top middle, and bottom of the sample and analyzed for the radionuclide present by the most sensitive and precise analytical methods available. The relative standard deviations of the individual measurements were generally in the range of 0.2 to 1%. Little or no statistical differences among the three fractions from any of the samples were present at the 95% confidence level. - Anal. Chem. 61, 2255-2258 (1989). Idaho Nat. Engin. Lab., EG&G, Idaho Falls, ID (USA) A different perspective on the theoretical plate in equilibrium chromatography. P.J. Karol. The differential rate model for equilibrium chromatography is used to derive both the continuous (Martin and Synge) plate model and the stepwise (Craig) plate model. The latter have previously been regarded as severely deficient because of the ad hoc manner in which the plate height is related to the chemistry and physics of the chromatographic process. However, it is demonstrated that the "height equivalent to a theoretical plate" arises naturally from a finite different approach to solving the rate equation. It is also argued that the much maligned step model is a phenomenologically valid approximation to the continuous plate model and also to the rate model. - Anal. Chem. 61, 1937-1941 (1989). Dept. Chem., Carnegie Mellon Univ., Pittsburg, PA (USA) Effect of some operational variables on the efficiency of ion chromatographic separations. D.R. Jenke. The influence of injection mass, eluent composition and operating temperature on the efficiency of six commercially available ion chromatography columns was examined. Efficiency was linearly related to injection mass even at masses well below the column overload limit. The linear relationship was maintained at injection masses approaching the method's quantitation limit. Injection mass had little influence on the nature of the efficiency versus linear velocity relationship. Changing the concentration of the eluent ion (ionic strength) in the mobile phase influenced efficiency; however, the nature of the effect was analyte and column specific. Modifying the speciation of the mobile phase at constant ionic strength produced a marked effect on efficiency with the multivalent form of the eluent ion producing a better efficiency. For silica based stationary phases, addition of up to 10% by volume methanol had no impact on chromatographic performance. Increasing the column temperature increased efficiency at high linear velocities but decreased efficiency at low linear velocity in accord with theoretical expectations. - J. Chromatogr. 479, 387-400 (1989). Baxter Healthcare, Corp., Willam B. Graham Sci. Center, Round Lake, IL (USA)

1.:1 Fundamentals, methods, apparatus, reagents, automation, data processing Performance of porous silica layers in open-tubular columns for liquid chromatography. P.P.H. Tock, C. Boshoven, H. Poppe, J.C. Kraak and K.K. Unger. Progress has been made in the preparation of porous silica layers in fused-silica capillaries for open-tubular liquid chromatography. The porous silica layer is prepared ba (i) static coating of the silica precursor, polyethoxysiloxane (PES), followed by (ii) converting the PES film into a porous silica layer with ammonia solution, The porous silica layer can be easily modified by silane reagents commonly used in packed column high-performance liquid chromatography. The performance of the silica layer with the different phase systems was tested with polyaromatic hydrocarbons and derivatized amino acids as samples. - J. Chromatogr. 477, 9 5 - :106 (1989). Lab. Anal. Chem., Univ., Amsterdam (NL); Inst. Anorg. Anal. Chem., Univ., Mainz (D) Synthesis and characterization of a hydride-modified porous silica material as an intermediate in the preparation of chemically bonded chromatographic stationary phases. J.E. Sandoval and J.J. Pesek. A novel synthetic approach to produce chemically bonded silica-based chromatographic stationary phases is presented and discussed. The procedure involves the preparation of a silica intermediate containing stable silicon hydride (silane) surface species followed by the catalytic addition of these to organic compounds bearing a terminal vinyl group. This paper deals with the preparation of the hydride intermediate via chlorination of silica followed by reduction with lithium tetrahydridoaluminate. Several spectroscopic and thermoanalytical techniques were used to obtain information regarding the structural characteristics of the surface-reduced silica material. It was found that the surface Sill species formed were hydrolytically stable at low pH and thermally stable in the presence of oxygen at temperatures up to about 450°C. Postreaction treatment of the hydride-derivatized solid with aqueous hydrochloric acid was also found to be essential to remove aluminum byproducts from the silica surface while presumably increasing the extent of silane formation. Anal. Chem. 61, 2067-2075 (:1989). Dept. Chem., San Jose State Univ., San Jose, CA (USA) Chemically bonded liquid crystals as stationary phases for high-performance liquid chromatography. Effects of mobile-phase composition. J.J. Pesek and A.M. Siouffi. The compound [4-(allyloxy)benzoyl]-4-methoxyphenyl (ABMP), shown to possess liquid crystal properties when bonded to a polysiloxane backbone, was covalently attached to silica and tested chromatographically for similar properties by mobile-phase-composition studies. Methanol, acetonitrile, and tetrahydrofuran are mixed with water in various proportions in order to determine the bonded material's reversephase behavior. The separation of anthracene and phenanthrene as well as that of carvone and pulegone is used to monitor the mobile-phase effects on the stationary phase. In all cases a plot of log k' vs percentage of organic solvent in the mobile phase is not completely linear. At higher percentages of organic solvent the plots is linear without separation of either pair of solutes. At lower percentages of organic solvent the plot is nonlinear and the two pairs of compounds are separated. This observation is attributed to a phase transition in the bonded material. Variable-temperature experiments also support the possibility of a phase transition. - Anal. Chem. 61, :1928-1931 (:1989). Dept. Chem., State Univ., San Jose, CA (USA) Determination and characterization of reversed-phase bonded ligands by chemical cleavage with aqueous hydrofluoric acid. K. Miyabe and N. Orita. Zur Bestimmung und Charakterisierung yon chemisch gebundenen Liganden in RP-Sfiulenffillmaterial (Variationen yon ODS: ODDMCS, ODDMFS, YMC ODS) wird eine Methode beschrieben, bei der das Material mit w/iBriger Fluorwasserstoffs/iure (konz.) chemisch zersetzt wird und die dabei entstehenden Produkte durch GC, NMR- und Massenspektrometrie bestimmt werden. Mit Hilfe von 13C-NMR-Spektren wird gezeigt, dab die Struktur der gebundenen Liganden durch die wS.13rige FluorwasserstoffsS.ure nicht ver/indert wird. Die Zersetzung verl/iuft schnell, so dab das Verfahren vor der chromatographischen oder spektrometrischen Analyse nur 15 min in Anspruch nimmt. Die rel.

429

Standardabweichungen liegen bei 3 - 4 % . - Talanta 36, 897-902 (1989). Central Labs., Kurita Water Ind. Ltd., Morinosato, Atsugi (J) W. Czysz Study of the changes in mono-, di- and trifnnctinnal octadecyl-modified packings for reversed-phase high-performance liquid chromatography with different eluent compositions. M. Hetem, L. van de Ven, J. de Haan, C. Cramers, K. Albert and E. Bayer. Two different types of silica substrates uniformly modified with reversed-phase high-performance liquid chromatographic (RP-HPLC) phases obtained with mono-, di- and trifunctional octadecylsilanes were subjected to artificial ageing under simulated routine conditions and were subsequently analyzed and evaluated. Changes in the properties of the bonded phase packings were characterized and quantified with chromatographic techniques, solid-state N M R and elemental analysis. These changes were correlated with selectivity, loss of silanes, gain in silanol content and rearrangement of the silica to silane bonding, When eluents of extremely high pH were used, the multifunctional octadecylsilane stationary phases showed a higher resistance towards ligand stripping. A chromatographic characterization method for obtaining information about the stability, capacity, selectivity and silica degradation of different RP-HPLC stationary phases is also presented. - J. Chromatogr. 479, 269-295 (1989). Univ. Technol., Dept. Chem. Technol., Lab. Instr. Anal., Eindhoven (NL) New perspectives in micellar liquid chromatography. M.F. Borgerding, R.L, Williams, Jr., W.L. Hinze and F.H. Quina. This paper will summarize several new findings obtained in our laboratory on the use of micellar mobile phases in liquid chromatography. The topics to be addressed include (i) stationary phase modification by the mobile phase surfactant in micellar liquid chromatography, (ii) investigation of the retention mechanism in micellar liquid chromatography (MLC) using an alkylbenzene homologous series, (iii) evaluation of the effects of organic additives upon retention and efficiency in MLC, and (iv) preliminary characterization of several new classes of surfactant molecules for use in MLC. The information gained from these studies provides new insights into the dynamic of MLC and demonstrates their potential usefulness in several new separation applications including the resolution of optical isomers. - J. Liquid Chromatogr. 12, 1367-1406 (1989). Dept. Chem., Wake Forest Univ., Winston-Salem, NC (USA) Influence of mass transfer kinetics on the separation of a binary mixture in displacement liquid chromatography. S. Golshan-Shirazi, B. Lin and G. Guiochon. The derivation and properties of the system of equations describing a nonlinear, nonideal model of chromatography are discussed in the case of the separation of the components of a binary mixture by displacement chromatography. This is a three-component problem and the system of equations includes three mass balance equations and three kinetic equations, one mass balance equation and one kinetic equation for each component of the binary mixture and for the displacer. The nature of the specific problem (displacement) is accounted for in the boundary conditions: a rectangular pulse of the sample is injected in a column containing only the pure mobile phase. After the injection, a stream of a solution of displacer is passed through the column. The procedure for calculating numerical solutions of the system of nonlinear partial differential equations obtained is explained and justified. The critical parameters for a displacement separation are the displacer concentration, the loading factor (ratio of sample size to column saturation capacity), and the number of theoretical plates as measured in linear elution, for a very small sample size. - Anal. Chem. 61, 1960-1970 (1989). Dept. Chem., Univ., Knoxville, TN (USA) Micro-liquid chromatography with diode array detection. M. Verzele, G. Steenbeke and J. Vindevogel. Commercial diode array detectors can be adapted to micro LC by replacing their detector cell with a miniaturized detector cell. In appropriate conditions, micro-LC can then generate an useful UV spectrum with 10 times less sample than needed with conventional LC. Some aspects of detector cell miniaturization are discussed. Results with two commercial

430 diode array detectors, modified with a miniaturized detector cell, are presented. - J. Chromatogr. 477, 8 7 - 9 3 (1989). Lab. Org. Chem., State Univ., Ghent (B)

Conditions for detecting overlapped peaks with principal component analysis in hyphenated chromatographic methods. P.J. Gemperline and J.C. Hamilton. The purpose of this paper is to describe the effect of spectral similarity and chromatographic resolution on the limit of detection for severely overlapped peaks using principal component analysis of data from hyphenated chromatographic techniques. A method is reported here for estimating the net signal due to minor components when overlapped with major components. The effects of relative concentrations, spectral similarity, and chromatographic resolution are each considered independently. Simulated and real data are analyzed to illustrate the method. Anal. Chem. 61, 2240-2243 (1989). Dept. Chem., East Carolina Univ., Greenville, NC (USA)

Electron spin resonance spectroscopic detection in high-performance liquid chromatography: Determination of metal complexes with radical-containing chelating reagents. Y.A. Zolotov, O.M. Petrukhin, A.R. Timerbaev, M.V. Evstiferov, V.V. Salov and N.G. Vanifatova. The possibilities of the application of electron spin resonance (ESR) spectroscopy as a method of detection in HPLC are described. For this purpose a commercially available high-performance liquid chromatograph and an ESR spectrometer were combined; no special interface was required for connecting the two instruments. The conditions for measurement of the ESR signal under flow conditions were optimised. The applicability of HPLC with ESR spectroscopic detection was demonstrated by determining a number of metals in the form of their complexes with spin-labelled nitrosyl-containing chelating reagents. For the determination of mercury(II) as its complex with 2,2,5,5-tetramethyl4-(thiobenzoylmethylidene)imidazolidine-J-oxyI a detection limit of 1 x 10 - 5 M can be achieved. The linear dynamic range covers more than two orders of magnitude and the relative standard deviation is 5% (5 x 10 .4 M Hg). The method should find wide application owing to the differences in the nature of the ESR spectra of the complexes and the reagent. - Analyst 114, 1337-1339 (1989). V.I. Vernadsky Inst. Geochem. Anal. Chem., Acad. Sci., Moscow (SU)

Examination of the automated soluteqndependent calibration technique. C.N. Renn and R.E. Synovec. The solute independent calibration (SICAL) method is used to simultaneously measure analyte concentration and to provide information, namely, the equivalent ionic conductance, leading to solute identification. The SICAL method was fully automated for sampling, chromatographic separation, data collection, and analysis and applied to ion chromatography using conductivity detection. Theoretical predictions for the precision and accuracy of the fully automated method are presented and experimentally validated. The sample was varied with respect to analyte concentration and identity, with the automated method successfully monitoring real-time changes. Over a 24-h period under steadystate sample conditions (26 measurements), the relative standard deviation of concentration was 2.5% for fluoride and 3.9% for chloride, while the relative standard deviation of the SICAL calculated equivalent ionic conductance was 0.9% for fluoride and 1.7% for chloride. Precision of automated injection for a single chromatographic system over the 24h period was better than 0.7%. Potential use of the method as a process monitor is discussed. - Anal. Chem. 61, 1915-1921 (1989). Cent. Process Anal. Chem., Dept. Chem., Univ. Washington, Seattle, WA (USA)

Multidimens!onai packed capillary column supercritical-fluid chromatography using a flow-switching interface. K.M. Payne, I.L. Davies, K.D. Battle, K.E. Markides and M.L. Lee. A two-dimensional supercritical-fluid chromatographic (SFC-SFC) system with a flow-switching interface was used with 250 pm I.D. packed capillary columns to separate polycyclic aromatic hydrocarbons (PAHs) in a standard coal tar extract. A solvent-venting injection technique was also used which allowed the injection of several microliters of sample. Compared to open-tubular columns, packed capillary columns provided

1 General analytical chemistry shorter analysis times and higher sample capacities; compared to conventional size packed columns, they provided higher efficiencies and lower volumetric flow-rates, allowing the total effluent to be introduced into a flame-based detector without the need for splitting. The performance of packed capillary SFC-SFC was compared to that of open-tubular capillary SFC-SFC. In the first dimension, separation according to the number of aromatic rings was achieved as desired within 30 min, two times faster than previously reported for an open tubular column using the same sample. However, the selectivity and efficiency obtained in the second dimension, using a packed capillary, was not sufficient to fully separate all of the PAH isomers. - J. Chromatogr. 477, 161 - 168 (1989). Dept. Chem., Univ., Provo, UT (USA); School Chem., Univ., Leeds (GB)

Supercritical-fluid extraction of aqueous samples and on-line coupling to supercritical-fluid chromatography. D. Thiebaut, J.-P. Chervet, R.W. Vannoort, G.J. de Jong, U.A.Th. Brinkman and R.W. Frei. The potential of segmented-flow systems for on-line liquid/supercritical-fluid extraction was explored. The use of a phase separator (PS), its design and performance were investigated, utilizing phenol and 4chlorophenol as the test compounds, water as the liquid phase and supercritical carbon dioxide as the extractant. On-line coupling of such a liquid/fluid extraction (SFE) system to supercriticaI fluid chromatography (SFC) was demonstrated, as was the feasibility of extracting phenol from an urine sample. The extraction efficiency for the test compounds was over 85%. The repeatability was about 8% relative standard deviation (R.S.D.) ( n = 8 ) for the total SFE-PS-SFC system and 4% R.S.D. for both the SFE-PS and the SFC operation. The potential of coupling SFE to other chromatographic and detection principles is discussed. - J. Chromatogr. 477, 151-159 (1989). Dept. Anal. Chem., Free Univ., Amsterdam (NL)

High-performance liquid chromatographic columns and stationary phases in supercritical-fluid chromatography. H. Engelhardt, A. Gross, R. Mertens and M. Petersen. Packed columns show identical efflciencies when used in HPLC or with fluid carbon dioxide in SFC. Maximum plate numbers, however, are achieved at linear velocities 5 - 10 times higher in SFC than in HPLC. The advantage of SFC is the possibility of high speeds of analysis. Problems with HPLC stationary phases arise from the ever present unshielded surface silanols. The use of columns specially prepared for HPLC separations of basic solutes is advantageous. Polymer-encapsulated stationary phases with aliphatic groups seem to have advantages over polystyrene resins. On the other hand, modifiers can be used to reduce silanophilic interactions. Water as a modifier is compatible with flame ionization detection. Equilibrium in modified systems is achieved very rapidly. In combination with fluid density (pressure and/or temperature) variations, system optimization in SFC seems to be less time consuming than in HPLC. - J. Chromatogr. 477, 169-183 (1989). Angew. Physik. Chem., Univ., Saarbriicken (D)

High-pressure adsorption of carbon dioxide on supercrifical-fluid chromatography adsorbents. J.F. Parcher and J.R. Strubinger. Gibbs adsorption isotherms for sub- and supercritical carbon dioxide were measured on four common supercritical-fluid chromatography adsorbent, viz., silica and octadecyl-, cyano- and diol-bonded silica, at 40°C from ambient pressure to 140 bar. All of the isotherms for supercritical carbon dioxide displayed maximum adsorption at pressures close to the critical pressure. Multilayer adsorption occurred at pressures close to the critical pressure in each system, and the type of bonded phase had little or no effect on the CO2 adsorption isotherms. At subcritical pressures, multilayer adsorption of CO2 occured at relatively low pressures (PR ~>0.4). The adsorbed layer of"mobile" phase persisted to the highest experimental pressures (140 bar). Thus, at least a monolayer of adsorbed CO2 will exist on the surface of adsorbent stationary phases under the conditions normally used for supercritical-fluid chromatography with COz as the mobile phase. Both the density and dimensions of the adsorbed layer will vary with temperature and pressure. - J. Chromatogr. 479, 251--259 (1989). Dept. Chem., Univ. Mississippi, University, MS (USA)

1.1

Fundamentals, methods, apparatus, reagents, automation, data processing

Characterization of the nitrogen and phosphorus thermionic detector response in capillary supercritical fluid chromatography. P.A. David and M. Novotny. Selective response of the thermionic detector in the nitrogen and phosphorus modes was characterized with respect to (1) detector gas flow rates, (2) thermionic source composition, and (3) supercritical mobile-phase composition. The most critical detector parameters were the hydrogen detector gas flow rate and the position of the thermionic source with respect to the flame jet. The optimum thermionic source consisted of approximately 73% SiO2 and 12% each of Rb20 and Na20. Additionally the selective thermionic response could be obtained with silicate sources containing sodium exclusively. However, source background current stability and lifetime were much poorer than those with mixed alkali silicate sources. The detector sensitivity and selectivity were similar with either CO2 or N20 mobile phases. Additionally, up to 10 tool% of an organic modifier was added to the supercritical mobile phase without causing large increases in the detector background response. The separation of model nitrogen- and phosphorus-containing compounds was used to demonstrate the feasibility of modified mobile phase pressure programming in conjunction with selective thermionic detection. Anal. Chem. 61, 2082-2086 (1989). Dept. Chem., Univ., Bloomington, IN (USA) Element selective detection after supercritical fluid chromatography using a radio frequency plasma detector. R.J. Skelton, Jr., P.B. Farnsworth, K.E. Markides and M.L. Lee. A radio frequency plasma was evaluated as an element selective detector for capillary SFC. Atomic emission from S and C1 was detected at 921.3 and 837.6 nm, respectively. The analytical performance of the detector was evaluated by monitoring its response to component of several mixtures introduced chromatographically, and to test solutes introduced by using an exponented dilution flask. Minimal spectral interferences were found for the CO2 and N20 doped plasmas. Detection limits and sensitivities were dependent on the mass flow of CO2 into the detector. The detection limits ranged from 50 to 300 pg/s. - Anal. Chem. 61, 1815-1821 (1989). Dept. Chem., Univ., Provo, UT (USA) Concurrent eluent evaporation with co-solvent trapping for on-line reversed-phase liquid chromatography-gas chromatography. Optimization of conditions. K. Grob. The pressure drop over a restriction built into the carrier gas supply line allows monitoring of the carrier gas flow-rate during transfer of a liquid chromatographic eluent into a gas chromatograph. A high inlet pressure indicates blockage of the gas flow by the plug of sample liquid; a layer of evaporating solvent still reduces the flow-rate owing to its vapour pressure, causing the inlet pressure to remain above that prior to transfer. The decrease in the inlet pressure at the end of the transfer provides the signal for closing the vapour exit, but also gives information for the optimization of the co-solvent concentration in the sample and of the column temperature during transfer. The co-solvent peak within the highly attenuated solvent peak indicates the amount of co-solvent left in the precolumn after the main solvent has been fully evaporated, helping to find the optimum co-solvent concentration in the sample. J. Chromatogr. 477, 7 3 - 8 6 (1989)~ Kant. Lab., Ztirich (CH) Deactivation with polymethylhydrosiloxane. A comparative study with capillary gas chromatography and solid-state 29Si nuclear magnetic resonance spectroscopy. M. Hetem, G. Rutten, B. Vermeer, J. Rijks, L. van de Ven, J. de Haan and C. Cramers. Deactivation of fused-silica capillary columns and vitreous silica surfaces with polymethylhydrosiloxanes (PMHS) at temperatures between 240 and 360°C was investigated by GC and solid-state 29Si NMR spectroscopy. The influence of temperature, amount of water at the surface and film thickness on the stability and nature of the polymer deactivation layer was studied by solid-state 29Si NMR of the model substrate CabO-Sil, a fumed silica. These NMR measurements match the GC results and offer additional information relating to the nature of the deactivating layer at surfaces silylated under various reaction conditions. Differences in the nature and structure of the deactivating film occur when the silica surface is coated with a different thickness. Optimum deactivation is achieved when a few monolayers of densely cross-linked polymers

431

anchored to the silica surface are formed. On top of this thin, rigid layer, longer mobile polymer chains containing unreacted silicon hydride groups are present. After optimum deactivation, the fused-silica capillary column wall shows no interaction with various critical test components as used in GC practice. The deactivating films exhibit good thermal stability and solvent resistance. - J. Chromatogr. 477, 3 - 2 4 (1989). Lab. Instr. Anal., Univ. Technology, Eindhoven (NL)

Evaluation of direct axial sample introduction for ion mobility detection after capillary gas chromatography. R.H.St. Louis, W.F. Siems and H.H. Hill, Jr. An ion mobility detector has been designed and constructed for direct axial interfacing with capillary gas chromatography. The principle advantages of this detector were the following: (1) Direct concentric introduction of the capillary column into the ionization region, eliminating peak broadening in the transfer line and improving the efficiency with which neutral molecules were swept from the detector. (2) A variable capillary insertion distance, providing a sensitivity/resolution interplay that could be modified in response to the needs of the assay. (3) An inert gas flow external to the drift cylinder, preventing atmospheric impurities from infiltrating the ultratrace detector. Qualitative and quantitative capabilities of the detector were evaluated using standard preparations of n-hexyl ether. - J. Chromatogr. 479, 221-231 (1989). Dept. Chem., Washington State Univ., Pullman, WA (USA) Turbulent flow in capillary gas chromatography. A. van Es, J. Rijks and C. Cramers. The possibilities of turbulent flow capillary gas chromatography for increasing the speed of analysis were examined by use of previously developed sample introduction, detection and registration systems, which are compatible with peak widths in the millisecond range. Existing theoretical models for axial turbulent dispersion in capillary columns were evaluated experimentally. Substantially decreases in reduced plate heights were obtained (h < 1) for unretained components at an average linear velocity of 15 m/s for column diameters of 320 ~tm. Unfortunately, the plate height increased greatly with increasing solute capacity factor (by a factor 15 from k = 0 to k = 1). Comparison with theoretical models shows that this effect is mainly due to mobile phase mass transfer. Therefore, the gain in analysis speed is limited to low capacity factors. In addition the pressure drop required is considerably higher than for a comparable improvement in speed obtained by decreasing the column inside diameter. - J. Chromatogr. 477, 3 9 - 4 7 (1989). Lab. Instrum., Dept. Chem. Technol., Univ. Technol., Eindhoven (NL) Membrane focusing - a new injection method for capillary gas chromatography. C. Lanzerstorfer and H. Puxbaum. Es wird eine neue Technik zur Fokussierung der Probe fiir die CapillarGas-Chromatographie (CGC) beschrieben. Die an einem Feststoffsorbens (Tenax GC/80-100 mesh, Molekiilsieb 5A/60-80 mesh, Carbosieb SII/60-80 mesh) angereicherte Probe wird thermisch freigesetzt und aus dem Prober6hrchen mittels Trfigergas in eine Membrankammer iiberfiihrt. Dort wird die Probe yon einer Gastrennmembran zurtickgehalten, die hochdurchlfissig nur fiJr das Trfigergas ist. Danach wird die so konzentrierte gasftrmige Probe in den Injektor des CGC-Systems iiberfiihrt. In dem beschriebenen Modellversuch wird Propan als Analyt und Helium als Trfigergas verwendet. Die Trennmembran ist eine asymetrische Polyetherimidmembran, die fiir Helium hochpermeabel ist. Fiir die allgemeine Anwendung dieser Technik mug prinzipieI1 eine Membran gew/ihlt werden, deren Permeabilit/it fiir das Trfigergas grog, ftir den Analyten gering ist. Die Ltslichkeit des Analyten in der Membran mug ebenfalls so gering wie mtglich sein. - Anal. Lett. 22, 1375-1387 (1989). Inst. Anal. Chem., Techn. Univ., Wien (A) W. Czysz Fluidic and syringe injection study by peak shape analysis. M. Remelli, G. Blo, F. Dondi, M.C. Vidal-Madjar and G. Guiochon. Fluidic and syringe injections with different splitting conditions are compared by using the Edgeworth-Cramtr peak shape analysis. Nonretained component peaks on capillary and packed columns were considered. Skewness values as low as 0.02, with precision and repeatability of + 0.005, were obtained when using the capillary column with fluidic injection. Extracolumn contributions coming from the injection

432 system were evaluated by using peak skewness under the hypothesis of exponential decay extracolumn factor. The corrected column efficiency values are in good agreement with the theoretically expected van Deemter equation data. A syringe injection system with high split rate can produce, for unretained samples, peak fidelity values greater than 0.8, which are comparable with those observed with the fluidic injection system. Applications in column performance studies are discussed. -Anal. Chem. 61, 1489-1493 (1989). Dipt. Chim., Univ., Ferrara (I) Zone gas chromatography. E. Fuggerth. A new gas chromatographic arrangement is outlined in which a narrow heat pulse scans slowly down a relatively short column. The above scan effects unusual separations and simultaneously creates favorable boundary conditions for cold storing of the uneluted component. This cold-storing feature offers a new approach to any stopped-flow gas chromatographic application; multidimensional gas chromatography stands to benefit if this new arrangement replaces the usual precolumn. -- Anal. Chem. 61, 1478-1485 (1989). Res. Inst. Ferrous Metall., Environ. Dept., Budapest (H) Empirical correlations between gas-chromatographic retention data and physical or topological properties of solute molecules. K. Heberger, Im Zuge einer systematischen Untersuchung werden K6vats-Indices (I) und relative Retentionszeiten (tr) an GC-S/iulen mit Silikon61 550 oder Bentone 34 als stationfire Phasen for 20 Kohlenwasserstoffe (fiberwiegend Alkylbenzole) bestimmt. Die statistische Aufarbeitung der Ergebnisse wiederholter Messungen zeigt, dab die empirisehe Verteilungsfunktion der Retentionsindices nicht normal ist; die relativen Standardabweichungen nehmen mit steigendem Retentionsindex ab. Es werden verschiedene Modelle zur Beschreibung der Retentionsdaten als einer Funktion des Siedepunkts, der Molarfraktion, des Molekfilvolumens, Bindungsindices etc. geprfift. Daraus wird eine universelle Anpassungsgleichung entwickelt, die sich fiir die gestellte Aufgabe einer korrekten Korrelation zwischen tr und den verschiedenen statistischen Daten bzw. physikalischen oder topologischen Eigenschaften der untersuchten Molekfile eignet. - Anal. Chim. Acta 223, 1 6 1 - J74 (1989). Max-PlanekInst. Str6mungsforschung, D-3400 G6ttingen W. Czysz Quantitation capability of a directly linked gas chromatography]Fourier transform infrared/mass spectrometry system. D.F. Gurka, I. Farnham, B.B. Potter, S. Pyle, R. Titus and W. Duncan. Although the identification confirmation capability of directly linked gas chromatography/Fourier transform infrared/mass spectrometry (GC/FT-IR/MS) has been reported, the capability of such a system to confirm quantitation on-line has not yet been ascertained. Accordingly, the relative quantitation abilities of the system detectors were determined by analyzing 15 typical environmental contaminants, at several concentration levels, and then subjecting the results to regression analysis. Slopes of mass spectral (MS) and Fourier transform infrared (FT-IR) area counts versus nanogram injected usually increased with increasing injection volume. MS results were acquired in the total ion chromatogram (TIC) and single ion chromatogram (SIC) modes, while FT-IR data were collected in the Gram-Schmidt (G-S), maximum absorbance (MA), and the integrated absorbance (IA) modes. Correlation coefficients indicated that the degree of scatter in the regression plots increased in the order, TIC approximately equal to SIC < MA < IA which was < G-S. Omission of a single outlier result for G-S and MA made the regression scatter comparable for the five methods. The best combinations of these MS and FT-IR quantitation techniques are proposed for the environmental target list and screening approaches. The effect of sample background on selectivity and detectability was examined by analysis of a spiked crude oil sample. - Anal. Chem. 61, 15841589 (1989). US Environ. Prot. Agency, Environ. Monitor. Syst. Lab., Las Vegas, NV (USA) Gas chromatographic sample introduction into the collision cell of a triple quadrupole mass spectrometer for mass selection of reactant ions for charge exchange and chemical ionization. M.E. Hail, D.W. Berberich and R.A. Yost. A gas chromatograph has been interfaced to the collision cell of a triple quadrupole tandem mass spectrometer for performing mass-selected ion-

1 General analytical chemistry molecule reactions. Reactant ions are selected with the first quadrupole and are allowed to react in the second quadrupole collision cell with the effluent from a short open tubular GC column. The ion-molecule reaction product ions are mass analyzed by the third quadrupole. Charge exchange (CE) and chemical ionization (CI) reactions have been studied. The advantages of using mass-selected reactions for controlling the selectivity of charge exchange and chemical ionization are demonstrated. In addition, this configuration is shown to provide both structural information and molecular weight information in the same chromatogram by alternating between different reactant ions. The possibility of searching CE spectra against the NBS E1 library has also been investigated. With the benzene molecular ion as a charge exchange reactant and benzophenone as the analyte, the system is shown to detect 100 pg of the analyte utilizing a full scan (comparable to or better than the detection limit obtainable with conventional gas chromatography/mass spectrometry) and 15 pg with selected reaction monitoring. - Anal. Chem. 61, 1874-1879 (1989). Dept. Chem., Univ., Gainesville, FL (USA) Preparation, stability and quantitative analysis by gas chromatography and gas chromatography-electron impact mass spectrometry of tert.butyldimethylsilyl derivatives of some aikylphosphonic and alkyl methylphosphonic acids. J.G. Purdon, J.G. Pagotto and R.K. Miller. Studies of tert.-butyldimethylsilylation of several alkyl methylphosphonic, alkylphosphonic and chlorine-substituted alkylphosphonic acids by several derivatizing reagents under differing reaction conditions are reported and a simple procedure for formation of these derivatives is identified. Determination of the stabilities of representative derivatives are reported and capillary GC retention data for all the derivatives studied are tabulated. General sensitivities for detection and quantitation of these compounds by GC-flame photometric detection and GC-electron impact mass spectrometry in both full-scan and multiple-ion detection modes are presented. - J. Chromatogr. 475, 261-272 (1989)i Chem. Detect. Decontam. Sect., Protective Sci. Div., Dept. Nat. Defence, Ottawa, Ontario (CDN) Utilization of spectrometric information in linked gas chromatographyFourier transform infrared spectroscopy-mass spectrometry. J.R. Cooper and C.L. Wilkins. Fourier transform infrared and mass spectral data collected with linked GC-IR-MS systems are combined in a complementary fashion to identify organic mixture components. Methodology to combine and compare infrared and mass spectral information generated by the linked system is discussed. A 30-component mixture is analyzed to demonstrate application of the system to mixture analysis. Analysis of a complex environmental soil sample further illustrates the value of the methodology. Concurrent utilization of both types of spectral information increases the reliability of library-search-based identifications. Thus, use of a 3304-member library of combined IR-MS spectral information was more efficacious than use of either type of spectral information separately. - Anal. Chem. 61, 1571 - 1 5 7 7 (1989). Dept. Chem., Univ., Riverside, CA (USA) Direct coupling of planar chromatography to gas chromatography by laser desorption. J.-Z. Zhu and E.S. Yeung. A method of direct coupling of TLC to GC is demonstrated with pesticide samples. Laser desorption with a special TLC cell was used for the interface. Factors affecting the transfer efficiency and the parent peak ratio were studied. The fragmentation pattern in the gas chromatogram provides a fingerprint for each TLC separated compound. For TLC separations of complex mixtures, GC provides one more dimension of separation and sensitive detection. Laser desorption with electron capture detection (no GC column) was also demonstrated as a universal quantitative technique for TLC. The limit of detection was in the low nanogram range. The scan speed was 5 times faster, the detection limit was 20 times lower, and the resolution was 2 times better than the analogous laser pyrolysis method. - Anal. Chem. 61, 1906--1910 (1989). Ames Lab., USDOE, Dept. Chem., State Univ., Ames, IA (USA) Multivariate methods to evaluate the role of mixed support in reversedphase thin-layer chromatography. G. Gullner, T. Cserhfiti, B. Bordfis and K. Valk6.

1.1

Fundamentals, methods, apparatus, reagents, automation, data processing

Hydrophobic properties of 17 aniline and phenol derivatives were characterized by reversed-phase TLC and HPLC. In order to elucidate the role of thin-layer chromatographic supports in the hydrophobicity determination paraffin coated silica, aluminium oxide, cellulose, diatomaceous earth and their mixtures were used. Water, water/methanol (7: 3) and 1 M NaCI served as mobile phases. The values ofhydrophobicity are influenced by the kind of stationary phase but not by the mobile phase. The two dimensional non linear mapping of spectral data clearly showed that each sorbent influenced considerably the selectivity. Good linear correlations were found between the reversed-phase HPLC parameters and the RF values measured on supports containing high percentage of silica and diatomaceous earth. - J. Liquid Chromatogr. 12, 957-978 (1989). Cent. Res. Inst. Chem., Hungarian Acad. Sci., Budapest (H)

Analysis of chromatographic parameters in the systems with ternary mobile phases. II. Two polar solvents in mobile phase. B. O~cik-Mendyk. The experimental data are presented on Gibbs triangles in the form of isolines. The effect of change of the type of two polar mobile phase components on the chromatographic parameters of model substances has been investigated. The presence of alcohol in ternary mobile phase leads to formation double or "closed" RF isolines on Gibbs triangles. Such presentation of the experimental data allowed to complex analysis of the chromatographic process in systems with ternary mobile phase. The measurements were made by adsorption thin layer chromatography on silica gel at temperature 293 K. - J. Liquid Chromatogr. 12, 891 906 (1989). Inst. Chem., M. Curie-Sktodowska Univ., Lublin (PL)

The effect of substituent groups on the migration of metal ions in thin layer chromatography. I. Deshmukh and R.B. Kharat. A reverse phase thin layer partition chromatography has been performed on metal ions using silica gel G as an adsorbent. The effect of chlorosubstituent groups on the migration of cations has been studied. The use of aqueous solutions of acetic acid, monochloro, dichloro and trichloro acetic acid in the solvent system revealed profound effect of substituent groups on the Rf values of metal ions. The effect of concentration and pH of the mobile phases have been studied. Many qualitative ternary separations have been sucessfully achieved. - J. Liquid Chromatogr. 12, 937-947 (1989). Dept. Chem., Inst. Sci., Nagpur (IND)

Simplex optimization of densitometer parameters for maximum precision in quantitative thin-layer chromatography. J.E. Haky, D.A. Sherwood, and S.T. Brennan. Simplex optimization was employed for the selection of densitometer slit width and wavelength settings to maximize the reproducibility of the determination of diphenhydramine hydrochloride and pseudoephedrine hydrochloride in Benadryl-DIMcapsules by thinqayer chromatography. The two densitometer parameters were simultaneously adjusted in a systematic manner to minimize the sum of the squares of the relative standard deviations of the respective peak areas from the two active compounds on a developed thin layer chromatographic plate. The optimization process was followed graphically and resulted in the rapid establishment of a single set of densitometer parameters giving peak areas with relative standard deviations of less than 1% for each of the active components in the formulation. -- J. Liquid Chromatogr. 12, 907 - 917 (1989). Parke-Davis Pharmac. Res. Div., Warner-Lambert Co., Ann Arbor, MI (USA)

Laser-based indirect fluorometric detection and quantification in thin-layer chromatography. Y. Ma, L.B. Kounty and E.S. Yeung. A laser-based indirect fluorometric detection method for thin-layer chromatography is described. The new technique can be easily used for quantitative measurements because of its two-dimensional scanning capability. Since it is based on the indirect fluorescence mode, universal detection is possible without derivatization. Also, it takes only 35 s for acquiring a data array of 256 x 64 points with this technique to achieve a detection limit of 6 pg. This is 100 times lower than when the human eye is used as a detector for the same samples based on indirect fluorometry. The linearity in indirect fluorometric detection is found to

433

be over 2 orders of magnitude. - Anal. Chem. 61, 1931-1933 (1989). Ames Lab., USDOE, Dept. Chem., State Univ., Ames, IA (USA)

Resonant two-photon ionization spectroscopic analysis of thin-layer chromatography using pulsed laser desorption]volatilization into supersonic jet expansions. L. Li and D.M. Lubman. Pulsed laser desorption has been used as a means of directly vaporizing TLC spots into the gas phase. The resulting neutral plume of molecules is then entrained into a supersonic jet expansion of CO2 and transported into a time-of-flight mass spectrometer (TOFMS) where resonant twophoton ionization (R2PI) is performed. By use of this method, various thermally labile biological molecules, including indoleamines, catecholamines, peptides, and drugs have been detected from silica gel TLC plates with production of the molecular ion in a TOFMS device. The spectroscopic nature of R2PI has been used to obtain cold sharp wavelength spectra in the TOFMS of several compounds desorbed from the TLC plate into the jet expansion. The combination of wavelength selectivity and mass spectrometric identification has allowed us to uniquely identify components that have not been completely separated by TLC. In addition, quantitation has been achieved for indole-3-acetic acid and imipramine over 4 orders of magnitude using this method with detection limits in the low nanogram range. - Anal. Chem. 61, 1911 1915 (1989). Dept. Chem., Univ., Ann Arbor, MI (USA)

Liquid adsorption chromatography of metal chelates. Peculiarities of chromatographic behaviour of nitroxyl-containing reagents. A.R. Timerbaev, N.G. Vanifatova, M.V. Evstiferov, V.V. Salov and O.M. Petrukhin. Es wird das Verhalten von 20 chelatbildenden, die Nitroxyl-Gruppe enthaltenden Reagentien sowie von ihren Komplexen mit Metallionen (namentlich mit Cd(II), Cu(II), Hg(II), Pd(II) und Zn(II)) mittels der Fliissigkeits-Adsorptionschromatographieuntersucht. Gearbeitet wurde auf Silufol-Platten mit Kieselgel- bzw. Cellulose-Dfinnschicht (CS) oder mit A1203-Diinnschicht (Aktivitrit II nach Brockmann; H) bzw. auf mit den gleichen Adsorptionsmitteln bzw. mit Carboxylmethylcellulose gefiillten Sriulen; als mobile Phase benutzte man das Gemisch Chloroform/Aceton (1 : 1 bzw. 9:1). Zur Sichtbarmachung der chromatographischen Zonen benutzte man spezifische Reagentien, wie Dithizon, Diphenylcarbazid, Rubeanwasserstoffsriure u. a., radioaktive Indicatoren, z.B. ~gSAg, 6¢Cu, 2°aHg und l°9pd und auch das EPR-Signal. Besondere Aufmerksamkeit wurde den O und N bzw. S und N im Molektil enthaltenden Reagentien gewidmet. Von diesen Reagentien zeigten sich als wirksam diejenigen mit relativ niedriger totaler Elektronegativitrit von Donoratomen, besonders 2,2,5,5,-Tetramethyl-4-phenthioacytmethyliden-l-oxyl und 2,2,5,5-Tetramethyl-4-thioxo-3-imidazolidin-l-oxyl, die sich zur chromatographischen Trennung der erwrihnten Metallionen bewrihrten. Die Komplexe weisen erheblich unterschiedliche EPR-Spektren auf. - Zh. Anal. Khim. 44, 834-841 (1989) (Russisch, mit engl. Zus.fass.). Vernadskii Inst. Geochem. Anal. Chem., Akad. Wiss., Moskau (SU) F. Jancik

Countercurrent partition chromatography (liquid-liquid chromatography with a free stationary phase, chromatographic extraction) in inorganic analysis. Literature survey and experimental check. I.V. Pavlenko, V.L. Bashlov, B.Ya. Spivakov and Yu.A. Zolotov. Die Fliissig/Fliissig-Chromatographie mit freier stationrirer Phase wurde verhriltnismfiBig sprit in die analytische Chemie eingefiihrt (cf. Y. Ito, M. Weinstein, I. Aoki et al. : Nature 212, 1985 (1966)). Das Prinzip dieser Methode bildet die Retention einer der Phasen des zweiphasigen Fliissigkeitssystems in der Sriule durch den Einflul3 der Wirkung yon Massenkrriften bei kontinuierlicher Str6mung der zweiten Flfissigkeitsphase. Die Stofftrennung verl/iuft infolge der Differenz ihrer Verteilungskoeffizienten bei dem Transport des Gemisches mit dem FluB der mob ilen Phase in der S/iule. Von verschiedenen Varianten der Apparatur bewrihrte sieh die Planetenzentrifuge: Die Sriule dreht sich in diesem Fall um ihre Achse und die ganze Apparatur um die Zentralachse herum mit Hilfe des Planetengetriebes; bei der einfachsten Variante sind die beiden Drehgeschwindigkeiten gleich (schemat. Abb. der Planetenzentrifuge ist beigefiigt). Man diskutiert die Vor- und Nachteile der Gerriteausrfistung mit Beriicksichtigung yon Literaturangaben. Die Effektivitrit der besprochenen Methode wird am praktischen Beispiel der Trennung von dreiund sechsgliedrigen Peptiden sowie von Zr und Hf in Form ihrer Kom-

434 plexe mit l-Phenyl-3-methyl-4-benzoylpyrazolon-5 im System Methylisobutylketon/1,5 tool/1 HNO3 demonstriert. Arbeitsweisen s. Original. - Zh. Anal. Khim. 44, 827-833 (1989) (Russisch, mit engl. Zus.lass.). Inst. f. Bau anal. Ger/ite, Akad. Wiss., Leningrad (SU) F. Jancik

A thin-layer multistrip polyacrylamide gel electrophoresis apparatus for Ferguson plot analysis at the submicrogram load level. L. Orbfin, J.V. Sullivan, C. Zwieb and A. Chrambach. A procedure was developed for casting thin-layer multistrip polyacrylamide gels and using them for the simultaneous gel electrophoresis at several gel concentrations (Ferguson plot analysis) at the sub-microgram load level, using silver staining, autoradiography and, potentially, blotting for detection. The lower viscosity &polymerization mixtures, compared to agarose gelation mixtures, required the redesign of the multistrip cassette with separation of channels by rubber gaskets and the application of a cassette press. The lowered viscosity also required addition of 35% sucrose and an increased rate of polymerization in application to multistrip gels formed on a common NetFix backing. The present design allows one to obtain Ferguson plots exemplified by those of gaP-labeled DNA followed by autoradiographic detection. Electrophoresis 10, 726-729 (1989). NIH, Bethesda, MD (USA) Electrophoresis in one buffer at two pH values. B.M. Michov. A theory for discontinuous electrophoresis in a polyacrylamide gel is presented for one buffer at two pH values. It is shown that polyions stack between identical leading and trailing ions, and resolve in a gel of constant polyacrylamide concentrations. The theory is illustrated by the separation of serum protein polyions in a Tris-glycinate buffer of pH 8.19 in the well-forming gel, and pH 9.16 in the resolving gel. The selected concentrations and electrolyte ionization degrees of Tris and glycine have values of which the serum protein polyions stack between the resolving and electrode buffer followed by separation in the resolving gel. - Electrophoresis 10, 686-689 (1989). Inst. Lebensmitteltechnolog., Anal. Chem., TU Mfinchen (D) A one-step, low background Coomassie staining procedure for polyacrylamide gels. B.D. Zehr, T.J. Savin and R.E. Hall. Die Coomassie-Anffirbeverfahren ffir Polyacrylamidgele ben6tigen Stunden zur Entffirbung oder/und weisen hohe Untergriinde auf. Hier wird ein einstufiges Anf/irbeverfahren beschrieben, welches bei gleicher Empfindlichkeit weniger Chemikalien ben6tigt, einfacher und schneller ist und niedrigere Untergrfinde hat. Dazu werden die Gele in einer L6sung von 10% Ethanol/5% Essigs~iurein Wasser + 0,0004-0,0016% Coomassie Brilliantblau R-250 angeffirbt. Die besten Ergebnisse werden bei Anffirbung fiber Nacht erhalten. Andere Alkohole in der Anf/irbel6sung werden ebenfalls getestet. Optimale Konzentrationen und Anf/irbezeiten ffir verschiedene Gelgr6Ben werden ermittelt. Ffir Minigele mit 1,5 m m x 8,5 cm × 7,5 cm ist eine Anf/irbezeit von 4 - 5 h mit 0,0008% Coomassie optimal. AnschlieBend kann noch ein Silberanf/irbeschritt erfolgen, um die Empfindlichkeit zu erh6hen. - Anal. Biochem. 182, •57--159 (1989). Lab. Tumor Immunol., Guthrie Res. Inst., Sayre, PA (USA) R.H.S. Rapid and sensitive silver-lipopolysaccharide staining using PhastSystem in fast horizontal polyacrylamide gel electrophoresis. K.K. Lee and A.E. Ellis. A rapid and sensitive silver-lipopolysaccharide staining method has been developed by using PhastSystem. The total time of the procedure (including time of Phastgel electrophoresis) is within 2 h. It is at least 10 times faster than the previous reported methods and the sensitivity is also increased. - Electrophoresis 10, 729--731 (•989). Dept. Agricult. Fish. Scotland, Marine Lab., Aberdeen (GB) On-line radioisotope detection for capillary eleetrophoresis. S.L. Pentoney, Jr., R.N. Zare and J.F. Quint. Two simple, on-line radioactivity detectors for capillary electrophoresis are described. The first capillary electrophoresis/radioisotope detector system utilizes a commercially available semiconductor device, which is positioned external to the separation channel and which responds directly to impinging y or high-energy ~3radiation. The second capillary

1 General analytical chemistry electrophoresis/radioisotope detector utilizes a commercially available plastic scintillator material that completely surrounds (360 °) the separation channel, thereby improving the efficiency of detection. The system performance is evaluated for both detection schemes by using synthetic mixtures of a2P-labeled sample molecules. The efficiency of the semiconductor detector (planar geometry) is determined to be approximately 26%, whereas that of the plastic scintillator is found to be approximately 65%. The detection limits are determined to be in the lownanocurie range for separations performed under standard conditions (an injected sample quantity of 1 nCi corresponds to 110 x 10 18 tool of 3zp). The lower limit of detection is extended to the subnanocurie level by use of flow (voltage) programming to increase the residence time of labeled sample components in the detection volume. - Anal. Chem. 61, 1642-1647 (1989). Dept. Chem., Univ., Stanford, CA (USA)

Capillary isotachophoretic determinations of metal ions by use of complexation equilibria in acetone-water medium. Y. Nakabayashi, K. Nagaoka, Y. Masuda and R. Shinke. Verff. untersuchen die M6glichkeit, Metallionen mit Hilfe der Capillar-Isotachophorese zu bestimmen. Gleichzeitig bestimmen sie die Komplexierungsgleichgewichte zwischen Metallionen und Polyaminopolycarbonsfiuren. Bei Benutzung von EDTA oder DCTA in Aceton/Wasser (45:55 v/v) kann ein Gemisch aus sieben Metallionen einwandfrei getrennt werden. Lineare Eichkurven erh/ilt man ffir Standardgemische der Ionen Mn 2+ , Cu 2+ , Zn 2+ , Cd 2+, Pb 2+ und Fe 3+ im Bereich 0,5 bis 5 nmol-L6sungen (gearbeitet wird mit gl-Gemischen yon 1 mM L6sungen). Die rel. Standardabweichungen sind 1,0% und besser. Die effektiyen Mobilitfiten der Komplexe von Mn(II), Co(II), Ni(II), Cu(II) und Zn(II) nehmen parallel mit ihren Stabilit/itskonstanten zu. Abweichungen bei Cu(II) werden diskutiert. - Talanta 36, 639-643 (1989). Environ. Quality Administr. Centre, Kobe Univ., Nada-ku, Kobe-shi (J) W. Czysz Isoelectric focusing in immobilized pH gradients. P. Giorgio Righetti, E. Gianazza, C. Gelfi, M. Chiari and P.K. Sinha. Immobilized pH gradients (IPG), introduced as early as 1982, have been plagued by several problems that have hampered their use over the years. We review here recent technical advances that have led to the solution of these problems and to the development of a successful and trouble-free IPG technique. In particular, it was discovered that the buffers used (acrylamido weak acids and bases) were prone to two major degradation pathways, hydrolysis at the amido bond and autopolymerization. A new generation of these buffers is described, in which both degradation routes are completely inhibited. In addition, the formulas and physicochemical properties of these acrylamido buffers are described for the first time. These buffers consist of a set of eight weak acrylamide acids and bases, with pK values evenly distributed in the 3.1 -10.3 pH range, and two strong titrants: 2-acrylamido-2-methylpropanesulfonic acid (pK = 1) and QAE-acrylamide (pK > 12). The advantage and limitations of the IPG technique are evaluated. In particular, examples of difficult separations at very acidic and alkaline pH values, where conventional isoelectric focusing would fall, are described. Applications of the IPG technique to the fields of human and animal genetics, for the resolution of "neutral or electrophoretically silent" mutants, are discussed. - Anal. Chem. 61, 1602-1612 (1989). Chair Biochem. Fac. Pharm. Dept. Biomed. Sci. Technol., Univ., Milan (I) Preparation and electrochemical characterization of conical and hemispherical uitramicroelectrodes. R.M. Penner, M.J. Heben and N.S. Lewis. We describe a new ultramicroelectrode fabrication technique that has allowed the preparation of conical Pt-Ir ultramicroelectrodes with radii of 0 . 5 - 1 0 pro. These electrodes have been characterized by scanning electron microscopy, cyclic voltammetry, and chronoamperometry. The smallest radii electrodes (r < 2 pro) exhibited diffusional behavior at times longer than 70 ~ts in accord with a hemispherical geometry, while larger radii electrodes exhibited diffusional behavior consistent with a conical geometry. A first-order mathematical approach to diffusion at conical surfaces has been developed to explain these results. - Anal. Chem. 61, 1630--1636 (1989). Die. Chem. Chem. Engin., Calif. Inst. TechnoI., Pasadena, CA (USA)

1.1

Fundamentals, methods, apparatus, reagents, automation, data processing

Quantitative relationship between electron transfer rate and surface microstructure of laser-modified graphite electrodes. R.J. Rice and R.L. McCreery. Previous investigations demonstrate that increases in electron transfer rate constant, k °, on highly ordered pyrolytic graphite (HOPG) basal plane correlate with the appearance of edge plane defects and that such defects may be created with laser or electrochemical pretreatment. In the current work both capacitance (C0obs) and k°ob~ for Fe(CN)63-/4- on HOPG were measured as functions of power density of the activating laser. Over a power density range from 0 to 130 MW cm 2, k0obs increased by more than 5 orders of magnitude while C°obsincreased by a factor of 8. Both k°ous and C°obs may be expressed as linear combinations of the basal and edge plane k ° and Co values, weighted by the fractional coverage of edge plane on the electrode surface (fe). Determinations offe from both k°obsand C°obsare quantitatively consistent and in both cases increase with power density above a threshold of 45 MW cm- 2. Although effects of surface roughness may also be involved, the results indicate that the electron transfer activity of laser-modified HOPG is predominantly dependent on edge plane density. - Anal. Chem. 61, 1637-1641 (1989). Dept. Chem., Ohio State Univ., Columbus, OH (USA) Polymer-coated cylindrical waveguide absorption sensor for high acidities. W.P. Carcy, M.D. DeGrandpre and B.S. Jorgensen. The development of a chemical sensing scheme for the detection and quantitation of greater than 1 M concentration of acids, particularly nitric acid, is presented with the overall goal of using this chemistry to create optical sensors. The detection chemistry is based on the physical entrapment of Hammett indicator in a polymer blend of polybenzimidazole and polyimide, which is silane-coupled to optical elements. The polymer coating protects the optical element from chemical attack, and its hydrophilic nature and low porosity make the sensor more selective. By use of the indicator chromazurol-S, nitric and hydrochloric acid concentrations ranging from 2 to 10 M can be measured with a precision of 0.05 M. Indicators that cover a range of 0.5-10.0 M acid concentrations have also been investigated. Cylindrical waveguide sensors, using both a fiber optic and a sapphire rod with the immobilized polymer chemistry, were constructed based on the absorption of light by the acid indicator, chromazurol-S. Because of the difference in the refractive index of the optical elements and the polymer material, separate detection techniques for the two sensors are presented. The fiber-optic sensor uses an absorption measurement of a thin film, and for the sapphire rod, an evanescent field absorption process occurs. - Anal. Chem. 61,1674 1678 (1989). Chem. Laser Sci. Div., Los Alamos Nat. Lab., Los Alamos, NM (USA) Electrochemical probes of oxidation state, product distribution, and redox activity for Ba2YCuaO~.x in halide solutions. J.M. Rosamilia and B. Miller. Measurements at a carbon or platinum ring electrode of a rotating Ba2YCu3Ov.x disk-ring electrode configuration in acidified aqueous halide solutions allow several schemes for the real-time analysis of x. These methods, based on analyzing the flux of soluble material from the disk into chloride, bromide, and iodide solutions, can be applied over the range from semiconductor (06-06.5) to superconductive phases (O6.s Or). Since the analytical methods depend on measuring either Cu2+:Cu I+ ratios (for semiconductor phases) or the ratios (for superconducting phases) of oxidized products to copper species (Brz to Cu 2+, I3- to CuI2 , in the respective halides), they are independent of such factors as sample size and dissolution rate, as long as the latter process is nonselective. Results for Ov and 06. 2 content specimens have been confirmed against standard procedures. No Cu 3+ or readily reducible species surviving beyond the tens of milliseconds transit time from the disk to the ring are detectable in the chloride experiments. Model experiments with CuO and Cu20 disks established the identification of species and the quantitative basis of the methods. - Anal. Chem. 61, 1497-1502 (1989). AT&T Bell Labs., Murray Hill, NJ (USA) Development of an optical relative humidity sensor. Cobalt chloride optical absorbency sensor study. F. Boltinghouse and K. Abel.

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Cellulose impregnated with cobalt chloride was investigated for use in quantitative relative humidity (RH) measurements. Two cellulose substrates were tested: (a) unmodified cellulose chromatography paper and (b) the same paper after acetylation. Decreasing the amount of cobalt chloride in the cellulose matrix decreases both hysteresis effects and the effective RH range over which the salt/substrate combination can be used for RH measurement. Acetylafion of the cellulose extends the effective RH range, increases reproducibility, and decreases hysteresis effects. - Anal. Chem. 61, 1863-1866 (1989). ABEL Co., Pembroke, VA (USA) Automated kinetic-based determinations for routine analysis: recent developments. D. Perez-Bendito, M. Silva and H. Gomez-Hens. Bestimmungen auf der Grundlage von kinefischen Analysen sind durch die Automationsm6glichkeiten wieder yon gr6Berer Bedeutung. Ein modulares Stopped-flow(SF) System mit einer konfinuierlichen Addition von Reagentien wird hier ffir schnelle Reaktionen beschrieben und diskutiert. Der Einsatz dieser einfachen automatisierten Anordnungen ist yon groBem Wert bei der L6sung yon Problemen. Das modulare SF-System besteht aus einem SF-Modul, einem Detektor und einem Mikrocomputer. Der SF-Modul besteht aus dem Mischsystem, dem Spritzensystem und einer thermostatisierten Kammer. Das Mischsystem besteht aus zwei automatisch betreibbaren Spritzen, die fiber ein Dreiwege-Ventil verbunden sind. Diese Anordnung gestattet, Fraktionen der Proben automatisch zu nehmen und mit dem Reagens in einer DurchfluBzelle oder einer Mischkammer zu mischen. Ein Dreiwege-Venfil ist auBerdem am ZellenausfluB installiert, durch welches der Druck wfihrend der Reakfion aufrechterhalten und Blasenbildung vermieden wird. Vergleichend werden Ergebnisse mit SF-Technik und konvenfioneller Technik bei der Bestimmung yon Cu(II) und Mn(II) in Gegenwart verschiedener Fremdionen angegeben. Allgemein wird mit der SF-Technik eine Beschleunigung der Reaktionsrate beobachtet. Die M6glichkeiten des Einsatzes yon Diodenstrahl- und Chemiluminescenz-Detektoren werden beschrieben. Der Einsatz dieser SF-Verfahren wird vor allem bei automatisierten kinefischeu Bestimmungen fiir klinische und pharmazeutische Analysen, Umweltproben, Nahrungsmittel und landwirtschaftliche Proben gesehen. - Trends Anal. Chem. 8, 302--308 (1989). Dept. Anal. Chem., Fac. Sci., Univ., Cordoba (E) R.H.S. Linearized model for error-compensated kinetic determinations without prior knowledge of reaction order or rate constant. J.A. Larsson and H.L. Pardue. This paper describes a new algorithm for calculation of reaction orders, rate constants, and initial and final values of detector signal from several signal vs time data points. The algorithm utilizes a linearized version of the rate equation and is intended primarily to provide initial estimates of these kinetic parameters for other curve-fitting methods. However, under some circumstances, the linearized model can provide sufficiently reliable results that subsequent processing by other methods is not needed. Simulated data with different levels of superimposed noise, data densities, reaction orders, rate constants, and signal change are used to evaluate the algorithm both for its primary purpose of providing initial estimates for other curve-fitfing methods and as an independent method. Results are compared with those obtained with a nonlinear least-squares method and two initial-rate methods. The new algorithm provides less reliable results than those obtained by the nonlinear curvefitting method for some situations (e.g. reaction orders greater than two, low data densities) but has the advantage that it is applicable to reaction orders at and near unity where the nonlinear method to which it is compared fails. - Anal. Chem. 61, 1949-1954 (1989). Dept. Chem., Purdue Univ., West Lafayette, IN (USA) Simulation of acid-base titration curves. C. Rbzycki. An equation was derived, which enables the calculation of the concentration of hydrogen ions in the any solution of acids, bases and their salts as a function of the volume of the titrant added. On the basis of this relationship a program has been written, which enables proper calculations as well as plotting of titrafion curve or its first derivative and calculation of the end-point. The titration simulation may be performed as follows: 1. On the basis of automatically chosen portions of fitrant (minimal and maximal portions are limited) ; 2. On the basis

436 of the subsequent portions of titrant which volume is established by the user of the program knowing the existing value of hydrogen ions concentration and pH; 3. On the basis of the subsequent portions of titrant which volume is established by the user observing the course of titration on the diagram pH vs. volume of the titrant added. Before the calculations user establishes the name of exercise and introduces such data as: the composition of solution, concentrations, dissociation constants, the kind of titrant, its concentration and dissociation constants, titration fraction and the indicator. The calculations of hydrogen ions concentrations are performed by the halving of the range. The final results may be printed and presented as a plot of: 1) pH vs. titrant volume; 2) pH vs. titraton fraction; 3) the first derivative of titration curve vs. titrant volume; 4) the first derivative vs. titration fraction. On I and 2 plots the range of the colour change of the chosen indicator is indicated. - Chem. Analit. 33, 963-975 (1989) (Polnisch, mit engl. Zus.fass.). Dept. Fund. Chem., Inst. Chem., Univ. Technol., Plock (PL) Automated titrations using a discontinuous programmed flow analyzer. D.P. Arnold, R.M. Peachey, J.D. Petty and D.R. Sweatman. The technique of automated discontinuous programmed flow analysis is described, together with a working prototype instrument employing syringe pumps driven by interchangeable cams. This technique relies on the cyclic generation of flow profiles for both a suction and a discharge pump, such that at various times sample only, reagent only, or a predefined combination of the two is conveyed via a mixing chamber to a detector. Different cam profiles allow a number of direct reading or reagent addition analysis methods, as well as both single and dual flow titrations. Results are presented for argentometric titrations of chloride in water using as detectors anodized silver microelectrodes contained in two alternative mixer/sensor assemblies. In the range of 6 0 - 1 6 0 rag/1 precision for analysis times of 30 s or less is typically better than 1%, with sample consumption of 0.9 ml. Accuracy for chloride determinations in city water samples is limited by the characteristics of the electrodes to ca. 2 - 3 % . Cycle times for this instrument are selectable from 6 to 90 s. Carryover from sample to sample is negligible because of the incorporation of a sample flush step to commence each cycle. The operating characteristics of this analyzer were studied by using a conductivity detector, and pump displacement precision is better than 0.1%. - Anal. Chem. 61, 2109-2116 (1989). Cent. Anal. Sci. Dept. Chem., Queensl. Univ. Technol., Brisbane, Queensl. (AUS) Complexing sorbents based on glycidyimethacrylate gels with imidazole groups for preconcentration of trace elements. N.I. Shcherbinina, G.R. Ishmiyarova, J. Kahovec, F. Svec, L.I. Bol'shakova, G.V. Myasoedova and S.B. Savvin. Man beschreibt die Synthese yon zwei neuen Sorbentien mit Imidazol(G-Ira) und Benzimidazol-Gruppen (G-BIm) auf der Basis des Glycidylmethacrylat-Copolymers. Sie werden durch Aminierung des Copolymers nach Aufquellen in w/il3riger L6sung (60 ml) mit 40%iger w~if3riger Imidazoll6sung bzw. mit 17%iger ethanolischer Benzimidazoll6sung bei 70°C innerhalb 7 h u n t e r mildem Rtihren synthetisiert. Auf diese Weise gewinnt man ein weiBes granuliertes Pulver, K6rngral3e 100-300 pro. Der Gehalt von Imidazol-Gruppen (retool/g) entspricht in dem auf diese Weise synthetisierten Sorbens aufgrund der Elementaranalyse 2,06 in G-lm bzw. 1,36 in G-BIm; man bestimmte auch die acido-basischen Eigenschaften und Sorptionseigenschaften der beiden Sorptionsmittel. Sie weisen gute kinetische Eigenschaften und hohe Werte yon Verteilungskoeffizienten (n x 104 ml/g) besonders bei der Sorption von Au(III), AGO), Cu(II), Zn(II) und Ni(II) auf. Der optimale Bereich der Au(III)Sorption bei 2 moi/1 HC1 liegt bei pH 7, derjenige der Ag(1)-Sorption bei pH 1 -- 7 und der Sorption von Ubergangselementen bei pH >~6. Das G-Im-Sorbens eignet sich zur selektiven Trennung von Cu, Ni, Zn und Au sowie von Co und Pb sogar aus L6sungen mit hohem Salzgehalt (bis zu 230 g/l); zu diesem Zweck wird die entnommene Probe durch Ansfiuern mit HC1 (pH ~ 1,5) konserviert bzw. im Kiihlschrank aufbewahrt. 100 ml Probel6sung werden mit Natronlauge auf pH ~ 6 eingestellt, mit 0,10--0,15 g G-Ira versetzt und 1 h durchgemischt. Das Sorbens wird abgetrennt, 4mal mitje 50 ml Wasser gewaschen, die sorbierten Metallionen werden mit 5 ml 2 M HC1 eluiert und mittels AES mit induktiv gekoppeltem Plasma bestimmt. Bei der Bestimmung von 0,5 bis 21 gg/1 der erw/ihnten Metalle in Salzl6sungen (60-104 g/l) ent-

1 General analytical chemistry spricht der sr-Wert h6chstens 0,21. - Zh. Anal. Khim. 44, 615-619 (1989) (Russisch, mit engl. Zus.fass.). Vernadskii Inst. Geochem. u. Anal. Chem., Akad. Wiss., Moskau (SU) F. Jancik Reversed-phase ion-pair partition liquid chromatography of chelates with 2-(3,5-dibromo -2-pyridylazo) -5-(N-ethyl -N-(3-sulfopropyl)amino)phenol and analogues. C. Ohtsuka, H. Wada, T. Ishizuki and G. Nakagawa. Pyridylazophenolderivate werden h/iufig als chromogene Chelatbildner ffir Metallionen verwendet. Das im Titel genannte Derivat, 3,5-diBrPAESPAP, wurde nfiher untersucht. Insbesondere seine Chelate mit V(V), Cr(III), Fe(II), Co(II) und Ni(II), die an einer ODS-Sfiule zur/ickgehalten werden, w/ihrend die Chelate mit Cu(II), Zn(II) und Cd(II) an der ODS-S/iule dissoziieren, wobei Acetonitril/Wasser (37 + 63, v/v), 0,01 M Acetat, 0,01 M 3-(N-Morpholino)propansulfonat-Puffer (pH 7,0) und 0,05 M Na + enthaltend, als mobile Phase verwendet wird. Die Chromatogramme dieser Chelate werden mit solchen verglichen, die man mit anderen Pyridylazophenolderivaten, z.B. 3,5-diBr-PASPAP, erh/ilt. - Anal. Chim. Acta 223, 339-347 (1989). Mizuho Coll., Mizuho-ku, Nagoya (J) W. Czysz New chelating sorbents based on pyrazolone containing amines immobilized on styrene-divinylbenzene copolymer. - I. Synthesis and analytical characterization. O. Todorova, E. Ivanova, A. Terebenina, N. Jordanov, K. Dimitrova and G. Borisov. Durch Modifikation yon Styrol-Divinylbenzol-Copolymer mit verschiedenen Pyrazolon enthaltenden Aminen wurde eine Reihe yon chelatbildenden Sorbentien dargestellt. Sie werden durch Elementaranalyse und IR-Spektroskopie charakterisiert. Ihre Komplexbildungseigenschaften gegeniiber Alkali-, Erdalkali-, f.)bergangs- und Edelmetallen wurden untersucht. Dabei zeigte sich eine gute Eignung zur gleichzeitigen Sorption und Anreicherung yon Erdalkali- und Ubergangsmetallen in neutralem Medium sowie fiir die selektive Abtrennung yon Edelmetallen in saurem Medium. - Talanta 36, 817-820 (1989). Inst. Gen. Inorg. Chem., Bular Acad. Sci., Sofia (BU) W. Czysz Chromatographic determination of metal ions after complexation with bis(qnaternary ammonium hydrazones) of 2,6-diacetylpyridine. M.V. Main and J.S. Fritz. Two new bis hydrazones of 2,6-diacetylpyridine were prepared and characterized. Both of these contain a quaternary ammonium group that greatly enhances the water solubility of the reagent and its metal-ion complexes. When the solid reagent was dissolved in water, an equilibrium was attained in which three geometric forms coexist. A rate constant was determined for this equilibrium. Several metal ions were determined quantitatively and selectively by complexation with one of the bis hydrazones and chromatographic separation of the metal ion complexes. Interferences due to the presence of other ions in solution were investigated. Anal. Chem. 61, 1272-1275 (1989). Ames Lab. Dept. Chem., State Univ., Ames, IA (USA) Cacotheline as a redox indicator in the determination of antimony(V), thallium(III), osmium(VIII) and iridium(IV) with iron(II). K. Vijaya Raju, G. Madhu Gautam and V. Rama Rao. Cacotheline is proposed as a redox indicator in the determination of antimony(V), thallium(III), osmium(VIII) and iridium(IV) with iron(II) in an orthophosphoric acid medium. The proposed method was applied to the determination of antimony in tin- and lead-based white metal alloys and in antimony potassium tartrate. The method was extended to the analysis of binary thallium(III)-thaliium(I) mixtures. - Analyst 114, 1293- •295 (1989). Dept. Engin. Chem., Andhra Univ., Waltair (IND) Some examples of using a complex approach to elucidation of reasons for the selectivity of reactions between organic reagents and metal ions. A.V. Kotov. Zur Beurteilung der Selektivit/it der Reaktionen yon organischen Reagentien mit Metallionen w~ihlte man die Differenzen zwischen der Energie der OR-Donor- und MI-Akzeptororbitale, der MI-Basizit/it und der durch das Liganden- und MI-Entladungsfeld beeinflul3ten Stabilisierung des Komplexes. Diese komplexe L6sung bewfihrte sich zur Voraussage der Eigenschaften von neuen OR. Das vorgeschlagene Verfahren wird durch zahlreiche Beispiele demonstriert; so die Bestimmung von Pd mit

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Fundamentals, methods, apparatus, reagents, automation, data processing

437

5-S-Amyl-8-mercaptochinolin in starksaurem Milieu, mit 2,2'-Furyldioxim, mit Rhodamin-(5-azo-3)-5-chlor-2-hydroxybenzoesulfonsfiure oder mit Isonitrosoacetophenon, von Rh(I) mit 5-Sulfoallthiox, von Ni mit Diacetyldioxim bzw. Cyclohexandion-~,2-dioxim und yon Fe mit 2,9-Dimethyl-l,10-phenanthrolin. Die angeffihrten Beispiele werden in Tabellen veranschaulicht. - Zh. Anal. Khim. 44, 842-848 (1989) (Russisch, mit engl. Zus.fass.). Allunion Forsch. u. Projekt.-konstr. u. technol. Inst. f. Stromquellen, Moskau (SU) F. Jancik

Alkali auf den Glaszylinder, wenn der Titrant in st/indigem Kontakt mit dem Glas ist. Es zeigt sich u.a. daran, dab bei der Standardisierung des Titranten der Faktor gr613er wird; man kann es aber auch bei der Kalibrierung der Bfirette feststellen. Allerdings werden die Titrationsergebnisse davon nicht beeinflugt, weil man ja dieselbe Bfirette normalerweise auch zur Standardisierung des Titranten benutzt. - Anal. Chim. Acta 223, 461 --468 (1989). Astra Pharm. Product. AB, Anal. Control, S6dertfile (S) W. Czysz

Recent advances in detection in flow injection systems. M. Vaicfircel and M.D. Luque de Castro. Durch Einsatz moderner Detektionssysteme in der FIA k6nnen die Analysenparameter dieser Systeme beeinflul3t und gezielt verfindert werden. Die Selektivit/it kann durch Mehrfachbestimmung mit schnellen Detektoren oder durch die Elimination yon Matrixeffekten durch integrierte Reaktions-Detektions-Systeme verbessert werden. Durch Entwicklung kinetischer Vorkonzentrierungsschritte mit integrierten Reaktions-Detektions-Konfigurationen und automatischer Ver/inderung des Konzentrationsbereiches des Analyten kann die Empfindlichkeit sowohl ffir konventionelle als auch ffir schnelle Detektoren verbessert werden. Mehrfachbestimmungen nach einmaliger Probeninjektion bei gleichzeitiger Verwendung yon schnellen Detektoren und/oder Vorkonzentrierungsschritten aus geringen Probenvolumina verbessern die Schnelligkeit des Verfahrens. Durch Verwendung automatischer Verdfinnungsprozesse und/oder integrierter Reaktions-Detektionssysteme kann die Genauigkeit im ppb-Bereich auf rel. Standardabweichungen yon 3 - 4 % verbessert werden. Mit den neuen Verfahren k6nnen kinetische und thermodynamische Konstanten, St6chiometrien und Viskositfiten bestimmt und Bestimmungen ohne Phasentrennungen durchgefiihrt werden. Das Einsatzgebiet dieser verbesserten FIA-Analysen wird in Umweltkontrollen, der klinischen Chemie und der Nahrungsmittelchemie gesehen. Beispiele werden gegeben. - Anal. Proc. 26, 3 1 3 - 315 (1989). Dept. Anal. Chem., Fac. Sci., Univ., Cordoba (E) R.H.S.

A procedure for analysis of densitometric spectra. A. Galat. Computer-aided quantitative analysis of densitometric spectra is presented. The densitometric spectra are decomposed into component bands using the Powell and Marquardt minimizers. Several different functions for the component bands are utilized. It is shown that the densitometric spectra can be decomposed into component bands with high accuracy only if the proper shapes of the bands are chosen. The method described was used for quantitative analysis of densitometric spectra of DNA cleaved by neocarzinostatin. The procedure is general and can be applied to analyses of autoradiographic films and to direct scans of electrophoretic gels. It is shown that densitometric spectra which show highly overlapped bands are well approximated by asymmetric Cauchy and Gauss functions. Well separated densitometric bands which have substantial asymmetry can be fitted to more sophisticated shapes formed by combinations of symmetric and asymmetric Cauchy and Gauss functions. High accuracy fitting to asymmetric densitometric curves may only be achieved using the cosine function introduced by Mignot and Rondot, J. Appl. Cryst. 9, 460 (1976). - Electrophoresis 10, 6 5 9 - 667 (1989). Dept. Biol. Chem. Mol. Pharmacol., Harvard Med. School, Boston, MA (USA)

Prediction of FIA peak width for a flow-injection manifold with spectrophotometric or ICP detection. P.L. Kempster, H.R. van Vliet and J.F. van Staden. Verff. entwickeln ein System yon Gleichungen, die zur Vorhersage eines FIA-Peaks bei Probeninjektionsvolumina yon 300 gl geeignet sin& Experimentell wird mit einem konventionellen FIA-System gearbeitet, Analyt ist der Diaquatetraamin-Cu(II)-komplex. Die Gleichungen ffir spektralphotometrische Detektion und mit ICP-AES sind /ihnlich. Talanta 36, 969-972 (1989). Hydrol. Res. Inst., Dept. Water Affairs, Pretoria (ZA) W. Czysz Determination of ethylenediaminetetraacetic acid by flame atomic absorption spectrometry with a chelating ion-exchange flow injection conversion system. E.B. Milosavljevi~, L. Sol@d, J.L. Hendrix and J.H. Nelson. A flow injection method (FI) has been developed for the determination of EDTA by FAAS. In the first step a copper(II) regenerant solution was injected on to an on-line column packed with Chelex-100 resin. The excess of copper ion, not retained on the column, was washed by an ammonia solution carrier. In the second step an EDTA sample was injected. The analyte displayed an equivalent amount of copper(II) from the chelating column. Eluted copper was determined by an FAA spectrometric detector positioned downstream. The signal obtained was proportional to the concentration of EDTA present in the injected sample. Using this FI-FAAS conversion method the detection limit was 0.1 gg/ml. The precision of the technique was better than a relative standard deviation of 1.5% at 0.50 p.g/ml levels, with a throughput of 45 samples/h. The effect of sample volume and of ionic and organic ligand interferents on the FI-FAAS signals was studied. Only glycylglycine was found to interfere significantly. - Analyst 114, 805-808 (1989). Inst. Chem., Fac. Sci., Univ. Belgrade (YU); Dept. Chem., Univ. Reno, NV (USA) Volume increase of piston burettes used for sodium hydroxide titrants. P.A. Johansson and U. Stefansson. Verff. berichten fiber eine Beobachtung, nach der das Volumen yon Kolbenbfiretten, die ffir NaOH-Titrationen benutzt werden, pro Jahr um 0 , 2 - 0 , 6 % zunimmt, und zwar als Folge des L6severm6gens yon

Application of factor analysis to the study of the forms of succinylfluoreseein present in buffer solutions in aqueous methanol. F. Amat-Guerri, M.E. Martin, J, Sanz and R. Martinez-Utrilla. Die in 1 : 1 (v/v) wfil3rigen Methanolpuffern angenommenen pH-abhfingigen Formen des Xanthinfarbstoffs Succinylfluorescein wurden durch Faktorenanalyse der bei sechs Wellenlfingen im sichtbaren Bereich gemessenen Absorptionsdaten und von 16 pH-Werten abgeleitet. Man kann daraus den Schlug ziehen, dab eine protonierte Species und ein zweifach geladenes Anion die beiden einzigen absorbierenden Species an den beiden Enden des untersuchten pH-Bereichs (1,40-9,77) sind. Die chinoiden neutralen und einfach geladenen Anion-Formen, beide mit /ihnlichen Absorptionseigenschaften, sind die Hauptkomponenten im pH-Bereich 5 - 6. AuBerdem ist es m6glich, dab eine farblose Komponente in geringerem Ausmag bei etwa pH 4 vorhanden ist. Scheinbare pK-Werte, die mit den drei Ionisationen korrespondieren, sind 2,90, 4,60 und 6,80. Diese Werte wurden potentiometrisch bestimmt. - Talanta 36, 704-707 (1989). Inst. Quim. Org. General, C.S.I.C., Madrid (E) W. Czysz Modifications to the simplex~optimized adaptive Kalman filter. H.R. Wilk and S.D. Brown. Verff. testen neue Responsefunktionen ffir den Simplex-optimierten adaptiven Kalmanfilter als Mittel zur Verbesserung der Bestimmung bekannter Komponenten in Gegenwart von unbekannten Komponenten oder anderen Matrixwirkungen. Vier Responsefunktionen auf der Grundlage der Neuerungssequenz wurden hinsichtlich h6herer Rechengeschwindigkeit des Filters und Reduzierung des Bestimmungsfehlers der quantifizierten Komponenten gepriift. Die Ergebnisse werden diskutiert. - Anal. Chim. Acta 225, 3 7 - 5 2 (1989). Dept. Chem. Biochem., State Univ., Newark, DE (USA) W. Czysz Analysis of partially resolved liquid chromatographic peaks using dynamic modelling with the Kalman filter. T.Q. Barker and S.D. Brown. Die Aufstellung eines Kalibriermodells ist ein wichtiger Teil jeder mathematischen Methode ffir Multikomponentenbestimmungen. Kalibrationsmodelle auf der Grundlage eines einzigen Spektrums sind leicht Fehlern unterworfen, da das gewfihlte Modellspektrum z. B. nicht reprfisentativ ffir die Response fiber den vollen Kalibrierbereich sein kann. Alternative Kalibriermodelle erfordern einen h6heren Zeitaufwand, was bei Realzeit-Bestimmungen Schwierigkeiten rnit sich bringt. Um diese Schwierigkeiten zu beheben, wird eine neue Kalibriermethode unter

438

1 General analytical chemistry

Einsatz von Kalmanfiltern eingeffihrt. Diese Methode, dynamisches Modellieren, basiert aufder Benutzung yon Kalibrationsspektren-Bibliotheken. Die Eignung dieses Verfahrens wird anhand yon simulierten und experimentellen Chromatogrammen demonstriert. Die notwendigen Spektrenbibliotheken mtissen nicht unbedingt sehr umfangrcich sein. Anal. Chim. Acta 225, 63 - 68 (1989). Dept. Chem., State Univ., Newark, DE (USA) W. Czysz Comparative study of several programs used in the potentiometric evaluation of equilibrium constants including an error sensitivity analysis. J.J. Baeza Baeza, G. Ramis Ramos and C. Mongay Fernandez. Zur Bestimmung der Protonierungskonstanten polyprotonierter Substanzen werden die Programme MINIQUAD, MINIPOT, SUPERQUAD und PHCONST in Verbindung mit simulierten Titrationen eingesetzt. Die dabei erhaltenen Werte fiir Pr/izision und Richtigkeit der Ergebnisse werden diskutiert und miteinander verglichen. Mit PHCONST erhfilt man bessere Werte der Richtigkeiten. Die Analyse der Fehlerempfindlichkeit wird eingesetzt, um den EinfluB eines systematischen Fehlers auf die Richtigkeit der Bestimmung festzustellen. Dazu wird ein Algorithmus ffir die genaue Berechnung der Fehlerempfindlichkeiten vorgeschlagen und getestet. - Anal. Chim. Acta 223, 419-427 0989). Dept. Anal. Chem., Fac. Chem., Univ., Valencia (E) W. Czysz Application of principal component analysis to the study of multiple equilibria systems. Study of copper(I1)/salicylate/mono-, di- and tricthanolamine systems. P. Tauler and E. Casassas. Zur Untersuchung yon zusammengesetzten Gleichgewichtssystemen auf der Grundlage yon Cu(II)-Ionen mit Salicylat und Mono-, Di- oder Triethanolamin als Liganden wird die Hauptkomponentenanalyse benutzt. Mit der Methode der repetitiven Faktorenanalyse (H. Gampp et al.: Talanta 32, 1133 (1985); vgl. diese Z. 325, 210 (1986)) wird eine modellfreie Bestimmung von Verteilungspunkten durchgeffihrt und individuelle Spektren verschiedener Species erstellt, die im Verlaufe einer spektralphotometrischen Titration entstehen. Die Ergebnisse werden mit denen yon least-squares-Methoden verglichen. - Anal. Chim. Acta 223, 257-268 (1989). Dept. Anal. Chem., Univ., Barcelona (E)W. Czysz Application of the three-distance clustering method in analytical chemistry. J. Zupan and D.L. Massart. First, the three-distance method (3-DM) was evaluated by comparing produced clusters with clusters obtained by a usual clustering technique (unweighted pair group method), and then the 3-DM was employed for classifcation of 572 oils (described by eight variables) into nine categories. The training set of 300 oils exhibited 100% recognition ability, and for the rest of the 272 oils in the testing set the classification (prediction) into nine categories (known in advance) was over 90% in all cases. It was concluded that, besides giving results completely comparable with those of the usual clustering methods, the 3-DM is far superior to them where the time factor is concerned. For the classification of 272 objects, 168 s (0.618 s/search) was needed, compared to 10 times more (6.0 s/ search) for finding the best match by comparing test compounds with each compound in the reference set (KNN method, with K = ] and K = 3). - Anal. Chem. 67, 2098-2102 (]989). Farm. Inst., Vrije Univ., Brussel (B)

1.2

Inorganic analysis

Adsorption of cesium on, and desorption from, controlled porous glasses. Column experiments. M. Kosmulski, A.L. Dawidowicz and J. Szczypa. Cesium contained in aqueous solutions of different composition was adsorbed in columns packed' with controlled porous glasses (CPG) and then removed by means of 1 M HCI: Recovery of cesium in the eluate was studied as a function of the solution composition and the kind of

CPG. - J. Radioanal. Nucl. Chem., Art. 131, 377-383 (1989). Lab. Adsorp. Phys. Chem. Interfaces, Polish Acad. Sci., Lublin (PL) Application of macrocyclic Schiff's bases for selective extraction and spectrophotometric determination of copper. N.V. Isakova, Yu.A. Zolotov and V.P. Ionov. Man untersuchte die Eignung von vier durch die Ringgr6Be sich unterscheidenden macrocyclischen Schiff-Basen (SB) ftir die selektive Cu(II)-Extraktion mit anschliel3ender spektralphotometrischer Bestimmung. Auf diese Weise kann Cu(II) entweder in Form der Komplexe mit den genannten SB allein oder mit Zusatz eines geeigneten Anions (z. B. Pikration) mit Chloroform aus w/il3rigen L6sungen be] pH 5,5 - 9,0 extrahiert werden. Die Cu(II)-Extraktionskonstanten in den erw/ihnten Systemen sind in einer Tabelle zusammengefagt. Die Cu(II)-Extraktion verl/iuft am besten mit SB, die zwei CH2-Gruppen enth~ilt. In diesem Fall wird es im Konzentrationsbereich I x 10 7 _ I x 10-4 mol/1 durch I mol/1 Na, Ca, Mn(II), Zn, Cd, Pb, Ag und TI(I), 0,5 mol/1 Co01), Ni, AI und Cr(III), 0,1 mol/l Fe(III) (in F--Anwesenheit) und TI(III) und 0,001 mol/1 Sn(IV) nicht beeinfluBt, w/ihrend mehr als 0,0] tool/1 C1st6rt. Man bestimmte auf die beschriebene Weise Cu-Spuren in metalIischem Zn und Cd aus 1 g (Cd) bzw. 2 g (Zn) Probeneinwaagen. Opt]male Bestimmungsbedingungen: Reagensl6sung in CHC13:3 x 10 -~ tool/l; Acetatpuffer (pH 5,6); das Beer-Gesetz gilt im Bereich 0 , 0 5 - 6 gg Cu/ ml; )~,,ax = 455 nm; a = 1,25 × 104. Arbeitsweise s. Original. - Zh. Anal. Khim. 44, 8 5 9 - 865 (1989) (Russisch, mit engl. Zus.fass.). Vernadski] Inst. Geochem. Anal. Chem., Akad. Wiss., Moskau (SU) F. Jancik 4-(3,5-Dichloro-2-pyridylazo)-l,3-diaminobenzene as a metaHochromic indicator for the complcxometric determination of Cn(II) with EDTA. C.A. Fontan and R.A. Olsina. Das oben genannte Reagens (R) bildet mit Cu(II) in schwach sauren L6sungen einen r6tlich-purpurfarbenen Komplex (e = 5,0x 104 1 mol-lcm 1 be] 547 nm). Dieser Komplex wird leicht durch EDTA zersetzt, wobei ein scharfer Farbwechsel zum gelben Reagens (Extinktions/inderung i 10 nm be] pH 3,5) eintritt. Dieser Farbunterschied, die Umkehrbarkeit der Bildungsreaktion zusammen mit der Wasserl6slichkeit des Komplexes machen R zu einem geeigneten metallochromen Indicator f i r Kupfertitrationen im Bereich pH 2,7-5,5. Beispiele der praktischen Anwendung dieser Methode, auch be] Analysen yon Gugeisen, kommerziellem Aluminiumsulfat und synthetisch gemischten D/ingern, werden angegeben. - Talanta 36, 945-949 (1989). Dept. Quire. Anal. ,,Carlos Marone", Univ. Nac., San Luis (RA) W. Czysz Traceability of zinc, cadmium, cobalt, copper, lead and manganese standard solutions based on EDTA chelatometric titration method. A, Hioki, N. Fudagawa, M. Kubota and A. Kawase. To establish the traceability of metal standard solutions of Zn, Cd, Co, Cu, Pb and Mn, the concentration of each metal standard solution (Cs) measured by EDTA chelatometric titration was compared with that (C) calculated from the weight of the dissolved metal. The EDTA solution was standardized with a high-purity Zn solution. The intersection of both the tangent at an inflection point and q) (indicator transition) = I was adopted as an end point of titration. The inflection point was calculated from experimental data near the point with the approximation as a curve of the third order. The difference between Cs and C was within __+0.1% for each metal standard solution. The traceability of the metal standard solutions ofZn, Cd, Co, Cu, Pb and Mn was thus confirmed. Bunseki Kagaku 38, T149 - T 1 5 5 (1989) (Japanisch, mit engl. Zus.fass.). Nat. Chem. Lab. Ind., Tsukuba-shi, Ibaraki (J) Precise polarographic determination of the stability constants of cadmium and lead with oxalate and sulfate. L. Nyholm and G. Wikmark. Genaue polarographische Bestimmungen der Stabilit~itskonstanten einiger Blei- und Cadmiumkomplexe mit Oxalat und Sulfat werden mit Hilfe von Differentialpuls-, Normalpuls- und Gleichstrom-Polarographie be] drei verschiedenen Konzentrationen der Metallionen im Bereich ] x 10-4 bis 9 x 10- 8 M durchgef/ihrt. Die Ergebnisse werden mit Literaturwerten verglichen, mit denen sich gute Ubereinstimmungen zeigten. Notwendige Korrekturrechnungen werden eingebaut; bestimmte Effekte, wie Anderungen des Diffusionskoeffizienten des Reaktanten, wer-

1.2

Inorganic analysis

den beriicksichtigt. - Anal. Chim. Acta 223, 429-440 (1989). Dept. Anal. Chem., Univ., Uppsala (S) W. Czysz Anodic-stripping voltammetry of heavy metals in the presence of organic surfactants. W.W. Kubiak and J. Wang. Die Wirksamkeit von reiner Kieselsfiure (fumed Silica; Sigma) zur Entfernung von St6rungen durch sorbierte organische Tenside bei der anodischen Abl6sevoltammetrie (ASV) yon Schwermetallen (Cd, Pb, Zn) wird untersucht. Die Zugabe der Kiesels/iure zur Probel6sung bewirkt eine sofortige Eliminierung yon st6renden Tensiden wfihrend der Stickstoffeinleitung. In Zahlen ausgedriickt, bewirken dann bis zu mindestens 6 ppm Gelatine, Triton X-100, Albumin oder Liqui-Nox keine St6rung mehr bei den Abl6sesignalen von Cd, Pb und Zn an der HMDE. Man erh~ilt z.B. bei 20 aufeinanderfolgenden Messungen von 1 x 10-7 M Pb in Gegenwart yon 2 ppm Triton X-100 eine rel. Standardabweichung von 5,5%. Analoge Verbesserungen wurden auch an der Quecksilberfilmelektrode in Gegenwart yon bis zu 60 ppm Tensid beobachtet. Die Verwendung yon Kieselsfiure bietet Vorteile an Schnelligkeit, Effizienz, Einfachheit und geringen Kosten im Vergleich zu anderen Techniken zur Beherrschung von Tensidst6rungen bei der ASV. - Talanta 36, 821 824 (1989). Dept. Chem., State Univ., Las Cruces, NM (USA) W. Czysz Effects of anions on the extraction/fluorometric determination of aluminium with 2,2'-dihydroxyazobenzene. K. Watanabe, K. Yokoo and I. Aoki. 2,2'-Dihydroxyazobenzene (DHAB) and 4,4'-dimethyl derivative (DDAB) react with aluminium(III) in an aqueous solution to form fluorescent 1:1 (metal-DHAB or DDAB) complexes. We studied the effects of anions and neutral ligands on the extraction/fluorometric determination of aluminium by using these complexes. The aluminiumDHAB complex was extracted with tributyl phosphate (TBP), and with benzene by adding trioctylphosphine oxide (TOPO). A large amount of appropriate anions i.e. acetate, propionate, thiocyanate and perchlorate, was required for the extraction of the complex. Especially the addition of propionate and thiocyanate gave a strong fluorescence. TBP and TOPO acted as neutral adductants and remarkably increased both the extractability and fluorescence quantum yield of the complex. TOPO also acted as a catalyst for the reaction between aluminium and DDAB. The ratio of the composition of the extracted complexes AI-(DHAB or DDAB)-(anion)-(TBP or TOPO) was 1:1:1:2 in the presence of acetate, and 1 : 1 : 1:3 in the presence of perchlorate. - Bunseki Kagaku 38, 458-461 (1989) (Japanisch, mit engl. Zus.fass.). Fac. Sci. Technol., Sci. Univ. Tokyo, Noda-shi, Chiba (J) Microviscosity of ions and salting-out in the extraction of rare-earth and transplutonium elements. B. Gorski, N. Gorski and Chr. Winde. The use of ion microviscosity - the viscosity of the first hydration shell - for the description of salting-out effect in extraction systems has been investigated. The dependences of the extraction of REE and TPE with trioctylphosphine oxide, trioctylamine and Aliquat 336 on the microviscosity of various ions (A13+, Fe 3+, Mg 2 +, Cu 2+, Ni 2+, Pb 2 +, Li +, Cs +) as a salting-out agent were determined. The extraction was carried out from nitric acid solutions and also from solutions containing strong complexing agents. The results indicate that it is possible to use the microviscosity of ions for the explanation of the salting-out action of cations. -- J. Radioanal. Nucl. Chem., Art. 131, 111-119 (1989). Joint Inst. Nucl. Res., Dubna (SU) An improved laser fluorimeter for the detection of traces of uranium. R. Zhang, Y. Lin and J. Cheng. An improved laser fluorimeter and its application for the determination of ultratrace concentrations of uranium are described. The system developed uses a collecting lens-filter system, by which the density of laser radiation on the sample is increased greatly and the interfering stray light can be reduced to a great degree. In addition, both laser and lamp sources are joined together in the instrument. A strong green phosphor from uranium-doped sodium metaphosphate (NaPO3:U) has been found suitable and has been used for the determination of ultratraces of uranium. A detection limit (3cQ of 0.36 pg of uranium (in 30 mg NaH2PO4 per pellet) was obtained. In the case of peak-to-

439 background intensity ratios relative standard deviations (RSD) are 6.4% and the linear dynamic range extends from 1 pg to 103 ng of uranium. Mikrochim. Acta 1989, I, 365 - 372. Beijing No. 5 Inst., Beijing (RC) Determination of hexavalent plutonium using differential spectrophotometry. V.K. Bhargava, G. Chourasiya, D.R. Chadse, U.M. Kasar and M.S. Oak. A differential spectrophotometric method has been developed for plutonium in hexavalent state using a double beam spectrophotometer. The absorbance measurements were made at 835 nm in 4 M sulfuric acid. In the method developed the absorbance of Pu(VI) standards were recorded against a molybdenum blue solution in the reference cell. A least-squares fit of data on absorbance and concentration of plutonium standards gave slope F and intercept Co which were used to determine the unknown concentrations using the relationship, C = Co + F. Ar where Ar is the absorbance of a plutonium solution of unknown concentration C mg/g. Various parameters like choice of acid and acidity, slit width, oxidant etc. were studied and the conditions optimized. Plutonium in the concentration range of 0.1 - 0 . 3 mg/g could be determined with a precision of _+0.5%. Uranium does not interfere. The method is useful for the analysis of a large number of samples on a routine basis. - J. Radioanal. Nucl. Chem., Art. 132, 179-187 (1989). Fuel Chem. Div., Bhabha Atomic Res. Cent., Bombay (IND) Influence of surfactants on the complexaton of zirconium and tungsten with p-nitrobenzeneazocatechol. V.G. Amelin, V.M. Ivanov and G.P. Svistunova. Es wird der Einflui3 von Kationen-, Anionen- und nichtionogenen oberfl/ichenaktiven Stoffen (OFAS) auf die physikalisch-chemischen Eigenschaften des p-Nitrobenzolazobrenzcatechins(NBAB) und die Bildung seiner Komplexe mit Zr(IV) und W(VI) untersucht. Zr(IV) bildet mit NBAB in Anwesenheit yon OP-10 bei pH 1,4-4,0 (HC10¢) den Komplex Zr:NBAB = 1:4 mit )~ma~ = 540 nm und ~ = 6,6 x 104; das Beer-Gesetz gilt im Bereich 0,04-0,2 pg Zr(IV)/ml. Die Bestimmung yon 5 lag Zr(IV) bei pH 1,1-1,3 (HC104) wird durch 5 mg Cu, Ca, Zn, Cd, Y, Ag, Cr(VI) und Fe(II), 1 mg A1, Au(III), Mg, Sr, Hg(II), La, Cr(III) und Ce(IV), 0,1 mg Fe(III), Be, Ba, V(V) und Mn(II), 0,05 mg Ga, 0,02 mg Ti(IV), 0,01 mg Sb(III), Mn(VII) und W(VI) nicht gest6rt (st ~<0,05); es st6ren dagegen Ge, Sn(IV), Bi, Mo(VI), F , EDTA und Weins/iure in gleichen Konzentrationen wie Zr(IV). W(VI) bildet mit NBAB in Anwesenheit yon Cetylpyridinium bei pH 0,6-2,5 (HzSO4) den Komplex W:NBAB = 1:2 mit ~max : 520 nm und ~ = 2,5 x 104. Das Beer-Gesetz gilt im Bereich 0 , 4 - 2 pg W(VI)/ml. Die Bestimmung von 20 gg W(VI) wird durch 0,01 tool/1 EDTA, 30 mg SO42- , 5 mg Zn, Cd, Y, Cr(VI) und Fe(II), I m g AI, Mg, Sr, La, Cr(III) und Ce(IV), 0,2 mg Fe(III), 0,1 mg Cu, Be, Pb, Ca und Mn, 0,01 mg Ti(IV) nicht gest6rt; es st6ren dagegen Ag, Ge, Sn, Sb, Bi, M o u n d F . Die Bestimmung von kleinen Zr- und W-Mengen in Glas mit diesen Komplexen in Anwesenheit von OFAS wurde ausgearbeitet; zugeh6rige Arbeitsweisen s. Original. - Zh. Anal. Khim. 44, 866-872 (1989) (Russisch, mit engl. Zus.fass.). Polytechn. Inst., Vladimir (SU) F. Jancik Adsorption of traces of hafnium on manganese dioxide from acid solutions. S.M. Hasany and M.H. Chaudhary. Adsorption of hafnium on manganese dioxide from nitric and perchloric acid solutions has been studied and optimized with respect to shaking time, concentration of acid, oxide and metal. Maximum adsorption has been noticed from 0.1 mol/1 acid solutions in 20 minutes around 10- ~ mol/1 hafnium concentration. The adsorption of hafnium follows a Freundlich adsorption isotherm. Oxalate, thiosulfate, Na(I) and AI(III) from nitric acid and K(I) and Zn(II) from perchloric acid increase the adsorption, whereas all other anions and cations tested reduce the adsorption from both media Fe(III) and Sn(IV) significantly. Zn(II) and Co(II) show low adsorption affinity. - J, Radioanal. Nucl. Chem., Art. 131, 425--434 (1989). Nucl. Chem. Div., Pakistan Inst. Nucl. Sci. Technol., Islamabad (PAK) Durable poly(vinyl chloride) matrix ion-selective field effect transistors for nitrate ions. S. Wakida, M. Yamane, A. Kawahara, S. Takasuka and K. Higashi.

440 A nitrate/ion-selective field effect transistor (ISFET) with a conventional ion-exchanger using trioctylmethylammonium nitrate (TOMANO3) showed unstable potential response because of the poor adhesion of the ion-sensing membrane onto the Si3N4 insulator thin film of the ISFET device. In order to improve the adhesion on the device, highly lipophilic nitrate ion-exchangers such as tridodecylmethylammonium nitrate (TDMA-NO3) and tetradecylmethylammonium nitrate (TTMANO3) were used. The ISFETs with nitrate-sensing membranes composed of 70 wt% the ion-exchanger and 30 wt% PVC were prepared by dipcoating onto the gate region of the ISFET device. The nitrate/ISFETs with TDMA-NO3 and TTMA-NOa showed the slope of 55 mV per decade in the range from 10 .4.5 M to 10 ° M and that of 56 mV in the range 10 -s M ~ I0 ° M, respectively. Both nitrate/ISFETs showed the response time of some seconds, stable potential response time of some seconds, stable potential responses and almost the same selectivity corresponding to "Hofmeister's series". - Bunseki Kagaku 38, 510-514 (1989) (Japanisch, mit engl. Zus.fass.). Governm. Ind. Res. Inst., Ikedashi, Osaka (J) A nitrate-selective electrode based on bis(triphenylphosphine)iminium salts. G. Werner, I. Kolowos and J. Senk)L Es wird die Herstellung einer nitrat-ionenselcktiven Elektrode beschrieben. Die elektroaktive Komponente der Elektrodenmembran besteht aus dem Ionenassoziat zwischen Bis(triphenylphosphin)iminium und Nitrationen in Nitrobenzoll6sung. Die Elektrode kann im Bereich 10- 6 _ 0,1 M Nitrat eingesetzt werden. Reproduzierbarkeiten: + 0,5 mV (10-4--0,1 M) und __+ 1 mV ( 1 0 - 5 - 1 0 -4 M). Nachweisgrenze p a o = 6,1. Die Selektivit/itskoeffizienten gegenfiber 12 Anionen sind in einer Tabelle angegeben. - Talanta 36, 966-968 (1989). Anal. Centre, Dept. Chem. Univ. Leipzig (DDR); Dept. Anal. Chem., Univ., Brno (CS) W. Czysz Indirect atomic-absorption spectrophotometric determination of phosphorus after flotation as the ion-pair of molybdophosphate with bis(2-(5chloro-2-pyridylazo)-5-diethylaminophenolato)eobalt(III). M. Taga and M. Kan. Zur Bestimmung yon Phosphor wird eine indirekte AAS-Methode entwickelt, die u.a. auch ffir die P-Bestimmung in geologischen und Umweltproben eingesetzt werden kann. Man gibt zu der bis 0,2 ~tg P enthaltenden Probe je 1 ml 1,25 M HzSO4, 2,25 mM Ammoniummolybdat und 0,25 mM Co-5-C1-PADAP (s. im Titel) und ffillt im Scheidetrichter auf 10 mI mit Wasser auf. Das dabei entstehende Molybdophosphat bildet mit dem Co-haltigen Reagens ein Ionenpaar, das an der GrenzflG che zu Butylacetat flotiert wird. Die w/tBrige Phase wird verworfen, das Ionenpaar unter Zugabe von 3,0 ml Aceton in der organischen Phase gel6st. Anschliegend bestimmt man den Co-Gehalt der organischen Phase durch AAS in einer Luft/Acetylen-Flamme. Die Eichkurve ist linear von 0,025-0,2 pg P mit RSD fiir 0,2 pg von 1,3% (n=6). Das Verfahren kann auch bei natfirlichen Wgtssern angewendet werden. Talanta 36, 955--956 (1989). Dept. Chem., Fac. Sci., Hokkaido Univ., Sapporo (J) W. Czysz Polymer-bound tetrahydroborate for arsine generation in a flow injection system. S. Tesfalidet and K. Irgum. Generation of arsine for subsequent atomic spectrometric determination was carried out in a flow system using a column packed with a macroporous strong anion-exchange resin (Amberlyst A-26) in the tetrahydroborate form as a polymer-supported reducing agent. The analysis cycle comprised regeneration, washing, and injection of acidified sample, and could be repeated every 4 rain, resulting in a detection limit for trivalent arsenic of 60 pg in a 40 gl sample, with a linear working range up to 4 ng. Nickel, cobalt, copper, or iron ions caused less than 10% signal degradation when present in the sample at concentrations between 2500 and 5000 rag/1 when L-cystine was added to the hydrochloric acid as masking agent. The column could be used for at least 3 months without performance degradation. - Anal. Chem. 61, 2 0 7 9 2082 (1989). Dept. Anal. Chem., Univ., Umea (S) Solvent extraction of antimony(H1) with 18-crown-6 from iodide media. R.G. Vibhute asand S.M. Khopkar.

1 General analytical chemistry Zur Extraktion von Sb(III) mischt man 50 btg Sb(III) enthaltende Probenaliquots mit genfigend H2SO4, Ascorbins/iure und KI-L6sung, dab deren Konzentrationen in l0 ml 1, 0,1 und 0,25 M betragen. Diese L6sung mischt man im Scheidetrichter mit 10 ml 0,02 M 18-Krone-6L6sung in Methylenchlorid, schfittelt 5 rain, zieht nach Phasentrennung die gelbe organische Phase ab und photometriert sie bei 430 nm. Die Einflfisse der verschiedenen experimentellen Parameter (Konzentratiohen des Kronenethers, yon KI und Ascorbins/iure) wurden vorher optimiert, desgleichen Wahl und Menge der organischen Phase. Die wahrscheinliche Zusammensetzung der extrahierten Species Sb:Kronenether:Iodid = 1 : 1:4. Der Einflug zahlreicher Ionen auf die Extraktion und Bestimmung von Sb(III) ist in einer Tabelle mit Toleranzgrenzen aufgeffihrt. Das Verfahren wird auf die Analyse von Pb, Sn und Sb enthaltendem WeiBmetall angewendet. - Talanta 36, 957-959 (1989). Dept. Chem., Ind. Inst. Technol., Bombay (IND) W. Czysz The determination of bismuth by hydride generation and non-dispersive atomic fluorescence detection. Y.W. Chen and A. D'Ulivo. Verff. beschreiben ein empfindliches Verfahren zur Bestimmung yon Bismuth mit Hydridtechnik und nichtdispersiver AtomfluorescenzSpektrometrie (ND-AFS). Als Lichtquelle dient eine kommerziell erh/iltliche elektrodenlose Entladungslampe (Radiofrequenz-angeregte EDL; Perkin-Elmer). Verff. berichten fiber Interferenzeffekte durch andere Elemente (Cu(II), AgO) , Au(III), Pt(IV), Pd(II)). AbschlieBend geben sie die Arbeitsvorschrift ffir die Bestimmung von Bismut in metallischem Kupfer (gg/g). Es wird gezeigt, dab Verdfinnen der Probe der einfachste Weg zur Kontrolle der St6rung durch Kupfer darstellt. Man kann auch Thioharnstoffzum Maskieren verwenden, doch muB damit sehr vorsichtig umgegangen werden, da sonst Verluste an Empfindlichkeit und Pr~zision eintreten. - Anal. Lett. 22, 1609--1622 (1989). Chengdu Coll. Geol., Dept. AppI. Chem., Chengdu (RC) W. Czysz The complexation of Cr(III) and Cr(VI) with flavones in miceUar media and its use for the spectrophotometrie determination of chromium. M.J. Gonzalez Alvarez, M.E. Diaz Garcia and A. Sanz-Medel. Eine Reihe von Flavonoid-Farbstoffen (Quercetin, Fisetin, Myricetin, Morin, Apigenin, 3-Hydroxyflavon, Naringenin) werden hinsichtlich ihrer Komplexbildung mit Chrom-Species in micellaren L6sungen (mit Cetyltrimethylammoniumbromid und, zum Yergleich, einigen analogen Tensiden: CTAC, CPB, TTAB, SLS) untersucht. Micellare Effekte, spektrale Parameter mit und ohne Micellen, Absorptionsspektren und Yerlauf der Komplexierungen werden diskutiert. Desgleichen die St6chiometrie der Komplexe und der EinfluB evtl. st6render Begleitionen im Hinblick auf ein noch zu verbesserndes Verfahren der Bestimmung von Cr(VI) und Cr(VI) + Cr(III)-Gemischen. Das System Cr(VI)-QuercetinCTAB wird optimiert. - Talanta 36, 919-923 (1989). Dept. Phys. Anal. Chem., Univ., Oviedo (E) W. Czysz Vnltammetric behaviour of the chromium(lH)-5-sulfosalicylate complex. I. Drela, J. Szynkarczuk and J. Kubicki. Verff. beschreiben voltammetrische Untersuchungen, die sie mit L6sungen des Chrom(III)-5-sulfosalicylatkomplexes (CrL) in Gegenwart yon 5-Sulfosalicylsfiure und 0,5 M Natriumperchlorat durchgeffihrt haben. Das elektrochemische Verhalten des Komplexes zeigt an, dab bei h6heren Konzentrationen von CrL ein Adsorptions-/ElektroreduktionsProzeB vorherrscht. Diese Beobachtung ist ffir die Praxis elektrometrischer Chrombestimmungen yon Bedeutung. - Talanta 36, 789-791 (1989). Inst. Inorg. Technol., Mineral Fertil., Techn. Univ., Wroclaw (PL) W. Czysz Benzylamine as a regulator in ion flotation of chromium(Ill) and cobalt(II). S.E. Ghazy and M.A. E1-Tanbouly. An experimental investigation is presented of ion flotation of chromium(III) and cobalt(II) from an aqueous solution with the use of benzylamine (BA~,) and oleic acid (HOL). The effects ofpH, the concentrations of HOL and BArn, the order of the addition of the reagents, the ionic strength and temperature on the floatability of the ions were studied. The maximum flotation efficiency of nearly 100% Cr 3+ and 98% Co 2+ was obtained in the optimum pH ranges 5.5 to 9 and 7 - 9 respectively. It was also found that the order of the addition of the reagents markedly affects the floatability. The ionic strength and tern-

1.2

Inorganic analysis

perature have no appreciable effect on flotation efficiency. The selective flotation of Cr z + and Co 2 + ions in the presence of each other was also reported. It was confirmed that Cr 3+ and Co 2+ ions were floated as precipitated amine complexes. - Analusis 17, 151-155 (1989). Chem. Dept., Fac. Sci., Univ., Mansoura (ET)

Simultaneous determination of molybdenum and tungsten by first-derivative synchronous spectrofluorimetry. F. Salinas, A. Mufioz de la Pefia, L.F. Capitan-Vallvey and A. Navalon. A method for the simultaneous determination of molybdenum and tungsten in mixtures by first-derivative synchronous spectrofluorimetry is described. The method is based on the formation of fluorescent complexes with carminic acid at pH 5.1. The constant wavelength difference chosen to optimise the determination was A)~ = )~em. - )~ox. = 50 nm. Molybdenum was measured at )~ox./)~om.= 550/600 nm and tungsten at )~ex./~om. = 561/611 rim. The range of application is between 1 and 12 ~M molybdenum and between 1 and 6 gM tungsten. The accuracy and precision of the method are reported. - Analyst 114, 1297 - 1301 (1989). Dept. Anal. Chem., Univ. Extremadura, Badajoz (E) Simple flow system for the rapid pre-concentration and potentiometric determination of fluoride using a micro-column and a wall-jet electrode. Y. Okabayashi, M. Hikawa, T. Nakagawa, H. Tanaka and M. Chikuma. A flow system for the selective pre-concentration and determination of ppb levels of fluoride has been developed. The system consisted of two micro-columns (150 × 0.5 mm i.d.) packed with an anion-exchange resin loaded with alizarin fluorine blue sulfonate-lanthanum complex and a fluoride ion-selective electrode in a wall-jet type cell. The fluoride present in 1 ml of sample was adsorbed on the resin and eluted with 1 M sodium hydroxide containing 0.5 M sodium chloride. This system allowed 24 samples to be treated in 1 h. Interference by the ubiquitous foreign ions Ca z +, Mg 2+ and H2PO4- at levels 300 times higher than that of fluoride was not observed but A1z + and Fe z ÷ interfered seriously at much lower levels; this interference could be eliminated by application of a previously reported method. - Analyst 114, 1267-1270 (1989). Fac. Pharm. Sci., Kyoto Univ., Sakyo-ku, Kyoto (J) Voltammetric determination of chloride ion with gold-platinum bipolar electrode. T. Ozaki, K. Hirayama and N. Unohara. A cyclic voltammetry was applied to the determination of chloride ion by the four electrodes method. A designed apparatus can concurrently measure the working electrode potential regulation and bipolar current, by using the gold working and platinum counter electrodes against the current-carrying electrodes as a bipolar electrode. As the result of scanning potential in the anodic direction in 0.1 M potassium nitrite at pH 2.9 as the supporting electrolytes, the correlation between the peak current at about + ] .0 V (vs. Ag/AgC1) and chloride concentration was linear. Chloride ion, ranging from 2 to 900 mg/1, can be determined by scanning several times in the narrow range from +0.5 to + 1.3 V at a rate of 5 V/min. A small amount of silver, mercury, iodide and bromide ions interferes the determination of chloride, while most heavy metal ions do not interfere. - Bunseki Kagaku 38, 438 - 442 (1989) (Japanisch, mit engl. Zus.fass.). Dept. Ind. Chem., Coll. Engin., Nihon Univ., Koriyama-shi, Fukushima (J) Iodimetric determination of iodate, bromate, hypochlorite, ascorbic acid and thiourea using flow injection amperometry. M.A. Abdalla and H.M. A1-Swaidan. Iodate, bromate and hypochlorite were determined as iodine by flow injection amperometry at a platinum or glassy carbon electrode by injecting them into an eluent 0.20 M in hydrochloric acid and 0.024 M in potassium iodide or an eluent 2 M in sulfuric acid and 0.12 M in potassium iodide. The rectilinearity range is from 10 3 to 10 -7 M. Organic compounds that can be oxidised or iodinated by iodine were determined on-line by injecting them in acidic solution into an iodateiodide eluent and observing the decrease in the iodine signal. The determination was also performed by injecting a pre-reacted solution of iodine and the organic compound and monitoring the excess of iodine. Analyst 114, 583 - 5 8 6 (1989). Dept. Chem., Coll. Sci., King Saad Univ., Riyadh (Saudi Arabia)

441 Spectrophotometric determination of trace amounts of iron(III) with norfloxacin as complexing reagent. P.B. Issopoulos. The complexation of iron(III) with norfloxacin in acidic solution at 25°C, at an ionic strength of about 0.3 M and a p H of 3.0 has been studied. The water-soluble complex formed, which exhibits an absorption maximum at 377 nm, was used for the spectrophotometric determination of trace amounts of iron(III). The molar absorptivity was 9.05 x l03 1 m o l - l c m -1 and the Sandell sensitivity 6.2 ng cm -2 of iron(III) per 0.00l A. The formation constant (K0 was determined spectrophotometrically and was found to be 4.0 x 108 at 25°C, The calibration graph was rectilinear over the range 0.25-12.0 ppm of iron(III) and the regression line equation was A = 0.163c-0.00042 with a correlation coefficient of 0.9998 (n = 9). Common cations, except cerium(IV), did not interfere with the determination. The results obtained for the determination of iron(III) using the described procedure and the thiocyanate method were compared statistically by means of the Student t-test and no significant difference was found. - Analyst 114, 6 2 7 - 6 3 0 (1989). Lab. Anal. Chem., Dept. Inorg. Anal. Chem., Univ., Ioannina (GR) Separation of metal ions by reversed-phase high performance liquid chromatography using in-situ complexation. Application to determination of Fe(III) and Fe(II) as o-phenanthroline complexes. F. Fernandez, M.L. Marina, and A.R. Rodriguez. The separation of different mixtures of the metal ions Fe(III), Fe(II), Ni(II), Co(II), Cu(II), Zn(II), Cd(II), Hg(II), Ca(II), Mg(II), AI(III), Cr(III), Sn(II), and Sn(IV) has been performed by using reversed-phase high performance liquid chromatography and o-phenanthroline in mobile phase. Among others, the separation of Fe(III) and Fe(II) has been achieved and detection limits for these species are given. The detection limit for Fe(II) at 509 nm is 240 times minor than at 340 nm. This last wavelength allows the simultaneous detection of both cations. - J. Liquid Chromatogr. 12, 1253-1260 (1989). Dept. Anal. Chem., Fac. Sci., Univ. Alcal~ de Henares, Madrid (E) Ion chromatographic separation of cobalt cyanide complexes. J.C. Thompsen and A.B. Carel. The method was developed to study the synthesis of cobalt(III) hexacyanide and to determine the purity of cobalt(III) hexacyanide solutions. Separation of the cobalt cyanide complexes is achieved on an ion-pairing column, followed by chemical suppression and conductivity detection. An application of the method for the determination of radiolabelled cobalt(III) hexacyanide at levels 1000-fold below the detection limit with conductivity detection is described. In this instance, fractions of the effluent are collected and analysed by liquid scintillation counting. Analyst 114, 1197-1200 (1989). Res. Dev., Conoco Inc., Ponca City, OK (USA) Determination of osmium and osmium isotope ratios by microelectrothermal vaporization inductively coupled plasma mass spectrometry. T. Hirata, T. Akagi, H. Shimizu and A. Masuda. A new merging introduction technique has been developed for Os analysis with ICP-MS. The sample was placed in a microheater ceil in a merging chamber and vaporized OsO4 was carried to the ICP with a blank matrix mist flow sprayed from a nebulizer. In the merging introduction, the best operational parameters could be obtained by the usual optimization using a standard solution. The laTOs/lSSOs ratio and the Os abundance were measured simultaneously by spiking 192Os. The precisions of the ratio and abundance measurements using 0.8 ng of Os were 5 and 4%, respectively. The detection limit of Os by this method was lower than 100 fg, which is almost one-twelfth of that obtained by conventional nebulization introduction. - Anal. Chem. 61, 2263 - 2 2 6 6 (1989). Dept. Chem., Fac. Sci., Univ., Hongo, Tokyo (J) Isonitrosothiocamphor as a spectrophotometrie reagent for platinum. P.K. Paria, T.K. Thokdar and S.K. Majumdar. Pt(IV) reacts with isonitrosothiocamphor to form a greenish chelate suitable for extractive spectrophotometry of the metal. The chelate shows ~max at 369 and 435 nm (e369 0.8 × 104) and obeys Beer's law from 2 25 ppm of Pt(IV) concentration. In determination of 19 ppm Pt, the following ions (in ppm) do not interfere: I - , $2032-, C2Ov. 2 -, tartrate,

442

1 General analytical chemistry

PO43 , citrate, EDTA (1000); Pb, Zn (550); Ca(520); Cd, Cr 3+, La, Zr 4+, Mo 6+ (450); Ce 3+, U 6+ (400); Mn 2+ (320); Bi3+, Th ~+ (300); Mg, A1 (100) and F - (<50). Co 2+, Ni 2+, Pd 2+ and Cu 2+ can be masked. Procedure. To an aliquot of Pt(IV) soln. add 0.5 ml of 0.4% reagent soln. (in ethanol) and phthalate buffer (pH 7 - 8 ) . Dil. to 10 mi and heat on a water bath for 10 rain. Cool and extract with 10 ml chloroform. Measure the absorbance of the extract at 369 nm against a reagent blank. - Curr. Sci. 58, 739-740 (1989). Dept. Chem., North Bengal Univ., Darjeeling (IND) M. Katyal

1.3

Organic analysis

Determination of the concentration and stable isotopic composition of oxygen in organic matter containing carbon, hydrogen, oxygen, nitrogen, and sulfur. M.J. DeNiro and S. Epstein. A method for the quantitative production of carbon dioxide from oxygen in organic matter consisting of carbon, hydrogen, oxygen, nitrogen, and sulfur has been developed. Manometric and mass spectrometric analysis of the CO2 permit direct determination of the concentration and isotopic composition of oxygen in CHONS compounds with accuracy comparable to that previously achievable for CHO and CHON compounds. Samples containing as little as 187 gmol of oxygen with S/O ratios as high as 0.16 have been analyzed by using this method. Anal. Chem. 61, 1887-1889 (1989). Div. Geol. Planet Sci., Calif. Inst. Technol., Pasadena, CA (USA)

fluorescence at 590 nm ()~ex. -- 450 rim). The detection limits were in the sub-picomole range. - Analyst 114, 1233-1240 (1989). Div. Foods, Nat. Inst. Hyg. Sci., Kamiyoga, Setagaya-ku, Tokyo (J)

Ionic-strength dependence of formation constants XII. A model for the effect of background on the protonation constants of amines and amino acids. A. Casale, C. De Stefano, S. Sammartano and P.G. Daniele. Aus der Analyse yon Literaturdaten fiber die Protonierung yon NDonor- und N,O-Donor-Liganden bei 25°C wurde ein einfaches Modell ftir die Abh/ingigkeit der Protonierungskonstanten yon Aminen und Aminos/iuren von den Untergrundelektrolyten abgeleitet. Das Modell berficksichtigt dabei die Bildung von schwachen Komplexen zwischen den protonierten Formen der Amine oder Aminos/iuren und den Untergrund-Anionen sowie zwischen der Aminos/iuren-Carboxylatgruppe und Alkalimetall-Kationen. - Talanta 36, 9 0 3 - 907 (1989). Ist. Chim. Anal., Univ., S. Agata di Messina (I) W. Czysz Automatic stopped-flow determination of L-cysteine. A. Cardoso, M. Silva and D. Perez-Bendito. Ein automatisiertes stopped-flow-Verfahrenwird zur Routineanalyse yon gg-Mengen L-Cystein ausgearbeitet. L-Cystein wird mit 2,6-Dichlorphenolindophenol (DPIP) in schwach basischem Medium oxidiert; die dabei auftretende Abschw~ichung der Extinktion bei 615 nm, der Maximumwellenlfinge yon DPIP, entspricht der L-Cysteinkonzentration. Der lineare Eichkurvenbereich liegt bei 2 - 32 gg/ml, die Nachweisgrenze bei 300 ng/ml. Die meisten in die Prfifung einbezogenen Aminosfiuren (Tabelle) haben keinen Einflug auf die Oxidation und k6nnen auch in h6heren Konzentrationen toleriert werden. Der Probendurchsatz betr~igt 80/h. - Talanta 36, 963-965 (1989). Dept. Anal. Chem., Fac. Sci. Univ., Cordoba (E) W. Czysz

Supercritical fluid chromatographic determination of fatty acids and their esters on an ODS-silica gel column. A. Nomura, J. Yamada, K. Tsunoda, K. Sakaki and T. Yokochi. Free fatty acids and their esters were determined by SFC on an inert packed column using supercritical carbon dioxide as a mobile phase without addition of any modifier. The column used was ODS-silica gel having a pore diameter of 300 A_and end-capped as enough as possible to decrease residual silanoI groups on the silica surface. The retention behavior of free fatty acids and their esters was investigated in terms of the density of a mobile phase, and they were separated according to a reversed-phase mode like in LC. Lipids extracted from fungus and their esterified products were separated by the SFC using a pressure programming mode and a constant pressure mode, respectively, and the chromatograms obtained with both FID and UV detector were compared. - Anal. Chem. 61, 2076-2078 (1989). Nat. Chem. Lab. Ind., Tsukuba, Ibaraki (J)

Quantification of 14C_iabeled amino acids by reverse-phase high-performance liquid chromatography. B.J. Micallef, B.J. Shelp and R.O. Ball. This study provided the first evidence indicating that ophthalaldehyde-amino acid-derivatives are unstable during high performance liquid chromatographic separation on a reverse-phase Cls column. Instability of these derivatives on the column resulted in the formation of 14C-labeled degradation products, and caused excessive 14C-fronting of amino acid peaks. The column halflives of glutamate, arginine and ornithine were 16, 40, and 54 minutes, respectively. Derivative break-down during derivatization also gave rise to these degradation products in the ~4C-distribution profile. Thus, if OPA-derivatization is used to quantify the a4C-distribution in an unknown mixture of amino acids it is necessary to determine correction factors for each amino acid of interest. A method which uses stable phenylthiocarbamate-derivatives did not exhibit these problems and is therefore more suitable for the quantification of 14C-amino acids. - J. Liquid Chromatogr. 12, 1281 1300 (1989). Dept. Hortic. Sci., Univ. Guelph, Guelph, Ont. (CDN)

Evaluation of benzofurazan derivatives as fluorogenic reagents for thiols and amines using high-performance liquid chromatography. T. Toyo'oka, T. Suzuki, Y. Saito, S. Uzu and K. Imai. The reactivities of three reagents, 4-(N,N-dimethylaminosulfonyl)7-fluoro-2,1,3-benzoxadiazole (DBD-F), 4-(aminosulfonyl)-7-fluoro2,1,3-benzoxadiazole (ABD-F) and 4-(fluorosulfonyI)-7-phenoxy-2,1,3benzoxadiazole (PBD-SOzF), towards thiols and amines were compared. All three reacted with thiol compounds to give derivatives which fluoresced at ca. 515 nm (excitation at ca. 388 nm). However, the PBD-SO2 derivatives were not very stable. The rate of reaction of DBD-F with proline was faster than that of PBD-SO2F or ABD-F. The three reagents and their hydrolysates exhibited extremely low fluorescence. The fluorescence intensities of the proline derivatives synthesised were higher in neutral and acidic solutions than in alkaline solution. The strength of the fluorescence intensities was in order PBD-SO2-proline > DBDproline > ABD-proline at all pH values tested. The mean values of the maximum wavelengths of DBD-proline, ABD-proline and PBD-SO2proline were 596 nm 0~ex. = 466 nm), 602 nm ()~cx. = 466 nm) and 566 nm ()~ex.453 nm), respectively. Of the three reagents, DBD-F seemed to be applicable to the determination of amino acids. Nine amino acid derivatives of DBD-F were separated by RP-HPLC and detected with

Reevaluation of the phenol-sulfuric acid reaction for the estimation of hexoses and pentoses. P. Rao and T.N. Pattabiraman. Evidence is provided to show that in the conventional phenol-sulfuric acid reaction procedure, phenol underwent sulfonation in situ and the phenolsulfonic acid formed decreased the color intensity for hydroxymethyl furfural (HMF), furfuraI, and many hexoses and pentoses tested. A modified method is described to overcome this problem in which phenol was added after the dehydration of carbohydrates by sulfuric acid and after cooling the system. The color intensity around 475 485 nm for different compounds was fairly proportional to the amount of furfural derivatives (absorption at 310 - 320 nm) formed from the sugars in the modified method unlike in the conventional procedure. The studies also show that for condensation of HMF derivatives with phenol, heat is not necessary. The color intensity in the modified method also increased compared to that in the conventional method. The increase in the modified method compared to that in the conventional method was 6.0-fold for furfural, 9.1-fold for hydroxymethyl furfural, 3.7-fold for fructose, 2.3-fold for xylose, and 2.0-fold for glucose and arabinose. The possible reasons for this difl'erential increase are discussed. - Anal. Biochem. 181, 1 8 - 2 2 (1989). Dept. Biochem., Kasturba Med. College, Manipal (IND)

1.3

Organic analysis

Electrocatalysis and detection of amino sugars, alditols, and acidic sugars at a copper-containing chemically modified electrode. S.V. Prabhu and R.P. Baldwin. Chemically modified electrodes (CMEs) produced by deposition of a Cu/Cl-containing crystalline species onto glassy carbon exhibited stable electrocatalytic oxidation of numerous polyhydroxyl compounds including carbohydrates, amino sugars, alditols, and aldonic, uronic, and aldaric acids. In cyclic voltammetry, the electrocatalysis appeared as an irreversible anodic wave that occured only at hydroxide concentrations of at least 10-3 M and was centered at + 0.5 V vs Ag/AgC1. The CMEs were readily adapted for constant-potential amperometric detection of these compounds in flow injection analysis and liquid chromatography. When used in this fashion, the electrodes provided detection limits in the nanomole-to-picomole range and were compatible with a relatively wide range of anion-exchange chromatography mobile phases. Examples of possible applications included the separation and quantitation of amino sugar mixtures, antibiotics, and mono- and disaccharides in tobacco. - Anal. Chem. 61, 2258-2263 (1989). Dept. Chem., Univ., Louisville, KY (USA) The effect of surfactants on the chromatographic separation of phenols on papers impregnated with hydrated cerium oxide. S.K. Dabral. Die chromatographische Beweglichkeit yon 16 Phenolen auf chromatographischen Papierstreifen (Whatman No.2), die mit Cer(IV)-oxidHydrat impr/igniert sind, wird durch Zugabe yon Tensiden beeinfluBt. Es wird gezeigt, daB die Zugabe von Natriumdodecylsulfat zur mobilen Phase sowohl die Selektivitfit der Trennungen als auch die Kompaktheit der Flecken verbessert. Zahlreiche bin/ire und tern/ire Gemische biologisch wichtiger Phenolverbindungen werden getrennt. Die genauen Arbeitsparameter einschlieBlich optimaler Laufmittelgemische sind in umfangreichen Tabellen aufgefiihrt. - Anal. Lett. 22, 1623-1629 (1989). Dept. Chem., Govt. Post Grad. Co11., Uttarkashi (IND) W. Czysz The behavior of some carboxy and hydroxy benzene derivatives on thin layers of plain and Fe(III)-impregnated silica-gel. O. Had~ija, M. Tonkovi6, and S. Iskri& The behaviour of some carboxy and hydroxy benzene derivatives related to lignin and humic materials was examined by thin layer chromatography on plain and Fe(III)-impregnated silica-gel plates, in three solvent systems. The mobility differences on impregnated and plain plates, expressed as R~ values, were calculated and can be used as one of the parameters for identification of the compounds tested. J. Liquid Chromatogr. 12, 979-985 (1989). Ruder Boskovic Inst., Zagreb (YU) Isomer discrimination of disubstituted benzene derivatives through gasphase iron(I) ion reaction in a Fourier transform mass spectrometer. A. Bjarnason, J.W. Taylor, J.A. Kinsinger, R.B. Cody and D.A. Weil. Gas-phase reactions of Fe ÷ with the isomers of several disubstituted benzene derivatives were studied in a Fourier transform mass spectrometer. The electron impact mass spectra of these compounds are generally too similar for routine isomer identification. The iron ion complexes and their fragments produce spectra that reveal isomer differentiation. The method presented here fundamentally relies on the ability of Fe ÷ to form a bridge between the two substituents. Where such a bridging reaction is observed, an ion unique to that isomer is produced and identifies the isomer. In all the cases studied but one (xylene), the ortho isomer can easily be identified, and in some cases all three isomers can be differentiated with this method. Pressure variations within the normal operating range of the mass spectrometer were found not to interfere with the isomer identification. - Anal. Chem. 61, 1889-1894 (1989). Dept. Chem., Univ., Madison, WI (USA) Ionic equilibria of picric acid in mixed amphiprotic solvents. The 2methoxyethanol/water solvent system. A. Marchetti, E. Picchioni, L. Tassi and G. Tosi. Picric acid is the guide solute used in our studies in order to verify the applicability of an empirical treatment that describes the dependence of the dissociation constant on temperature and composition of the solvent mixture (~ is mole fraction). The 2-methoxyethanol/water solvent system has been employed in this work operating at 19 temperatures ranging from - 1 0 to +80°C; by use of the conductometric method the dis-

443 sociation constant values ofpicric acid have been evaluated by the FuossHsia equation. The data have been fitted by three empirical equations that represent the functions K = K(T), K = K(Z), and K = K(T,?0. The K = K(T,);) equation in its complete form is composed of 20 terms, some of which can be eliminated because of small statistical weight; the nmnber and type of these terms vary on passing from one solvent system to another, and the best-fitting form, which in this case represents 13 terms, is suggested. The possibility of extrapolating K values of picric acid in a pure water solution is investigated and compared with similar previous calculations. - Anal. Chem. 61, 1971-1977 (1989). Dept. Chem., Univ., Modena (I) Continuous separation of glucosides in dual-flow extraction system. H. Nishizawa, Y. Watanabe, S. Okimura and Y. Abe. A new separation system in dual-flow countercurrent extraction has been established. As a result, a two-component mixture could be separated with the improved apparatus, liquid particle extractor, whose working principle is the same as that in liquid particle chromatography (LPC). Liquid particle chromatography has been used as a means to determine the distribution constants of components in a sample, which were necessary for setting the operating condition of the extractor. The optimum condition for the best separation of two compounds (distribution constant of D1 and D2) was deduced theoretically. Thus, the flow rate of the aqueous phase (H) could be determined by a calculation using the flow rates of the sample feed (A, fed as an organic solution) and the organic phase (S) by the relation: H = (S + A/2)~/Di xD2. With the extractor, a continuous and complete separation of phenyl-13-Dglucopyranoside (D = 1.17) and esculin (D = 1.58) in a 100 mg-scale (100 mg each in 20 ml of water saturated 1-butanol) could be executed in 14 h. A precise separation of a mixture with a separation factor (D1/D2) of 1.23 was also accomplished. Anal. Sci. 5, 345 - 350 (1989). Kyoritsu Coll. Pharm., Minato, Tokyo (J) Mixture analysis and quantitative determination of nitrogen-containing organic molecules by surface-enhanced Raman spectrometry. J.J. Laserna, A.D. Campiglia and J.D. Winefordner. Surface-enhanced Raman spectrometry (SERS) on a silver-coated filter paper substrate of nitrogen-containing organic molecules is reported. A correction procedure for standardization of measurements is proposed and evaluated to solve the difficult problem of quantitation of adsorbate in SERS. The relative standard deviation obtained through this procedure is around 15%. Linearity (r=0.999) was achieved up to 50 gg/ml aminoacridine. A limited dynamic range is observed, however, due to the limited number of SERS active sites in the substrate. Spectral fingerprinting of three-componentmixtures by concentration-dependent selective molecular adsorption on the substrate is also reported. - Anal. Chem. 61, 1697-1701 (1989). Dept. Chem., Univ., Gainesville, FL (USA) Evidence for electrostatic interactions of steroids in thinqayer chromatography. H. Lamparczyk, R.J. Ochocka and P. Zarzycki. The retention behaviour of steroids was investigated using normal and reversed-phase high-performance TLC systems. Homologous series of esters and n-alcohols were applied as the mobile phases. The electrostatic interactions operating in these chromatographic systems were analysed by studying the relationship between the log (I/RF) values and the molecular polarizabilities of the solvents. - Chromatographia 27, 565 568 (1989). Med. Acad., Fac. Pharm., Gdafisk (PL) The reversed-phase HPLC behavior of retinyl esters. H.E. May and S.I. Koo. Fifteen retinyl esters were synthesized. The esters were purified by HPLC and their chromatographic behavior on reversed phase HPLC was studied. The monoenes were relatively difficult to separate from esters with saturated acyl groups with two fewer carbons. Retinyl esters with polyene acyl groups showed decreased effective carbon numbers (ECNs) of 3.32-3.47 for dienes; 4.64-4.84 for trienes; and 5.92 for the one tetraene tested. The usefulness of ECN is discussed. Retinyl arachidonate (R20:4) was not separated from both and retinyl palmitoleate (R16:1) and retinyl myristate (R14:0), using any one condition. Under the chromatography conditions used, the complex lipids

444

2 Particular products and fields of application

eluted soon after the solvent front. Thus the Folch extract of liver or plasma could be used directly for analysis of retinyl esters monitored at 325 nm without preliminary separation from other lipids. - J. Liquid Chromatogr. 12,1261 - 1280 (1989). Dept. Biochem. Oral Roberts Univ. Sch. Med., Tulsa, OK (USA) Desorption chemical ionization, thermospray, and fast atom bombardment mass spectrometry of dihydropyridine ~ pyridinium salt-type redox systems. L. Prdkai, Bih-Hsiung Hsu, H. Farag, and N. Bodor. Trigonellyl-substituted (pyridinium salt type) compounds decompose during sample introduction using desorption chemical ionization (DC1) and thermospray (TSP) ionization. Thermal dequaternization is the main degradation process in DCI, while hydrolytically sensitive bonds are subject to cleavage in the TSP source, and dequaternization and reduction to the dihydropyridine analogues are also observed. Fast atom bombardment (FAB) is the suggested method of ionization because of its ability to provide an intense intact cation. The neutral dihydropyridine analogues can be effectively ionized by DCI and TSP. These methods are recommended, because bombardment-induced oxidation produces artifacts and shows a matrix effect in positive FAB. - Anal. Chem. 61, 1723-1728 (1989). Cent. Drug Design Deliv., Coll. Pharm., Univ., Gainesville, FL (USA) The effects of ~-eyclodextrin on the fluorescence, UV absorption and solubility of selected bimanes in aqueous solutions. I.R. Politzer, K.T. Crago, D . L Kiel and T. Hampton. Man untersuchte den Einflul3 von [3-Cyclodextrin auf FIuorescenzemission und -anregung sowie die UV-Absorption und L6slichkeit einiger Bimane (bicyclische Pyrazoi-Derivate) in w~il3riger L6sung. In verdiinnten L6sungen zeigten die syn-(CH3CH3)-Bimane und syn(C6Hs,C1)-Bimane Verst/irkung ihrer relativen Fluorescenzintensitfiten bei der Zugabe von [3-Cyclodextrin; desgleichen anti-(CHaCH3)-Biman. Nur dieses letztere zeigte auch eine signifikante Ver/inderung seiner UVAbsorption, wenn [3-Cyclodextrin zugegeben wurde, syn-(CH2OCOCH3,CH3)-Biman und syn-(CH3,CH3)-Biman wiesen erh6hte L6slichkeiten auf. Als Erkl/irung ffir diese Verhaltensweisen wird die Bildung von J3-Cyclodextrin-Einschluf3komplexen angenommen. - Anal. Lett. 22, 1567 - 1580 (1989). Dept. Chem., Xavier Univ., New Orleans, LA (USA) W. Czysz One-line electrochemistry/thermospray/tandem mass spectrometry as a new approach to the study of redox reactions: The oxidation of uric acid. K.J. Volk, R.A. Yost, and A. Brajter-Toth. The electrochemical oxidation pathway of uric acid was determined by on-line electrochemistry/thermospray/tandem mass spectrometry. The tandem mass spectrometric results provide convincing evidence that the primary intermediate produced during the electrooxidation of uric acid has a quinonoid diimine structure. The results indicate that once formed via electrooxidation, the primary intermediate can follow three distinct reaction pathways to produce the identified final products. The final electrochemical oxidation products observed in these studies were urea, CO2, alloxan, alloxan monohydrate, allantoin, 5-hydroxyhydantoin-5carboxamide, and parabanic acid. The results show that the on-line combination of electrochemistry with thermospray/tandem mass spectrometry provides otherwise difficult to obtain information about redox and associated chemical reactions of biological molecules such as the structure of reaction intermediates and products, as well as providing insight into reaction pathways. - Anal. Chem. 61, 1709-1717 (1989). Dept. Chem., Univ., Gainesville, FL (USA)

2

PARTICULAR PRODUCTS AND FIELDS OF APPLICATION

2.1

Inorganic industrial products

Direct analysis of coal by electrothermal atomization atomic-absorption spectrometry. A.H. Ali, B.W. Smith and J.D. Winefordner. Verff. beschreiben eine neue Methode zur Bestimmung von Spurenelementen in Kohleproben. Man mahlt die Proben zu weniger als 200 mesh,

,,pipettiert" das Material in den becherf6rmigen Ofen und bestimmt die Atomabsorption nach elektrothermischer Atomisierung. Zur Erstellung analytischer Kalibrierkurven kann man entweder feste Standardreferenzproben oder Aliquots synthetischer L6sungen von Pb, Zn und Mn verwenden. Die SRM-Proben werden vor der Probeneingabe mit spektralreinem Graphit gemischt. Nach Atomisierung und Reinigungsstufe werden Aschenreste mit Hilfe einer Pasteur-Pipette entfernt. Die Me/3ergebnisse ftir Pb, Zn und Mn stimmen gut mit den SRM-Zertifikatwerten fiberein. Die Methode weist eine ausreichende Pr/izision ( 5 - 1 4 % ) und Richtigkeiten innerhalb 5 - 1 2 % der SRM-Werte auf. - Talanta 36, 893-896 (1989). Dept. Chem., State Univ., Gainesville, FL (USA) W. Czysz Limitations of spectrophotometric multicomponent analysis of metal ions with mixed reagents. M. Otto and W. Wegscheider. Simultaneous analysis of metal ions is explored by means of a twocomponent reagent consisting of Tiron and 2-pyridine-aldoxime. The influence of experimental conditions, i.e. pH and metal and reagent concentrations, on the spectral system is studied by computer simulations in a model system containing six metal analytes and 24 equilibrium species in total. From this study an analytical procedure on the basis of multivariate calibration and data reduction with the partial least-squares algorithm is derived that enables copper, iron, and titanium to be determined simultaneously in aluminum reference samples with mean relative errors of less than 15%. -- Anal. Chem. 61, 1847-1851 (1989). Dept. Chem,, Bergakad. Freiberg, Freiberg (DDR) Spectrophotometric determination of bismuth with semi-xylenol orange and its application in metal analysis. Zhou Nan, Yu Ren-Qing, Yao XuZhang and Lu Zhi-Ren. Semi-Xylenolorange bildet mit Bi(III) ein 2: l-Chelat, dessen konditionelle Bildungskonstante einen logarithmischen Wert von 3,08 hat; der molare Extinktionskoeffizient betrfigt 4,2 x 10~ 1mol- lcm- 1. Das Beersche Gesetz gilt bei 540 nm im Bereich 1 0 - 3 0 pg Bi(III) mit einer rel. Standardabweichung von 1,1 gg (n = 18). Milchs/iure wird als Hilfskomplexbildner verwendet, der O1- und Oxolbildung verhindert. St6rungen durch bis zu 1,3 mg Kupfer k6nnen durch den kombinierten Einsatz der Maskierung mit Thioharnstoff, Ascorbins/iure und Thiosemicarbazid und anschliel3ende ,,Maskierung" von Bi(III) mit NaC1 eliminiert werden. Das Verfahren wurde mit Erfolg eingesetzt bei der direkten Bestimmung von 0,002% und mehr Bi in metallischem Blei, wobei der Variationskoeffizient zwischen 3,7% und 6,9% lag. - Talanta 36, 733-737 (1989). Shanghai Res. Inst. Materials; Tird Factory of Shanghai Reagent Chem., Shanghai (RC) W. Czysz Determination of trace metals in vanadium metal and vanadium-aluminium alloy by ICP-AES after bismuth hydroxide coprecipitation separation. H. Yoshikawa, K. Isobe, H. Iwata, N. Benitani. Trace amounts of Co, Cu, Fe, Mg, Mn, Ni, Ti and Zr in vanadium metal and vanadium-aluminium alloy were determined by ICP-AES after coprecipitation with bismuth hydroxide. After V(III, IV) ions were oxidized to V(V) ion with hydrogen peroxide at pH i2, the 8 trace elements were coprecipitated quantitatively with bismuth hydroxide and separated from the V and A1 matrices. Cr, Mo and Pb did not show quantitative recovery, due to the formation of their oxocompounds under these conditions. The precision of the present method was within 10% relative standard deviation for each element. - Bunseki Kagaku 38, 535-537 (1989) (Japanisch, mit engl. Zus.fass.). Anal. Res. Dept., Adv. Technol. Res. Center NKK, Kawakasi-shi, Kanagawa (J) Determination of phosphorus in nonferrous metal alloys containing tungsten by phosphomolybdate blue spectrophotometric method after beryllium coprecipitation separation. H. Yoshikawa, H. Iwata, H. Seno and T. Misumi. The amount of phosphorus in nonferrous metal alloys containing tungsten was determined by phosphomolybdate blue spectrophotometric method with beryllium hydroxide coprecipitation technique. More than 4 mg of beryllium hydroxide was required for the quantitative coprecipitation of phosphorus. Nickel and cobalt could be masked by

2.1

Inorganic industrial products

EDTA for the quantitative separation of phosphorus. Chromium was vaporized as chromium dichloridedioxide (CrO2C1;). Molybdenum and zirconium showed no interference in the present method. However, the presence of above 1% of zirconium together with above 2% of tungsten interfered. The solvent extraction method with 1-pentanol was also studied, and the extraction condition could be determined. The extraction was completed in 30 s, and the extracted complex was stable at least for 120 min. The limit of determination for phosphomolybdate blue spectrophotometric method and the solvent extraction method were 20 ppm and 1 ppm, respectively. - Bunseki Kagaku 38, T134- T139 (1989) (Japanisch, mit engl. Zus.fass.). Adv. Technol., Res. Center, Kawasakishi, Kanagawa (J)

Determination of chloride in platinum-rhenium alumina-based reforming catalyst by ion chromatography. R.P. Singh, K. Alam, D.S. Redwan and N.M. Abbas. An ion chromatographic method was developed for the fast and accurate determination of chloride in Pt-Re/A1203 catalysts using a Dionex Model 2120i ion chromatograph. Extraction of chloride was carried out with sodium hydroxide solution in a Teflon Parr bomb at 150°C. After filtration, ion chromatographic analyses were made by injecting 100 pl of the diluted solution into the sample port. Separation of chloride was achieved on a Dionex AS-4 separator and AG-4 guard column with sodium carbonate-bicarbonate eluent. The proposed method is free from interferences of sulfide and halides generally encountered in conventional potentiometric and spectrophotometric methods. The total analysis time of less than 1 h was considerably shorter than that reported for conventional methods. The minimum detectable chloride in a catalyst sample was 0.1% by weight with a relative standard deviation of about 3%. - Anal. Chem. 61, 1924-1927 (1989). Res. Inst., King Fahd Univ. Petrol. Miner., Dhahran (Saudi Arabia) XRF analysis of magnetic thin film conducted by a fundamental parameter method. J. Yoshitomi, S. Nakahama, H. Naganuma and H. Oguro. XRF analysis carried out by the fundamental parameter (FP) method was made to determine the composition and film thickness of thin film of Co-Cr and Tb-Fe-Co systems. For many standard samples, composition and thickness are known, and complicated pretreatment has been required for multicomponent thin film analysis conducted by a conventional calibration curve method. Analysis of thin film in a shorter period, for which for less amounts of standard samples are required, is possible by the FP method. The accuracy became six times as much by preparing a calibration curve based only on several standard thin film samples in making analysis using only the FP method. This method showed good repeatability, and relative standard deviation of each composition and thickness were less than 0.5%. - Bunseki Kagaku 38, T160 - T 163 (i 989) (Japanisch, mit engl. Zus.fass.). Matsushita Technores. Inc., Moriguchi-shi, Osaka (J) Direct analysis of molten steel by chlorination]lCP-AES technique. T. Akiyoshi, T. Takahashi and T. Kondo. For direct analysis of molten steel, the chlorination and transportation technique was examined. The analytical system consisted of a probe for chlorination of molten steel and an ICP spectrometer, the sample injection tube of which was connected to the probe by a fluoride rubber tube. Consequently, the intensity of each element in ICP-AES reflected the amount of elemental chloride. The most influential factor in measurement stability was the amount of oxygen and oxide gases passing through the ICP torch. As a slight excess of these gases extinguished the ICP torch, special treatment, such as the addition of A1 to steel, was required to suppress oxide gases. The intensity of Fe varied inversely with the Mn content in steel in the range of 0.1 ~ 1% Mn. This was in good correlation with the thermodynamically calculated value. For Si, Mn, Cr and Ni, it was possible to get calibration curves of intensity in ICP-AES relative to the elemental content in steel. However, Mo could not be analyzed by this technique. Carbon was transported as the oxide and influenced by solute oxygen in steel. As a result, for the determination of carbon in steel, it was necessary to combine the analyses for C and A1. - Bunseki Kagaku 38, 486-490 (1989) (Japanisch, rnit engl. Zus.fass.). Keihin Works, NKK Corp., Kawasaki-shi, Kanagawa (J)

445 Determination of the various phases of aluminium in steel by X-ray fluorescence spectrometry. R. Klockenkfimper and K.H. Koch. The total content of aluminium in steel can be determined from the Kc~line in the x-ray spectrum with a detection limit of 0.001%. However, aluminium is generally present in three phases, as metal, as nitride and as oxide; these different phases are of metallurgical significance and have to be distinguished. This is possible from their different K]3 bands in the x-ray spectrum, which were found at 1555.3, 1553.9 and 1552.5 eV, respectively. The physical bandwidth of about 7 eV, however, causes overlapping of the peaks, so that an unfolding procedure is needed. The detection limit of the different phases was determined to be 0.06% which, unfortunately, is above the region of interest for modern steel analysis. In addition, the analysis time of about 3 min is too long for use in process control, so that the classical methods for phase determination cannot be replaced by x-ray fluorescence analysis. - X-Ray Spectrom. 18, 177181 (1989). Inst. Spektrochem. Angew. Spektrosk., Dortmund (D) Rapid method for the determination of phosphides in stainless-steel slag by inductively coupled plasma atomic emission spectrometry. E. Novaro, R. Pagnozzi and R. Tomellini. A rapid and simple method to determine phosphides in stainless-steel slag is described. Phosphides are determined in stainless-steel slag either to check the extent of de-phoshorisation of the steel or when the slag is to be disposed of on the land. Dissolution of the slag with hydrochloric acid was carried out to generate phosphine, which was fixed in a saturated bromine solution. After removal of the excess of bromine, the concentration of phosphorus was determined by inductively coupled plasma atomic emission spectrometry. The limit of detection was 0.5 Ixg/g of phosphorus, i.e., 1 gg/g in analysing a 50-g sample. - Analyst 114, 1335--1336 (1989). Cent. Svil. Mat., Grup. IRI-ILVA, Rome (I) Photometric determination of nickel with acetohydrazine in asbetos-containing materials. G.N. Dudareva, B.V. Kudryavtsev and G.I. Guzieva. Ni wurde in asbesthaltigen Materialen mit 2-Benzoyl-4-(2-nitrophenyl)acetohydrazin (BNAH) als Reagens ohne Matrixtrennung spektralphotometrisch bestimmt. Die BNAH-Dissoziationsformen wurden in w/il3rigem Aceton (20% Aceton) untersucht, Ni(II) bildet mit BNAH bei pH 7,4-9,5 in diesem Milieu einen blaugeffirbten Komplex ()~max = 580 rim), der Ni in Gegenwart yon K, Na, NH4 + (1 : 104), Ca, Mg, NO3 (1:5000), Zn, A1 (1:1000), Fe(III) (1:500), F - , C1- (1:4000) sowie SO42- und PO~ 3- (1 : 2500) zu bestimmen erm6glicht. Auf diese Weise bestimmte man Ni-Spuren in drei Referenzstandardmustern mit 0,04, 0,06 und 0,08% Ni. Arbeitsweise. 0,I - 1,0 g Probe werden durch Erw/irmen in HNO3/HC1 (1:3) gel6st, die L6sung wird 1 0 - 1 5 min gekocht, filtriert und das Filtrat in einem 100 ml-Megkolben mit Wasser zur Marke erg/inzt. Ein Aliquot davon (5-100 gg Ni enthaltend) wird in einem 50 ml-Mel3kolben mit 10 ml 0,006%iger BNAH-L6sung in Aceton, 1 ml 20%iger Seignette-Salz-L6sung und 10 ml Pufferl6sung (Ammoniumacetat mit NH3-Zusatz, 1:4, pH 7,4-9,5) versetzt und mit Wasser zur Marke erg/inzt. Die Extinktion wird in einer 3 cm-Kfivette bei 580 nm gemessen und der Ni-Gehalt anhand der Eichkurve (Ni(II)Konzentrationsbereich 5 - 1 0 0 pg) ermittelt. - Zh. Anal. Khim. 44, 883-885 (1989) (Russisch, mit engl. Zus.fass.). Allunion Forsch.inst. Geol. nichtmetallischen Minerale, Kazan (SU) F. Jancik Spectrophotometric determination of arsenic in zinc concentrates and other lead-zinc smelter roasted products. R. Raghavan, S.S. Murthy and C.S. Rao. Bei der industriellen Gewinnung yon Zink mit elektrolytischen Verfahren gilt Arsenals ,Problemverunreinigung", die die Stromeffizienz reduziert, eine Wiederaufl6sung von Zink f6rdert und in weiteren Punkten das Verfahren negativ beeinflu3t. Es wurde deshalb ein Verfahren zur Bestimmung von As in Zinkkonzentraten und anderen Blei-ZinkSchmelz- und R6stprodukten im Konzentrationsbereich 0,001-0,3% ausgearbeitet. Die Proben werden mit einem HNOa/H2SO4-Gemisch aufgeschlossen und der Rfickstand mit 6 M HC1 aufgenommen. As(V) wird durch Ti(III)-chlorid zu As(III) reduziert und dieses als Iodid mit Chloroform extrahiert. Aus der organischen Phase wird es dann mit Wasser abgezogen, mit Cer(IV)-sulfat oxidiert und nach der Molybd/inblaumethode bei 825 nm photometriert. Die Ergebnisse der Analyse yon SRM-Proben und die Wiederfindungen mit Standardzugaben sind

446 gut. - Talanta 36, 951-954 (1989). Process Investig. Control. Lab., Hindustan Zinc Ltd., Debari, Udaipur (IND) W. Czysz Ion flotation of metals with N-dodecanoyl-N-methyl-aminoacetic acid. T. Nozaki, H. Yamashita and K. Kanda. An ion-flotation method has been developed for the determination of traces of Zn(II), Pb(II), Cd(II), Ni(II) and Bi(III) in aluminium nitrate and gallium hydroxide. Dissolve 1 g of aluminium nitrate in dil. nitric acid, adjust the final pH to 11.0, add 3 ml of 1 . 0 x l 0 -z tool/1 Ndodecanoyl-N-methyl-aminoaceticacid (DMAA), followed by diluting the solution to 100 ml with water. For the gallium sample dissolve 0.1 g, adjust the final pH to 9.5, add 10 ml of the DMAA solution, followed by diluting to 100 ml with water. The solutions are made to float in a cell for about 10 rnin with nitrogen bubbles. Trace amount recovery of these metal ions was from 96.2~99.5%. - Bunseki Kagaku 38, 5 3 7 539 (1989) (Japanisch, mit engl. Zus.fass.). Fac. Engin., Univ. Ehime (J) Spin dynamics in the analysis of carbonaceous deposits on zeolite catalysts by carbon-13 nuclear magnetic resonance with cross polarization and magic-angle spinning. B.R. Richardson and J.F. Haw. The potential of solid-state ~3C nuclear magnetic resonance spectroscopy with cross polarization and magic-angle spinning (CP/MAS) for the characterization of the carbonaceous deposits that form on zeolite catalysts during hydrocarbon processing is explored. Particular attention is given to the extent to which the results can be regarded as quantitative. The samples considered in this investigation were prepared by reaction of butadiene on catalyst pellets containing zeolite HY in a flow reactor at temperatures between 150 and 600°C. The NMR studies performed included relaxation measurements to characterize the spin dynamics relevant to quantitation and a variable-temperature ~3C CP/MAS experiment. Comparison of carbon spin counting results with carbon content from combustion analysis revealed that although 78% of the carbon was detected by NMR for the sample obtained from 150°C reactor run, significantly less carbon was detected for samples coked in the reactor at higher temperatures. This result correlated with the observation of organic free radicals in the samples, but it could also be due in part to inefficient cross polarization in hydrogen-deficient regions. - Anal. Chem. 61, 1821 - 1825 (1989). Dept. Chem., Texas A&M Univ., College Station, TX (USA) Simultaneous determination of a group of platinum metals by adsorption HPLC. A.Yu. Malykhin, T.A. Bol'shova, I.N. Ermolenko, I.B. Bobrorich, I.A. Nikishkin and L.A. Polyakova. Pt(II), Pd(lI) und Ru(III) k6nnen nebeneinander in Form ihrer 8Hydroxychinolinate mittels Adsorptions-HPLC auf eine Silasorb-600S/iule mit Chloroform/Isopropylalkohol (98 : 2) als Eluent bestimmt werden. Die Nachweisgrenzen liegen bei 1,5 ng (Pt), 1,0 ng (Pd) und 4,0 ng (Ru) beim Probenvolumen 5 gl. Das Verfahren wurde zur Bestimmung dieser Metalle in Modell6sungen sowie in Katalysatoren auf der Basis yon Faserkohle-Tr/igern eingesetzt. Arbeitsweise. 1 0 - 20 mg Faserkatalysator werden in einem 50 ml-Kolben mit 3 ml konz. H2SO4/1 ml 30%igem H202 auf dem Sandbad unter Erw/irmen gel6st, die L6sung wird mit i ml konz. HC1/HNO3 (3 : 1) bis zum Erscheinen weiBer Dfimpfe und danach dreimal mit je 1 ml konz. HC1 fast zur Trockne verdampft und der abgekfihlte Riickstand in einem 25 ml-MeBkolben in Wasser gel6st und zur Marke erg/inzt. 1 - 2 ml davon, ( 5 - 50 gg Metalle enthaltend) werden in einem 15 - 2 0 ml-Probierglas mit 1 ml 5%iger Ascorbins/iure-L6sung (Reduktion yon Pt(IV) zu Pt(II)) versetzt, die L6sung wird mit Acetatpuffer auf 10 mI verdiinnt, 30 mg 8-Hydroxychinolin werden zugesetzt und 2 h in einem siedenden Wasserbad erw/irmt. Nach Abkfihlung wird die L6sung mit 2,0 ml Chloroform 1 - 2 rain ausgeschiittelt, die organische Phase mit 15 ml 0,1 tool/1 NaOH gewaschen, und 5 ~1 davon werden chromatographiert. Die zugeh6rigen 8-Hydroxychinolinate werden in der Reihenfolge Pt, Pd und Ru eluiert. Gearbeitet wurde mit dem Mikrosfiulen-Flfissigkeitschromatographen Milichrom (SU) auf einer Silasorb-600 (5 gm)-Sfiule (62 x 2 mm); DurchfluB 100 gl/min; UV-Detektor (254 nm). Der Metallgehalt wird anhand der zugeh6rigen Eichkurve ermittelt. - Zh. Anal. Khim. 44, 886-892 (1989) (Russisch, mit engl. Zus.fass.). Lomonosov Univ., Moskau (SU) F. Jancik SIMS analysis of joining interface between silicon nitride and metal. Y. Shichi, K. Matsukiyo and M. Matsunaga.

2

Particular products and fieids of application

Joining interfaces between silicon nitride (Si3N4) and metal were analyzed by SIMS. The depth profile and 3-dimensional analyses of the joining interfaces were carried out using selected specific ions. Analytical conditions were as follows: primary ion, 02 +, 12 kV, 500 nA; sweep area, 0.01 ram2; and acquiring area, 100 gm 2. As the specific ion of titanium silicide (TisSi3), m/z=76 was chosen. Analytical results comfirmed the previous results by X-ray photoelectron spectroscopy and AEM that the joning interface of Si3N4-metal with active metal and brazing metals consisted of two layers. - Bunseki Kagaku 38, 5 0 5 509 (1989) (Japanisch, mit engI. Zus.fass.). Mat, Lab., Centr. Engin. Lab., Nissan Motor Co., Yokosnka-shi, Kanagawa (J) The application of multivariate techniques to data from Spanish glassmaking objects from the Roman era. F.X. Rius, M.S. Larrechi, C. Benet, E. Subias, D.L. Massart and A. Thielemans. Verff. wenden drei Multivariantenmethoden (Hauptkomponentenanalyse, Korrespondenzfaktoranalyse und spektrale Kartierungsanalyse) an, urn die R6ntgenfluorescenzdaten verschiedener Glaswaren aus der R6merzeit (5. Jh. v. Chr.) in Spanien (Tarragona) zu untersuchen und zu klassifizieren. Projektionen yon jeweils 50 Proben unter Anwendung yon 10 Variablen zeigen brauchbare M6glichkeiten auf, auch in Gegenwart redundanter Informationen zu guten Ergebnissen zu kommen. Die Visualisierung der Gruppen yon Objekten und der Beziehungen zwischen Objekten und Variablen (Abb.) erlauben die Formulierung yon relativ eindeutigen Hypothesen in bezug auf die Zusammengeh6rigkeit von Proben (Artefakten) und die Existenz lokaler Glasfabrikationen. Anal. Chim. Acta 223, 69-81 (1989). Dep. Quim., Univ. Barcelona, Tarragona (E) W. Czysz Radio frequency powered glow discharge atomization/ionization source for solids mass spectrometry. D.C. Duckworth and R.K. Marcus. A radio frequency (rf) powered glow discharge atomization/ionization source has been deveIoped for solids mass spectrometry. By use of a 13.56-MHz generator to supply the discharge operating potential, a pseudocontinuous plasma is produced that permits the sputtering of electrically insulating materials such as glasses and ceramics. The rfpowered source operates at argon pressures of 100-500 mTorr and powers of 5 - 50 W. The effect of discharge parameters on the observed analyte ion signals is explained in part as a spatial, ion sampling effect. Mass spectra are presented for alloy, metal oxide, and glass matrix samples. For each of the matrix types analyte ion currents for the major species are on the order of t0-11 A, a value similar to those observed in the conventional dc glow discharge ion sources. - Anal. Chem. 61, 1879-1886 (1989). Dept. Chem., H.L. Hunter Chem. Labs., Clemson Univ., Clemson, SC (USA) Scanning electrochemical microscopy. Apparatus and two-dimensional scans of conductive and insulating substrates. J. Kwak and A.J. Bard. The application of scanning electrochemical microscopy (SECM) in the feedback mode to two-dimensional scans over conductive and insulating substrates to obtain topographic information at the micrometerlevel is described. In the feedback mode the effect of the conductivity of the substrate and distance of the substrate from a scanning ultramicroelectrode tip on the current flowing at the tip caused by an electrode reaction is recorded as a function of the tip x-y position. Experiments with a 50-gm Pt wire on glass, a ca. 50-gin glass fiber on glass, a gold minigrid, a Pt foil, and a KC1 crystal in both aqueous and acetonitrile solutions are presented. The construction of the SECM and the hardware and software that control three-dimensional tip movement and data acquisition are also described. - Anal. Chem. 61, 1794 1799 (1989). Dept. Chem., Univ., Austin, TX (USA) Coulometric determination of the average valencies of copper and bismuth in the superconducting bismuth-strontium-calcium-copper-oxygen system. K. Kurusu, H. Takami and K. Shintomi. The average valencies of copper and bismuth in the superconducting Bi-Sr-Ca-Cu-O system have been determined using a coulometric titration technique. Both copper(III) and bismuth(V) were allowed to react with an excess of copper(I) and the excess of copper(I) was then back-titrated by an anodic oxidation. Bismuth(V) was determined alone by taking advantage of the reaction with manganese(II). In the Bi-Sr-

2.2

Organic industrial products

Ca-Cu-O sample having a high transition temperature (To) of 90 K, the average valencies of copper and bismuth were found to be 2.144 and 3.119, respectively, using these techniques. -- Analyst 114, 1341 - 1343 (1989). Yokohama R&D Labs., Furukawa Electr., Okano, Nishi-ku, Yokohama (J) Characteristics of aerosols produced by the spark discharge. R.L. Watters, Jr., J.R. DeVoe, F.H. Shen, J,A. Small and R.B. Marinenko. A detailed study of the physical properties and the chemical composition of spark-produced aerosol and corresponding erosion craters has been undertaken. A high repetition rate (1 kHz), electronically controlled waveform spark source was used to generate the aerosol from samples of Standard Reference Materials (SRMs). The feasibility of using an online electrical mobility analyzer to monitor real-time particle concentrations was examined. Consistent bias in the Zn/Cu ratios of aerosols from a series of brass SRMs corresponded to a reverse bias in the Zn/ Cu ratios measured in the spark erosion pits. Collected particles were dissolved and analyzed by inductively coupled plasma spectrometry. A predominance of small particles ( ~ 10 nm) was observed, and confirming analyses were performed with the analytical electron microscope on individual particles. - Anal. Chem. 61, 1826-1833 (1989). Cent. Anal. Chem., Nat. Inst. Stand. Technol., Gaithersburg, MD (USA) Reactivity of the cadmium ion in concentrated phosphoric acid solutions. J. de Gyves, J. Gonzales, C. Louis and J. Bessiere. Im Zusammenhang mit der Phosphors~iureproduktion ffir die Diingemittelindustrie werden verschiedene Verhaltensweisen yon Cadmium in Phosphorsfiure untersucht. Sic sollen dazu dienen, Cd aus der produzierten Phosphorsfiure quantitativ zu eliminieren. So werden die Solvatationstransfer-Koeffizientenbestimmt, die die Ver~inderungen der Ionenreaktivitfit bei sich/indernder Phosphors~iure-Konzentrationcharakterisieren. Die Versuche zeigen, dab die starke Desolvatation der Cadmiumspecies in konz. Phosphors~iure eine merkliche Steigerung ihrer Reaktivit/it bewirken. Bei der Extraktion des Cadmiums ist zu beachten, dab bei der Reaktion mit sauren Reaktanten (HA; A = Anion) das Ansteigen der AciditS.t die Extraktion von CdA2 versfiirkt. Ahnliche Verhaltensweisen gelten auch ffir Zink. - Talanta 36, 727-731 (1989). Univ. Autonoma Mexico, Fac. Quim., Dep. Quim. Anal., Cd. Universitaria (MEX) W. Czysz

2.2

Organic industrial products

Fast non-destructive determination of silicon in coal by means of (n,n'?) and (n,y) processes. M. Vobecky, Z. Janout, J. Koni~ek and S. Pospigil. The possibilities were evaluated of non-destructive determination of silicon content in large-scale samples of coal, based on the spectrometry of prompt y-radiation from processes (n,n'y), E 7 = 1779 keV and (n,y), Ey = 3539 keV and 4935 keV. The neutron sources were either 241AmBe or 252Cf located additionally in D20 moderator. A Ge/Li-detector was used for y-radiation detection. In exposure times of up to 2 h, the detection limits of 1.3% and 0.9% and accuracies of silicon determination of 0.66% and 0.40% have been achieved in case of (n,y) and (n,n'?) processes, respectively. - J. Radioanal. Nucl. Chem., Lett. 136, 411 -421 (1989). Inst. Nucl. Biol. Radiochem., Czech. Acad. Sci., Prague

(CS) Fast non-destructive determination of iron and sulfur in coal by means of neutron radiative capture. Z. Janout, J. Koni~ek, S. Pospi~il, M. Vobeck~ and R. Drahofiovsk~. The possibility of determination of iron and sulfur in large-scale samples of coal, based on process (n,7) , was evaluated. The spectral lines of the doublet 7631 keV and 7645 keV were used for the determination of iron, while the line at 5421 keV was used for the determination of sulfur. The neutron source was 2s2Cf located additionally in D20

447 moderator. A Ge/Li-detector was used for gamma radiation detection. The calibration dependencies of the analyzer were linear. In exposure times of up to 1 h, the detection limits of 0.34% and 0.64% and accuracies of 0.25% and 0.4% have been achieved in case of iron and sulfur, respectively. - J. Radioanal. Nucl. Chem., Lett. 136, 423-435 (1989). Fac. Nucl. Sci. Phys. Engin., Techn. Univ., Prague (CS) Radio frequency plasma detector for sulfur selective capillary gas chromatographic analysis of fossil fuels. R.J. Skelton, Jr., H.-C.K. Chang, P.B. Farnsworth, K.E. Markides and M.L. Lee. Flame photometric detection is often used for sulfur selective GC analysis. However, nonlinear response and quenching are significant drawbacks to this detector. Due to the relatively low abundances of sulfur compounds in extremely complex fossil fuels, capillary GC coupled with element selective radio frequency plasma detection was used to provide sulfur selective ( > 103) analysis of petroleum distillates and coal extracts. This detector was evaluated as a sulfur selective detector and was found to possess low limits of detection (0.5 pg/s) and good linear response (4 decades). Various numbers of phenyl groups attached to the base thiophenic ring had little effect on the intensity of the sulfur emission signal. Coelution of hydrocarbons was found to affect sulfur response only at high concentrations. - Anal. Chem. 61, 2292-2298 (1989). Dept. Chem., Univ., Provo, UT (USA) Electroanalytical chemistry of sulfur compounds for the new coal conversion technologies. J. Jordan, J. Talbott and J. Yakupkovic. Fiir die Speciation und Bestimmung yon schwefelhaltigen Verunreinigungen in Kohlevergasungs-/-verfltissigungs-Prozef3str6men werden ,,maBgeschneiderte" polarographische Verfahren angegeben. In Proben, die Anionen Sx2- enthalten, wird der sulfidische Schwefel durch anodische Depolarisation der DME quantifiziert. Polysulfidischer Schwefel wird demgegentiber mit Hilfe eines Elektroreduktionsprozesses unter Einschlul3 von 2(x-1) Elektronen bestimmt. Polythionate werden zu Thiosulfat, Sulfit, Sulfid und/oder Gemischen davon elektroreduziert, wobei mit streng kontrollierten experimentellen Bedingungen zu arbeiten ist. Thiosulfat und Sulfit bestimmt man durch Differentialpulse-Polarographie an tropfenden Quecksilber-Anoden fiber Reaktionen, die Bildung yon Thiosulfato- und Sulfitmnercurate einschliegen. Schlie31ich werden diese Untersuchungen speziell im Zusammenhang mit neuen Kohleumwandlungs-Technologien diskutiert. - Anal. Lett. 22, 15371546 (1989). 152 Davey Lab., State Univ., University Park, PA (USA) W. Czysz Determination of conjugated dienes in gasoline by differential pulse polarography. S.J. Swarin and K.L. Perry. A rapid, repeatable technique for the determination of conjugated dienes in gasoline has been developed. The method, which is based on the reduction of conjugated dienes at a dropping-mercury electrode, is faster (15 min vs. 160 rain) and more precise (5.3% vs 10% relative standard deviation) than the maleic anhydride method currently used. It is applicable to fuels containing alcohols, which cannot be analyzed by the current method. Application of this method to 25 model compounds and 37 gasolines of varying conjugated diene contents demonstrates that it is the method of choice for this determination. - A n a l . Chem. 61, 1502-1504 (1989). Anal. Chem. Dept:, Gen. Motors Res. Labs., Warren, MI (USA) Identification of soot produced from aromatic hydrocarbon by pyrolysis GC (Study on identification of soot III). M. Takatsu and T. Yamamoto. Basic experiments for identifying the intact material of soot before combustion were carried out by using trace amount of soot produced from eight aromatic hydrocarbons; benzene, toluene, o-, rn-, p-xylene, ethylbenzene, styrene and cumene. The soot was collected with glass fiber filter paper. The contents in the soot were determined by Curie point pyrolysis GC, at both pyrolysis temperatures 358°C and 590°C. Though little amount of intact materials such as benzene was detected in a lot of soot at 358°C, the detectable amount of characteristic content such as benzene, toluene, o-, m - , p-xylene, styrene and biphenyl increased and the difference between pyrograms became more clear at 590°C. Especially, xylene in xylene soot and biphenyl in benzene soot were

448 useful content to identify its soot. - Bunseki Kagaku 38, 449-453 (1989) (Japanisch, mit engl. Zus.fass.). Sci. Invest. Res. Lab. Pref. Hyogo

(J) Improved method for the separation of methylolmelamines by high-performance liquid chromatography. S. Kawai, H. Nagano and T. Marl. Ein schnelles und empfindliches Reversed-Phase HPLC-Verfahren wird beschrieben, welches die Mikroanalyse von Methylolmelaminen gestattet. Dazu werden Tassen aus Melaminharz mit Wasser oder mit Essigs~ture geffillt, dann wird 2,5 rain erhitzt und 10 ~tl des erhaltenen Extraktes auf einer ODS-5-S/iule mit einem Gradienten von Actonitril/ Essigs~iure/Wasser von (5:0,5:94,5) bis (1:0,5:98,5) chromatographiert. Der Nachweis wird bei 235 nm durchgef/ihrt. Vergleichsweise wird das Reaktionsgemisch aus 0,16 mol/l Formaldehyd und 0,033 tool/1 Melamin nach 120 h Stehen bei 28°C analysiert. Mit dem Verfahren kann das Austreten yon Melamin und Monomethylohnelamin aus MelaminharzGeschirr nachgewiesen werden. Die Nachweisgrenze liegt bei 20 pl Injektionsvolumina bei 10 ng/ml. - J. Chromatogr. 477, 467-470 (1989). Pharm. Univ., Gifu (J) R.H.S.

Liquid chromatographic method for the determination of thiophanatemethyl in technical concentrates and formulated products. Comparison with the CIPAC method. F. Sanchez-Rasero. An HPLC method for the analysis of thiophanate-methyl in technical concentrates and formulated products has been developped and a comparison with the respective CIPAC method has been made. The new method uses the same elements and reagents as the CIPAC one but a narrow bore column and a diode array detector are used instead of a normal column and single wavelength detector. Precision, accuracy and resolution are very similar for both methods but the new one gives more information on the integration process, informs about the purity of peaks and causes a great saving in operating costs. - J. Liquid Chromatogr. 12,. 1473-1483 (1989). Estac. Exp. Zaidin, CSIC, Granada (E)

Supersonic jet spectrometry of chemical species laser ablated from organic polymers. T. Imasaka, K. Tashiro and N. Ishibashi. Laser ablation/supersonic jet spectrometry is applied to several organic polymers. For sample ablation, a first dye laser beam (337.5 nm) is focused onto the polymer surface. A second synchronized tunable dye laser excites ablated chemical species in a supersonic jet. A sharp spectral feature (7.3 cm-2) is observed in the excitation spectrum for the polystyrene sample, which is assigned to originate from a styrene monomer. • The signal is much weaker for acrylonitrile/butadiene/styrenecopolymer (ABS resin), and no peak is observed for polycarbonate containing no styrene segments. The ablated chemical species is localized to 2.4 mm (4 ps) in the jet pulse. Sufficient rotational and translational coolings provide good selectivity and sensitivity, by spectral narrowing and sample focusing in the jet pulse. - Anal. Chem. 61, 1530-1533 (1989). Fac. Engin., Kyushu Univ., Hakozaki, Fukuoka (J)

Characterization of single-ply and polyaminate films by nuclear magnetic resonance spectroscopy. G.R. Hatfield. The ability of sofid-state NMR to obtain detailed information on structure and morphology in polyaminate films is demonstrated for the first time. The polylaminates studied here contained layers of polyethylene, Nylon 6, Surlyn, and/or ethylene-vinyl acetate copolymers. The multilayer films examined were chosen with the intent of illustrating the relative strengths and weaknesses of this analytical approach. The most notable strength is the ability of NMR to obtain morphological information on the interior layers of polylaminates without resorting to ply dissolution or separation. - Anal. Chem. 61, 1870-1873 (1989). Corp. Technol., Allied-Signal, Morristown, NJ (USA)

Density determination of low-density polymer latexes by sedimentation field-flow fractionation. D.J. Nagy. Particle density must be accurately known to characterize particle size distributions of polymeric latexes by sedimentation field-flow fractionation (SFFF). In this work, it is demonstrated that SFFF can be used to determine in situ density of copolymer latexes in the range from 1.00 to 1.02 g/cm 3. To perform these measurements the density of the SFFF

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Particular products and fields of application

mobile phase is decreased to less than 1.00 g/cm 3 with the use of methanol as an eluant modifier. Retention data are measured for the latexes by using several low-density mobile phase solutions. This method is feasible for low-density polymers since particle retention time by SFFF is directly related to the density difference between the particles and the mobile phase. This technique has been successfully applied to narrow distribution styrene-butadiene and to narrow and broad particle size distribution vinyl acetate-acrylic copolymer latexes. - Anal. Chem. 61, 1934-1937 (1989). Air Prod. Chem. Inc., Corp. Res. Serv., Allentown, PA (USA)

Size exclusion chromatography/differential viscometry of cationic polymers. D.J. Nagy and D.A. Terwilliger. When employed as an on-line SEC detector, differential viscometry can be used to characterize the molecular weight distribution of watersoluble cationic polymers. This technique is demonstrated Using cationic poly(2-vinyl pyridine) for calibration on SynChrom CATSEC columns in a mobile phase of 0.1% trifluoroacetic acid/0.20 N NaNO3 at 35°C. Characterization of broad molecular weight distribution polymers, such as poly(allyl amine), is presented based on universal calibration. Preliminary characterization of poly(2-vinyl pyridine) in THF under universal calibration conditions is also reviewed. - J. Liquid Chromatogr. 12, 1431-1449 (1989). Air Prod. Chem., Inc., Corp. Res. Serv. Div., Allentown, PA (USA)

Separation mechanism of copolymers from styrene and methyl methacrylate according to composition by liquid adsorption chromatography. S. Mori. Silica gel and a mixture of chloroform and ethanol were used as the stationary and the mobile phases, respectively. At the isocratic elution mode, the copolymers tended to adsorb on the column with increasing MMA content in the copolymers, with increasing column temperature, and with decreasing ethanol content in the mobile phase. The copolymers appeared always at the position proportional to the interstitial volume in the column, otherwise they adsorbed on the column. The equilibrium distribution of the copolymers between the mobile phase and the stationary phase cannot be considered in this system. Hydrogen bonding of carbonyl groups in MMA units of the copolymers to silanol groups on the surface of silica gel was considered to be the main interaction between the copolymers and the adsorbent. The hydrogen bonding increases with increasing the number of carbonyl groups per unit surface of copoiymer coil in solution and with increasing free silanol groups on the silica surface. Ethanol in the stationary phase controls the content of the free silanol groups on the surface and is controlled by the content of ethanol in the mobile phase in addition to column temperature. - J. Liquid Chromatogr. 12, 323-336 (1989). Dept. Ind. Chem., Fac. Engin., Mie Univ., Tsu, Mie (J)

X-Ray photoelectron spectroscopicanalysis of surface degradation in poly(vinyl chloride). Y, Shichi and M. Arita. A quantitative analysis of chlorine and oxygen relative to carbon on the surface of degraded PVC by using C12p, Ols and Cls peak areas of XPS data are described. Since additives such as plasticizer contained in PVC exude on the surface, they have to be removed by extraction prior to XPS analysis. After examination, a solvent extraction method with diethyl ether for 8 h and then water for 16 h was selected. After this pretreatment, relative standard deviation of this method were 6% for the quantitative analysis of chlorine and 13% for that of oxygen. The heat degradation of PVC surface was caused by simultaneous dehydrochlorination and oxidation reactions which produced carbonyl and carboxyl groups. The formation of carbonyl and carboxyl groups was confirmed by peak fitting of Cls peak of the degraded PVC. Bunseki Kagaku 38, 463--467 (1989) (Japanisch, mit engl. Zus.fass.). Mat. Anal. Center, Centr. Engin. Lab., Nissan Motor Co., Yokosukashi, Kanagawa (J)

FIA of anionic surfaetants using a double-line solvent extraction system. S. Motomizu and K. Korechika. FIA of anionic surfactants was examined by using a double-line system. A reagent solution and an extraction solvent were propelled. Sample solutions were injected into a reagent solution stream, which was marged

2.4

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Environmental matrices

in an extraction solvent stream. An improved segmentor made smaller segments, which enabled to have higher peaks. The efficiency of the smaller segments on the peak height was higher when the extraction tubing was shorter than 1 m. Three kinds of reagent solutions were examined; one comprised 1-methyl-4-(4-diethylaminophenylazo)pyridinium (MEP) chloride (extraction solvent, chloroform; MEP- C1 method), another an iodide of MEP (extraction solvent, chloroform; MEP - I method) and the other methylene blue (extraction solvent, odichlorobenzene; MB method). By the MEP- I method, negative peaks were obtained in the range below 10 -6 M of anionic surfactants. The highest peaks were obtained by the MB method. The peak height, the standard deviation and the relative standard deviation obtained by 10 times injection of 10 .6 M laurylsulfate (LS-) were 200.6 ram, 0.8 mm and 0.4%, respectively, by the MB method; 121.1 ram, 0.3 mm and 0.3%, respectively, by the MEP. C1 method. The detection limit corresponding to a signal to noise ratio (S/N) of 3 was about 1 x 10 -8 M of LS- by the MB and MEP. C1 methods. This method was capable of analyzing 20~30 samples per hour. - Bunseki Kagaku 38, T 1 4 3 T148 (1989) (Japanisch, mit engl. Zus.fass.). Dept. Chem., Fac. Sci., Univ., Okayama (J) The semi-quantitative identification of hydrophohes in normal alcohol eth0xylates by hydriodie acid cleavage and reversed-phase HPLC analysis with UV detection. M. Benning, H. Locke, and R. Ianniello. A method is described for the quantitative reversed-phase HPLC analysis of n-alkyl iodides obtained from HI cleavage of linear alcohol ethoxylated surfactants. The method is an improvement over previous techniques in that the detection is both iodide specific and is demonstrated for carbon chain lengths from 1 to 18. - J. Liquid Chromatogr. 12, 757-770 (1989). GAF Chem. Corp., Wayne, NJ (USA) Aqueous size exclusion chromatography for strong anionic polyelectrolytes on hydrnphilic polymer gel. S. Mori. Elution behavior of sodium polystyrenesulfonates (NaPSS) on a TSKGMPW column was discussed. Mobile phases were aqueous solutions of a mixture of Na2HPO4 and NaH2PO~ at pH 8.0 (A), NaH2PO¢ (B), and Na2CO3 (C) at various concentrations. At low concentration of monomeric electrolytes in the mobile phase, peaks of NaPSS were sharp and Gaussian and the early elutiou of NaPSS relative to nonionic polymers was observed. Elution of NaPSS compounds retarded with increasing the concentration of electrolytes in the mobile phase and retained in the column over some value of the concentration. For a low molecular weight compound, sodium-p-toluenesulfonate, a concentration of 0.01 M of a buffer solution was adequate because both electrostatic and hydrophobic interactions were minimized and ideal SEC was achieved. - J. Liquid Chromatogr. 12, 785-798 (1989). Dept. Ind. Chem., Fac. Engin., Mie Univ., Tsu, Mie (J) Association of molecules of some dyes in solution. N.A. Gracheva, D.S. Lychnikov and E.N. Dorokhova. Mittels der Diffusionsmethode (ausffihrliche Beschreibung s. Original), die feindisperse Fraktionen der L6sungen zu bewerten erm6glicht, untersuchte man die Assoziation von Farbstoffmolekiilen in L6sungen bei 0-10°C. Auf diese Weise wurden Kristallviolett (KV, w/iBrige L6sung, pH 4,0), Methylviolett (MV, whA3rige L6sung, pH 2,0), Brillantgrtin (BG, w/iBrig/ethanolische (1:1) L6sung, pH 2,0) und Chrompyrazol II (CP, Bis-(methylbenzylaminophenylantipyrylcarbinol, L6sung in 1,5 mol/1 H2SO~) untersucht. Es wurde festgestellt, dab KV, MV und BG unter diesen Bedingungen schon bei Labortemperatur assoziiert werden, w/ihrend CP bei dieser Temperatur in breitem S~iurebereich in der L6sung nur als Monomer vorliegt. Durch die Temperaturerniedrigung wird die Assoziation yon allen genannten Farbstoffen wesentlich gesteigert. Die MV-Assoziate bestehen aus sechs und CP-Assoziate aus drei Molekfilen. BG und KV k6nnen unbegrenzt assoziiert werden, so dab sic zum Schlul3 kolloidale Teilchen bilden. Die Assoziation yon KV-, MV- und BG-Molekiilen wird durch Wasserstoffbindungen, dagegen die CP-Molektilassoziation durch van der Waalsche Kr/ifte bewirkt. - Zh. Anal. Khim. 44, 849--852 (1989) (Russisch, mit engl. Zus.fass.). Lomonosov Univ., Moskau (SU) F. Jancik

Adsorption characteristics of organic dyes in aqueous solutions on mixedoxide gels. Silica-containing mixed-oxide gels. S. Kaneko, H. Saltoh, Y. Maejima and M. Nakamura. Verff. untersuchen die Adsorptionseigenschaften yon vier organischen Farbstoffen (C.I. Acid Red 114, C.I. Basic Red 18, C.I. Reactive Blue 4, C.I. Direct Blue 90; Strukturformeln im Original) in w~il3riger L6sung an sieben kieselsh~urehaltigen gemischten Oxidgelen (Titan-, Aluminium-, Magnesiumoxide; Tabelle). C.I. Basic Red 18 wird gut an allen sieben Gelen adsorbiert. Unter den Sorbentien erzielt man mit SilicaMagnesia, hergestellt durch homogene Ffillung, die besten Ergebnisse (maximale Adsorption) unter den sieben getesteten Substraten. - Anal. Lett~ 22, 1631 - 1641 (1989). Dept. Materials Sci. and Technol., Shizuoka Univ., Johoku, Hamamatsu (J) W. Czysz Determination of the enantiomeric composition of carprofen by proton nuclear magnetic resonance spectroscopy with a chiral lanthanide-shift reagent. G.M. Hanna and C.A. Lau-Cam. Die enantiomere Zusammensetzung des Entflammuugshemmers Carprofen (6-Chlor-~-methylcarbazol-2-essigsfiure) wurde durch 1H-NMRSpektroskopie und Verwendung eines chiralen Lanthanid-Shiftchelats bestimmt. Carprofen wurde in ein Gemisch enantiomerer MethylesterDerivate umgewandelt, die dann mit Tris(3-(heptafluorpropylhydroxymethylen)-(+)-camphorato)-Europium(III) in CDC13 komplexiert wurden. Die Substratkonzentration in der Testprobe war 0,15 M, das molare Verhfiltnis chirales Verschiebungsreagens:Substrat 0,453. Die Bestimmung der Enantiomere beruhte auf den relativen Intensit/iten der Signale f/ir die ~-Methylprotonen. Die mittlere Wiederfindung _+ SD von S(+)Carprofen in synthetischen Enantiomergemischen war 99,3 + 1,7%. Talanta 36, 883-887 (1989). Food and Drug Admin., Dept. Health Human Serv., NY Reg. Lab., Brooklyn, NY (USA) W. Czysz

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Environmental matrices

Determination of sulfur dioxide based on spectral-phase effects. A.A. Ganeev, A.D. Timofeev and Yu.I. Turkin. Man untersuchte die Spektral-Phaseneffekte (SPE) bei der Konstruktion eines hochempfindlichen Analysators zur SO2-Bestimmung in der Luft, die mit Hilfe yon Rotations- und Vibrationskomponenten des SO2Spektrums unter Anwendung yon Resonanzlinien Zn (213,8 nm) und Bi (206,1 nm) ftir die Bande bei 195-225 nm bzw. Bi (306,7 nm) fiir die Bande bei 280 bis 310 nm durchgef/ihrt wurde; man benutzte zu diesem Zweck auch Sn-Resonanzlinien (300,91 nm bzw. 303,41 nm). Die theoretischen Unterlagen der Ausn/itzung des SPE-Mechanismus wurden schon frfiher ver6ffentlicht (cf. A.A. Ganeev und Yu.I. Turkin: Zh. Prikl. Spektrosk. 41,549 (1989)). In der vorgelegten Arbeit sind die Ergebnisse der Optimierung der SO2-Bestimmung sowie die zugeh6rigen theoretischen und Eichcharakteristiken angegeben. Bei der optimalen Einhaltung yon Analysenbedingungen kann auf die besehriebene Weise ffir eine 87 cm dicke Schicht die Nachweisgrenze 1,2 mg SO2/m 3 erreicht werden. Eingehende experimentelle Bedingungen der beschriebenen SO2-Bestimmung sind beigefiigt. - Zh. Anal. Khim. 44, 877 - 882 (1989) (Russisch, mit engl. Zus.fass.). Univ., Leningrad (SU) F. Jancik Gas sampling- and column-switching systems in high-resolution gas analysis. F. Mfiller, H. Mfiller and H. Straub. The introduction of capillary separation columns with solid porous layers, so-called PLOT columns for the gas chromatographic analysis of gases causes the substitution of conventional techniques which were developed for packed separation columns by systems compatible to capillary columns. This particularly applies to automatic gas samplingand column-switching systems. It is described that new pressure- and flow-controlled switching techniques are remarkably qualified for highresolution gas chromatography. A representative example of application is given to demonstrate the development and relevancy to the practice of such systems. - J. Chromatogr. 477, 2 5 - 3 8 (1989). Siemens AG, Analysentechnik, Karlsruhe (D)

450 Determination of trace impurities in high-purity oxygen by gas chromatography with photoionization detection. H. Ogino, Y. Aomura, M. Komuro and T. Kobayashi. A GC system used for the analysis of trace impurities in high-purity oxygen (99.99-99.9999 % (v/v)) is described. This system consists of a gas chromatograph equipped with a photoionization detector (PID), a gas sampler, a precolumn filled with a catalyst, and a computerized integrator with an interface. The analytical reproducibilities (relative standard deviation, n = 15) for Ar (0.50 ppm), N2 (0.10 ppm), Kr (4.0 ppm), CH 4 (6.0 ppm), and Xe (0.30 ppm) were 1.7%, 4.8%, 0.5%, 0.6%, and 4.2%, respectively. The detection limits were as follows: Ar, 0.03 ppm; N2, 0.04 ppm; Kr, 0.01 ppm; CH4, 0.01 ppm; and Xe, 0.01 ppm. These limits are in a practical concentration range (sub parts per million to several tens of parts per million) in high-purity oxygen. - Anal. Chem. 61, 2237 - 2240 (1989). Techn. Res. Lab., Toyo Sanso Co., Kawasaki-ku, Kawasaki-shi, Kanagawa (J) Diffusion coefficients of gases in liquids and partition coefficients in gasliquid interphases by reversed-flow gas chromatography. N.A. Katsanos and J. Kapolos. Diffusion coefficients of two gases (propene and ethene) in three liquids (hexadecane, heptane, and water) have been determined in a very simple way by using the new technique of reversed-flow GC. In the same experiment the partition coefficient of each gas between the liquid and the carrier gas (nitrogen) was measured simultaneously, and from this the respective Henry's law constant was calculated. The determination of both physicochemical quantities above was based on the extension of a previous mathematical model. The diffusion coefficients measured have the same order of magnitude as those calculated by using the WilkeChang formula. The Henry's law constants, however, are found much smaller than those calculated from a nomogram. This is attributed to the fact that the partition coefficients found pertain to the gas-liquid interphase layers rather than to the bulk phases. - Anal. Chem. 61, 2231-2237 (I989). Phys. Chem. Lab., Univ., Patras (GR) Determination of total inorganic carbon in aqueous samples with a flame infrared emission detector. S.W. Kubula, D.C. Tilotta, M.A. Busch and K.W. Busch. A specially designed system, using a flame infrared emission (FIRE) detector, was developed to permit the determination of total inorganic carbon (TIC) in water samples. Carbon dioxide, released from 1.0 ml samples upon acidification, was purged from solution with He and excited in a hydrogen/air flame. The carbon dioxide emission intensity at 4.42 gm (2264 cm- 1) was monitored by use of a lead selenide detector in conjunction with a 4.4-gin band-pass optical filter. Peak emission intensity measurements from multiple injections of 1.0 ml water samples gave a relative standard deviation of 1.35%. The average relative standard deviation of the TIC measured with the FIRE system was found to be 0.89%. The accuracy of the FIRE technique was determined by comparing the FIRE-TIC results with those obtained by total alkalinity titrations for five natural water samples and was found to be 1.22%. The detection limit for the system was found to be equivalent to 3.05 x 10 .2 mM NazCO3 and calibration curves were linear up to 50 mM Na2CO3. Elevated levels of purgeable organic compounds were found to be a potential interference in the determination of TIC with the FIRE system. - Anal. Chem. 61, 1841 -1846 (1989). Dept. Chem., Baylor Univ., Waco, TX (USA) Continuous monitoring method of trace silicon in industrial water using continuous micro flow analysis. M. Goto, W. Hu and D, Ishi. A continuous monitoring method was developed for the automatic determination of trace silicon in industrial water, based on the molybdenum blue absorption spectrophotometry. The sample is mixed with the molybdic acid reagent in a mixing joint and then introduced into a reaction tube (0.5 mm inner diameter, 8 re'length) in an aluminium block bath at 23°C, in which the molybdosilicic acid is formed. A platinum wire with a diameter of 0.2 mm is inserted into the reaction tube to assist the mixing of sample with reagent. The stream from the reaction tube is mixed with a stream of the reducing reagent to form the molybdenum blue, which is then introduced into a flow cell (10 mm light pass length, 8 ~1 volume) of a spectrophotometer. The absorbance at 815 nm based

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Particular products and fields of application

on the molybdenum blue is continuously recorded to measure the trace silicon in samples. The method was successfully applied to the determination of trace silicon in commercial pure waters and to the continuous monitoring of trace silicon (2 ~ 2000 ppb) in water. - Bunseki Kagaku 38, 4 1 9 - 423 (1989) (Japanisch, mit engl. Zus.fass.). Pharm. Univ., Gifu

(J) Rhodamine 6G chemiluminescence for the determination of free chlorine in tap water by a flow-injection method, T. Nakagama, M. Yamada and T. Hobo. A chemiluminescence system is described for the specific determination of free chlorine by a reversed flow-injection method. The light emitted from the reaction between Rhodamine 6G and free chlorine (HOCI) under unbuffered conditions allows free chlorine in tap water to be determined with no interference from combined chlorine (chloramines). The limit of determination (signal to noise ratio = 3) is 1 x 10-v M, the linear range is two orders of magnitude, the sampling rate is 240 samples/h and the relative standard deviation (n = :10) is 2.0% for I x 10 -s M free chlorine. Common inorganic species give rise to no light emission. Among oxo acids of chlorine, only chlorite ion slightly elicits light, 1 x 10- 3 M C102- providing a signal 3 % of that for 1 x 10- 5 M HOC1. Inorganic species and chloramines co-existing in tap water do not interfere. - Analyst 114,1275-1278 (1989). Dept. Ind. Chem., Fac. Technol., Tokyo Metropol. Univ., Setagaya, Tokyo (J) Potentiometric determination of phosphate ions with a glass electrode. V.G. Derkasova, V.A. Karelin, L.A. Moskalenko and T.M. Potapova. Zur indirekten Bestimmung yon PO43- im Kesselwasser wird ein potentiometrisches Verfahren unter Verwendung der ionenselektiven Glaselektrode (GE) vorgeschlagen, das auf der F/illung yon PO4 amit AgNO3-Oberschul3 und der potentiometrischen Bestimmung des AgNO3-Uberschussesgegen GE (Bezugselektrode Ag/AgC1) beruht. Die Berechnung der PO43 -Konzentration (c) erfolgt aufgrund der Beziehung: c = (ca - c l x 10-AS/K)× 0,33 (Cl = Ag+-Konzentration 200 rag/l; AE = Differenz der elektromotorischen Kraft vor und nach dem Probenzusatz; K = Gradient mV/pAg bei 20-200 mg Ag+/l; 0,33 = der praktische Umrechnungsfaktor). Der sr-Wert liegt bei 0,027, Nachweisgrenze 0,22 mg pO43-/1. Arbeitsweise. In einem 250 ml-Mel3kolben werden 50 ml AgNOa-L6sung (1000 rag/l) mit der Probenl6sung zur Marke erg~inzt und zwei Parallelmessungen mit der beschriebenen potentiometrischen Vorrichtung (s. Original) durchgeffihrt, wobei eine Messung zur Bestimmung des K-Gradienten dient. Die metrologischen Charakteristiken des vorgeschlagenen Verfahrens werden vorgelegt. - Zh. Anal. Khim. 44, 873-876 (1989) (Russisch, mit engl. Zus.fass.). Polytechn. Inst., Tomsk (SU) F. Jancik Indirect spectrophotometric determination of fluoride in water with zirconinm-SPADNS by flow injection analysis. A.T. Haj-Hussein and I.F. A1-Momani. Die Zr-SPADNS-Methode zur Bestimmung yon Fluorid beruht auf der Wirkung des Fluorids auf das Farbsystem Zr-SPADNS. Diese Merhode wird von den Verff. auf die Verwendung in der kontinuierlichen DurchfiuB-Spektralphotometrie mit einem zweikanaligen FIA-System (Schemaskizze im Original) eingesetzt. Die Abnahme der Extinktion des Zr-SPADNS-Reagens bei 590 nm ist linear der Fluorid-Konzentration im Bereich 0,00 - 3,5 ppm. Nachweisgrenze 0,02 ppm Fluorid. Bei einem Probendurchsatz von 50/h wird eine rel. Standardabweichung von 1% festgestellt. - Anal. Lett. 22,1581 - 1599 (1989). Chem. Dept., Yarmouk Univ., Irbid (JOR) W. Czysz Determination of radon-222 and radium-226 in mineral water and drinking water - a survey in Austria. F. Sch6nhofer. A very simple and time saving liquid scintillation counting method that avoids the need for any chemical separation has been developed for the determination of both 222Rn and 226Ra in water. This method takes advantage of the very low background level of the liquid scintillation counter "Quantulus" and of spectral control. The method is very sensitive and specific for the above radionuclides. The lower limit of detection is well below maximum contaminant levels set even by the most strict regulations. In a pilot project for a first surveillance of the drinking water in Austria it was shown that the proposed method was suitable

2.4

Environmental matrices

for large scale surveillance and routine analysis. Its application to mineral waters sold in Austria showed elevated levels of 226Ra in some brands and one exceeded the maximum permissible level by a factor of 20. Considerable concentrations of 22aRn were found in drinking waters from certain areas, but no 226Ra concentrations higher than the lower limit of detection (1.3 pCi/1) (48.1 mBq/1) were found. Future work to improve the method further and to apply it to large scale surveillance is discussed. - Analyst 114, 1345-1347 (1989). Fed. Inst. Food Control Res., Vienna (A) Determination of 21°pb, 21°Bi and 2~°po in natural waters and other materials by electrochemical separation. H. Narita, K. Harada, W.C. Burnett, S. Tsunogai and W.J. McCabe. Verff. entwickeln ein verbessertes Verfahren zur Bestimmung der Nuklide 21°Pb, 21°Bi und 21°po in natiirlichen W/issern und in festen Materialien. Polonium-210 wird spontan aus verdfinntem salzsaurem Medium auf eine Silberscheibe platiert. Bismut-210 wird dann auf einer Kathode aus Platin-Gaze aus derselben L6sung elektrisch abgeschieden (1,4 V, 60°C, 30 rain; rotierender Graphitstab als Anode). Zum Schlu3 wird Blei-210 aus Fluoroborat-Medium auf der gleichen Platin-Gaze, jetzt eingesetzt als Anode, abgeschieden (2,3 V, 60°C, 45 rain; Pt-Spirale als Kathode). Alle drei Nuklide werden dann durch Standardverfahren der Alpha- und Betastrahlen-Zfihlung (niederenergetisch) ausgezS,hlt. Weitere Einzelheiten im Original. - Talanta 36, 925-929 (1989). Dept. Oceonogr., State Univ., Tallahassee, FL (USA) W. Czysz Determination of trace metals in reference water standards by inductively coupled plasma mass spectrometry with on-line preconcentration. D. Beauchemin and S.S. Berman. A preliminary implementation of on-line preconcentration in ICP-MS improved the detection limits of several elements by a factor of 2 - 7 compared to ICP-MS alone. The on-line preconcentration system was first assessed by using the method of standard additions to determine Mn, Co, Ni, Cu, Pb, and U in the certified riverine water SLRS-1 whose salt content was low enough to allow monitoring both the preconcentration and the elution processes. Results in good agreement with the certified values were obtained for all but Ni, because of a spectral interference by CaO from eoeluted Ca, The system was successfully applied to the determination of Mn, Mo, Cd, and U in the reference open ocean water NASS-2 by using an isotope dilution technique and the method of standard additions. - Anal. Chem. 61, 1857-1862 (1989). Anal. Chem. Sect., Chem. Div., Nat. Res. Counc. Canada, Ottawa, Ont. (CDN) Pre-concentration of cadmium from environmental samples by an alga and analysis by graphite furnace atomic absorption spectrometry. V. Majidi and J.A. Holcombe. A pure algal strain (Stichococcus bacillaris) is utilised to pre-concentrate Cd ions from fresh water and marine reference samples. This preconcentration is achieved by mixing 10 mg of freeze-dried alga with 100 ml of a Cd containing solution and subsequent separation by centrifugation. The alga pellet is then suspended in 1 ml of solution and analysed as a slurry by graphite furnace atomic absorption spectrometry. The removal and pre-concentration of Cd from a riverine reference water sample (SLRS-I) demonstrated the analytical utility of this alga. Preconcentration of Cd from the two sea water samples, CASS-1 (near shore sea water) and NASS-2 (open ocean sea water), was not possible with this algal strain due to the high salinity of these solutions. The concentration of Cd in the riverine sample was determined to be 16.6 + 1.9 ng/1, which is in good agreement with the certified value of 15 -± 2 ng/I. The time necessary for the pre-concentration of six samples is less than 20 min, which amounts to less than 4 min per sample. - J. Anal. At. Spectrom. 4, 439 442 (1989). Dept. Chem., Univ., Texas, Austin, TX (USA) Atomic absorption determination of lead at picogram per gram levels by ethylation with in situ concentration in a graphite furnace. R.E. Sturgeon, S.N. Willie and S.S. Berman. A method is described for the atomic absorption spectrometric determination of lead in natural waters and biological tissues based on the generation of Pb(C2H5)4 using NaB(C2Hs)4 with its subsequent

451 trapping in a graphite furnace at 400°C. Quantitation is achieved by using a simple calibration graph prepared from aqueous standards having a sensitivity of 0.150 _4 0.006 A/ng. An absolute detection limit (3cr) of 14 pg is achieved. Precision of determination at 100 pg/ml is 4% relative standard deviation. Results are reported for the determination of Pb in suite of marine reference materials. - Anal. Chem. 61, 18671869 (1989). Div. Chem., Nat. Res. Counc. Canada, Ottawa, Ont. (CDN) 1.5th-Differential polarographic determination of trace amounts of selenium(IV) and selenium(VI) in natural waters at a dropping mercury electrode. Wu Dunhu, Zhang Diyang and Li Xiaoming. This paper describes a polarographic method for the determination of trace amounts of Se(IV) and Se(VI) in natural waters using a dropping mercury electrode. In an HCIO4-Na~SO3-NH3-NH4CI-NH2OH " HC1KIO3 system (pH 10), the selenium complex SeSO32 gave a peak potential at -0.57 V versus Ag. The peak current was directly proportional to Se in the concentration range 0.01-1 pg/l. The limit of detection was I0 ng/l. The proposed method is rapid, simple, sensitive and accurate. The recovery of Se from standard additions to samples of natural waters was between 93 and 105%. - Analyst 114, 793-797 (1989). Changchun Inst. Geogr., Acad. Sin., Changchun, Jilin Prov. (RC) Studies on the liquid-liquid phase distribution equilibria of selenium, and its measurement in water using extraction plant with a pulsation column. F. Iskanderani, K.M. Sobhi and M. Ejaz. Normal heptane, xyiene, and 0.01 molar solution of 4-(5-nonyl)pyridine in toluene have been investigated as extractants for selenium(IV) from nitric acid media in potassium iodide. Various parameters affecting the distribution of the element are investigated. Extraction at high aqueous to organic phase volume ratio has been studied, using a Iiquidliquid extraction plant with a pulsation column. The results have been employed to measure selenium in spiked water samples. - J. Radioanal. Nucl. Chem., Art. 132, 159-169 (1989). Dept. Chem. Engin., Coll. Engin., King Abdul'Aziz Univ., Jeddah (Saudi Arabia) Interference-free determination of selenium in the presence of iron using a graphite furnace with carbon monoxide-platinum modification. R. Peile, R. Grey and R. Starek. A method is described which eleminates tile spectral interference currently attributed to iron, during the determination of selenium. Carbon monoxide was used as an auxiliary gas at a flow-rate of 0.1 l/rain to remove oxygen from the furnace. This prevented the formation of iron oxide which had been previously shown to be implicated in causing spectral interference. Matrix modification was performed by pre-treating the pyrolytic graphite platform with a 1% m/v platinum solution. Studies were carried out with aqueous solutions containing 70 ng/ml of Se, with Fe concentrations varying from 50 to 2000 pg/ml. Recoveries ranged from 98.0 to 104.7%. Further studies were carried out on solutions containing 100 ng/ml and 200 ng/ml of Se and varying Fe concentrations. The method of standard additions was used to analyse these solutions. The procedure is rapid, simple and allows the use of deuterium-arc background correction during the determination of Se in water. Previously it was thought that a Zeeman-effect or Smith-Hieftje background correction system was required. - J. Anal. At. Spectrom. 4, 407-410 (1989). GBC Sci. Equipm. Pty. Ltd., Dandenong, Vict. (AUS) Simultaneous kinetic spectrophotometric determinationof manganese(II) and zine(II) with 2-hydroxybenzaldehyde guanylhydrazone (2-HBGH). E. Kavlentis. Zn activates and Mn catalyses oxidation of 2-HBGH by I-[20. This reaction is thus used to determine 10-100 Zn and 1 - 3 0 ppm Mn in potable water. RSD's are 2 - 3 % . Interference for 20 other species are studied. Procedure. Sample containing < 300 ppm Mn(II) and < 1000 ng Zn(II), 1 ml of 5 x 10 .4 M C N - solution, I ml of 0.01 M aq. 2HBGH, 2 ml of buffer (NH~OH-NH4C1, pH 9.40, I = 0.1 M) and 1 ml 0.2 M H202 are made up to 10 ml with H20. Mix well and measure absorbance after 2 rain at 490 nm. Repeat in absence of CN- and Mn(lI) concn of 20 ppb. Keep temperature constant. - Analusis 17, 136-138 (1989). Dept. Chem.. Univ., Thessaloniki (GR) J.S. Dunnett

452 Microdetermination of trace cobalt in water by direct polyurethane foam thin-layer spectrophotometry. M.N. Abbas, N.B. E1-Assy and S. AbdelM0niem. Spuren Cobalt in Wasser werden vor der Bestimmung an weil3en D/innschichten von parallelstrangigem Polyurethanschaum durch Sorption des Thiocyanatkomplexes aus saurem Medium angereichert. Der Cobaltthiocyanatkomplex ist blaugef~irbt mit einem Absorptionsmaximum bei 625 nm. Die Messung der blauen Species wird direkt in der Schaummatrix bei den Wellenl/ingen 680, 625 und 540 nm vorgenommen, wobei der Schaum in der MeBzelle in verschiedenen Medien eingetaucht wird: Wasser, Ethanol, Isopropanol, Chloroform, Benzol. Berechnet wird die Nettoextinktion bei 625 nm, und zwar mit Hilfe eines Multiwellenlfingenprogramms. Der Blindwert des Polyurethanschaums wird ebenfalls ber/icksichtigt. Das Beersche Gesetz ist im Bereich 0,025 2,0 gg/dl erffillt; Nachweisgrenze 25 gg Co/dl bei Verwendung einer 100 ml-Probe. - Anal. Lett. 22, 1555-1565 (1989). Microanal. Res. Lab., Nat. Res. Centre, Dokki-Cairo (ET) W. Czysz Determination of Cadmium, copper, iron, manganese, lead and zinc in sewage sludges with prior acid digestion in a microwave oven and slurry introduction. A. Morales, F. Pomares, M. de la Guardia and A. Salvador. A method is proposed for the determination of six elements in sewage sludges by flame atomic absorption spectrometry. The recommended procedure consists of introducing 500 mg of sample, 5 ml of HNOa and two drops of 2-ethylhexan-l-ol into a 100-ml reaction vessel, which is then hermetically sealed and introduced into a microwave oven, and the contents digested for 3 rain. After digestion the residue is allowed to cool and is then diluted with distilled water. The resulting slurries of the digested samples in water are introduced directly into the flame using multi-elemental aqueous solutions as standards. The variables of the digestion procedure in the microwave oven, such as power, time, sample mass and acid volume, have been studied and the validity of the conditions for using aqueous standards in the analysis of slurries has been evaluated. The proposed method has been applied to the analysis of certified sewage sludge samples and the analytical parameters of the method have been evaluated. - J. Anal. At. Spectrom. 4, 329-332 (1989). Dept. Anal. Chem., Univ., Valencia (E) Extraction-spectrophotometric determination of chromium(VI) with hydroxyamidine and amides. C. Agarwal, K.S. Patel and R.K. Mishra. Ein neues Verfahren zur selektiven Extraktion und spektralphotometrischen Bestimmung yon Mikrogramm-Mengen yon Cr(VI) mit NHydroxy-N,N'-diphenylbenzamidin (HOA) und N-Arylacetamiden (HL) in Kohle, Staub, Asche, Zementstaub und industriellen Abw/issern wird beschrieben. Dazu wird die 5 M salzsaure L6sung [50 gg Cr(VI)] mit 15 ml Wasser verdfinnt. Die w/iBrige Phase wird mit einer chloroformischen L6sung von 0,14% HOA und 0.5% HL extrahiert. Der Extrakt wird mit Chloroform aufgeftillt und die Absorption bei 408 nm im Falle yon N-Phenylacetamid gemessen. Die molare Absorption des [CrO2(OA)2]2HL-Komplexes mit drei unterschiedlichen Amiden in Chloroform liegt im Bereich yon 1,1 - 1 , 3 x 10" 1 tool-1 cm ~ bei ~maxDie Nachweisgrenze liegt bei 0,01 pg Cr/ml. Die rel. Standardabweichung des Verfahrens in Umweltproben wird mit 0,8 - 1,3 % angegeben. Der EinfluB verschiedener Ionen auf die Chrombestimmung wird untersucht. AuBer Mn(VII) st6ren die meisten Elemente nicht. -- Intern. J. Environ. Anal. Chem. 36, 95--/01 (1989). Dept. Chem., Ravishankar Univ., Raipur (IND) R.H.S. Single-column i°n-chr°mat°graphic determination of chromium(V1) in aqueous soil and sludge extracts. H.C. Mehra and W.T, Frankenberger, Jr. Ionenchromatographie mit einer Sfiule (SCIC) wurde bei der selektiyen Bestimmung yon Cr(VI) in wfif3rigenBoden- und Schlammextrakten eingesetzt. Die chromatographischen Parameter wurden dabei auBer ffir Cr(VI) auch ffir die Abtrennung und Bestimmung yon NOa - und SO42 optimiert, Als S~iulenffillung niedriger Kapazit/it wurde Anion/R (Wescan 269--029) benutzt. Eluiert wurde bei pH 8,5 mit 5 mM p-Hydroxybenzoes/iure, die Detektion erfolgte konduktometrisch. Die Nachweisgrenze, definiert als S/N = 3 lag bei 92 gg Cr(VI)/1; die Aufl6sung zwisehen Cr(VI) und SO42 betrug 2,8. Die Pr/izisionen lagen bei 500

2

Particular products and fields of application

pl-Injektionen zwischen 0,9% (ffir NOB-) und 2,0% (ffir Cr(VI)). Talanta 36, 889-892 (1989). Dept. Soil and Environ. Sci., Univ. Calif., Riverside, CA (USA) W. Czysz Extraction of butyltin species and their gas chromatographic determination as chlorides in a sediment certified reference material for trace metals, PACS-1. K.W.M. Siu, P.S. Maxwell and S.S. Berman. A GC method has been developed for the determination of butyltin species in sediments. The butyltin species are separated as chlorides by using a DB-608 open tubular column after their extraction from the sediment using a combination of sonication in methanolic HC1 and solvent extraction. Two extractants are possible: toluene/isobutyl acetate/tropolone and hexane-isobutyI acetate. The efficiencies for the first extractant are: tributyltin, 94.4 __+4.7%; dibutyltin, 94.9 + 2.2%; and monobutyltin 86.3 _+ 4.2%. The absolute detection limits are about 30 pg tin. Using a l-g sample, the relative detection limits are about 30 ng tin per g sediment. These may be lowered to 3 ng tin per g by starting with a 4-g sample and adding a concentration step. The reference material PACS-1 was found to contain 1.08 _+ 0.31 pg tin per g of tributyltin and 1.13 _+ 0.30 gg tin per g of dibutyltin. - J. Chromatogr. 475, 373-379 (1989). Div. Chem., Nat. Res. Council Canada, Ottawa, Ont. (CDN) Ionspray mass spectrometry]mass spectrometry: Quantitation of tributyltin in a sediment reference material for trace metals. K.W. Siu, G.J. Gardner and S.S. Berman. Tributyltin (TBT) concentration in a sediment reference material for trace metals, PACS-I, was determined by using ionspray MS/MS. TBT was extracted into isooctane or 1-butanol, diluted with methanol containing I mM ammonium acetate, delivered to the ionspray tandem mass spectrometer by using flow injection, and quantitated by means of selected reaction monitoring of the daughter/parent pair of m/z 179/291. The minimum detectable amount of TBT was about 5 pg of Sn absolute or 0.2 gg of Sn/g of sediment. PACS-I was found to contain tributyltin at a concentration of 1.29 _+ 0.07 pg of Sn/g of sediment. - Anal. Chem. 61, 2320-2322 (1989). Div. Chem., Nat. Res. Council Can., Ottawa, Ont. (CDN) Fortschritte bei der Bestimmung yon Kation- und Aniontensiden (LAS) in Sedimenten, Schwebstoffen und Schliimmen. H. Hellmann. Aufbauend auf bereits bekannten photometrischen Bestimmungsmethoden, z. B. mit Methylenblau, sowie der kfirzlich publizierten Probenaufbereitung fiber Aluminiumoxid werden bezfiglich der LAS mehrere Varianten f/Jr den UV und siehtbaren Bereich vorgestellt. Mit Hilfe der Derivativ-Spektroskopie wird die Bestimmungsgrenze yon etwa 1 ~g/ 10 mi L6sung erreicht bzw. sogar unterschritten. Analog 1/iBt sich die Bestimmung der Kationtenside (z. B. DSDMAC) verfeinern, z.T. mit einer neuen photometrischen Methode mit Disulfinblau sowie fiber die Derivativ-Spektroskopie. Auch hier wird eine Bestimmungsgrenze yon 1 gg/10 ml erreicht. Mit diesem Verfahren k6nnen sowohl hochbelastete (>1000 mg/kg) Klfirschlfimme wie auch gering belastete Sedimente < 100 mg/kg einwandfrei analysiert werden. - Z. Wasser-AbwasserForsch. 22, 131 - 1 3 7 (1989). Bundesanst. Gew/isserkunde, D-5400 Koblenz R.H.S. *****

2.6

Foods

Rubidium determination in mineral and thermal waters by atomic-absorption spectrometry. P. Bermejo Barrera, A. Bermejo Barrera, C. Herrero Latorre and F. Bermejo Martinez. Zur Bestimmung yon Rb in Mineral- und Thermalwfissern wird ein Flammen-AAS-Verfahrenvorgeschlagen. Zur Unterdrfickung von Ionisatonsinterferenzen wird Kaliuml6sung zugegeben. Unter diesen Bedingungen kann Rb in Gegenwart yon Ca, Mg, Sr, Li, Cs, Fe, AI, Carbonat, Fluorid und Sulfit bestimmt werden, auch wenn diese in h6heren Konzentrationen vorliegen als iiblicherweise in derartigen W/issern (Tabel-

2.6

Foods

len). In ] 63 Mineral- und Thermalw/issern wurden Rubidiumkonzentrationen zwischen 0,08 und 0,84 gg/ml gefunden. Die Richtigkeit und PrS~zision des Verfahrens wurde an synthetischen L6sungen best~itigt. Anal. Lett. 22, 1601-1608 (1989). Anal. Chem., Nutr., Bromat. Dept., Fac. Chem., Santiago de Compostela (E) W. Czysz Mineralization procedure for use with the fluorometric determination of zinc in biological samples. P. Fernandez, C. Perez Conde, A.M. Gutierrez and C. Camara. Verff. pfiifen mehrere Mineralisationsverfahren in Verbindung mit einer Methode zur Bestimmung yon Zink in Milch, Eiern, Wasser und Di/itnahrung auf der Basis der Bildung und Extraktion yon Zn-5,7dibromoxin. Die besten Ergebnisse erhfilt man bei nasser Veraschung mit einem HNOa/HClO4/H2SO,-Gemisch (1:1:3) bei 2 h Erhitzen auf 200°C in einem Aluminiumblock (Vol. 1,6 ml). Man erh/ilt mit dieser Methode eine untere Nachweisgrenze yon 0,3 mg/kg und Werte, die mit denen eines AAS-Verfahrens vergleichbar sind (CV % yon 1,5 bis 7,5% fiir Zn-Konzentrationen yon 0,13-54,0 gg/g; Anregung/Emission bei 410/550 nm). - Talanta 36, 960-962 (1989). Dept. Anal. Chem., Fac. Chem., Complutense Univ., Madrid (E) W. Czysz Free amino acid determination in whole peanut seeds. H.F. Marshall, Jr., G.P. Shaffer and E.J. Conkerton. A method which circumvents the lengthy procedural steps for sample preparation in the analysis of free amino acids (FAA) in the peanut is described. Sample preparation consists of extracting a full fat meal with a lithium citrate sample buffer for 15 min. The sample is centrifuged and filterd with two Millipore filters in series. The resulting extract is analyzed "as is" for FAA via a physiological amino acid procedure. The method significantly reduces sample preparation time and eliminates the use of hazardous chemicals. It is well adapted to the analysis of large numbers of samples or samples of limited quantity. It should be applicable to the analysis of FAA in other oilseeds. - Anal. Biochem. 180, 264-268 (1989). U.S. Dept. Agric., Agric. Res. Serv., Southern Reg. Res. Center, New Orleans, LA (USA) Volatile nitrogen-containing bases in metabolic products of microorganisms (Review). M.V. Terenina, R.V. Golovnya and I.L. Zhuravleva. Die vorgelegte Ubersicht (94 Literaturhinweise bis zum Jahr 1987) bespricht die Isolierung, Identifizierung (zumeist mittels Papier-Chromatographie) und gas-chromatographische Bestimmung yon fliiehtigen stickhoffhaltigen Basen (FSB) in Metaboliten yon Mikroorganismen, die in der Bfickerei, dem Weinbau, der K/iserei und der Produktion von acidophilen Milchprodukten verwendet werden. Die U-bersicht besteht aus zwei Teilen: Der erste behandelt die Amine in fliichtigen metabolischen Produkten und ihre Anwendung zur Bestimmung yon Mikroorganismuskulturen, der zweite das gaschromatographische Profil der Amine bei der Produktionskontrolle von Lebensmittelprodukten. In den erwfihnten Metaboliten identifizierte man prim/ire, sekund/ire und terti/ire sowie heterocyclische Amine (insgesamt 83; Tabelle). Neben den angefiihrten FSB wurden in den besprochenen Metaboliten auch pathogene FSB nachgewiesen. Es wurden einige FSB identifiziert, die sich in Lebensmitteln, namentlich in Brot, K/ise und Wein befinden. Die gr6gte Zahl von FSB wurde in metabolischen Produkten von acidophilen Milchbakterien identifiziert. Fiir ihre gas-chromatographische Bestimmung verwendete man Chromosorb G mit drei station/iren Phasen (Apiezon L/ KOH, Triton X-305/NaBPO4 und PEG-1000/NaBPO4) bzw. Gaschrom R mit Penvolt 223/KOH; die einzelnen Komponenten der zu analysierenden Gemische wurden durch Vergleich ihrer Retentionsindices identifiziert. Es bewS,hrte sich vor allem die Kombination der GC mit der Rechentechnik, die erm6glicht, unbekannte Stoffe ohne Vergleichsstandards zu identifizieren. - Zh. Anal. Khim. 44, 773-793 (1989) (Russisch, mit engl. Zus.fass.). Nesmeyanov Inst. organoelement. Verbin., Akad. Wiss., Moskau (SU) F. Jancik Gas chromatographic separation of diastereomeric dicarbamate derivatives of ~- and 6-1actones. K.-H, Engel, R.A. Flath, W. Albrecht and R. Tressl. Zur Bestimmung von chiralen Lactonen in Nahrungsmitteln wird ein Verfahren beschrieben, bei dem die Lactone erst durch Reduktion mit Lithiumaluminiumhydrid in die entsprechenden 1,4- und ~1,5-Diole urn-

453 gewandelt werden. Diese werden dann durch Derivatisierung mit (R)(+)-l-Phenylethylisocyanat in die diastereomeren Dicarbamate tiberfiihrt, welche dann gaschromatographisch auf einer Capillars/iule mit DB 210 Beschichtung mit einem Temperaturprogramm yon 220 - 260°C getrennt werden k6nnen. Die Identifizierung der Derivate kann anschlieBend durch Massenspektrometrie erfolgen. Das Verfahren wird zur Analyse der 7- und 8-Lactone in Mangofrfichten eingesetzt, es k6nnen jedoch mit diesem Verfahren nur Lactone bis zu Kettenl/ingen yon C8 bestimmt werden. - J. Chromatogr. 479, 176-180 (1989). Techn. Univ. Berlin, Inst. Biotechnol., Chem.-Techn. Anal., D-1000 Berlin 65 R.H.S. Robust statistics and functional relationship estimation for comparing the bias of analytical procedures over extended concentration ranges. M. Thompson. Kane's Kjeldahl protein data were assembled to compare the efficacy of a copper sulfate catalyzed procedure with that of the standard procedure employing mercury(II) oxide. The original data analysis was carried out by a conventional analysis of variance at each level, after the rejection of outliers. The data have now been reexamined by a functional relationship method after the estimation of robust means and standard deviations. The combined methods gave the rapid and unambiguous result that there was no measurable relative bias between the two procedures. - Anal. Chem. 6I, 1942-1945 (1989). Dept. Chem., Birkbeck Coll., London (GB) Chromatographic techniques for lipid analysis. E.W. Hammond. Lipide, wichtige Bestandteile der Nahrung, k6nnen mit verschiedenen chromatographischen Techniken bestimmt werden. Probleme, die sich mit gepackten S/iulen und wide-bore-S/iulen, vor allem bei der Routineanalyse und der quantitativen Analyse ergeben, werden er6rtert. Vielfach werden heutzutage zur Analyse der Fetts/iuremethylester und Triglyceride OV-1 Capillaren verwendet. Reproduzierbare und gute Ergebnisse werden auf 7 - 1 0 m langen 0,34 mm i.D. Capillaren mit maximal 0,1 ~tm OV-1 Beschichtung erhalten. Auch die Drucke k6nnen optimiert werden, mit 120 kPa werden gute Ergebnisse erzielt. Bei der HPLCAnalyse der Lipide auf Spherisorb ODS-SS,ulen mit Gradienten zwischen Methanol/Acetonitril (i :9) und Tetrahydrofuran/Dichlormethan (1:9) wird festgestellt, dab vermehrt Probleme bei der Wahl von komplizierten Gradienten auftreten. Wichtig ist auch die richtige Wahl der Injektionstechnik, kurze Vors/iulen verbessern in der HPLC die saubere Trenn u n g . - Trends Anal. Chem. 8, 308-313 (1989). United Biscuits R& D Centre, High Wycombe, Bucks. (GB) R.H.S. High-performance liquid chromatography and capillary supereritical-fluid chromatography separation of vegetable carotenoids and carotenoid isomers. H.H. Schmitz, W.E. Artz, J.M. Dietz and J.W. Erdman, Jr, Carotenoids from carrots and tomatoes were separated with highperformance liquid chromatography (HPLC) and capillary snpercritical fluid chromatography (SFC). All trans alpha- and beta-carotene were separated from their respective cis-isomers with capillary SFC. Carotenoids extracted from tomatoes included xanthophyll, lycopene and beta-carotene, while alpha- and beta-carotene were extracted from carrots. The HPLC separations were accomplished isocratically with a 25-cm column containing 5-gm ODS and methanol-actonitrile-chloroform (47: 47 : 6) or acetonitrile-dichloromethane (80 : 20) beta-Carotene cis-isomers were separated with SFC with a SB-cyanopropyl-25polymethylsiloxane column, while alpha-carotene isomers were separated with two SB-cyanopropyl-50-polymethylsiloxane columns. Carotenoids from carrots and tomatoes were separated with a SB-phenyl-50-polymethylsiloxane column. Carbon dioxide with 1% ethanol was the SFC mobile phase. The eluent was monitored at 461 nm for HPLC and either 453 or 461 nm for SFC. - J. Chromatogr. 479, 261 -268 (1989). Dept. Food Sci., Univ. Illinois, Urbana, IL (USA) Nachweis und Bestimmung yon ~-Carotin in fetthaltigen Lebewnsmitteln. A. Etournaud, P. Beaud and J.-D. Aubort. Eine schnelle und einfache Methode zum Nachweis yon [3-Carotin in fetthaltigen Lebensmitteln wird beschrieben. Nach Verseifung des Fettes wird der Farbstoff direkt aus der Reaktionsmischung durch Festphasenextraktion auf einer C 18-S/iule isoliert und durch Dfinnschichtchromatographie identifiziert. Die quantitative Bestimmung kann auf einer C18-

454 Reversed-Phase S/iule in weniger als 6 min durch isokratische Elution mit Acetonitril/Dichlormethan/Ethanol (70:20:10) oder durch Aceton/ Wasser (95 : 5) erfolgen. Durch die Verwendung des nicht-w/il3rigen Eluens wird die Trennung des 13-Carotins von seinem eMsomeren erreicht, so dab eine genaue Bestimmung dieses Provitamins m6glich ist. Der Nachweis wird bei 455 nm durchgef/ihrt. Die Ergebnisse der Untersuchungen von 26 Proben fetthaltiger LebensmitteI werden angegeben. Mitt. Geb. Lebensm. Hyg. 80, 335-344 (1989). Lab. Canton., Epalinges-Lausanne (CH) R.H.S.

Determination of thiamine using continuous flow molecular emission cavity analysis. N. Grekas, A.C. Calokerinos and T.P. Hadjiioannou. A continuous flow method for the determination of thiamine hydrochloride (20.0-240.0 gg/mI, 5.9× 10-5-7.1 × 10 -4 M) is described. The sample was mixed with an excess of sodium hydroxide and remained in the delay coil for 20 min at 90°C. The solution was then mixed with an excess of orthophosphoric acid and the hydrogen sulfide evolved was transferred continuously into the cavity to generate a molecular emission of Sz. The analysis is completely automated, requires no sample pre-treatment and samples can be analysed at a rate of 30 samples/h with a relative error of 1 - 2 % . The method was evaluated by carrying out an interference study with common excipients and other water-soluble vitamins, a recovery study and by the analysis of commericial formulations. Results compared well with those obtained using the official method. The method was alos applied to content uniformity tests. - Analyst 114, 1283-1286 (1989). Lab. Anal. chem., Univ., Athens (GR) Potentiometric homogeneous enzyme-linked competitive binding assays using adenosine deaminase as the label. T.L. Kjellstr6m and L.G. Bachas. Homogeneous enzyme-linked competitive binding assays for biotin are described that are based on the competition between an enzymebiotin conjugate and free biotin for a fixed number of binding sites of avidin. Unlike conventional homogeneous enzyme immunoassays, in this system the analyte (biotin) is labeled with adenosine deaminase (ADA), an ammonia-producing enzyme. Consequently, potentiometric rather than photometric methods can be used as means of detection. Several ADA-biotin conjugates were prepared and showed as high as 97% inhibition of the enzymatic activity in the presence of avidin. Addition of free biotin reverses this inhibition in an amount proportional to the concentration of analyte. Relatively steep dose response curves were observed, leading to a precise and accurate assay for biotin. The detection limits of these curves were as low as 1 × 10- 8 M. Varying the concentration of the reagents in the assay allowed the detection limit and working range to be altered to a desired value. The proposed method was applied in the determination of biotin in a horse-feed supplement. Anal. Chem. 61, 1728-1732 (1989). Dept. Chem., Univ., Lexington, KY (USA) Separation of tocopherol and tocotrlenol isomers using normal- and reverse-phase liquid chromatography. B. Tail and L. Brzuskiewicz. This optimization study for tocopheroIs and tocotrienols involved both normal- and reverse-phase LC using various columns and mobile phases. Normal-phase systems showed elution of the homologs in order of increasing polarity with separation based on methyl substituents on the chromanol moiety. Reverse-phase systems showed class separation based on the saturation of the phytyl side chain; the more saturated tocopherols were retained on the column longer. When the Zorbax ODS was used with an isocratic ternary acetonitrile/methanol/methylene chloride (60:35:5) mixture, the optimized resolution was >2.0 and separation was achieved in < 13 rain, but there was no separation of 13and 7-tocopherols. The normal-phase silica and amino columns provided separation of all available isomers with resolution > 1.1 and separation times of < 5.5 and < 10 min, respectively. Optimized isocratic binary solvent mixtures of hexane/2-propanol were used for silica (99:1) and amino (98 : 2) columns. Derivative spectra showed differences depending on substituents in the chromanol moiety but not the phytyl side chain. Second- and fourth-derivative spectra gave the best differentiation of the vitamin E isomers. - Anal. Biochem. 180, 368-373 (1989). Dept. Chem., Univ., Amherst, MA (USA)

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Particular products and fields of application

Cathodic adsorptive stripping square-wave voltammetry of folic acid (vitamin B9). N. Abo E1 Maali, J.-C. Vire, G.J. Patriarche and M.A. Ghandour. A rapid and sensitive square-wave voltammetric method is proposed for the determination of folic acid (vitamin B9) after its adsorptive preconcentration onto a hanging mercury drop electrode. The first of the three peaks developed by this compound has been considered for analytical purposes. A 0.03 M sodium perchlorate supporting electrolyte at pH 4.2 allows one to obtain the most sensitive signal. A preconcentration potential of - 0 . 2 V vs. Ag/AgC1/KCI(s), a 100 Hz frequency and a 200 mV s - ~ scan rate have been selected as the best experimental parameters. When the complete coverage of the electrode surface is reached, each molecule is found to occupy an area of 5.7 nm z. Folic acid can be determined in a 1 x 10 .7 to 1 x 10 -1° M concentration range using deposition times between 30 and 300 seconds. A detection limit of 2 x 10 11 M is achieved after a 5 min accumulation time. - Analusis 17, 213-216 (1989). Free Univ. Brussels, Inst. Pharm. Brussels (B) Photoreduction fluorescence detection of qninones in high-performance liquid chromatography. J.R. Poulsen and J.W. Birks. A simple, reagent-free photochemical reaction detector for quinones including, but not limited to, the K vitamins is presented. Quinones are photoreduced to dihydroquinones via hydrogen abstraction from the HPLC mobile phase in a postcolmnn photoreactor. An advantage over previous reaction-detection methods for quinones is the simplicity of this system. No postcolumn reagent addition pumps are required. Additionally, the reaction is accomplished in a very short reactor which minimizes band broadening and analysis time. Detection limits for many quinone derivatives are in the low picogram range with good selectivity. In this paper, the photochemistry of the detection scheme and its optimization for use in HPLC are discussed. As a sample application, the detection of vitamin K~ in a plant extract (Capselia bursa pastor&s) without prefractionation is included. A new photoreactor housing for carrying out anaerobic reactions in low-dispersion, PTFE photoreactors is described. - Anal. Chem. 61, 2267-2276 (1989). Dept. Chem. Biochem., Coop. Inst. Res. Environ. Sci., Univ., Boulder, CO (USA) Validation of a quantitative procedure for the extraction of sterols from edible oils using radiolabelled compounds. G. Lognay, P. Dreze, P.J. Wagstaffe, M. Marlier and M. Severin. The work described in this paper is integrated in an analytical programme organised by the Community Bureau of Reference with the aim of developing reference materials certified for sterol content. Preliminary intei:comparison of methods showed that the level of agreement of the results was insufficient for certification purposes. Errors could occur in the different steps before the final determination by GC. It was, therefore, decided to validate a quantitative procedure for the isolation of sterols. A well defined saponification-extractionmethod was tested using labelled sterols ([3H]cholesterol and [3H]cholesteryl oleate) and radiochemical measurements. The study has shown that total cholesterol recovery reached 100.5 ± 1.4%, that cholesteryl ester was saponified quantitatively and that there were no appreciable amounts of degradation products. The procedure has been used as the basis for the certification of three reference materials and it has been shown that the saponification and extraction procedure leads to the quantitative recovery of sterols regardless of the nature of the fatty material tested. Analyst 114, i287-1291 (1989). U.E.R. Chim. G6n. Org., Fac. Agric. Sci., Gemblonx (B) Zur Cholesterinbestimmong und Eigehaltsberechnung in Lebensmitteln. I. Mitteilung: Gaschromatographische Cholesterinbestimmung; Ringversuch an Biskuit und Trockenei. M. Dresselhaus-Schroebler und G. Becker. Ein Ringversuch zur gaschromatographischen Cholesterinbestimmung und zur Eigehaltsbestimmung in Biskuit und Trockenei-Proben wird durchgeffihrt. Dazu wird das nach §35 LMBG beschriebene Verfahren eingesetzt. Aul3erdem wird auch eine an Biskuit getestete Schnellmethod, welche sich vonder Referenzmethode in der Hydrolyse und der Isolierung des Unverseifbaren durch den Verzicht auf quantitative Ausschfittlung unterscheidet, eingesetzt. Dazu wird 1,0 g der vorgetrockneten und homogenisierten Probe mit 5 ml HC1 (18%) versetzt und 30 min erhitzt (Abdecken). Nach Abk/ihlen wird KOH zugesetzt und weitere

2.6

Foods

30 rain erhitzt. Dann wird 5~-Cholestan als interner Standard zugeffigt und nach Abkiihlen und Verdiinnen mit Wasser mit Diethylether extrahiert. Der Extrakt wird eingeengt und der Riickstand des Unverseifbaren silyliert und gaschromatographisch nach der amtlichen Methode analysiert. Cholesterin kann mit dem gesetzlichen Verfahren mit guter Genauigkeit bestimmt werden. Die Schnellmethode weist stfirkere Streuungen auf, eignet sich jedoch als Screening-Verfahren. - Lebensmittelchem. Gerichtl. Chem. 43, 97 - 100 (1989). Chem. Untersuchungsinst. Wuppertal:Solingen, D-5600 Wuppertal R.H.S.

Inter-laboratory determinationof bis(tributyltin) oxide in timber and timber-treatment solutions. B.S.W. Dawson, N.H.O. Cummins, G.F. Parker, F.J. Cowan and S.O. Hong. Accurate analysis of timber preservatives in timber-treatment solutions and in treated timber is an essential aspect of quality control in the New Zealand wood preservation industry. The increasing use of light organic solvent preservatives in recent years has drawn attention to the need for dependable methods for the determination of bis(tributyltin) oxide (TBTO). As part of an on-going programme of timber preservative analyses at the Forest Research Institute the determination of TBTO was studied in detail by an inter-laboratory comparison between six laboratories. Significant differences between laboratories were found in the determination of TBTO (or tin) in timber preservative treatment solutions and preservative-treated timber. To rectify this situation, recommendations on the necessity to intensify quality assurance programmes are suggested. - Analyst 114, 827-833 (1989). Forest Res. Inst., Rotorua (NZ) Electrochemistry of triphenyltin acetate at a mercury-film glassy carbon electrode. C.B. Pascual and V.A. Vicente-Beckett. Verff. untersuchten das elektrochemische Verhalten yon Triphenylzinnacetat mit cyclischer Voltammetrie, Differentialpuls-Voltammetrie und Elektrolyse bei kontrolliertem Potential an einer QuecksilberfilmGlaskohlenstoffelektrode. Bestimmt wurden die Einfiiisse der Elektrolytzusammensetzung, des pH, der Rotationsgeschwindigkeit der Elektrode und der Konzentration des Triphenylzinnacetats auf die elektrochemischen Signale. Einzelheiten des Meehanismus im Zusammenhang mit Adsorption an der Elektrode, Reduktion des Triphenylzinnacetats zum Triphenylzinn-Radikal und der Reduktion des Radikals zum Triphenylzinn-Anion werden besprochen. Schliel31ich wird ein Verfahren zur Bestimmung von Triphenylzinnacetat durch Differentialpuls-Anodic-Stripping-Voltammetriein 50%igem (v/v) Ethanol mit 0,1 M Essigs~iure + 0,1 M Ammoniakl6sung ausgearbeitet. Es wird auf kommerzielle Pulverformulierungen, Wasser- und Fischproben angewendet. Dabei lagen die Wiederfindungen im Bereich 88 bis 93%. - Anal. Chim. Acta 224, 97-108 (1989). Inst. Chem., Univ. Philippines, Quezon City (Philippinen) W. Czysz Preparative isolation of destruxins from Metarhizium anisopliae by highperformance liquid chromatography. S. Gupta, D.W. Roberts, and J.A.A. Renwick. A method has been developed for preparative isolation of destruxins, a group of major insecticidal cyclodepsipeptides from culture broth of Metarhizium anisopliae. Prepurification of the crude extract by flash chromatography on silica gel followed by HPLC on reverse phase C18 column using linear gradients of acetonitrile-water permitted the isolation of ten destruxins. - L. Liquid Chromatogr. 12, 3 8 3 - 395 (1989). Boyce Thompson Inst., Cornell Univ., Ithaca, NY (USA) Separation of primicarb and its metabolites by high-performance liquid chromatography. P. Cabras, L. Spanedda, C. Tuberoso and M. Gennari. Ein HPLC-Verfahren zur Trennung und Bestimmung des selektiv wirkenden Aphizids Primicarb und seiner wichtigsten Abbauprodukte wird entwickelt. Die Retentionszeiten der Verbindungen auf einer RP-8-, einer RP-18- und einer NHz-S/iule in verschiedenen Puffer/Acetonitrilbzw. Wasser/Acetonitril-Gemischen sind tabelliert. Je nach Polaritfit erzielt man ffir einen Tell der Metabolite gute Trennergebnisse auf einer RP-8-S~iule mit Phosphatpuffer (10- 2 mol/1)/Acetonitril (65 : 35) und ffir den anderen Tell auf einer NH2-S/iule mit Wasser/Acetonitril (88 : 92). Die UV-Detektion wird bei 226, 236, 245 bzw. 295 nm ausgeffihrt. Gute lineare Eichkurven werden im Bereich yon 0 -- 1,5 ppm mit Korrelations-

455 koeffizienten besser als 0,999 erhalten. Die Nachweisgrenzen f/Jr die einzelnen Verbindungen werden mit 0,005 ppm angegeben. Das Verfahten kann nach geeigneter Extraktion und Reinigung auf die Bestimmung von Primicarb und seinen Metaboliten in verschiedenen Matrices angewandt werden. - J. Chromatogr. 478, 250-254 (1989). Ist. Chim. Farm., Tossicol., Appl. Cagliari (I) R.H.S.

Determination of carboxin with use of the iodine-azide reaction. E. Kotodziejczyk. The method is based on the reaction of sodium azide with iodine, induced by carboxin. The effect of carboxin and sodium azide concentration, pH of solution, and reaction time on induction coefficient was investigated. The induction coefficient defined as the ratio of a number of iodine gramatoms which reacted to that of sulfur is about 790, what indicates a very high sensitivity of the method. The method is simple, sensitive and does not require any apparatus. It is possible to apply the elaborated method for the determination of carboxin in soil, in waters, and in fungicidal preparations, - Chem. Analit. 33, 993-999 (1989) (Polnisch, mit engl. Zus.fass.). Inst. Organ. Ind,, Pszczyna (PL) Application of high-performance liquid chromatography with speetrophotometric and electrochemical detection to the analysis of alkylene-bis(dithiocarbamates) (ABDTCs) and their metabolites. V. Bardarov, C. Zaikov and M. Mitewa. Die ABDTCs, die als M +- gut wasserl6slich sind und schnellwirkende fungicide Eigenschaften besitzen und als M 2 +-Salze schwer 16slich sind und eine langdauernde fungicide Wirkung aufweisen, k6nnen mit Hilfe eines HPLC-Verfahrens mit spektralphotometrischer oder elektrochemischer Detektion in technischen Produkten, Blut, Luft und Gewebe und fihnlichen Matrices bestimmt werden. Die Extraktion der ABDTCs aus den verschiedenen Matrices ist relativ schnell und einfach. Dann werden die ABDTCs in Gegenwart von EDTA und einem Antioxidans (0,1% Ascorbins/iure) gel6st und anschlief3end durch Ionenaustauschchromatographie auf einer Partisil SAX 10-S/iule mit einer mobilen Phase aus 1 g EDTA, 0,150 C10~- und 0,05 tool PO43 - pro Liter Wasser (pH 6,8) analysiert. Der elektrochemische Nachweis wird bei 0,80 V mit einer Kohleelektrode gegen eine Ag/AgC1-Elektrode durchgeffihrt. Dabei k6nnen 0,1 - 20 ng injizier ter Verbindung und im Falle des UV-Nachweises bei 235 nm 20 - 5000 ng injizierter Verbindung nachgewiesen werden. Zur Bestimmung der Ethylen- und Propylenthioharnstoffe wird in normal-phase Arbeitsweise auf einer LiChrosorb Si 100-S~iule unter Vorschaltung einer LiChrosorb RP-8-Schutzs~iule mit einer mobilen Phase aus 6 - 8 % Methanol und Ethanol in Pentan gearbeitet. Der UV-Nachweis wird bei 235 nm durchgeffihrt, Hierbei k6nnen 0,1 - 1000 ng injizierter Verbindung bestimmt werden. - J. Chromatogr. 479, 97-105 (1989). Dept. Chem., Univ., Sofia (BG) R.H.S. Supercritical fluid extraction of s-triazine herbicides from sediment. V. Janda, G. Steenbeke and P. Sandra. Die Extraktion der s-Triazinherbicide Simazin, Atrazin, Propazin, Terbutylazin und Cyanazin aus Flul3sedimenten mit Hilfe yon superkritischem CO2 wird untersucht. Die Extraktionsanordnung wird beschrieben. Die Analyse der Extrakte wird anschliel3end gaschromatographisch oder durch HPLC durchgeffihrt. Die Konzentrationen und Extraktionsausbeuten sind ffir die verschiedenen s-Triazine tabelliert, - J. Chromatogr. 479, 200-205 (1989). Prag. Inst. Chem. Technol., Dept. Water Technol. Environ. Engin., Prag 6 (CS) R.H.S. High-sensitivity high-performance liquid chromatographic analysis of diquat and paraquat with confirmation. V.A. Simon and A. Taylor. Ein isokratisches HPLC-Verfahren zur Bestimmung der Herbicide Diquat und Paraquat in Brunnenwassser wird vorgeschlagen. Dazu werden die Proben, die mit Diethylparaquatdiiodid (200 ng) als internem Standard verst/irkt werden, fiber Silicagel-S/iulen geleitet. Dann wird mit 12 g Tetrametyhlammoniumhydroxid-Pentahydrat ÷ 30 g Ammoniumsulfat in 1 1 Wasser (pH 2,5--5,0) eluiert. Anschliegend wird mit Hilfe eines automatischen Probenaufgebers auf Silicagel-Kartuschen gegeben, die auf 70°C erhitzt werden. Als mobile Phase wird das Elutionsmittel jedoch mit nur 10 g Tetramethylammoniumhydroxid eingesetzt. Diquat wird bei 310 nm und Paraquat bei 255 nm mit einem Diode-ArrayDetektor nachgewiesen. Aul3erdem kann auch noch mit post-column

456

2 Particular products and fields of application

Reaktion mit NaOH und NaHSO3 und Nachweis bei 379 nm gearbeitet werden. Dieses Verfahren ist schneller und empfindlicher als frtiher ver6ffentlichte Verfahren. Konzentrationen yon 0,1 - 1 0 gg/kg Diquat und Paraquat kSnnen in 100 ml Proben bestimmt werden. - J. Chromatogr. 479, 153-158 (1989). Dept. Health Rehabilitative Serv., State Florida, Jacksonville, FL (USA) R.H.S. Spectrophotometric assays for the enzymatic hydrolysis of the active metabolites of chlorpyrifos and parathion by plasma paraoxonase/arylesterase. C.E. Furlong, R.J. Richter, S.L. Seidel, L.G. Costa and A.G. Motulsky. Human serum plasma paraoxonase/arylesterase exhibits a genetic polymorphism for the hydrolysis of paraoxon. One alMic form of the enzyme hydrolyzes paraoxon slowly with a low turnover number and the other(s) hydrolyzes paraoxon rapidly with a high turnover number. Chlorpyrifos-oxon, the active metabolite of the insecticide chlorpyrifos (Dursban), is also hydrolyzed by plasma arylesterase/paraoxonase. A specific assay for measuring hydrolysis of this compound is described. This assay is not subject to interference by the esterase activity of serum albumin. The Km for chlorpyrifos-oxon hydrolysis was 75 gM. Hydrolysis was inhibited by phenyl acetate, EDTA, and organic solvents. Enzyme activity required calcium ions and was stimulated by sodium chloride. Hydrolysis was optimized by using methanol instead of acetone to dissolve substrate. An improvement in the assay for hydrolysis ofparaoxon by plasma arylesterase/paraoxonase was achieved by elimination of organic solvents. - Anal. Biochem. 180, 242-247 (1989). Dept. Med., Dept. Genetics, Univ., Seattle, WA (USA) The determination of reducible pesticides by adsorptive stripping voltammetry. C.L. Bourque, M.M. Duguay and Z.M. Gautreau. Reduzierbare Pesticide wie die nitrierten phosphororganischen Substanzen Methyl-Parathion, Parathion, Dicapthon und Fenitrothion, das asymmetrische Triazin Guthion und das s-Triazin Simetryn k6nnen durch ASV nach Akkumulation bestimmt werden. Die optimalen Akkumulationspotentiale und die Strippingspannung ffir die sechs Pesticide bei pH 4,5 werden ermittelt. Es wfrd mit einer Scanrate von 10 mV/sec, einer Akkumulationszeit von 60 sec und einer Pulsamplitude von 100 mV gearbeitet. Das Verfahren ist 20 - 50mal empfindlicher als die DPPAnalyse ohne vorherige Akkumulation. Die rel. Standardabweichung im 10 7 mol/l-Bereich liegt unter 3%. Das Verfahren kann auf die Analyse von drei Pesticiden in einer Probel6sung angewandt werden. Ergebnisse ftir eine Anzahl von Umweltproben werden angegeben. Hohe Konzentrationen von Elektrolyten oder Stoffen, die ebenfalls adsorbiert werden, st6ren. Die Nachweisgrenzen liegen f/Jr Simetryn und Gutathion nach Akkumulation bei 2 x 1 0 -9 mol/1, und ffir Fenitrothion bei I x 10 -s tool/1. - Intern. J. Environ. Anal. Chem. 37, 187-197 (1989). Cent. Rech. Sci., Environ., Univ., Moncton, NB (CDN) R.H.S.

2.8

Pharmaceuticals and cosmetics

Extraction and AAS determination of trace amount of cobalt in medicinal samples. S.R. Dan (Biswas) and A.K. Das. Co(II) is determined by AAS method after its extraction with the 13diketo liquid chelating exchanger, CgH~gCOCHaCOCF3 in chloroform as diluent. The extracted species is bis-chelated. The metal is stripped back into 0.1 N HC1 and determined at 240.7 nm using air-C2Hz flame. In determination of 7 ppm Co(II), the following ions do not interfere: CI- (1000-fold); NO3 , C104 , SO42 (600-fold); C N - (300-fold); Li, Na, K (2000 ppm); Ca, Sr, Ba (1000 ppm); Mg, Sn 2+, Pb 2+ , Mn 2+, Zn, Cd, Ga, In 3+, Cr 3+ (200 ppm); Fe 3+ (250 ppm in presence of 1,10phenanthroline); Ni 2+, Cu 2+, Pd 2+ and Pt e+ (180 ppm in presence of CN-). The method is applied to determine cobalt in mixtures and medicinal samples. -- J. Indian Chem. Soc. 66, 69--70 (1989). Chem. Dept., Univ. Burdwan (IND) M. KatyaI

Analysis of siderophores and synthetic hydroxamic acids by high-performance liquid chromatography with amperometric detection. J.D. Glennon, M.R. Woulfe, A.T. Senior and N. NiChoileain. Microbial siderophores are an important class of secreted metal sesquestering agent with applications ranging from chelation therapy to precious metal recovery. The analysis of siderophores and of synthetic models of siderophores by HPLC is hampered by metal sequestering problems during the chromatography. The biocompatibility of HPLC systems is examined here by comparison of the reversed-phase chromatographic behavior of a series of synthetic dihydroxamic acids, HONHCO(CH2)n-CO-NHOH ( n = 3 - 7 ) on metal-free and stainless-steel HPLC systems. Problems associated with chelate formation on column are not encountered on the metal-free system. An applied voltage of + L0 V (vs Ag/AgC1) is optimum for amperometric detection and is used in conjunction with detection at 220 nnr. - Anal. Chem. 61, 14741478 (1989). Dept. Chem., Univ. Coll. Cork (IRL)

Indirect spectrophotometric determination of BIDA, DISIDA, DTPA and MDP in labelled compounds. T.N. van der Walt, P.P. Coetzee and P.J. Fourie. N-(4-(n-butyl)-acetanilide)iminodiacetic acid (BIDA), N-(2,6-diisopropylacetanilide)iminodiacetic acid (DISIDA), diethylenetriaminepentaacetic acid (DTPA) and methylene diphosphoric acid (MDP) are used in labelling kits. The contents of BIDA, DISIDA or MDP of the 99mTc-labelled compounds can be determined (indirectly) spectrophotometrically with copper, eriochrome cyanine R (ECC) and dodecylethyldimethylammonium bromide (DEDA) in a sodium barbital buffered system at pH 8.5. The calibration curves obeys Beer's Law from 0 to 40 gg/ 25 ml for BIDA and DISIDA, 0 to 60 gg/25 ml for DTPA and 0 to 100 gg/20 ml for MDP. - App. Radiat. Isot. 40, 525-529 (1989). Dept. Chem., Rand Afrikaans Univ., Johannesburg (ZA)

Separation of cationic technetium-99m amine complexes on porous graphitic carbon. M.F. Emery and C.K. Lim. Die vollstfindige Trennung yon TcO4- und den monokationischen Aminkomplexen Dioxo(ethylendiamin)-, Dioxo(1,5,8,12-tetraazdodecan)- und trans-Dioxo(1,4,8,11-Tetraazacyclotetradecan)-Technetium auf einer S/iule mit portsem Graphit (PGC-S/iuIe) wird beschrieben. Als Eluens wird Acetonitril in 1% Trifluoressigs/iure eingesetzt. Der Nachweis erfolgt radiometrisch. Das Verfahren wird zur Uberwachung der radiochemischen Reinheit dieser m6glichen Radiopharmazeutika und ftir Stoffwechseluntersuchungen empfohlen. - J. Chromatogr. 479, 212-215 (1989). Div. Clin. Cell Biol., MRC Clin. Res. Centre, Harrow, Middlesex (GB) R.H.S.

Reversed-phase high-performance liquid chromatography of unsubstituted aminobenzoic acids. S.L. Abidi. HPLC characteristics of three position isomers of aminobenzoic acids (potential metabolites of important anesthetic drugs), were delineated with respect to their interactions with various mobile phases and stationary phases. HPLC with five hydrocarbonaceous phases, J3-cyclodextrin silica (CDS), macrophase MP-1 polymer (MP), macroporous polystyrene/divinylbenzene (MPD), octadecylsilica (ODS), and propylphenylsilica (PPS), yielded results explicable in terms of substituent effects derived from the bifunctional amino- arid carboxy groups. For cases where mobile phases contained sulfonates or quaternary ammonium salts both having longer chain alkyls, retention of analytes on all but CDS appeared to proceed predominantly via an ion-pairing mechanism. The extent of the corresponding counter-ion effects decreased in the order: MPD > ODS > PPS > MP, while the analyte retention order paralleled their pH2 values. On the other hand, an inverse relationship between the magnitude of capacity factors (k') and pK~ values of the title compounds was observed in experiments that produced retention data incompatible with ion-pair interaction rationales. The unique HPLC results obtained with the CDS phase are compared with those obtained with other phases. - J. Liquid Chromatogr. 12, 595-611 (1989). U.S. Fish Wildlife Serv., Nat. Fish. Res. Cent., La Crosse, WI (USA)

2.8

Pharmaceuticals and cosmetics

Spectrophotometric characterization of some analgesics and antipyretics. A. Djoki6, D. Dumanovi6, D. Markovi6 and A. Muk. Dissoziationskonstanten und andere ffir die spektralphotometrische Charakterisierung notwendige Parameter werden fiir eine Reihe von Analgetika und Antipyretika (Coffein, Pyrophenazon, Phenacetin, Pyrithyldion, Paracetamol) bestimmt; insbesondere pK-Werte verschiedener Dissoziationsstufen and bei unterschiedlichen pH. Mehrere Tabellen und Absorptionskurven werden angegeben bzw. abgebildet. - Talanta 36, 931-935 (1989). Pharm./Chem. Ind. ,,Galenika", Belgrad (YU) W. Czysz Analysis of bambuterol hydrochloride chemical reference substance and tablets by liquid chromatography. O. Wannerberg, P. Persson and P. Lindroth. A reversed-phase ion-pair LC was applied to the analysis of bambuterol hydrochloride chemical reference substance (CRS) and tablets. The purity evaluation of the reference substance was performed with amperometric, UV, diode array and mass spectrometric detection. The total amount of impurities found was less than 0.I %. For the determination of bambuterol hydrochloride in tablets the method reproducibility was 0.9% and the recovery was in the range 99.8-100.7%. Detection limits for conceivable degradation products were about 1 ng. The suitability of different column packing materials was investigated. J. Liquid Chromatogr. 12, 465-478 (1989). AB Draco, Res. Dev. Dept., Anal. Chem., Lund (S) Simple calorimetric estimation of furosemide in dosage forms - Part I. P. Mishra, D. Katrolia and P.K. Agrawal. Furosemide (4-chloro-N-furfuryl-5-sulfamoylanthranilic acid) reacts with Cu(II) to form a green complex suitable for spectrophotometry of the drug. The complex (?~..... 742 nm) contains metal and the drug in 1 : 2 ratio and obeys Beer's law from 1 - 5 mg/ml of the drug concentration. The method is applied to determine the drug in tablets and injections (recovery 98-100%). Procedure. To an aliquot of the drug soln. (in methanol) add 2 ml of 1% copper(II) acetate (in 60% methanol). Dil. to 10 ml with methanol, Measure the absorbance at 742 nm against a reagent blank. - Curr. Sci. 58, 5 0 3 - 505 (1989). Dept. Pharm. Sci., Dr. Hari Singh Gaur Viswavidyalaya, Sagar (IND) M. Katyal

457 photometriert. Die Megl6sungen sind bis 24 h stabil. - Talanta 36, 941 - 9 4 4 (1989). Dept. Pharm. Chem., Fac. Pharm., Assiut Univ., Assiut (ET) W. Czysz

Acid-base equilibria and assay of bezodiazepines in acetonitrile medium. J. Barbosa and V. Sanz-Nebot. Verff. untersuchen die Sfiure/Base-Gleichgewichte von zehn pharmazeutisch verwendeten Benzdiazepinen in Acetonitril. Dissoziationskonstanten pKHB÷and effektive Acidit/itenp k'nB +werden bes timmt (Tabelle). Die Theorie der Titration in Acetonitril wird ausfiihrlich diskutiert; auf dieser Grundlage werden Arbeitsvorschriften ffir potentiometrische und visuelle Titrationen angegeben. Sie k6nnen zur Bestimmung der Benzdiazepine in pharmazeutischen Formulierungen eingesetzt werden. - Talanta 36, 837-842 (1989). Dep. Quire. Anal., Univ., Barcelona (E) W. Czysz Extraction spectrophotometric determination of some adrenergic drugs using fast green FCF or orange-If. D.G. Sankar, C.S.P. Sastry, M.N. Reddy and M. Aruna. Six adrenergic drugs (isoxsuprine, nylidrin~ naphazoline, tetrahydrozoline, xylometazoline, oxymetazoline) are spectrophotometrically determined based on their formation ofcoloured ion-association complexes with the dye fast green FCF (C.I. No. 42053) or orange-II (C.I. No. 15510). The complexes formed are extracted in chlorotbrm and their absorbances measured at Lmax630 nm (e 3.31 x 104 - 9.83 x 104) when fast green is used or at 495 nm (e 9.04 x 103 - 2.13 x 104) when orangeII is used. The methods are used to determine the drugs in tablets, injections and solns. (recovery 92.2-99.8%) without interference from active ingredients and excipients usually present in the preparations. Indian Drugs 26, 348 351 (1989). School Chem., Andhra Univ., Waltair (IND) M. Katyal Spectrnphotometric determination of ranitidine hydrochloride. S.C. Chattaraj, S.K. Das and B.K. Gupta. Based on characteristic absorption maxima of ranitidine hydrochloride at 225 nm in 0.1 N HC1 and at 314 nm and 228 nm (relatively weak) in phosphate buffer (pH 7.4), the drug is determined spectrophotometrically. The photometric linearity range is obeyed within 2 - 3 0 ppm of the drug concentration. The method is applied to determine the drug in tablets and raw material (recovery 99.24-100.61%) both in 0.1 N HC1 and in phosphate buffer. - Indian Drugs 26, 365--367 (1989). Dept. Pharmacy, Jadavpur Univ., Calcutta (IND) M. Katyal

Resolution of antihypertensive aryloxypropanolamine enantiomers by reversed-phase chromatography of (-)-menthyl chloroformate derivatives. H.F. Schmitthenner~ M. Fedorchuk and D.J. Walter. Racemische Aryloxypropanolamine kann man gut mit ( - ) - M e n thylchloroformat derivatisieren. Die entstehenden diastereomeren ( - ) Menthylcarbamatderivate k6nnen direkt durch HPLC getrennt werden. Mit diesem Verfahren werden beispielsweise die einzelnen Flavodilolenantiomeren und racemisches Propranolol aufgetrennt. Die Vorteile dieses Derivatisierungsagens gegeniiber anderen chiralen Derivatisierungsreagentien werden diskutiert. Zur Derivatisierung werden die zu bestimmenden Verbindungen in Form ihrer Maleatsalze oder ihrer salzsauren Salze eingesetzt und die freie Base durch Extraktion mit 10% Natriumcarbonat and Dichlormethan freigesetzt und abgetrennt. Die organische Phase wird mit Triethylamin and Derivatisierungsreagens in Methylenchlorid versetzt. Im Falle yon Propranolol wird kein Triethylamin ben6tigt. Die Derivatisierung dauert 0,5 - 4 h. Die Derivate k6nnen direkt mit Methanol/Wasser (78 : 22) unter Zusatz yon 0,2% Essigs/iure und 0,2% Triethylamin auf einer Zorbax Cs-SS_ule chromatographiert werden. -- J. Chromatogr. 487, 197-203 (1989). Dept. Med. Chem., Pennwalt Pharm. Civ., NY (USA) R.H.S.

Liquid chromatography-mass spectrometry of trace compounds with a moving-belt interface and multi-dimensional chromatography. W. Luijten, G. Damien and J. Capart. A HPLC method with on-line MS detection is described for the structural analysis of a number of synthetic impurities, present at trace levels in almitrine. To obtain mass spectra with various ionization methods and high-resolution mass measurements, a moving-belt interface is used. A two-column switching system allows the injection of large amounts of almitrine, from which the trace compounds are trapped on a second column, while discarding the major component. This permits the introduction of the impurities into the mass spectrometer by elation of the second column, without the risk auf introducing too large an amount of the major compound into the mass spectrometer. The mass spectra thus obtained are of sufficient quality to permit a correct structural assignement of the impurities. - J. Chromatogr. 474, 2 6 5 - 273 (1989). Technol. Servier, Orl6ans (F)

Spectrophotometric determination of some diazepine drugs by electrophilic coupling. S.A. Hussein, M.E. El-Kommos, H.Y. Hassan and AbdelMarboud I. Mohammed. Es werden zwei spektralphotometrische Methoden zur Bestimmung yon Imipramin-, Clomipramin- und Desipraminhydrochlorid und Trimipraminmaleat in der Synthesel6sung und in Formulierungen angegeben. Das erste Verfahren beruht auf der Reaktion mit diazotiertem pNitroanilin in 5 M HC1; das zweite auf der oxidativen Kupplung des Diazepins mit 3-Methylbenzothiazolin-2-on-hydrazon(MBTH) in Gegenwart vorl Ammonium-Eisen(III)-sulfatin 0,1 M HC1. Die resultierenden chromophoren L6sungen werden bei 575 nm bzw. 620--630 nm

Analysis of barbiturate mixtures using HPLC with diode array detection. T.D. Wilson, W.F. Trompeter, and H.F. Gartelman. A study has been conducted on the HPLC analysis of barbiturate mixtures in which coeluting components with similar UV spectra could be distinguished by diode array detection. The separations were performed on a Partisil PXS column with water/methanol (30: 70). Mixtures containing phenobarbital and barbital in combination from about 0.25 to 0.00025 mg/ml each were measured using the spectral overlay, absorbance ratio, peak maximum absorbance and purity parameter techniques. The most sensitive of the standard methods available was absorbance ratio plotting in which the presence of 0.0125 mg/ml barbital

458 could be distinguished from phenobarbital at 0.2375 mg/ml. - J. Liquid Chromatogr. 12, 1231-I251 (1989). Pharmaceut. Sci. Anal. Chem. Depts., Sterling-Winthrop Res. Inst., Rensselaer, NY (USA) HPLC analysis of methoxamine in rabbit plasma and pharmaceutical formulations. I.A. A1-Meshal, M.M. EI-Domiaty and Al-Obaid. A rapid, selective and simple high-performance liquid chromatographic (HPLC) assay for methoxamine HC1 has been developed. The analytical procedure involved the use of internal standardization method (/-norephedrine). The HPLC-analysis is performed on a gPorasil column with dichlorethane/n-propanol/acetic acid/ diethylamine/water (840:160:10: 5 : 5) and UV detection at 220 nm. It has been applied for the qualitative and quantitative determination of methoxamine HCI in rabbit plasma and in pharmaceutical formulations using an adsorption column in an isocratic mode, with resulting relative standard deviations of 1.7% and 3.3.%, respectively. The applicability of the assay procedure to pharmacokinetic studies was demonstrated. Detection limits were as low as 15 ng for a 30 gI injection and the determination time was less than 6 minutes. - J. Liquid Chromatogr. 12, 1589-1600 (1989). Dept. Pharmac., Coll. Pharm., King Saud Univ., Riyadh (Saudi Arabia) A multiresidue method for the isolation and liquid chromatographic deterruination of seven sulfonamides in infant formula. A.R. Long, L.C. Hsieh, M.S. Malbrough, C.R. Short, and S.A. Barker. A multiresidue method for the isolation and high-performance liquid chromatographic (photodiode array, UV 270 nm) determination of sulfathiazole, sulfisoxazole, sulfamerazine, sulfamethazine, sulfamethoxazole, sulfisoxazole and sulfadimethoxine in a milk-based infant formula is presented. Blank or sulfonamide spiked infant formula samples were blended with octadecylsilyl derivatized silica (C-18) packing material. A column made from the C-18/infant formula matrix was first washed with hexane following which the sulfonamides were eluted with methylene chloride. The eluate contained sulfonamide analytes which were free from interfering compounds when analyzed by liquid chromatography. This resulted in correlation coefficients (0.9973 + 0.0016 to 0.9992 + 0.0006), recovery percentages (75.91 + 11.12% to 112.01 +_ 8.15%) and inter- (5.51 _+ 1.74% to 15.27 + 8.14%) and intra-assay (1.71 to 8.89%) variabilities for individual sulfonamides, over the concentration range (62.5 to 2000 ng/ml) examined, that are indicative of a useful method for the multiresidue analysis of milk-based infant formula for the presence of sulfonamides. - J. Liquid Chromatogr. 12, 1601 1612 (1989). Dept. Vet. Physiol., Pharmacol. Toxicol., Sch. Vet. Med., Louisiana State Univ., Baton Rouge, LA (USA) Reversed-phase chromatography of novel biologically effective aminoacridine-N-glycosides by OPLC. K. Kovfics-Hadady and A. Kovfics. The reversed-phase chromatographic behavior of novel biologically active aminoacridine-N-glycosides is studied. The chromatographic experiments are performed with overpressurized layer chromatography. Weak ion pairs are formed with methanesulfonic acid, but only at low concentrations of the ion-pairing reagent. The retention seems to involve a reversed-phase mechanism. The base compounds only slightly modify the retention, while the number and polarity of the substituents have larger effects. The pH dependence of the retention is very typical for the aminoacridine-N-glycosides, and it plays an important role in the separation. The monoglycosides are completely separated from the corresponding base compounds, as are the diglycosides from the monoglycosides, on RP-2, RP-8, and RP-I 8 layers with eluents containing 30 to 60% acetonitrile and at least 0.005 M ammonium carbonate at pH 4 to 6. - J. Chromatogr. Sci. 27, 221-224 (1989). BIOGAL Pharmac. Works, Debrecen (H) Chromatography of rhodamine 123 and rhodamine 110 on reverse-phase liquid chromatographic column. M.M. Vora. Rhodamine 123 (Rh 123), a cationic fluorescent dye that accumulates in mitochondria of living cells, is widely used in study of mitochondria and has potential use as anticarcinoma agent. HPLC methods for analysis of Rh 123 have been reported but detailed study of the chromatographic behavior of Rh 123 has not been previously described. Described in this paper is a simple isocratic HPLC method for optimal separation

2

Particular products and fields of application

of Rh 123, and Rh 110 which is an impurity present in commercial supply of Rh 123 and also a potential metabolite of Rh 123, resulting from detailed investigation of the effect of various mobile phase parameters on retention behavior of Rh I23. - J. Liquid Chromatogr. 12, 583-593 (1989). Radionucl. Cyclot. Operat. Dept., Hosp. Res. Cent., Riyadh (Saudi Arabia) Differential pulse polarographic determination of some (5-nitro-2-furyl)alkylldene-2-hydrazinothiazole derivatives. S. Kit, D.D. Erol, H. Erdogan and A. Temizer. Vier antimikrobielle (5-Nitro-2-furyl)alkyliden-2-hydrazinthiazolDerivate werden in 0,1 M Tetramethylammonium-terafluoroborat- als Elektrolytl6sung durch DPP bestimmt. An der statischen Quecksilbertropfelektrode wird, wie festgestellt wurde, die Nitrogruppe der Yerbindungen in einem 6-Elektronenprozel3 zu dem entsprechenden Amin reduziert. Man erhfilt lineare Responsen im Bereich 0,2-140 mg/1 der betreffenden Verbindungen mit einer RSD von 3,3%. - Anal. Lett. 22, 1527-1535 (1989). Dept. Pharm. Chem., Anal. Chem., Fac. Pharm., Hacettepe Univ., Ankara (TR) W. Czysz Amphoteric tetracycline-sensitive electrodes and their seleetivities. Yao Shou-Zhou, Shiao Jing and Nie Li-Hua. Verff. stellen Elektroden her, die auf kationische und anionische Species von Tetracyclin ansprechen. Die in PVC-Membran eingearbeitete Ionenpaarkomplexe, die die elektroaktiven Substrate bilden, sind Tetracyclin-Silicowolframat, Tetracyclin-Dipikrylaminat, Cetyltrioctylammonium-Tetracyclinat sowie Tetracyclinate mit NH4 +-, P- und As-haltigen quaterngren Basen. Die kationensensitive Elektrode spricht auf monoprotonierte Tetracycline fiber den pH-Bereich 1,9 bis 3,2 an; die anionensensitive Elektrode bei pH 8,0 - 11,0 auf das einfachgeladene Tetracyclinat-Anion, das bei der Dissoziation der Enolgruppe im Ring B entsteht. Selektivit/itskoeffizienten und Elektronenempfindlichkeiten sind in Tabellen zusammengestellt. - Talanta 36, 8 4 9 - 854 (1989). Inst. New Mat. Res., Dep. Chem. Engin., Hunan Univ., Changsa (RC) W. Czysz Spectrophotometric estimation of norfloxacin in its dosage forms using 3-methyl-2-benzothiazolinone hydrazone hydrochloride. G.R. Rao, A.B. Avadhanulu, R. Giridhar and C.K. Kokate. Norfloxacin, chemically 1-ethyl-6-fiuoro-l,4-dihydro-4-oxo-7-(l-piperazinyI)-3-quinolinecarboxylic acid, reacts with 3-methyl-2-benzothiazolinone hydrazone hydrochloride (MBTH) in presence of Ce(IV) salt to form a green species ()~m~ 630 nm) suitable for spectrophotometric determination of the drug. The species is stable for 40 rain and obeys Beer's law from 1 - 2 0 ppm of norfloxacin concentration. The method is applied to determine the drug in commercial formulations (recovery 98.5-101.0%). Procedure. To an aliquot of the drug soln. (in 0.004 N H2SO4) add 3 ml of 0.2% MBTH and 7 ml of 0.5% ceric ammonium sulfate (in 0.2 N H2SO4). After a reaction time of 25 min, dil. to 25 ml. Measure the absorbance at 630 nm against a reagent blank. - Indian Drugs 26, 580-581 (i989). Quality Control Labs., IDPL, Hyderabad (IND) M. Katyal Separation of a new antidiabetie agent, N-(trans-4-isopropylcyclohexylearbonyl)-D-phenylalanine, and its isomers by ehiral high-performance liquid chromatography. H. Shinkai, M. Nashikawa and Y. Sato. N-(trans-4-Isopropylcyclohexylcarbonyl)-D-phenylalanine (A4166) is a new oral antidiabetic agent. In order to determine the purity of chemical samples of A4166, a HPLC method for the separation of A4166 and synthetic by-products (an L-enantiomer and a cis-isomer of A4166) has been developed. A chiral stationary phase column packed with 5 gm N(tert-butylaminocarbonyl)-L-valylaminopropyl silica gel was used for the direct separation of A4166 and its isomers after derivatization with an non-chiral reagent. -- J. Liquid Chromatogr. 12, 457-464 (1989). Cent. Res. Labs., Ajinomoto Inc.0 Suzuki-cho, Kawasaki-ku, Kawasaki

(J) Quantitative structure retention relationship studies of some basic antimalarial compounds. R.B. Taylor, N.A. Ochekpe and J. Wangboonskul. Studies have been made of the correlation between chromatographic retention parameter, k' and solute hydrophobicity as determined by the oil-in-water partition coefficient. Using a set of 29 basic antimalarial

2.8

Pharmaceuticals and cosmetics

drugs and analogues such correlations have been made under ion pairing and non ion pairing conditions. The capacity factors have been obtained extrapolated to pure water and in the case of ion pairing conditions, the k'max values have been used. J. Liquid Chromatogr. 12, 1645 - 1668 (1989). Sch. Pharm., R. Gordon's Inst. Technol., Aberdeen (GB)

Spectrophotometric determination ofiodochlorohydroxyquinoline in multicomponent pharmaceutical formulations especially in presence of diiodohydroxyquinoline. G. Podder, T.K. Das, A.K. Sen and S.K. Moitra. The drug iodoehlorohydroxyquinoline is determined based on its quantitative UV absorption maximum at 267 nm (a 2.8 × 104) in 3 N HC1 (reagent). Beer's law is obeyed from 1 - 25 ppm of the drug concentration. The absorbance of the soln. is measured within 48 h against 3 N HCI. No interference is observed from free chlorine, iodine, CI-, Br-, drugs (like diiodohydroxyquinoline, metronidazole, phthalylsulfathiazole, streptomycin, sulfadimidine, sulfaguanidine, diastase, yeast, hydrocortisone, balladonna, pectin, kaolin, chloroquine phosphate, berberine, backed bael, papain), diluents and additives. The method is applied to determine the drug in tablets, ointments and creams. - J. Indian Chem. Soc. 66, 51 - 5 2 (1989). School Trop. Med., Dept. Chem., Calcutta (IND) M. Katyal Spectrophotometric determination of bephenium hydroxynaphthoate, diiodohydroxyquinoline and iodochlorohydroxyquinoline with diazotized dapsone. C.S.P. Sastry and M. Aruna. Diazotized dapsone is used for spectrophotometric determination of the drugs bephenium hydroxynaphthoate (I), diiodohydroxyquinoline (II) and iodochlorohydroxyquinoline (III) in their formulations (recovery 98.2-99.2%). Beer's law limits (in ppm), )~max (rim) and molar extinction coefficients (l/mol cm) are 2 - 2 0 , 500, 1.57 x 104; 2-20,430, 8.47x103; 2 - 2 0 , 430, 6.17x 103 for (I), (II) and (III) respectively. Procedure. To 1 - 1 . 5 ml of 0.1% dapsone (in 0.5 M HC1) add 2 ml of 0.1% NaNOa and after 2 min add a suitable aliquot of the drug soln. (I in methanol, II or III in dimethylformamide). Add 1 ml of 1.5 M NaOH and dii. to 10 ml. Measure the absorbance at 500 nm (for I) or 430 nm (for II or III) against a reagent blank. - Indian Drugs 26, 567-569 (1989). School Chem., Andhra Univ., Waltair (IND) M. Katyal Chiral separation of the optical isomers of the antimalarial drug halofantrine. P. Camilleri, C. Dyke and F. Hossner. Halofantrin [1-(1,3-Dichlor-6-trifluormethyl-9-phenanthryl)-3-N,Ndibutylaminopropan-l-ol], welches als Antimalariamittel eingesetzt wird, kann durch ein HPLC-Verfahren in seine Enantiomeren getrennt werden. Racemisches Halofantrin wird als freie Base aus den Hydrochloriden dargestellt und die optischen Isomeren auf einer Pirkle-S/iule [LN-(3,5-Dinitrobenzol)leucinkovalent an 3-Aminosilicagel gebunden] bei 0°C mit n-Hexan/Chloroform/Propan-2-ol + 1% Trietbylamin (90: 5 : 5) chromatographiert. Die UV-Spektren werden bei 260 nm aufgenommen. Die Identifizierung der Enantiomeren kann aufgrund der spezifischen Rotation erfolgen. - J. Chromatogr. 477, 471-473 (1989). Smith Kline & French Res. Ltd., Welwyn, Hertforshire (GB) R.H.S. Stability-indicating capillary gas-liquid chromatographic assay of dicyclomine hydrochloride in some pharmaceutical formulations. H.S.I. Tan, Y.P. Yan and A.P. Thio. A stability-indicating assay method for some dicyclomine hydrochloride formulations was developed utilizing capillary GC. A methanolic extract of the sample, containing phenacetin as internal standard, was chromatographed by temperature programming on a 15 m x 0.524 mm I.D., DB-17 column with nitrogen carrier gas and FID (1 . 10 - l ° A). The dicyclomine hydrochloride was well resolved from phenacetin with retention times of ca. 9 and 7 min, respectively. Dicyclomine hydrochloride-iuternal standard peak area ratio was linear over 0 . 1 1.0 gg of dicyclomine hydrochloride injected (r = 0.999). Under the experimental conditions the limit of detection was 0.025 gg of dicyclomine hydrochloride injected. Validation studies with synthetic capsules, tablets and injectables covering a range of 5 - 2 5 mg of dicyclomine hydrochloride per unit gave an overall percent recovery (+_ relative standard deviation, n = 9 ) of 99.9 ± 1.7%. The method was successfully applied to the assay of commercial formulations. Stability tests indicated that degradation products of dicyclomine, formed upon acid treatment,

459 did not interfere with the dicyclomine and internal standard peaks. They further showed that dicyclomine is fairly stable in base. - J. Chromatogr. 475, 381 - 3 8 9 (1989). College Pharm., Univ. Med. Center, Cincinnati, OH (USA)

Use of liquid chromatography in the synthesis of isoluminol-labelled medroxyprogesterone acetate and zeranol. H. Koehler, L. Larocque and S. Sved. A HPLC method for monitoring the syntheses of two isoluminollabelled drugs, medroxyprogesterone acetate (MPA) and zeranol, has been developed. MPA and the ketone derivative of zeranol, zearalanone, were conjugated to N-(4-aminobutyl)-N-ethylisoluminol through the carboxymethyloxime derivative of the drug by using the N-succinimide ester as an intermediary. Reaction mixtures were sampled periodically and chromatographed directly by HPLC on a silica gel column, by using isocratic elution with mixtures of hexane-ethanol-acetic acid in several different proportions. The degree of reaction completion was determined by comparison of the peak area of the initial reactant to that present at sampling time. MPA oxime production was found to be complete after 15 min; 97.0% of the oxime was converted to succinimide ester in 24 h; 99.0% of the available ester reacted within 2.5 h to form the final labelled product. Zearalanone oxime production was found to be complete after 2 h; 93.3% of the oxime was converted to the activated ester within 24 h; 89.6% of available ester had reacted in 30 min to form the final labelled product. The chromatography can be performed in real time, permitting modification in the conditions of the reaction while in progress. J. Chromatogr. 469, 305 - 315 (1989). Bureau Drug Res., Health Protect. Branch, Health Welfare Canada, Ottawa, Ont. (CDN) Study of HPLC retention behaviour of furocoumarins in Peucedanum palustre with reference to solvent selectivity and molecular connectivity. H. Vuorela and P. Lehtonen. The separation factor (~) and molecular connectivity indices (~) up to the sixth order were calculated and compared with measured RP-HPLC retention data for eight closely related furocoumarins from Peucedanum palustre. Retention measurements were performed over the capacity factor (k') range 1 - 3 5 using organic solvent/water eluents containing acetonitrile, dioxan, ethanol, methanol, n-propanol and tetrahydrofuran. The solvents showed differences in the elution order of the furocoumarins. Decreasing the volume ratio (q)) increased in many cases the separation factor. The compounds were divided into two groups; the low-order valence level indices and path/cluster type of the fith order valence level indices best described the retention. As the high correlations between the calculated and observed retention indicate, retention could be predicted in six organic solvents with a high degree of accuracy by the molecular connectivity indices. - J. Liquid Chromatogr. 12, 221 234 (1989). Div. Pharmacog., Sch. Pharm., Univ., Helsinki (SF) HPLC analysis of nonvolatile flavor components in tamarind (Tamarindus indica L.). A.L. Khurana and Chi-Tang Ho. Nonvolatile flavor components in the pulp of Tamarindus Indica L. fruit have been identified and analyzed by using HPLC. Presence of total sugars, individual amino acids and organic acids was determined on PartiSphere-5 NH2 column. Various sugar components were resolved on PartiSphere-5 PAC column. Resolution of typical organic acids and amino acids was achieved on PartiSphere-5 WCX column. - J. Liquid Chromatogr. 12, 419-430 (1989). Whatman Inc., Clifton, NJ (USA) High performance liquid chromatographic determination of physostigmine and its degradation products in pharmaceutical dosage forms. J.T. Stewart and K.D. Quinn. A HPLC method for the simultaneous determination ofphysostigmine and its degradation products, eseroline and rubreserine, in pharmaceutical ointment and injection dosage forms is described. The compounds are separated isocratically on an octadecylsilane column using a 60:40 aqueous phosphate buffer pH 4.0-acetonitrile mobile phase containing 0.6% sodium dodecyl sulfate at a 1.0 ml/min flow rate. The column effluent was monitored by UV absorbance at 310 nm. Accuracy and precision of the method were in the 0.03-2.62 percent and 0.1-1.2 percent ranges, respectively, for the analytes studied. The method is linear for physostigmine, eseroline, and rubreserine in the 5-1000 gg/

460 ml range. - J. Liquid Chromatogr. 12, 673-683 (1989). Dept. Med. Chem., Coll. Pharm., Univ. Georgia, Athens, GA (USA) Polymeric activated ester reagents for off-line and on-line derivatizations of amine nucleophiles in high-performance liquid chromatography with ultraviolet and fluorescence detection. C.-X. Gao, T.-Y. Chon and I.S. Krull. A novel polymeric activated ester reagent has been developed that improves final detectability and chromatographic performance in HPLC for virtually all primary and secondary amines or amine analogues. This has involved the synthesis, characterization of final reagent, optimization of derivatization and separation conditions, and determination of analytical figures of merit. The polymeric reagent contained an activated ester linkage to the 9-fluorenyl group, which imparted UV and fluorescence (FL) detector properties to the final derivatives. Kinetic studies of these solid-phase (heterogeneous) reactions have been conducted, and specific rate constants were compared with those of the analogous solution reaction for the same substrates. Percent derivatizations have reached 90% and 70% for primary and secondary amines, respectively, under optimized conditions. These solid-phase derivatizations have led to detection limits for typical amines in the low-parts-per-billion range. As an illustrative example, amphetamine spiked in urine has been derivatized off-line and on-line, with minimum sample preparation, and detected via HPLC-UV/FL with acceptable accuracy and precision. Anal. Chem. 61, i538-1548 (i989). Dept. Chem. Barnett Inst., Northeast Univ.° Boston, MA (USA) Liquid chromatographic and mass spectral analysis of 1-(3,4-methylenedioxyphenyl)-l-ethanamines: Homologues of 3,4-methylenedioxyamphetamines. F.T. Noggle, Jr., C.R. Clark, and J. Deruiter. The deletion of a methylene unit from the arylamine sidechain of the 3,4-methylenedioxyamphetamines (MDAs) produces the homologous 1-(3,4-methylenedioxyphenyl)-l-ethanamines. These ethanamines were prepared via reductive amination of the corresponding ketone with a series of N-alkylamines. Analytical methods were developed to distinguish these compounds from the MDA series. The ethanamines were separated under RP-LC conditions using a Cls stationary phase and a mobile phase of aqueous acidic (pH 3) acetonitrile containing triethylmnine. The electron impact mass spectra of the ethanamines were determined by GC-MS and the fragmentation pattern clearly distinguishes these compounds from those of the MDA series having the same molecular weight. - J. Liquid Chromatogr. 12, 431-444 (1989). Alabama Dept. Foren. Sci., Auburn, AL (USA) Liquid chromatographic and mass spectral analysis of 1-(3,4-methylenedioxyphenyl)-3-butanamines, homologues of 3,4-methylenedioxyamphetamines. F.T. Noggle, Jr., C.R. Clark and J. DeRuiter. The 1-(3,4-methylenedioxyphenyl)-3-butanamines (HMDAs) are prepared via reductive amination of the corresponding ketone with a series of low molecular weight alkylamines. These amines are homologues of the N-substituted 3,4-methylenedioxyamphetamines (MDAs). Compounds of the HMDA series have UV absorption properties similar to the MDAs because both series contain the same 3,4-methylenedioxyphenyl chromophore. The HMDAs are separated via RP-LC methods using A C18 stationary phase and an acidic aqueous acetonitrile mobile phase. The mass spectra of these potential designer drugs are very similar to the spectra of the MDA homologues having the same N-substituent. - J. Chromatogr. Sci. 27, 240-243 (1989). Dept. Pharm. Sci., Sch. Pharm., Univ., Auburn, AL (USA) Quantitative estimation of nafidixic acid and its formulations. D.M. Shingbal and M. Sarjyotishi. Nalidixic acid (chemically l-ethyl-l,4-dihydro-7-methyl-4-oxo-l,8naphthyridine-3-carboxylic acid) is diazotized and coupled to form a reddish brown chromophore suitable for spectrophotometric determination of the drug. The chromophore shows )~maxat 470 nm and obeys Beer's law from 20--200 ppm of the drug concentration. The method is applied to determine the drug in its formulations (recovery 100.1100.5%) without interference from excipients and preservatives. Procedure. To an aliquot of the drug soln. (in methanol) add 0.4 mi of 0.2% sulfanilamide soln., 2 ml of 2% NaNO2 and 0.4 ml of 2% c~-

3 Biochemical and clinical analysis naphthylamine. Mix and warm for 10 min. Cool and diI. to i0 ml with methanol. Measure the absorbance at 470 nm against a reagent blank. Indian Drugs 26, 576-578 (1989). Pharm. Res. Lab., Goa College Pharmacy, Pan@, Goa (IND) M. Katya! Quantitation of polydimethylsiloxane in pharmaceutical formulations by gel permeation chromatography (GPC). S. Andersson, U. Hedsten and S. Jacobsson. Die GPC wird in Kombination mit einem Refraktionsindex-Detektor zur quantitativen Bestimmung yon Polydimethylsiloxan in komplexen Matrices wie Emulsionen pharmazeutischer Produkte eingesetzt. Dazu werden die in Methylisobutylketon gel6sten Emulsionen extrahiert. Der ~berstand wird auf einer Polystyroi/Divinylbenzol-S/iule mit Toluol als mobiler Phase chromatographiert. Die Extraktionsausbeute aus verschiedenen L6sungsmitteln unterschiedlicher Polaritfit wird bestimmt. Im 1 mg/ml-Bereich wird in Methylisobutylketon eine rei. Standardabweichung von 1,9% erhalten. Lineare Eichkurven werden von 0,5-2,5 mg/ml gefunden. Die untere Nachweisgrenze wird mit 1,5 pg (S/N = 3) angegeben. - J. Chromatogr. 477, 474-476 (1989). Kabi Pharma, Res. Developm. Dept., Solna (S) R.H.S. Analytical high-performance liquid chromatography system for separation of components in nonoxynol-9 spermicidal agents. D.B. Black, B.A. Dawson and G.A. Neville. Nonylphenoxypolyethoxyethanol (Nonoxynol-9), ein nichtionisches Tensid, welches spermizide Wirkung aufweist, kann in kommerziellen Produkten durch HPLC analysiert werden. Dazu wird auf einer S5W 5 gm-Sfiule mit Ethylacetat/Methanol (1:1) gearbeitet. Der Nachweis erfolgt im UV bei 280 nm. Die Charakterisierung der Peaks kann durch 1H-NMR erfolgen. Das Verfahren wird zur Charakterisierung eines kontrazeptiv wirkenden Vaginalschwammes eingesetzt. J. Chromatogr. 478, 244-249 (1989). Bureau Drug Res., Health Protect. Canada, Tunney's Pasture, Ottawa, Ontario (CDN) R.H.S.

3

BIOCHEMICAL AND CLINICAL ANALYSIS

A new way in homogeneous immunoassay: Reversed micellar systems as a medium for analysis. A.V. Kabanov, M.M. Khrutskaya, S.A. Eremin, N.L. Klyachko and A.V. Levashov. Possibilities of a new principle for the homogeneous enzyme immunoassay utilizing the systems of surfactant reversed micelles in organic solvents have been demonstrated taking thyroxine determination as an example. The catalytic activity of an enzyme, solubilized in such systems, is determined by the ratio of geometric dimensions of the micellar matrix and the enzyme molecule. The addition of antibodies against thyroxine to the peroxidase-thyroxine conjugate, solubilized in the system of reversed micelles of aerosol OT in octane, leads to the formation of the immune complex whose size differs substantially from that of the initial enzymeantigen conjugate. This induces changes in the peroxidase catalytic activity. The addition of free thyroxine to the system stimulates the conjugate release from the immune complex and, consequently, the reduction of the peroxidase activity to the initial level. Sensitivity of the analysis in reversed micellar systems can be regulated by changing the surfactant hydration degree. Substances of different nature (both hydrophobic and hydrophylic) can be solubilized in reverse micellar systems under standard conditions, which allows determination of water insoluble antigens. - Anal. Biochem. 181, 145-148 (1989). Div. Chem. Enzymol., State Univ., Moscow (SU) Glucose biosensor with extended linearity. M. Mascini and S. Selleri. Verff. beschreiben Versuche, die eine erh6hte Linearitfit ffir GlucoseBiosensoren zum Ziel hatten. Die Technik, die dabei angewendet wurde, beruht in der Einfiigung einer Membran zwischen Probe und GlucoseSensor, um die Diffusion der Glucose zum Sensor hin zu limitieren, ohne

3 Biochemical and clinical analysis die Diffusion des Sauerstoffs dabei zu beeinflussen. Benutzt wurden Membranen aus gegossenem Polynrethan, kommerzielle Polycarbonatmembranen, die konventionell silanisiert wurden, und nichtpermeable Gasmembranen, die so perforiert wurden, dab eine kontrollierte Diffusion m6glich wurde. Die Ergebnisse, die mit den drei Membrantypen erzielt wurden, werden verglichen. Vor einer abschliel3enden Beurteilung sind noch weitere Versuche notwendig. -- Anal. Lett. 22, 1429-1449 (1989). Ist. Chim. Anal., Univ., Florenz (I) W. Czysz Biothermal analysis performed in organic solvents. B. Danielsson, L. Flygare and T. Velev. Verff. verwenden eine thermische Sonde (Enzym-Thermistor) zur Untersuchung der Leistung enzymatischer Analysen mit immobilisierten Enzymen in organischen L6semitteln und im Gemisch solcher mit w/il3rigen Pufferl6sungen. Dabei wird festgestellt, dab ziemlich geringe Mengen Alkohol (ca. 5%, v/v) im Puffer bei Glucose-Oxidase und Katalase die gemessene Temperatur~inderung etwa verdoppeln, haupts/ichlich auf Grund des Anstiegs der Ver/inderung der Gesamtenthalpie der Reaktion. Die Wfirmeproduktion von durch Peroxidase katalysierten Reaktionen war in Toluo145mal gr613er als in Pufferl6sung. Der Vorteil der erh6hten Substratl6slichkeit in organischen L6sungsmitteln wird beim Arbeiten mit Cyclohexan in einer Lipasesfiule demonstriert. Alle Enzyme waren in den benutzten organischen L6sungsmitteln stabil. - Anal. Lett. 22, 1417-1428 (1989). Pure Appl. Biochem., Univ., Lund (S); Dep. Solid State Physics, Univ., Sofia (BG) W. Czysz Flow injection zymography - a novel procedure for the on-line detection of enzyme activity. W. Kfinnecke, H.M. Kalisz and R.D. Schmid. Fliel3injektions-Zymographie ist eine neue Analysentechnik zum Nachweis von Enzymaktivit/it wfihrend eines Enzymreinigungsverfahrens. Man arbeitet mit der Kombination aus FIA und FPLC (Fast Protein Liquid Chromatography) in einer FIA-FPLC-Einheit (Schemaskizze im Original; Pharmacia Lab. Sep. Div. 1985). Anhand dieser Schemaskizze werden die Reaktionsabl/iufe beschrieben. Das Verfahren ist schnell (3 Proben je Minute), ben6tigt nur geringe Probenvolumina und erfal3t einen breiten Aktivit/itsbereich (aufwS,rts bis 70 IE) eines Enzyms. Durch Arbeiten nach der Mischzonenmethode wird der Reagensverbrauch stark reduziert. - Anal. Lett. 22, 1471-1484 (1989). Gesellsch. Biotechnol. Forsch. (GBF), D-3300 Braunschweig W. Czysz Matrix corrections for quantitative determination of trace elements in biological samples using energy-dispersive X-ray fluorescence spectrometry. S. Kumar, S. Singh, D. Mehta, M.L. Garg, P.C. Mangal and P.N. Trehan. An experimental method for the evaluation of the matrix absorption correction (13)for the determination of trace elements in thick biological samples using EDXRF is discussed. The validity of the method was checked in two ways, first by comparing the experimental values with theoretical estimated values for samples of known matrix and second by analysing NBS biological standards in the form of thick pellets. It was found that a sample thickness of 4 0 - 70 mg cm z is, in general, optimum for the analysis of biological samples in pellet form with an excitation energy of 22.6 keV. - X-Ray Spectrom. 18, 207 210 (1989). Dept. Phys., Panjab Univ., Chandigarh (IND) Determination of silicon in national institute of standards and technology biological standard reference materials by instrumental epithermal neutron activation and X-ray fluorescence spectrometry. E.S. Gladney, P.E. Neifert and N.W. Bower. The measurement of silicon in biological standard reference materials has been investigated by both boron-filtered epithermal neutron activation analysis and wavelength dispersive X-ray fluorescence. Good agreement between the methods was obtained for 11 different materials ranging from the methods' detection limits of about 100 gg/g to the highest concentration in these samples of 12000 pg/g silicon. - Anal. Chem. 61, 1834-1836 (1989). Health Environ. Chem., Group HSE-9/ MS K-484, Nat. Lab., Los Alamos, NM (USA) Isotopic determination of selenium in biological materials with inductively coupled plasma mass spectrometry. B.T.G. Ting, C.S. Mooers and M. Janghorbani.

461 The method is based on hydride generation ICP-MS. The development is specifically related to the requirements of stable isotope tracer studies in human subjects. The method is based on isotope dilution using 82Se as the in vitro spike and can quantify the 74Se and 77Se contents of samples. It involves wet oxidation (HNO3-H202 or HNO3-HCIO4) of S2Se-spiked matrix, reduction to selenite by boiIing with HC1 followed by measurement of the isotope ratios (S2Se/TVSe and 74Se/77Se) in the gas stream (H2Se) generated from on-line reduction of the sample selenite with NaBH4. Compared with the isotopic signal resulting from a selenite solution containing 5 ng/ml of Se, the total sample blank contributions at m/z = 74, 77 and 82 were less than 5% of the respective isotope signal. Worst-case absolute detection limits were 0.2-0.9 ng of Se, depending on the isotope used. Ion beam intensity ratios were measured with an over-all precision [relative standard deviation (RSD)] of 1% for both isotope pairs. Measured ratios (MRajb) were stable during a given day's operation within the expected precision of the measurements but varied for different days. The precision/accuracy of the isotopic analysis was established by replicate measurements of the Se content of several biological matrices [National Bureau of Standards Standard Reference Material (NBS SRM) 1577a Bovine Liver, human plasma, red blood cells and human urine], and comparison of the results with independent measurements obtained using hydride generation AAS. Compared with other available methods of isotopic analysis, this method possesses the added advantage of requiring no chemical separation steps as the hydride generation is sufficient for removal of any potential matrix-related interferences. - Analyst 114, 667-674 (1989). Clin. Nutr. Res. Cent., Dept. Med., Univ., Chicago, IL (USA) Inductively coupled plasma mass spectrometric determination of the absorption of iron in normal women. P.G. Whittaker, T. Lind, J.G. Williams and A.L. Gray. The determination of iron isotope ratios in blood, without prior sample preparation, using inductively coupled plasma mass spectrometry (ICP-MS) with sample introduction by electrothermal vaporisation (ETV) is described. Following oral administration of 5 mg of enriched S~FeSO4 and intravenous administration of 200 pg of 57FESO4 to nonpregnant women, the 5~Fe/56Fe and S7Fe/S6Fe isotope ratios in serum were measured reliably within 20 min per sample in quintuplicate. Changes in the fractional absorption of iron during human pregnancy could therefore be assessed. - Analyst 114, 675--678 (1989). Univ. Dept. Obstet. Gynaecol., Princ. Mary Maternity Hosp., Newcastle (GB) Graphite furnace atomic absorption spectrometric determination of chromium, nickel, cobalt, molybdenum, and manganese in tissues containing particles of a cobaid-chrome alloy. F. Betts and A. Yau. An investigation of wear debris generation by cobalt-chrome alloy joint prostheses required analysis of human tissue containing metal in ionized or particulate form, at levels from less than 1 to over 3000 pg/g of dry tissue. Wet ashing by a number of published methods failed to dissolve high levels of the alloy particles. Other methods inadequately digested tissue lipids or were unsuitable for samples with very low metal content. A procedure using wet ashing was developed that has broad applicability to direct analysis, by flameless atomic absorption with Zeeman background correction, of tissues containing nonvolatile metals in ionic or particulate form. Direct analysis of a standard reference material containing from 0.4 to 2.4 pg/g of the elements of interest yielded average values within 5% or less of the certified content for all five metals, with a coefficient of variation less than 5%. When the standard material was spiked with powdered alloy at 3000 gg/g, recovery values for all metals ranged from 97% to 100% with individual coefficient of variation values of 4% or less. The detection limit was below 0.1 pg/g of dry tissue for Cr and Ni and below 0.03 Ixg/g for Co, Mn, and Mo. - Anal. Chem. 61, 1235-1238 (1989). Hosp. Spec. Surg., New York, NY (USA) Determination of nitrite, sulfate, bromide and nitrate in human serum by ion chromatography. Y. Michigami, Y. Yamamoto and K. Ueda. An ion chromatographic method has been developed for the determination of trace amounts of nitrite, sulfate, bromide and nitrate in human serum, using an ODS column dynamically coated with cetylpyridinium chloride. The anions studied were eluted with 1 mM citrate-2.5% meth-

462 anol (pH 6.5) as the mobile phase and detected by an UV detector. The interfering proteins in human serum were removed by an initial filtration through an ultrafilter-paper. The many inorganic and organic anions commonly found in serum had little effect on the determination of the four anions. Recoveries of nitrite, sulfate, bromide and nitrate in serum were 107-110, 94-106, 106-110 and 92-100%, respectively. The proposed method was also applied to human saliva and urine. - Analyst 114, 1201-i205 (1989). Dept. Chem. Chem. Engin., Fac. Technoi., Kanazawa Univ,, Kodatsuno, Kanazawa (J)

Assay of 1-hydroxy-3-aminopropylidene-l,l-bisphosphonate and related bisphosphonates in human urine and plasma by high-performance ion chromatography. P.T. Daley-Yates, L.A. Gifford and C.R. Hoggarth. Samples are spiked with 1-hydroxy-5-aminopentylidene-l,l-bisphosphonate as an internal standard and calcium chloride is added to precipitate the bisphosphonates. Following centrifugation the precipitate is redissolved in acetic acid, and the bisphosphonates are separated by high-performance ion chromatography on a Dionex AS7 column using nitric acid as mobile phase. The bisphosphonates are oxidised to orthophosphate using post-column addition of ammonium persulfate and this is followed by postcolumn reaction with molybdenum-ascorbate to yield the phosphomolybdate chromophore which is detected at 820 nm. A detection limit of 10 ng/ml is possible. - J. Chromatogr. 490, 329-338 (1989). Dept. Pharm., Univ., Manchester (GB) Voltammetric determination of cyanide and thiocyanate in small biological samples. A.M. Westley and J. Westley. The basic of the procedures is electrochemical determination of C N with a silver rotating disk electrode at 90 mV, relative to the Ag/AgC1 reference electrode, or with a dropping mercury electrode in differential pulse mode at - 2 4 0 inV. Thiocyanate is oxidized to C N - with permanganate under controlled conditions prior to its analysis. Endogenous cyanide and cyanide from SCN oxidation are recoverd, separately, by volatilization and trapping. Emphasis is placed on careful handling of specimens prior to analysis. Precautions include a provision for sequestering cyanide in storage, the use of an antioxidant, and an avoidance of the spontaneous sulfide formation from proteins that occurs in even mildly alkaline solutions. - Anal. Biochem. 181, 190-194 (1989). Dept. Biochem. Univ., Chicago, IL (USA) Second dissociation constant and pH of N(2-hydroxyethyl)piperazine-N'2-ethanesulfonic acid from 0 to 50°C. D. Feng, W.F. Koch and Y.C. Wu. HEPES (N-2-hydroxyethylpiperazine-N'-2-ethanesulfonic acid) has been recommended as a pH buffer for physiological measurements. The pH values for this buffer system, at ionic strengths similar to those in physiological fluids, have been determined at temperatures from 0 to 50°C by the emf method. The influence of NaC1 on this buffer and the liquid junction potential associated with this salt have been evaluated. Thus, the practical, operational pH value can be ascertained. The second dissociation constant of HEPES has been determined, and the thermodynamic properties have been calculated. - Anal. Chem. 61, 1400-1405 (1989). Nat. Inst. Stand. TechnoI., Gaithersburg, MD (USA)

3

Biochemical and clinical analysis

A spectral analysis of whole EDTA blood was undertaken by using attenuated total reflection and Fourier-transform infrared spectroscopy. The concentration of blood glucose was measured by an enzymatic method using glucose dehydrogenase and ranged between 40 and 290 mg/dl with an average concentration of 90.4 mg/dI. Multivariate calibration with the partial least-squares (PLS) algorithm was performed on spectraI data between 1500 and 750 cm a showing a varying background from different unidentified interfering compounds. Cross validation was carried out for optimizing the PLS model. PRESS 1/0~was 19.8 mg/dl, which was calculated on the basis of 127 standards, whereas the estimated standard deviation for the calibration fit was computed to be 11.9 mg/ dl. Infrared spectroscopy can be used for monitoring glucose levels within the normal physiological range in a complex matrix like whole blood as an alternative to electrochemical sensors. - Anal. Chem. 61, 2009-2015 (1989). Inst. Spektrochem. angew. Spektrosk., Dortmund

(D) Multivariate calibration for assays in clinical chemistry using attenuated total reflection infrared spectra of human blood plasma. G. Janatsch, J.D. Kruse-Jarres, R. Marbach, and H.M. Heise. A spectral analysis of human blood plasma was undertaken by use of a Fourier-transform infrared spectrometer with a circular attenuated total reflection cell. The concentrations of total protein, glucose, triglycerides, total cholesterol, urea, and uric acid were measured by chemical or enzymatic methods. For these constituents the partial least-squares (PLS) algorithm was used for a multivariate calibration including the infrared fingerprint region of the plasma spectra. Best results were achieved for total protein with an average prediction error (PRESS a/2 based on cross validation) of 2.1 g/l; other PRESS 1/2 results were for glucose 22 mg/dl, triglycerides 33 mg/dl, cholesterol 31 mg/dl, urea 4.4 mg/dl, and uric acid 1.6 mg/dI. - Anal. Chem. 61, 2016-2023 (1989). Inst. Klin. Chem. Lab. Med., Katharinenhosp., Stuttgart (D) Platinum-dispersed Nation film modified glassy carbon as an electroeatalytic surface for an amperometric glucose enzyme electrode. H. Gunasingham and C.B. Tan. A Nation film dispersed with platinum particles formed on a glassy carbon electrode combines the electrocatalytic activity of platinum with the background stability of glassy carbon. It serves as a selective and sensitive electrode surface for an amperometric glucose enzyme electrode. Details on the construction and the functional characteristics of the enzyme electrode are described. It is shown that the electrode is well suited to the determination of levels of glucose in blood by flow injection with amperometric detection. - Analyst 114, 695-698 (1989). Dept. Chem., Nat. Univ., Singapore (SGP)

Rapid headspaee gas chromatographic method for the determination of liquid/gas partition coefficients. R. Guitart, A. Puigdemont and M. Arboix. A rapid, efficient and low-cost headspace technique useful for the determination of liquid/gas partition coefficients of gases and volatile substances of low and intermediate solubility is described. The equilibration step is carried out at constant pressure using glass syringes, with a ratio of liquid/gas phase volumes of ca. 1:3, after 30 rain at the desired temperature, the headspace is recovered by transfer into another syringe and analyzed by GC. A study of the partition coefficients in water at 37°C of 27 volatile compounds demonstrated that the method is fully applicable for all gases, with exception of those with a partition coefficient higher than 300. - J. Chromatogr. 491, 271 --280 (1989). Dept. Pharmacol., Autonomous Univ., Barcelona (E)

Capillary column gas chromatography-mass spectrometry for the determination of the fatty acid composition of human adipose tissue. D.M. Cassidy, D.A. Pratt, R. Taylor, K.G.M.M. Alberti and M.F. Laker. Adipose tissue was obtained from the lateral upper aspect of the right thigh by needle biopsy and prepared for analysis by lyophilisation, total lipid extraction and base-catalysed transesterification of the complexed fatty acids to form fatty acid methyl esters. Capillary column GC resolved thirty different peaks, ranging in carbon length from 12 to 24. Provisional identification of the peaks was by cochromatography with authentic standards and confirmed by GC/MS using electron-impact ionisation. Fatty acid methyl esters were quantified in absolute amounts with respect to dry tissue weight and as a percentage of the total fat. Statistical analysis of the results from twenty healthy subjects using the two-tailed unpaired Student's t-test demonstrated women had significantly higher levels of myristoleic and palmitoleic acids (p <0.001) and lower levels of palmitic acid (p < 0.05) in adipose tissue when compared with the male group. Similarly total saturated fatty acids was lower (p <0.05) and total monounsaturated fatty acids was higher in women than in men. -- J. Chromatogr. 491, 1 - 1 3 (1989). Dept. Clin. Biochem. Metabolic Med., Royal Victoria Infirm., Newcastle upon Tyne (GB)

Multivariate determination of glucose in whole blood by attenuated total reflection infrared spectroscopy. H.M. Heise, R. Marbach, G. Janatseh and J.D. Kruse-Jarres.

Modern high-performance liquid chromatographic-radioimmunoassay strategies for the study of eicosanoids in biological samples. E. Gelpi, I. Ramis, G. Hotter, G. Bioque, O. Bulbena and J. Rosell6.

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Biochemical and clinical analysis

Es wird ein Oberblick fiber die jfingste Literatur (61 Zitate) zur Bestimmung von Eicosanoiden durch Immunoassay-Verfahren gegeben. Dabei wird das Fehlen geeigneter spezifischer Antik6rper ffir diesen Zweck deutlich. Immunologische Methoden (Radioimmunoassay oder Enzymimmunoassay) werden oft nach Festphasen-Extraktion und nachfolgender Reinigung der interessierenden Antigene durch Reversed-Phase HPLC-Verfahren eingesetzt. Dadurch k6nnen die analytischen M6glichkeiten von Radioimmunoassays deutlich verbessert und die Genauigkeit der Methode gesichert werden. Tabellarisch wird mit Literaturzitaten der Einsatz yon HPLC/RIA-Verfahren ffir verschiedene Typen von Proben dargestellt, wobei gleichzeitig die Extraktionsbedingungen und die HPLC-Reinigung sowie die Ausbeute angegeben sind. - J. Chromatogr. 492, 223-250 (1989). Dept. Neurochem., CID-CSIC Barcelona (E) R.H.S.

Measurement of hydroperoxydocosahexanoic (HPDHA) acid in rat brain homogenates by reversed phase high-performance liquid chromatography. K.A. Ansari and D.W. Shoemau. Freie Radikale verursachen eine Oxidation polyunges/ittigter Fetts/iuten, die ffir die Pathogenese von Gewebe~inderungen wie Alterung oder Trauma in Nervengewebe verantwortlich sind. HPDHA, welche im Nervensystem eine Rolle spielen k6nnte, wird hier mit Hilfe yon Sojabohnenlipoxygenase aus Docosahexaens/iure hergestellt und durch HPLC aus Rattenhirnhomogenaten bestimmt. Dazu werden die gefrorenen Gewebeproben 60 min bei 37°C in Gegenwart von Zimmerluft mit oder ohne Zusatz des Antioxidans butyliertes Hydroxytoluol oder in Gegenwart von Stickstoff inkubiert. Da HPDHA auch in Hydroxydocosahexaensg.ure umgewandelt werden kann, wird auch diese in die HPLC-Untersuchungen mit einbezogen. Die freien Fettsfiurefraktionen werden aus den Hexan/Isopropranol-Extrakten fiber eine Sep-pak Kartusche isoliert. Diese Fraktionen werden in Methanol auf eine Econosphere 5 ~tm C18Kartusche gegeben. Die Trennung wird mit einem Gradienten yon 48 100% Acetonitril in 0,1% Phosphors/lure durchgeffihrt. Der Nachweis erfolgt im UV bei 235 nm. Zus/itzlich kann man die Reaktionsprodukte durch GC-MS der Trimethylsilylderivate identifizieren. Die Wiederfindungsrate des HPLC-Verfahrens von HPDHA in Gewebe wird mit 78 % angegeben. Die Menge entstandenen HPDHAs nach den unterschiedlichen Inkubationsschritten wird miteinander verglichen. - J. Chromatogr. 475, 457-460 (1989). Dept. Neurol., Univ. Minnesota, School Med., Neurol. Sci., Med. Center, Minneapolis, MN (USA) R.H.S.

Determination of urinary 3-methoxy-4-hydroxyphenylethylene glycol and its conjugates by high-performance liquid chromatography with electrochemical and ultraviolet absorbance detection. J.G. Filser, S. Koch, M. Fischer and W.E. Mfiller. Ein einfaches Verfahren zur Bestimmung des Norepinephrinmetaboliten 3-Methoxy-4-hydroxyphenylethylen-glycol(MHPG)und seiner konjugierten Derivate in Urin wird beschrieben. Nach einem Extraktionsverfahren nach H.J. Gaertner und G. Wiatr [J. Clin. Chem. Clin. Biochem. 18, 579 (1980)] wird die Trennung auf einer Ultrasphere ODS-Sfiule isokratisch mit 2 mmol/1 KH2PO4 (pH 2,5) + 10% Methanol durchgeffihrt. Der Nachweis wird einmal im UV bei 278 nm und zum anderen elektrochemisch bei +0,80 V gegen eine Ag/AgC1-Vergleichselektrode durchgeffihrt. Freies MHPG kann direkt bestimmt werden, w/ihrend MHPG-Sulfat und MHPG-Glukuronid nach enzymatischer Hydrolyse bestimmt werden. Da das Gesamt-MHPG getrennt bestimmt wird, erlaubt der Vergleich der Ergebnisse eine Aussage fiber die Wirksamkeit der Hydrolyse der MHPG-Derivate ffir die verwendeten Urinproben. Fiir quantitative Bestimmungen werden Standardmengen yon MHPG den Proben zugesetzt. - J. Chromatogr. 493, 275-286 (1989). Psychopharm. Lab., Centr. Inst. Mental Health, Mannheim (D) R.H.S.

Determination of amino acids by high-performance liquid chromatography with electrochemical detection using ferrocene derivatization reagents. K. Shimada, Y. Kawai, T. Oe and T. Nambara. Two new reagents possessing ferrocene as an electrophore and isothiocyanate reactive toward the amino group were prepared and evaluated for pre-column derivatization of amino acids in HPLC with electrochemical detection. The utilities of these reagents were investigated employing glycine as a model compound. Ferrocenylisothiocyanate was more favorable with respect to reactivity and electrochemical

463 properties. The newly developed method was applied to the determination of 4-aminobutyric acid in biological specimens. - J. Liquid Chromatogr. 12, 359-371 (1989). Fac. Pharm. Sci., Kanazawa Univ., Takara-machi, Kanazawa (J)

Determination of free amino acids in biological samples: Problems of quantitation. G.A. Qureshi and A.R. Qureshi. An automatic on-line HPLC method was developed to study the effects of various precipitating agents and delayed deproteinization procedures on the estimation of plasma levels of amino acids. The optimized method for analysis is based on pre-column derivatization with ophthalaldehyde in the presence of 2-mercaptoethanol. The separation of 25 amino acids is accomplished within 45 min on a 5-gm C18 column, using a multi-step gradient with two solvents. The method is sensitive and reproducible, and the relationship between the fluorescence intensity and concentration is linear for each amino acid over a wide concentration range. - J. Chromatogr. 491, 281-289 (1989). Dept. Renal Med., Karolinska Inst., Huddinge Univ. Hosp., Stockholm (S)

Studies on the formation and stability of isoindoles derived from amino acids, o-phthalaldehyde and N-acetyl-L-cysteine. M.C. Garcia AlvarezCoque, M.J. Medina Hernfindez, R.M. Villanueva Camafias and C. Mongay Fernfindez. A kinetic-spectrophotometric study is performed on the formation and degradation of the isoindole derivatives of amino acids with ophthalaldehyde and N-acetyl-L-cysteine. The experimental and structural factors which affect the formation and stability of the compounds are considered, and the results are compared with those obtained for mercaptoethanol. N-Acetyl-L-cysteine derivatives are highly stable, not requiring a strict control of the time of reaction as in the case of mercaptoethanol. - Anal. Biochem. 180, 172-176 (1989). Dept. Quim. Anal., Fac. Quire., Univ., Valencia (E)

Optimization of the mobile phase for HPLC separation of S-alk(en)yI-Lcysteine derivatives and their corresponding sulfoxide isomers. S.J. Ziegler and O. Sticher. Using the "PRISMA" optimization model, a total of 15 S-alk(en)ylL-cysteine derivatives, including five thioethers and their corresponding sulfoxide isomers, could be separated following pre-column derivatization with o-phthaldialdehyde/tert.-butylthiol. Optimal isocratic separation of the sulfoxides was achieved with a limited number of experiments using a quaternary solvent system consisting of tetrahydrofuran, 1,4-dioxane, acetonitrile, and aqueous phosphate buffer of pH 7.15. Using a selective multisolvent gradient elution (SMGE) technique, which involves a simultaneous change in selectivity and solvent strength o f the mobile phase, the full range of the examined sulfur amino acids (most of them are found in various Allium species) could be resolved in a single chromatographic run. Development and realization of the chromatographic optimization is shown and discussed. A simple computer program (written in Microsoft Basic) for the calculation of the actual mobile phase composition is added. - J. Liquid Chromatogr. 12, 199-220 (i989). Dept. Pharm., Swiss Fed. Inst. Technol., Zfirich (CH)

Glutathione measurement by high-performance liquid chromatography separation and fluorometric detection of the glutathione-orthophthalaldehyde adduct. B.A. Neuschwander-Tetri and F. Joseph Roll. Glutathione reacts with orthophthalaldehyde to form a stable, highly fluorescent tricyclic derivative which is easily separated and quantitated by HPLC. Separation of the glutathione adduct is achieved by isocratic elution over a reverse-phase column with 7.5% methanol/92.5% 0.15 M sodium acetate, pH 7.00. The adduct is detected fluorometrically and quantitated by integration of peak area. Detection of 0.1 to 200 pmol glutathione produces a linear response and the recovery of reduced and oxidized glutathione from rat liver homogenate, bile, and plasma is quantitative. The chemical identity of the adduct was confirmed by mass spectrometry. - Anal. Biochem. 179, 236-241 (1989). Liver Center Lab., San Francisco Gen. Hosp., Univ., San Francisco, CA (USA)

Optimization of peptide separations in high-performance liquid chromatography. C.T. Mant and R.S. Hodges.

464 Optimization of peptide separations in HPLC involves more than simply optimizing the mobile phase in terms of flow-rate and gradient rate. The first step in optimizing the separation of a complex peptide mixture obtained from chemical and/or proteolytic digestion is the selection of the mode or combination of modes required for the separation. For example, should a single or multimodal approach be used, and which mode(s) (SEC, IEC, RPC) should be selected? The second step is to make an assessment of the performance characteristics of the HPLC columns (selectivity, efficiency and deviations from ideal behaviour) to be used. The most logical approach to assessing column performance is to employ HPLC peptide standards designed specifically for this purpose under a set of standard chromatographic run conditions. The third step involves utilizing the information obtained with the standards and any knowledge concerning the expected size, charge and polarity of the peptide fragments to select the initial mobile phase conditions for each mode of chromatography. The fourth step involves the optimization of the gradient-rate and flow-rate to provide maximum resolution in the minimum time period. A detailed explanation of these steps are included. - J. Liquid Chromatogr. 12, 139-172 (1989). Dept. Biochem. Med. Res. Counc. Canada, Gr. Prot. Struct. Funct., Univ., Edmonton, Alb. (CON)

A semiempirical model for the electrophoretic mobilities of peptides in free-solution capillary electrophoresis. P.D. Grossman, J.C. Colburn and H.H. Lauer. In this study an attempt is made to explore the effect of a peptide's size, charge, and hydrophobicity on its electrophoretic mobility (g) as measured by free-solution capillary electrophoresis with the aim of developing a semiempirical model which incorporates these effects. The effects of peptide size (which is measured by a number of amino acids in the polypeptide chain (n)) and charge on g are independently determined by experiment in a single solvent system and combined to give the relationship 5.23 x 1 0 - 4 I n ( q + 1) + 2.47x 10 .5 , ]/ ~ n0.4 3 where the constant 5.23 x 10 .4 is postulated to depend on the solvent system used. The form of Eq. was confirmed, and the values of the constants 5.23 x 10 -4 and 2.47 x 10 .5 were determined, by measuring the electrophoretic mobilities of 40 peptides varying in size from 3 to 39 amino acids and varying in charge from 0.33 to 14.0. Furthermore, the effect of noncharged neutral amino acids on mobility was investigated and shown to be present, but only as a minor perturbation on the effects of size and charge. - Anal. Biochem. 179, 28--33 (1989). Appl. Biosystems, Santa Clara, CA (USA)

A mass spectrometric technique for detecting and identifying by-products in the synthesis of peptides. S.K. Chowdhury and B.T. Chait. The utility of a new mass spectrometric technique for detecting and identifying peptide by-products produced in the synthesis of peptides is demonstrated. The technique involves three sequential steps: (1) practically nondestructive 2s2Cfplasma desorption mass spectrometric analysis of monolayer amounts of the peptide(s) of interest bound to a thin layer of nitrocellulose; (2) enzyme-catalyzed microscale chemical reaction of the surface-bound peptide(s) to produce structurally informative hydrolysis products; (3) plasma desorption mass spectrometric analysis of these hydrolysis products. The first step determines the presence and the molecular weights of unwanted by-products resulting from errors or incomplete reactions during synthesis. The subsequent two steps provide information on the precise location in the peptides where errors have occurred. In the present paper, the technique is applied to an investigation of unwanted peptide by-products associated with the use of tryptophan during stepwise solid-phase peptide synthesis. Synthetic preparations of melittin and [Bpa-8]dynorphin A ( 1 - I7) were each found to contain a major impurity with molecular weight 28 Da higher than that of the desired product. Anal. Biochem. 180, 387--395 (1989). Rockefeller Univ., New York, NY (USA) Application of free-solution capillary electrophoresis to the analytical scale separation of proteins and peptides. P.D. Grossman, J.C. Colburn, H.H. Lauer, R.G. Nielsen, R.M. Riggin, G.S. Sittampalam and E.C. Rickard.

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Biochemical and clinical analysis

The appIication of free solution capillary electrophoresis (FSCE) to the separation of protein and peptide mixtures is presented. Both qualitative and quantitative aspects of FSCE separations are considered. In addition, a brief introduction describing the separation principle behind FSCE separations and a discussion of electrophoretic mobility are included. The applications were chosen in order to highlight the selectivity of FSCE separations and to demonstrate applications of potential practical interest to the bioanalytical chemist. Comparison of FSCE relative to traditional analytical separation alternatives is stressed throughout. The examples are presented in three broad categories: protein separations, peptide separations, and the application of both to the analysis of recombinant protein products. Anal. Chem. 61, 1186 - 1194 (1989). Appl. Biosyst. Inc., Santa Clara, CA (USA)

Peptide and protein analysis by electrospray ionization-mass spectrometry and capillary electrophoresis-mass spectrometry. J,A. Loo, H.R. Udseth and R.D. Smith. The extension of mass spectrometry to high molecular weight biopolymers based upon electrospray ionization and the on-line combination with capillary electrophoresis is described. Electrospray ionization produces gas-phase intact multiply charged molecular ions of biomolecules from highly charged liquid droplets by a high electric field. For high molecular weight substances electrospray ionization results in a characteristic bell-shaped distribution of multiply charged ions, with each adjacent major peak in the spectrum differing by one charge. Multiply charged molecular ions of proteins with molecular weights greater than 130,000 have been observed with a quadrupole mass spectrometer of limited mass-to-charge range (m/z 1700). Molecular weights can be readily determined for large proteins with accuracies in the range of __+0.01 to 0.05%; at least an order of magnitude further improvement appears feasible with improved techniques and instrumentation. The electrospray ionization method is sensitive, presently requiring samples in the 100 fmol to 10 pmol range for proteins. Initial results combining rapid separations by capillary zone electrophoresis with on-line mass spectrometric detection via the electrospray ionization source are demonstrated for myoglobin and other proteins and polypeptides. The potential for extension of these methods to molecular weights on the order of 106 is discussed. - Anal. Biochem. 179, 404-412 (1989). Chem. Sci. Dept., Pacific Northwest Lab., Richland, WA (USA) A simple approach to recovery of proteins from polyacrylamide gel electrophoresis rods. R. Bhushan and K.R.N. Reddy. A simple approach to the recovery of proteins from polyacrylamide gel electrophoresis rods without using any special apparatus is reported. The recovery of proteins has been 92%. The bands from the polyacrylamide gel electrophoresis rods are cut, homogenised with sodium chloride solution and centrifuged. The supernatant is dialysed and lyophilysed. Polypeptides, snbunits and small fragments due to enzymatic hydrolysis can be easily isolated. - J. Liquid Chromatogr. 12, 529--533 (1989). Dept. Chem., Univ. Roorkee (IND) Western blots from sodium dodecyl sulfate-polyacrylamide gels stained by metal salts. D. Wang, J.K. Dzandu, M. Hussain and R.M. Johnson. Proteins separated by sodium dodecyl sulfate-gel electrophoresis can be stained in 5 rain with zinc or copper chloride. We here report that these stained but unfixed gels can be electrophoretically transferred to nitrocellulose filters and probed immunologically with the same efficiency and sensitivity as unstained gels. In this way, an immunologically defined polypeptide can be identified with a specific stained protein band on a single gel. - Anal. Biochem. 180, 311 - 313 (1989). Dept. Biochem. Ped., Wayne State Med. School, Detroit, MI (USA) Nonlinearity in protein assays by the Coomassie blue dye-binding method. A.G. Splittgerber and J. Sohl. The Coomassie brilliant blue (CBB) method for protein determination takes advantage of the fact that a low-pH red form of CBB reverts to a blue form when CBB binds to protein. The increase in absorbance at 595 nm of a protein-dye mixture compared to a blank containing only the dye reagent has been used to estimate the total amount of protein present in the sample mixture. A disadvantage of this method of protein determination is that the assay plot of absorbance at 595 nm versus total

3

Biochemical and clinical analysis

protein is not linear. - Anal. Biochem. 179, 198--201 (1989). Gustavus Adolphus College, St. Peter, MN (USA)

Luminescent immunodeteetion of western-blotted proteins from Coomassie-stained polyacrylamide gel. A. Vachereau. Immunodetection with horseradish peroxidase-linked antibodies on Coomassie-stained nitrocellulose blots can be performed efficiently and rapidly with the peroxidase substrate luminol. The luminescence produced is detected with radioautographic film. This procedure allows a direct identification of immunodetected bands of stained nitrocellulose sheets without using radiolabeled secondary antibodies. Because of its convenience and sensitivity, this method could be particularly suitable for purification of immunodetected proteins. - Anal. Biochem. 179, 206-208 (1989). Dept. Trop. Public Health, Harvard School Public Health, Boston, MA (USA) Isoeleetric points of proteins: Theoretical determination. A. Sillero and J.M. Ribeiro. Three methods for calculating the isoelectric points (p/) of proteins, provided that their amino acid compositions are known, are described. The comprehensive and abridged procedures involve solutions of polynomial equations of different degrees depending on whether pK values of the specific acid-base residues or the means of some of those values, respectively, are adopted. In the simplified procedure, approximate pI values of proteins can be determined easily with the help of calculated values, included in this paper, related to the amino acid composition of proteins. - Anal. Biochem. 179, 319--325 (1989). Dept. Bioqulm., Fac. Med. Univ. Extremadura, Badajoz (E) Identification of Dictyostelium discoideum plasma membrane proteins by cell surface labeling and quantitative two-dimensional gel electrophoresis. W.F. Patton, M.R. Dhanak and B.S. Jacobson. Plasma membrane proteins of the cellular slime mold Dictyostelium discoideum were characterized by two-dimensional polyacrylamide gel electrophoresis using a variety of labeling techniques and a microcomputer-based videodensitometer. Algorithms for the determination of molecular weights and isoelectric points were developed to aid in the comparison of polypeptides from different autoradiographs, Coomassie blue-stained gels, and Western blots. Cell homogenates were compared to plasma membranes isolated by a silica density perturbation technique and to cytoskeletons obtained by nonionic detergent extraction. Plasma membrane proteins were distinguished from subcellular contaminants by lactoperoxidase-catalyzed radioiodination, by selective labeling with N-hydroxysuccinimidyl-2-iminobiotin, and by quantitatively determining the enrichments of individual polypeptides from gels of plasma membrane proteins relative to their counterparts in gels of total cell lysate proteins. A high resolution two-dimensional gel catalog was generated containing information about plasma membrane protein orientation in the bilayer, association with the cytoskeleton, phospborylation state, glycosylation state, copy number, isoelectric point, and molecular weight. - Anal. Biochem. 179, 3 7 - 49 (1989). Dept. Biochem., Program Mol. Cell. Biol., Univ., Amherst, MA (USA) A least-squares computer method for the determination of the molecular ratio of conjugates between two different proteins from the results of the amino acid analysis. G. Antoni and R. Presentini. A method for the determination of the composition of a conjugate between two different proteins by amino acid analysis followed by leastsquares evaluation of the concentration ratio of the two components is presented. The method is based solely on calculations and avoids the use of labeled residues. A computer program, written in BASIC, is also presented to perform the calculations. - Anal. Biochem. 179, 158 - 161 (1989). Sclavo Res. Center, Siena (I) Amino acid analysis on polyvinylidene difluoride membranes. G.I. Tous, J.L. Fausnaugh, O. Akinyosoye, H. Lackland, P. Winter-Cash, F.J. Vitorica and S. Stein. A procedure for the amino acid analysis of proteins electrotransferred to polyvinylidene difluoride (PVDF) membranes is described. The proteins are first separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and then electroblotted onto a PVDF

465 membrane. After staining with Coomassie brilliant blue, the visualized protein bands are excised from the membrane. Each band is placed in a vial and subjected to gas-phase hydrolysis in 6 N HC1 in a vacuum desiccator at 110°C. The amino acids are extracted from the membrane into 0.1 N HC1/30% CH3OH and analyzed by reverse-phase HPLC using postcolumn o-phthalaldehyde-derivatizing reagent. The method was shown to give reproducible and reasonably accurate compositions for several proteins, as well as to provide an estimate of protein content. As little as 10 pmol of a 67-kDa protein can be determined. - Anal. Biochem. 179, 50--55 (1989). Center Advanced Biotechnol. Med., Piscataway, NJ (USA)

Analytical potential of protein A for affinity chromatography of polyelonal and monoclonal antibodies. B.J. Compton, M.A. Lewis, F. Whigham, J: Shores Gerald and G.E. Contryman. Protein A based rapid affinity chromatography for quantitation of various immunoglobulins of class G (IgG) is described. Three-minute analysis using either citrate or phosphate buffers and detection with 220or 280 nm UV absorption was found to be optimum for quantitation of IgG from 0.25 to 250 ~g of IgG on-column with a percent relative standard deviation (% RSD) of 2 - 3 % RSD. The method has a detection limit estimated to be 100 ng of IgG on-column. It has been used to analyze a variety of IgG-containing samples from such diverse sources as hybridoma selection, media cultivation, and purification studies. Gradient elution studies and the relationship of IgG elation to IgG isoelectric point (pI) are also described. - Anal. Chem. 61, 1314 - 1317 (1989). Ferment. Dev. Labs., Bristol-Myers Comp. Ind. Div., Syracuse, NY (USA) Determination of cyclodextrins and branched cyclodextrins by reversedphase chromatography with pulsed amperometric detection and a membrane reactor. J. Haginaka, Y. Nishimura, J. Wakai, H. Yasuda, K. Koizumi and T. Nomura. A HPLC method has been developed for the determination of cyclodextrins (CDs) and branched CDs. The method involves their separation on a reversed-phase column using a mixture of water and acetonitrile as an eluant, eluant pH modification with a cation-exchange membrane reactor surrounded by 1.5 M sodium hydroxide solutions, and pulsed amperometric detection with a gold working electrode. The calibration graphs constructed by peak height versus injected amount were linear over the ranges 50-1000 pmol. The detection limits for CDs and branched CDs were about i - 5 pmol at a signal-to-noise ratio of 3. The method was successfully applied to the assay of [3-CD in serum samples. - Anal. Biochem. 179, 336-340 (1989). Fac. Pharm. Sci., Mukogawa Women's Univ., Hyogo (J) A quantitative solid-phase assay for identifying radiolabeled glycosaminoglycans in crude cell extracts. A. Rapraeger and C. Yeaman. Extraction of radiosalfate-labeled cell layers in denaturing urea and nonionic detergent allows the quantitative binding of GAG-containing materials from up to 96 discrete samples to a single cationic nylon blot. Free sulfate and/or sulfated lipids fail to bind. Washing the blot with differential salt concentrations discriminates between native proteoglycans and free glycosaminoglycan chains or fragments. In addition, chondroitin sulfates and heparan sulfate are identified either by prior digestion with chondroitin ABC or AC lyase, as generated disaccharides fail to bind to the blot, or by treatment of the entire blot with nitrous acid following binding. Similarly, heparan sulfate can be identified on chromatograms or Western transfers from polyaerylamide gel electrophoresis by autoradiography before and after treatment of the blot with nitrous acid. - Anal. Biochem. 179, 361-365 (1989). Dept. Pathol., Univ., Madison, WI (USA) Direct N-terminal sequence analysis of rat liver plasma membrane glycoprotein separated by two-dimensional polyacrylamide gel electrophoresis. T. Benjamin, C.-H. Niu, D.C. Parmelee, A.C. Huggett, B. Yu, P.R. Roller and S.S. Thorgeirsson. Nine previously uncharacterized membrane glycoproteins from normal rat liver have been analyzed by amino acid sequencing from twodimensional polyacrylamide gel electrophoresis (2-D PAGE) after transblotting to lmmobilon-P membranes. Three of these components show

466 altered levels of expression in liver tumors. A single electroblotted polyacrylamide gel yielded sufficient quantities of these glycoproteins for amino acid sequencing asand the N-terminal structure could be determined for four of them. The remaining five glycoproteins of interest were not sequenceable in this manner, presumably because they had blocked N-termini. Prior to electrophoresis, two enrichment methods were applied to the crude liver membrane preparations: affinity chromatography with concanavalin A to isolate the plasma membranme glycoproteins and then fast protein liquid chromatography on Superose 12 to obtain components having a specific range of molecular weights. These materials were next subjected to 2-D PAGE using pH 4 - 6 carrier ampholytes in the first dimension and 7.5% sodium dodecyl sulfate gels in the second. The proteins were then electroblotted to Immobilon-P' membranes and located by staining with Coomassie Brilliant Blue R250. Our results demonstrate that N-terminal sequencing (gas-phase) can be achieved on polypeptides obtained from approximately 250 pg of total glycoproteins applied to a single 2-D gel. -- Electrophoresis 10, 447-455 (1989). Lab. Exp. Carcinogenesis, Div. Cancer Etiol., Nat. Cancer Inst., Bethesda, MD (USA)

Quantification of fibronectin in extracts of human aortae by an ELISA. L.M. Rasmussen and L. Heickendorff. Dried, defatted samples of human aortic tissue were subjected to sequential extraction with (i) 0.89% NaC1, 10 mmol/1 Tris/HC1, pH 7.4, (ii) 5 mg/ml heparin, 2 mol/1 urea and (iii) collagenase digestion. More than 75% of hexosaminercontaining molecules were solubilized by this procedure. Immunoblotting of extracted proteins separated by SDSPAGE showed that extracted fibronectin had a mobility in the same range as that of plasma fibronectin. Fibronectin ELISA performed on these extracts gave dilution curves parallel to the standard curve, the sensitivity was 2.7 gg/l. Recoveries of a fibronectin standard added to the NaC1, heparin/urea and collagenase solutions during extraction were 97%, 90% and 84% respectively. Normal aortic tissue from 31 patients was subjected to the sequential extraction scheme and fibronectin quantification in the various extracts demonstrated that 4.52 + 1.79 gg was dissolved in the NaC1 extracts, 5.41 +_ 2.28 in the heparin/urea extract and 1.08 + 0.43 in the collagenase digest, respectively, (Values are expressed as gg fibronectin/10 mg dry, defatted tissue (mean +_ SD)). Scan& J. Clin. Lab. Invest. 49, 205-210 (1989). Univ. Inst. Pathol., Dept. Clin. Chem., Kommunehosp., Aarhus C (DK) Direct determination of bound sialic acids in sialoglycoproteins by acidic ninhydrin reaction. K. Yao, T. Ubuka, N. Masuoka, M. Kinuta and T. Ikeda. A simple and rapid method for sialic acid determination in sialoglycoproteins by acidic ninhydrin reaction is described, The method is based on the reaction of sialic acids with an acidic ninhydrin reagent. By heating a sample solution containing sialoglycoprotein with the reagent at I00°C for 10 min, a stable color with an absorption maximum at 470 nm was produced. The standard curve was linear in the range of 20 gg to 3 mg of fetuin, a sialoglycoprotein, per 3.0 ml of the reaction mixture. The reaction is specific only for sialoglycoproteins among various proteins examined. The acidic ninhydrin method was applied to the determination of sialic acids in sialoglycoproteins in ascites fluids of Ehrlich ascites tumor-bearing mice. - Anal. Biochem. 179, 332-335 (1989). Dept. Biochem., Univ. Med. School, Okayama (J) Screening of steroids in horse urine and plasma by using electron impact and chemical ionization gas chromatography-mass spectrometry. A.K. Singh, B. Gordon, D. Hewetson, K. Granley, M. Ashraf, U. Mishra and D. Dombrovskis. Zum Screening von Steroiden in Pferdeurin und -plasma wird eine GC/CI-MS/SIM-Methode entwickelt. Urinproben werden mit Glucuronidase inkubiert, mit Natriumborat versetzt und mit Ethylacetat extrahiert. Nach Waschen mit 15% Na2SO4 in 1 mol/1 NaOH wird die Ethylacetatschicht mit Methoxyamin versetzt und dutch 45 rain Erhitzen bei 110°C und nachfolgenden Zusatz von BSTFA und weiteres 30 rain Erhitzen auf 120°C derivatisiert. Plasmaproben werden mit Petrolether zentrifugiert, der Extrakt eingedampft und der Rfickstand derivatisiert.

3

Biochemical and clinical analysis

Die GC-MS-Analyse erfolgt auf einer DB-5 Quarzcapillars/iule mit einem Temperaturprogramm von 150 -280°C. Ffir die CI-Ionisation wird Methan als Ionisierungsgas verwendet. Die CI-MS ist ffir die meisten Steroide empfindIicher als die EI-MS, mit Ausnahme yon Testosteron, Prednison-Metabolit-2 und Prednisolon-Metabolit-2. Mit dem beschriebenen Verfahren k6nnen verschiedene nattirliche und synthetische Steroide getrennt werden. Die Wiederfindungsrate betrfigt 75 - 85% der Steroide aus Plasma und 6 5 - 7 0 % aus Urin. - J. Chromatogr. 479, 233-242 (1989). Minnesota Racing Lab., Dept. Vet. Diagnos. Lab., Coll. Vet. Med., Univ. Minnesota, St. Paul, MN (USA) R.H.S.

Determination of HDL2 cholesterol by precipitation with dextran sulfate and magnesium chloride: Establishing optimal conditions for rat plasma. L. Sjoblom and A. Eklund. Optimal conditions for analyzing HDL2 cholesterol in small amounts of rat plasma have been studied using different concentrations of dextran sulfate and MgC12 to precipitate lipoproteins containing apolipoprotein B and/or apo E. When the MgCI2 level was 91 raM, the supernate cholesterol was rather constant at a level of about 5 0 - 60% of the total plasma cholesterol concentration. Immunochemical determination of the apo A-I content indicated that no major losses of the HDL2 fraction took place under these conditions. The recovery of about 96% of HDL2 lipoproteins after the precipitation of rat plasma and the almost complete absence of lipoproteins belonging to the VLDL, LDL and HDL1 fractions was demonstrated by agarose gel electrophoresis. Thus, the method should be suitable for screening the HDL2 cholesterol content in small volumes of rat plasma. - Lipids 24, 532-534 (1989). Dept. Med. Physiol. Chem., Univ. Uppsala (S) Ultramicro determination of 7-dehydrocholesteroi in rat skin by highperformance liquid chromatography with fluorescence detection. T. Iwata, H. Hanazono, M. Yamaguchi, M. Nakamura and Y. Ohkura. Das yon M. Yamaguchi, T. Iwata, M. Nakamura and Y. Ohkura [Anal. Chim. Acta 193, 209 (1987)] fiir Alkohole beschriebene Derivatisierungsverfahren mit 3,4-Dihydro-6,7-dimethoxy-4-methyi-3-oxochinoxalin-2-carbonylazid (DMEQ) wird bier zur Derivatisierung yon 7Dehydrocholesterin (7-DHC) eingesetzt und zu dessert Bestimmung in Haut von Ratten eingesetzt. Dazu werden die Gewebehomogenate mit 15 M KOH auf 80°C erhitzt, mit Benzol extrahiert, die organische Phase mit NaC1 und Wasser gewaschen, eingedampft, der Rfickstand wird in DMEQ-L6sung gel6st und 60 min auf I20°C erhitzt. Das Reaktionsgemisch wird nach Abkfihlung mit Methanol verdfinnt und diese L6sung durch HPLC auf einer TSK Gel ODS-120T-S/iule mit AcetonitriI/ Methanol/Wasser (80:12:8) chromatographiert. Der fiuorimetrische Nachweis der Derivate erfolgt bei 360/440 nm. Die Nachweisgrenze liegt bei 36 pmol 7-DHC pro 50 mg Gewebe und die Eichkurve ist bis hinauf zu 65,1 nmol linear. Die Wiederfindungsraten liegen zwischen 99,8 und 98,9%, die rel. Standardabweichungen werden mit 4,7% ffir freies und 5,2% fiir Gesamt 7-DHC angegeben. - J. Chromatogr. 491,404-409 (1989). Fac. Pharm. Sci., Univ., Fukuoka (J) R.H.S. Determination of serum levels of unesterified lathosterol by isotope dilution-mass spectrometry. E. Lund, L. Sisfontes, E. Reihner and I. Bjorkhem. The synthesis of 2H3-1abelled lathosterol is described. This compound was used together with 2HT-labelled cholesterol for simultaneous assay of unesterified lathosterol and cholesterol in serum by isotope dilutionmass spectrometry. After addition of a fixed amount of the two internal standards to a fixed amount of serum (in general 25 pl), the steroids were extracted with chloroform and subjected to Lipidex 5000 chromatography. The fraction containing cholesterol and lathosterol was converted into trimethylsilyl ether and subjected to MS with selected monitoring of the ions at m/z 458 and m/z 465. Individual standard curves were used for assay of each steroid. Under the conditions employed, the coefficient of variation of the two assays was less than 6%. In different recovery experiments the maximal difference between expected and found values was less than 7%. - Scand. J. Clin. Lab. Invest. 49, ~165171 (1989). Depts. Clin. Chem. Surg., Karolinska Inst., Huddinge Hosp., Huddinge (S)

3 Biochemical and clinical analysis

Quantitative determination of various hopanoids in microorganisms. H. Schulenberg-Schell, B. Neuss and H. Sahm. Ein schnelles und empfindlichesVerfahren zur Bestimmung yon Hopanoiden, pentacyclischen Triterpenoiden, die hfiufig in Prokaryoten gefunden werden, wird beschrieben. Dazu werdett die Mikroorganismen lyophilisiert, die Lipide mit Methanol/Chloroform/Wasser (2:1:0.8) extrahiert, die Lipide mit einem Gemisch yon Pyridin und Essigsfiureanhydrid durch 12 - 18 h Reaktion bei 33 °C acetyliert und dann eingedampft. Die Probe wird in Methanol unter Zusatz von 20% Acetonitril aufgenommen und die acetylierten Derivate auf einer C~8 Reversed-Phase S/iule mit einem Gradienten zwischen Methanol/Wasser/Acetonitril von 94,25 : 4,75". 1 bis 80,75 : 0,25 : 19 chromatographiert. Der UV-Nachweis erfolgt bei 206 nm. Mit dem Verfahren k6nnen Tetrahydroxybacteriophan (THBH), THBH-Ether und THBH-Glycosid bestimmt werden. Gereinigte Bacteriohopanoide werden als externe Standards verwendet. Im Bereich von 10-120 pg THBH und bis hinauf zu 200 gg THBHEther und THBH-Glycosid wird eine lineare Eichkurve erhalten. Diplopterol und Diplopten werden gaschromatographisch nach Silylierung mit BSTFA/TMSCI in Pyridin auf einer SS.ule mit 3 % OV-1 auf GasChrom Q analysiert. Im Bereich von 0,1 - 2 gg erh/ilt man bei Verwendung eines FID eine lineare Anzeige. - Anal. Biochem. 181, 120-124 (1989). Fraunhofer-Inst. Grenzfifichen-Bioverfahrenstechn.,D-7000 Stuttgart R.H.S.

High-performance liquid chromatographic analysis of steroid hormones. F. Unlfi Erko~, S. Ozsar, B. Gfiven, G. Kalkandelen and E. U~rar. In the present work, a practical, rapid, reliable and isocratic reversedphase HPLC method is described for the qualitative and quantitative analysis of estriol, estradiol-1713, estrone, testosterone, and progesterone. Chromatographic separation is complete in 16 min using a mobile phase of 50% acetonitrile (v/v) in water. The order ofelution is estriol, testosterone, estradiol-1713, estrone and progesterone; retention times are 2.5, 5.5, 5.6, 6.9, 116.3 rain, respectively. Absorbance maxima of individual steroids is the limiting factor in quantitative determination. The recommended wavelengths for UV monitoring are E3 214, E2 280, T 254, E1 214, and P4 254 nm. - J. Chromatogr. Sci. 27, 86 - 9 0 (1989). Turkish At. Energy Auth., Lalahan Nucl. Res. Inst. Animal Health, Lalahan, Ankara (TR)

Urinary oestriol-16-glucuronide determined by "on-line" liquid chromatography. U. Tiel, P. Heilmann, R. Rejaibi and M. Sch6nesh6fer. A fully automated method for the specific assessment of oestriol-16glucuronide in urine is described. "On-line" sample preparation, including enrichment, pre-purification, focusing and injection, is combined with automated HPLC separation and fluorimetric quantification. Losses of oestriol-16-glucuronide throughout the total procedure are negligible. Thus, external calibration is feasible for quantification. Coefficients of variation are 4.44% (n = 12) for intra- and 7.85% (n = 9) for interassay variability. Assay sensitivity is 430 nmol/1. The excretion rates of oestriol-16-glucuronide relative to creatinine were estimated in 85 pregnancy urines. These oestriol-16-glucuronide estimates correlated well with those of total urinary oestriol, determined by HPLC after acid hydrolysis (r=0.957). The reference ranges of oestriol-16-glucuronide for the different weeks of gestation were evaluated. Unlike the determination of total oestriol, the present method does not need an hydrolysis step. The method is therefore well suited for the biochemical monitoring of fetal well-being under emergency conditions. - J. Clin. Chem. Clin. Biochem. 27, 205 - 2 0 9 (1989). Stfidt. Krankenh. Berlin-Spandau, Abtlg. Labor-Med., Berlin (D)

Separation of C-17 fatty acid esters of 17~-estradiol by reversed-phase high-performance liquid chromatography. A. Paris, J.F. Sutra and D. Rao. Ein neues Reversed-Phase HPLC-Verfahren zur vollst/indigen Trennungder Fettsfiureester von Ostradiol wird beschrieben. Dabei wird auf einer Spherisorb ODS-2 Sfiule mit Methanol/Acetonitril (1 : 1) und Methanol/Acetonitril/Wasser (64: 30: 6) gearbeitet. Der Nachweis wird bei 280 nm im UV durchgeffihrt. Die Synthese der E2-Fetts/iureester wird beschrieben. Die Methode wird auf die Analyse nicht-polarer Stoffwechselprodukte von Ostradiol angewandt. - J. Chromatogr. 493, 367-372 (1989). I.N.R.A. Lab. Xenobiotiques, Toulouse (F)R.H.S.

467 Simultaneous measurement of prednisone, prednisolone and 6fl-hydroxyprednisolone in urine by high-performance liquid chromatography using dexamethasone as an internal standard. R.-L. Teng and L.Z. Benet. Ein HPLC-Verfahren zur Routinebestimmung von Prednison, Prednisolon und 613-Hydroxyprednisolon in Urin unter Einsatz yon Dexamethason als internem Standard wird beschrieben. Dazu werden die Urinproben nach Znsatz yon methanolischer interner Standardl6sung fiber eine Chem-Elut-Feststoffextraktions-Kartuschegegeben, die mit Ethylacetat eluiert wird. Das Eluat wird mit 0,2 mol/l NaOH gewaschen, getrocknet, eingedampft und der Riickstand in mobiler Phase aufgenommen. Diese L6sung wird auf einer Si-Sfiule mit Methylenchlorid/ Methanol/Tetrahydrofuran/Eisess;g (96,9:2,0:1,0:10,1) chromatographiert und im UV bei 254 nm nachgewiesen. Endogene Substanzen st6ren die Bestimmung nicht. Im Bereich yon 50 - 2000 ng/ml erh/ilt man lineare Eichkurven. Die Nachweisgrenzen liegen bei 50 ng/ml sowohl fiir Prednison als auch ffir Prednisolon und bei 60 ng/ml ffir 613-Hydroxyprednisolon. Die Wiederfindungsraten werden mit fiber 75% angegeben. Die Variationskoeffizienten liegen zwischen 3,3-14,2%, 2,7-12,8% bzw. 3,3-6,7% ffir Prednison, Prednisolon bzw. 613-Hydroxyprednisolon. - J. Chromatogr. 493, 421-423 (1989). Dept. Pharm., School Pharm., Univ. Calif., San Francisco, CA (USA) R.H.S.

Normal phase high-performance liquid chromatography of some prostaglandin B1 derivatives. W.F. Feely, R.V. Dorman. 15-Keto-13,14-trans-prostaglandin B1 methyl ester, 13,14-trans-prostaglandin B 1 methyl ester, 13,14-cis-prostaglandin B 1methyl ester, 13,14dihydro-prostaglandin B1 methyl ester und 13,14-dehydro-prostaglandin B~ are organic intermediates used in the synthesis of prostaglandin Bx, a polymeric derivative of 15-keto-prostaglandin B~ methyl ester. PGB x has been shown to protect laboratory animals against cardiogenic shock cerebral ischemia and hypoxia. A normal phase HPLC analysis is presented which permits the identification and quantitation of these PGB1 intermediates. - J. Liquid Chromatogr. 12, 515-527 (1989). Naval Air Dev. Cent., Warminster, PA (USA)

Purification of human chorionic gonadotropin hormone by anion-exchange high-performance liquid chromatography. [. Fellegvfiri, K. Valk6, G. VAradi, P. Bauer and M. Kramer. A HPLC method was developed for the purification of 50 mg crude human chorionic gonadotropin (HCG) hormone sample in one chromatographic run on a 250 x 10 mm SERVA DEAE Poliol-Si-500 column. During the 60-minute linear gradient of 0.05 M sodium sulfate, 0.05 M sodium hydrogen sulfate and 0.05% (v/v) acetonitrile in buffer "B" complete separation was accomplished in 40 rain. Identity and purity of the fractions were checked by SDS electrophoretic method. The eluted HCG fractions were dialyzed for 24 hours to remove the buffer salts and liophilized. The activity of the hormone did not decrease significantly during the purification procedure. - Chromatographia 27, 601-604 (1989). Cent. Res. Inst. Chem., Acad. Sci., Budapest (H)

Rapid micro isolation of thymosin ~1 from thymosin fraction 5 by reversedphased high-performance liquid chromatography. M. Badamchian, M.P. Strickler, M.J. Stone, and A.L. Goldstein. We have developed a rapid, efficient, and reproducible method for the purifcation of thymosin ~1 (T~I) from thymosin fraction 5 (TF5). This procedure can serve as a model for isolation of other biologically active peptides from TF5 in sufficient quantity for characterization. The purification procedure is based on the use of high-performance preparative/ semi-preparative and analytical reversed-phase (C 1s Delta-Pak) chromatographic columns. The HPLC retention time, pI, RIA, SDS-PAGE, and amino acid composition analysis have shown that natural, purified Tal is identical to synthetic ~1. - J. Liquid Chromatogr. 12, 845-860 (1989). Dept. Biochem., George Washington Univ., Sch. Med. Health Sci., Washington, D.C. (USA)

Chromatographic behavior of bile acids using cyclodextrin in mobile phase of high-performance liquid chromatography. K. Shimada, Y. Komine and T. Oe. The chromatographic behavior of bile acids was examined by the addition of cyclodextrin to the mobile phase of RP-HPLC. The separation of bile acids was much improved by the addition of 13-cyclodextrin.

468 The capacity factors of bile acids having a 12 ~-hydroxyl group were not so influenced but those of other bile acids were decreased sharply by the additives. The response of fluorescence labeled derivative of bile acid to a fluorescence detector was raised with an addition of cyclodextrin to the mobile phase. - J. Liquid Chromatogr. 12, 491-500 (1989). Fac. Pharmac. Sci., Kanazawa Univ., Takara-machi, Kanazawa (J) Separation of porphyrin isomers by high-performance liquid chromatography. S.W. Kennedy and A.L. Maslen. Ein Hochgeschwindigkeitsverfahren unter Verwendung einer Octadecylsilyl (3 g)-S~iule (3 cm lang) wird zur Trennung der freien Sfiuren yon Uroporphyrin I und III und Coproporphyrin I und III voneinander sowie yon Typ I Isomeren von verschiedenen anderen Porphyrincarboxylsfiuren eingesetzt. Es wird dabei mit einem Ammoniumacetat (l M, pH 5,2)/Methanol-Gradienten erst yon (30:70) his (45:55) und schliel3lich bis (90:10) gearbeitet. Der Nachweis wird fiuorimetrisch bei 365/ 624 nm durchgeffihrt. Die Trennung der Porphyrine dauert weniger als 8 min, alle 12 min ist eine neue Injektion m6glich. Die Nachweisgrenzen liegen fiir S / N = 2 flir Uroporphyrin bei 75 fmol, ffir Coproporphyrin bei 45 fmol und ffir Mesoporphyrin bei 35 fmol. Das Verfahren wird auf die Bestimmung der Porphyrinisomeren in Urin und Leber eingesetzt. J. Chromatogr. 493, 5 3 - 62 (1989). Canadian Wildlife Serv., Nat. Wildlife Res. Center, Environm. Canada, Ottawa, Ontario (CDN) R.H.S. Simultaneous determination of hemoglobin and coproporphyrin by second derivative differential spectrophotometry: application to the diagnosis of mecouium aspiration. H. Ficheux, P. Levillain, J. Francoual, R. Leluc and A. Lemonnier. Wesentliche Kennzeichen der Methode ist die Messung bzw. Registrierung des Differenzspektrums zwischen einer Probe mit neutralem pHWert (Erfassung des Hiimoglobins, weil Coproporphyrin sehr schwach absorbiert) und einer Probe, die mit Salzsfiure angesfiuert ist (starke Absorption des Coproporphyrins, Abbau des Hiimoglobins). Dabei wird auch die Absorption yon Urinpigmenten eliminiert. Die Spektren der zweiten Ableitung werden aufgezeichnet unter Verwendung eines AchtPunkt-Ableitungsfensters. Zur Analyse werden 2 Proben zuje 2 ml Urin bzw. Amnionfliissigkeit A) mit 0,2 ml 0.154 M NaC1-L6sung und B) mit 0,2 ml ].2 M HC1 gemischt und mit 1500 U/rain zentrifugiert. Dann wird das Spektrum yon B) gegen A) im Bereich 360 bis 440 nm registriert (Gilford 2600-Spectrophotometer, Hewlett-Packard 7225 B Recorder). Der Ableitungswert wird ffir H/imoglobin bei 427 nm und ffir Coproporphyrin bei 402 nm gemessen. Die Auswertung erfolgt nach der Tangenten-Methode yon T.C. O'Haver and G.L. Green (Anal. Chem. 48, 312 (1976)). Einzelheiten, insbesondere die statistische Auswertung, werden im Original beschrieben, in dem auch die Spektren abgebildet sin& Clin. Chim. Acta 182, 5 3 - 6 2 (1989). Lab. Central Biochim., Centre Hospitalier de Bic~tre, Kremlin-Bic~tre (F) A. Niemann Quantitation of methylated hemoglobin via hydrolysis of methyl esters to yield methanol. L.-S. Gan, J.S. Wishnok, J.G. Fox and S.R. Tannenbaum. Methyl esters formed by methylation of carboxylic acid groups on hemoglobin can be quantitated via GC/MS negative-ion chemical ionization analysis of the pentafluorobenzoate derivative of the methanol released from the hemoglobin upon base hydrolysis. Although the method requires extensive cleanup of extracting solvents because of the ubiquitous presence of trace levels of methanol, it is possible to quantitate adducted hemoglobin at levels as low as 4 ng per gram of hemoglobin using [13C,2H3]methy 1 alcohol as the internal standard. In principle this method can be used in humans as a dosimeter for exposure to environmental methylating or alkylating agents. - Anal. Biochem. 179, 3 2 6 - 3 3 ] (1989). Div. Toxicol., Inst. Technol, Cambridge, MA (USA) Determination of pseudouridine and 5-fluoropyrimidines in human serum by high-performance liquid chromatography with precolumn fluorometric derivatization. S. Yoshida, T. Adachi and S. Hirose. A definitive method to determine pseudouridine and 5-fluoropyrimidines was established by introducing a new fluorescent reagent, 4bromomethyl-6,7-dimethoxycoumarin, into HPLC. The reagent reacted with compounds in acetone in the presence of crystalline water-free

3

Biochemical and clinical analysis

potassium carbonate and 18-crown-6. The derivatives gave intense fluorescence having its excitation and emission maxima at 340 and 420 nm in 60% methanol (mobile phase), respectively. Under the optimum conditions, standard curves were generated from serum samples containing 0.1 - ] 0 lag/ml of 5-fluorodeoxyuridine, 0.06 - 10 gg/ml of 5-fluorouracil, 0.006-10 gg/ml of Ftorafur, and 1 - 20 gg/ml of pseudouridine, respectively (5 gl injected). This fluorometric HPLC technique was shown to be useful for the simultaneous analysis of pseudouridine estimated as a cancer marker and 5-fluoropyrimidines used as a chemotherapeutic in small volumes of serum. - Microchem. J. 39, 351 360 (1989). Kyoto Pharm. Univ., Misasagi, Yamashina-ku, Kyoto (J) Study of the simultaneous binding of ADP and ATP on coupling factor CF1 by a modification of the Hummel and Dreyer method. G. Berger, G. Girault and J.-M. Galmiche. A modification of the Hummel and Dreyer method, based on anion exchange separation is used here for the study of the simultaneous binding of ADP and ATP on spinach coupling factor CFj. This method gives the same results as gel filtration (dissociation constant and number of sites) when ADP alone is present. The extent of binding of ADP and ATP is approximately the same when mixed in equimolecular ratio, but since endogenous ADP is irreversibly bound, this nucleotide is predominant on CF t. The binding of one nucleotide is partly prevented by prelable mixing of CFa with the other nucleotide. This phenomenon occurs likely at the level of high affinity sites, where binding would not be entirely reversible, contrarily to low affinity sites. This method is of potential application for other Iigands separable by anion exchange chromatography and for other types of chromatography (reversed phase). - J. Liquid Chromatogr. 12, 535-551 (1989). Serv. Biophys., D6pt. Biol., CEN Saclay, Gif-sur-Yvette (F) A modified primer extension procedure for specific detection of DNARNA hybrids on nylon membranes. P. Kainz, M. Seifriedsberger and H.B. Strack. Alkali-fragmented total cellular RNA or some RNA fraction is hybridized to single-stranded or double-stranded M13 DNA containing the insert of interest which is immobilized on nylon membranes. Hybridized RNA is then detected by incubation of membranes with Escherichia coli RNase H and DNA polymerase I. RNase H is used for nicking the RNA in the hybrids. The resulting 3'-OH groups can subsequently be used by DNA polymerase I to synthesize a labeled complementary strand. The method described is both relatively fast and sensitive and particularly useful for screening large numbers of DNA clones for their representation in RNA populations. Using total cellular RNA as hybridization probe and single-stranded M13 DNA as "template as low as 0.25 ng of a specific mRNA was detected (Z5-fold background) when adding 1 ~LCi[3H]dCTP or 2.5 ~Ci[32P]d-CTP alternatively as radioactive precursor for the labeling reaction. The detection limit increased to 1 ng (2fold background) with denatured replicative form double-stranded M ] 3 DNA as template. - Anal. Biochem. 179, 366-370 (1989). Dept. Biochem., Inst. Gen. Biol., Univ., Salzburg (A) Chromatography of E. coil tRNA on 5 - 20 gm agarose beads. T. Srichaiyo and S. Hjert6n. Escherichia coli transfer RNAs have been separated by chromatography on 5 - 20 Ixm beads of divinylsulfone-crosslinked agarose with the use of isocratic elution combined with a negative salt gradient. For example, tRNA Leuwas resolved into six isoacceptor species and tRNA ser into four. Leucine-charged tRNA's were eluted after their corresponding uncharged isoacceptor species. By optimizing flow rate, column length and elution buffer the fractionation of tRNA could be performed within 3 hours. - J. Liquid Chroruatogr. 12, 809-826 (1989). Dept. Biochem., Biomed. Cent., Uniw, Uppsala (S) Identification of ADP-ribosylated histones by the combined use of highperformance liquid cbromatography and electrophoresis. H. Lindner, J. Wesierska-Gadek, W. Helliger, B. Puschendorf and G. Sauermann. Reversed-phase HPLC was employed for analysing mono- and oligo(ADP-ribosyl)ated histones. Under the chromatographic conditions described, the ADP-ribosylated histones showed similar retention times to the unmodified histones, although the molecular weight and the

3 Biochemical and clinical analysis charge of the proteins are significantly altered by their modification. The simultaneous elution of unmodified and labelled modified histones was detected by two types of gel electrophoresis and by autoradiography. In addition, the HPLC fractions did not display overlapping ladders of the multiply modified histones, as is commonly seen in one-dimensional electrophoretic analyses of unfractionated material. Hence individual bands could be unambiguously assigned. After in vitro labelling of isolated rat liver nuclei, the following ADP-ribosylated and unmodified histones were identified by HPLC and gel electrophoresis: histone Hi 0, four histone H1 subfractions, histone H2A.1, histone H2A.2, oxidized histone H2A.2, histone H2A.X, histone H2A.Z, histone H2B, three histone H3 variants and historic H4. -- J. Chromatogr. 472, 243-249 (1989). Inst. Med. Chem. Biochem., Univ., Innsbruck (A) Planar chromatographic techniques in the quantitative assay of enzymes. E.G. Van den Eeckhout and J.M. Coene. This review discusses the applicability of planar chromatographic techniques for the quantitative determination of enzymes. TLC, PC, and HPTLC coupled to different detection techniques such as radioactive detection and spectrophotometry are discussed. The basis of the quantitative assay in these thin layer techniques is separation of substrate from reaction product and, usually, quantitation of the formed reaction product. Different electrophoretic techniques - such as PAGE, isoelectric focusing, agarose gel electrophoresis, immunoelectrophoresis, immunoblotting electrophoresis, and electrophoresis on cellulose acetate membranes - combined with radioactive detection, specific staining and scanning, or specific staining and elution followed by spectrophotometry for the quantitative assay of enzymatic activity are discussed. Specific localization can be based on different techniques; namely, the use of labeled substrates, formation of immuno*complexes with the enzyme, or specific staining. It is evident from the presented examples that electrophoresis is the method of choice for the determination of molecules of large molecular masses (10 000 to over 100 000 daltons). J. Planar Chromatogr. 2,106-118 (]989). Fac. Pharm. Sci., Lab. Pharm. Chem. Drug Anal., State Univ., Ghent (B) Ammonia assimilating enzymes from cyanobacteria: in situ and in vitro assay using high-performance liquid chromatography. S. Marquis, F.J, Florencio and P. Candau. Bestimmungssysteme fiir Ammoniak-assimilierende Enzyme in Cyanobakterien werden entwickelt. Glutaminsynthetase, Glutamatsynthase und Glutamindehydrogenase k6nnen leicht in situ bestimmt werden oder, nachdem die Zellen fiir Reagentien durchlS.ssig gemacht wurden, auch in vitro. Das Verfahren beruht auf der quantitativen Bestimmung yon Glutamin oder Glutamat nach Trennung der o-Phthaldialdehydderivate durch Reversed-Phase HPLC auf einer C18-S/iule mit 20 mM Natriumphosphatpuffer (pH 6,5) + 22% Methanol und 2% Tetrahydrofuran. Der Nachweis kann bei 338/425 nm ausgeftihrt werden. Dieses schnelle, empfindliche und st6rungsfreie Verfahren kann auch in triiben Proben in situ fiir alle Enzyme aus Cyanobakterien, die entweder Glutamin und/oder Glutamat bilden oder verbrauchen, eingesetzt werden. Anal. Biochem. 180, 152-157 (1989). Dept. Bioquim. Veg. Biol. Mol., Univ. Sevilla, Inst. Bioquim. Veg. Fotosynth., Sevilla (E) R.H.S. Isolation and identification of acetyl-CoA carboxylase from rainbow trout (Salmo gairdneri) liver, J.M. McKim, Jr., H.W. Schaup, K. Marien and D.P. Selivonchick. Acetyl-CoA carboxylase is the pivotal enzyme in the de novo synthesis of fatty acids and is the only carboxylase with a biotin-containing subunit greater than 200,000 daltons. The biotin moiety is covalently linked to the active site and has a high affinity (Ka = 10 -15 M) for the protein avidin. This relationship has been used in previous studies to identify acetyl-CoA carboxylase isolated from mammalian species. However, acetyl-CoA carboxylase has not been isolated and characterized in a poikilothermic species such as the rainbow trout. The enzyme was isolated using two distinct procedures - polyethylene glycol precipitation and avidin-Sepharose affinity chromatography. Identification of the isolated protein as acetyl-CoA carboxylase was made by the following: (1) sodium dodecyl sulfate-polyacrylamide gel electrophoresis; (2) avidin binding; (3) in vivo labeling with [l~C]biotin; and (4) acetyl-CoA carboxylase-specific activity. The subunit molecular weight of the major

469 protein was 230,000 daltons ± 3,3%. This protein was shown to bind avidin (Mr = 16,600) prior to sodium dodecyl sulfate-polyacrylamide gel electrophoresis, indicating the presence of biotin. - Lipids 24, 1 8 7 192 (1989). Dept. Food Sci., State Univ., Corvallis, OR (USA) Indicator assay for amino acid decarboxylases. R.M. Rosenberg, R.M. Herreid, G.J. Piazza and M.H. O'Leary. Glutamatdecarboxylase und Arginindecarboxylase k6nnen als Mo~ dellsubstanzen ffir Aminos/iuredecarboxylasen mit Hilfe eines einfachen Indikator-Verfahrens bestimmt werden. Die Bestimmung beruht auf der Tatsache, dab die Decarboxylierung zu einer Absorption eines Protons im pH-Bereich maximaler enzymatischer Aktivit/it ffihrt. Die Messung der Anderung der Absorption eines Sfiure-Base-Indikators kann zur Verfolgung der enzymatischen Reaktion eingesetzt werden. Fiir Glutamatdecarboxylase werden die Messungen bei 37°C in 0,1 M Pyridinpuffer (pH 4,9), welches 0,025 M Glutamat und 0,07 M C1- enth/ilt, durchgeffihrt. 1,1'-Diethyl-2-2'-cyaniniodid wird als Indikator verwendet. Arginindecarboxylase wird bei 37°C in 0,05 M Acetatpuffer (pH 5,0) unter Zusatz yon 0,025 M Arginin und Bromkresolgrfin als Indikator bestimmt. Die Absorptionsfinderung ist linear, wenn der pK-Wert des Indikators mit dem des Puffers/ibereinstimmt. - Anal. Biochem. 181, 5 9 - 6 5 (1989). Dept. Chem. Biochem., Univ. Wisconsin, Madison, Wl (USA) a.H.S. Rapid high-performance liquid chromatographic separation of barley malt •-amylase on eyclobond columns. C.A. Henson and J.M. Stone. A procedure for separation of ~- and 13-amylases was developed with results in their complete resolution in less than 20 min. A cyclodextrin stationary phase column was equilibrated in 10 mM phosphoric acid at pH 7.0. Purified barley malt a- or 13-amylases, mixtures of both, or crude malt extracts were injected. [3-Amylase did not bind to the column and was rapidly eluted with water or buffer, a-Amylases specifically bind to the immobilized dextrin. Optimal elution of a-amylase was achieved with a 10 ml gradient from 0 mg/m113-cyclodextrin (cycloheptaamylose) in buffer to 12 mg/ml [3-cyclodextrin in 15 % aqueous methanol, followed by flushing with 20 ml of 12 mg/ml [3-cyclodextrin in 15% aqueous methanol. Elution buffer containing [3-cyclodextrin at pH values from 6.0 to 7.0 was not as effective in eluting a-amylase as was cyclodextrin in aqueous methanol. Inclusion of methanol in the gradient resulted in enhanced recoveries of s-amylase, a-Amylase did not bind to the column at pH values higher than 7.0. This procedure should be useful for rapid separation of plant ~- and [3-amylases, separation of pullulanases or debranching enzymes from other carbohydrases, and purification of aamylases. - J. Chromatogr. 469, 361 - 367 (1989). U.S.D.A. Agric. Res. Serv., Cereal Crops, Res. Unit, Dept. Agron. Univ., Madison, WI (USA) The quantitation of biotinidase activity in dried blood spots using microtiter transfer plates: Identification of biotinidase-deficient and heterozygous individuals. D.A.D. Pettit, P.S. Amador and B. Wolf. A simple and rapid method for the quantitation of biotinidase activity in blood-soaked filter paper spots was developed. The assay measures the release of p-aminobenzoate from N-biotinyl-p-aminobenzoate. A microtiter transfer plate is used to rapidly separate the reaction solution from the filter paper spots. Color is developed and the absorbance is determined using a microplate reader. The biotinidase activity in frozen filter spots correlates well with the activity in serum (r=0.94). The enzyme activities of obligate heterozygotes for biotinidase deficiency were significantly different from those with normal activity (P=0.03). This rapid screening procedure can be used to quantitate biotinidase activity in newborn screening samples, identify heterozygotes, and estimate the gene frequency and incidence of biotinidase deficiency in large populations. In addition, the use of microtiter transfer plates can be applied to other assays in which the separation of the incubation solution from a filter paper spot is required. - Anal. Biochem. 179, 3 7 1 - 374 (1989). Dept. Human Genetics Med. College, Richmond, VA (USA) Bioluminescent assays using glucose-6-phosphate dehydrogenase: Application to biotin and streptavidin detection. B. T~rouanne, M. Bencheick, P, Belaguer, A.-M. Boussioux and J.-C. Nicolas. A streptavidin-glucose-6-phosphate dehydrogenase (G6PDH) conjugate was synthesized and its properties were studied, along with those

470 of biotin-G6PDH conjugates. Two bioluminescent assays were used. Streptavidin was assayed in two steps: streptavidin samples were first incubated with a small amount of biotin-G6PDH and then with biotinylated rabbit 7-globulins. The complex was immobilized on a bioluminescent immunoadsorbent. In the single-step biotin assay, free biotin was allowed to compete with biotin linked to rabbit 7-globulins for binding to streptavidin-G6PDH in the presence of the bioluminescent immunoadsorbent. Neither assay required washing or separation steps and the sensitivity was 0.2 ng for streptavidin and 100 fg for biotin. Different applications are described: studies of biotin reactivity when linked to probes in solution or immobilized, and quantitation of biotin in biotinylated DNA probes and oligonucleotides. - Anal. Biochem. 180, 4 3 - 4 9 (1989). INSERM Unit~ 58, Montpellier (F) A chromogenic assay for catecholoxidases based on the addition of Lproline to quinones. L.M. Rzepecki and J.H. Waite. The coupling reaction between L-proline and the quinone products of the oxidation of various catechols serves as a sensitive assay for catecholoxidases. The chromogenic products, 4-N-prolyl-o-quinones, were unique and stable over the course of the reaction. The spectra of these adducts typically had two absorbance maxima, in the ranges 309 340 and 5 2 6 - 540 nm. Assay conditions in which the oxidation of catechols was rate limiting were developed, and initial rates of reaction, monitored spectrophotometrically at the ~-m,x of the adducts, showed improved initial linearity when compared with the direct spectrophotometric determination of quinone formation. The molar extinction coefficients (~) of a number of adducts ranged between 5310 and 9630 M - l c m ~, about five- to sevenfold greater than those of the corresponding quinones. Since 2 mol catechol must be oxidized to their quinones to generate 1 mol of adduct, this assay improves catecholoxidase detection sensitivity by approximately three- to fourfold compared with direct estimation of quinone formation. - Anal. Biochem. 179, 375-381 (1989). College Marine Studies, Univ., Lewes, DE (USA) A highly sensitive, mixed-phase assay for chloramphenicol acetyltransferase activity in transfected cells. D.A. Nielsen, T.-C. Chang and D.J. Shapiro. Using our modifed reaction conditions and the mixed phase assay, less than 0.000010 unit of chloramphenicol acetyltransferase (CAT) activity in transfected cells can be reliably detected. The mixed-phase assay is based on the inability of the polar [3H]-acetyl-Coenzyme A (CoA) substrate to partition out of a urea containing aqueous phase into the nonpolar scintillation fluor, while the [3HJchloramphenicol reaction products partition into the toluene scintillation fluor and are quantitated by scintillation counting. The increased sensitivity of this assay is due to the optimization of the acetyl-CoA concentration, to a urea-containing aqueous phase which lowers the assay background, and to the use of extract blanks. The mixed-phase assay is simpler, is quantitative, uses less costly substrates, and is far more sensitive than the most widely used CAT assays, which require solvent extraction followed by thin-layer chromatography to separate the unreacted substrate from product. Anal. Biochem. 179, 1 9 - 2 3 (1989). Dept. Biochem., Univ., Urbana, IL

(USA) Semimicrotitration device for cholinestcrase assay. L. Kamarid and S. Oman. A semimicrotitration device for reaction volumes of 0.5 to 2 ml and effective stirring of reaction solution or suspension is described. The principal part of the device is a combined glass electrode functioning as a reaction vessel (combined "cup"-glass electrode). Characteristics of the device are small volumes and great reliability. Nonspecific cholinesterase activities measured in rat plasma and liver tissue homogenates and compared with the activities of the same tissue and plasma samples measured radiometrically and spectrophotometrically illustrate the applicability of the device. The method is best suited for kinetic studies with multiple substrates of esterases, either in the soluble form or in tissue homogenates. - Anal. Biochem. 179, 120--123 (1989). Inst. Pathophysiol. Med. Fac., Ljubljana (YU) Spectrophotometric assay for the condensing enzyme activity of the microsomal fatty acid chain elongation system. M.N. Nagi, L. Cook, S.K. Suneja, P. Osei and D.L. Cinti.

3

Biochemical and clinical analysis

The intermediate product of the condensation reaction is the 13ketoacyl CoA which exists in two tautomeric forms, i.e., keto and enol. The addition of bovine serum albumin (BSA) to a cuvette cell containing a 13-ketoacyl CoA derivative resulted in the formation of a 303-nm absorbance peak, characteristic of enolate formation. The 13-ketoacyI CoAs with carbon chain length of 6 to 18 interacted with BSA to produce the 303-nm peak; acetoacetyl CoA was the only 13-keto compound tested which did not interact with BSA to produce the peak. Other compounds which were unaffected by BSA included CoA, free 13-keto acid, 13hydroxyacyl CoA, acyl CoA, trans-2-enoyl CoA, and malonyl CoA. BSA could not be replaced by ovalbumin; furthermore, denatured (boiling) BSA could not induce the 303-nm peak. The specifc activity of the condensing enzyme measured by the spectrophotometric method compares favorably with the activity obtained by the radioactive method. Anal. Biochem. 179, 251-261 (1989). Dept. Pharmacol., Univ. Health Center, Farmington, CN (USA) Determination of dehydrogenase substrates by Clark-type oxygen electrodes and photosensitized coenzyme oxidation. J. Polster and H.-L. Schmidt. Die photosensitierte Oxidation yon NADPH durch Sauerstoff kann zur Bestimmung von reduzierten Coenzymen mit Hilfe einer Clarkschen Sauerstoffelektrode benutzt werden. So lassen sich, nach Kopplung mit enzymkatalysierten Dehydrogenierungsreaktionen Glucose-6-phosphat mit G-6-P-Dehydrogenase und Glucose mit einem kombinierten ATP/ Hexokinase/-G-6-P-Dehydrogenase-System, auch unter Einsatz immobilisierter Mediatoren (z. B. Azur A, silanisiert und anschliel3end mit Natriumborhydrid reduziert), bestimmen. Reaktionsschemata und Sauerstoffverbrauchskurven sind abgebildet. - Talanta 36, 864-866 (1989). Lehrst. Allg. Chemic Biochemie, D-8050 Freising-Weihenstephan W. Czysz A high-performance liquid chromatography method for the simultaneous assay of diaminopimclate epimerase and decarboxylase. A.N.C. Weir, C. Bucke, G. Holt, M.D. Lilly and A.T. Bull. Ein empfindliches und vergleichsweise einfaches Verfahren zur Bestimmung von Diaminopimelat(DAP)-decarboxylase, welches gleichzeitig die DAP-Epimerase-Aktivit~t mil3t, wird beschrieben. Als Substrat wird meso-DAP eingesetzt und die Reaktionsprodukte LL-DAP und L-Lysin werden mit o-Phthaldialdehyd derivatisiert und durch HPLC auf einer Spherisorb Cta ODS-S/iule mit einem linearen Gradienten von 3 0 % 70% Methanol in 50 mmol/1 Na-Acetatpuffer (pH 5,9) chromatographisch getrennt. Der fluorimetrische Nachweis der Derivate erfolgt bei 340/455 nm. Mit dem Verfahren k6nnen Picomolmengen yon Substrat und Produkten getrennt und bestimmt werden. - Anal. Biochem. 180, 298 - 302 (1989). Inst. Biotechnol. Studies, Univ. Kent Canterbury, Kent (GB) R.!4.S. A spectrophotometric assay for the cyclization acitivity of cyclomaltohexaose (~-cyclodextrin) glucanotransferase. A. Lejeune, K. Sakaguchi and T. Imanaka. Ein empfindliches und reproduzierbares Verfahren zur Bestimmung von Cyclomaltohexaose (~-Cyclodextrin) wird beschrieben. Es beruht auf der Bildung eines EinschluBkomplexes zwischen Cyclodextrin und Methylorange bei niedrigen pH-Werten (pH 1,2) und niedrigen Temperaturen (16°C) und kann zur Bestimmung der Aktivit/it von CyclodextrinGlucanotransferase eingesetzt werden. Die Bildung des Einschlul3komplexes verursacht eine Abnahme der Absorption der MethylorangeL6sung, die bei 505 nm beobachtet werden kann. Die Abnahme der Absorption ist der Cyclomalatohexaose-Konzentration im Dichtebereich von 0,25 nnd 0,30 mM Cyclomalatohexaose linear zuzuordnen. Die Spezifizit/it des Verfahrens ist gut, lineare Oligosaccharide und andere Cyclodextrine st6ren nur wenig, Cyclomaltoheptaose und Cyclomaltooctaose verursachen Absorptions/inderungen von 16 bzw. 5%. Die Komplexbildung erfolgt so fort, der Komplex ist bei konstanter Temperatur best/indig. Methylorange hat keinen negativen Einflul3 auf die Enzymaktivitfit. Die Reaktion kann durch Zusatz von Sfiure abgestoppt werden. Dieses einfache colorimetrische Verfahren kann ffir verschiedene Cyclohaltohexaose-Glucanotransferase-Enzyme eingesetzt werden. Anal. Biochem. 181, 6 - 1 1 (1989). Dept. Ferm. Technol., Fac. Engin., Univ., Osaka (J) R.H.S.

3 Biochemical and clinical analysis

Detection and characteristics of DNA polymerase activity in serum from patients with malignant, viral, or B12-deficiency disease. M. Nemnuller, C.F.R. K/illander and J.S. Gronowitz. Using the current procedure, the activity was only detected in sera with pathological levels of thymidine kinase, i.e. no reference level of DNA polymerase activity in healthy individuals could be established. The activity detected for all three types of disease was similar to that of proliferation-associated DNA polymerase ct, both with respect to sensitivity to different chemical inhibitors and to inhibition by monoclonal antibody. The levels of activity o f D N A polymerase and thymidine kinase showed a wide variation and were not significantly correlated when all DNA polymerase-positive sera were included in the analysis. The variation in the ratio of polymerase to kinase activity within a given disease was smaller and the distribution of the enzyme ratios induced by the three types of disease differed significantly. Considering that DNA polymerase activity can be quantitated directly in crude sera, and that such analyses seems to give biological and clinical information, the development of an assay with improved sensitivity for extensive studies is justified. - Enzyme 41, 6 - 1 6 (1989). Dept. Med. Virol., Biomed. Cent., Univ., Uppsala (S) Separation and purification of porcine pancreatic enzymes by serial operation of ion-exchange and affinity columns. S.Y. Huang and C.H. Lin. Elastase and Trypsin aus Schweinepankreas, die sich chemisch und physikalisch sehr/ihneln, k6nnen fiber 13 cm lange CM-Sepharoses/iulen (schwacher Anionenaustauscher, Pharmacia) uud eine nachgeschaltete 7 cm lange Chitin-Hfihnerovomucoid-Affinit/itss/iule getrennt werden. Die erste S/iule adsorbiert beide Enzyme bei pH 4,5 und desorbiert sie bei pH 9 und hoher Ionenst~irke. Die Affinit/itssfiule adsorbiert Trypsin bei pH 8 und desorbiert dieses bei pH 2,5. Die Detektion erfolgte bei 280 nm, die Elastase- und Trypsintests sowie die Gradientenprogramme werden ausftihrlich beschrieben. Die Methode ist zeitsparender als bisher fibliche Verfahren, die Anreicherung betr/igt das 1 6 - 22fache, die Wiederfindung 25 bzw. 90%. - Chromatographia 27, 449 454 (1989). Dept. Chem. Eng., Nat. Taiwan Univ., Taipei, Taiwan (RC) F. Kreuzig A radioactive method for the measurement of trypsin and trypsin-like activities. P.F. Murray, S. Silberstein, M.L. Cantore and S. Passeron. A simple and highly sensitive method for the assay of trypsin has been developed by making use of the phosphorylated synthetic peptide LeuArg-Arg-Ala-Ser@2P)-Leu-Gly as substrate. The technique has been adapted from the phosphocellulose method of R. Roskoski, Jr. (in Methods in Enzymology, J. Crobin and J. Hardman, Eds., Vol. 99, 3 6, Academic Press, New York) used for measuring of protein kinases. In addition to measuring the activity of trypsin at the microgram level, the 32p-labeled peptide method can be used for measuring other trypsinlike enzymes. It has been successfully utilized for the identification of a new peptidase from the fungus S a c c o b o l u s p l a t e n s i s . - Anal. Biochem. 179, 5 6 - 5 9 (1989). Dept. Quire. Biol., Fac. Cie. Exactas y Naturales, Univ. Buenos Aires (RA) Rapid turbidimetric determination of lipase activity in biological fluids. P i . Arzoglon, A. Tavridou and C. Balaska. Zur Bestimmung der Aktivitfit von Lipase wird eine turbidimetrische Methode entwickelt. Als Substrat dient eine Trioleinemulsion mit Isopropanol in Glycinpuffer, in das die Probe, Serum- oder PankreassaftLipase eingebracht wird. Nach dem Mischen mif3t man die Ver/inderung der Extinktion des Gemischs bei 340 nm wfihrend 2 min. Ausgewertet wird mit HiKe eines Standards, bei dem die Extinktionsabnahme pro Minute als Faktor eingeffihrt wird. Eine Einheit Lipase ist definiert als die Menge des Enzyms, die die Hydrolyse von 1 gmol Triolein/min bei 30°C unter den Bedingungen der Analyse hydrolysiert. Die within-runPrfizision (CV) betrfigt 5,2%, die day-to-day-Pr~izision 7,3% ffir Enzymaktivit/iten um 400 E/1. Der Linearbereich liegt zwischen 60 nnd 780 E/ 1, die Nachweisgrenze bei 18 E/I. Durch Einsatz yon Colipase, Natriumtaurodesoxycholat und CaC12 in der Substratl6sung kann die Spezifit/it und analytische Empfindlichkeit des Verfahrens verbessert werden. Anal. Lett. 22, 1459-1469 (1989). Lab. Biochem., School Chem., Univ., Thessaloniki (GR) W. Czysz

471

Rapid analytical and preparative affinity chromatography, using resinbound heparin to resolve bile salt stimulated lipase from human milk whey. D.J. Gisch, T.S. Reid, J.S. Swan and J. Cheng. Zur Bestimmung bzw. Isolierung von durch Gallensalze stimulierter Lipase, welche die Fettverwertung verbessert, wurden zwei affinit/itschromatographische Methoden entwickelt. Analytische Trennung: Progel-TSK-Heparin 5PW-S/iule (75 x 7,5 mm, Supelco). Der Gradient (A: 20 mM Tris pH 7,5, B: 0,1 M NaC1, 20 mM Tris pH 7,5) wurde von 100% A fiber 20 min mit 1 ml/min gefahren, dann in gleicher Weise auf 100% A, )~quilibrierung 15 min. 100 gl surden eingespritzt, Messung bei 280 nm. Als pr/iparative S/iule diente eine AF Heparin-Toyopearl 650 M-Supelco (30 x 2,5 cm), der Gradient wie zuvor wurde mit 2 ml/min gefahren: 100%A 30 min, auf 0%A in 60 min und 60 min verbleibend, auf 100%A in 0,1 rain, 60 rain 5,quilibrieren. Einspritzmenge 15 ml. Die Retentionszeiten betragen 13 bzw. 120 min. Das neue Sorbens verffigt fiber hohe chemische und mechanische Stabilit/it. - J. High Resolut. Chromatogr. 12, 258-260 (1989). Supelco, Inc., Bellafonte, PA (USA) F. Kreuzig Improved separation of human pepsins from gastric juice by high-performance ion-exchange chromatography (HPIEC). K. Peek, N.B. Roberts and W.H. Taylor. Ein einfaches und genaues Verfahren zur Trennung der einzelnen Pepsine in Magensaft wird beschrieben. Dazu werden die Proben gegen 50 mM Natriumacetat (pH 4,1) dialysiert und dann nach Filtration direkt auf das HPIEC-System injiziert. Es wird auf einer TSK DEAE 5PW Ionenaustauschs/iule unter Vorschaltung einer TSK-Gel DEAE 5PW-Schutzs/iule gearbeitet. Die Elution der Pepsine erfolgt mit eincm linearen binfiren Gradienten aus 50 mM Natriumacetat (pH 4,1) und 50 mM Natriumacetat (pH 4,1) unter Zusatz yon 1 M NaC1. Durch direkte Messung der Proteinabsorption bei 280 nm k6nnen die Pepsine quantitativ bestimmt werden. Das Verfahren wird auf die Untersuchung von Magensfiften von Patienten mit Magengeschwfiren eingesetzt. - J. Chromatogr, 476, 291 297 (1989). Dept. Chem. Pathol., Royal Liverpool Hosp., Liverpool (GB) R.H.S. Visualization of acid phosphatase activity on nitrocellulose filters following electroblotting of polyacrylamide gels. A.K. Kanellis, T. Solomos and A.K. Mattoo. A method for visualizing acid phosphatase isoenzymes by activity staining on nitrocellulose filters after electroblotting of proteins fractionated on nondenaturing polyacrylamide gels is described. Reproducible results were obtained when 25 mM Tris-192 mM glycine was used as the transfer buffer instead of 0.7% acetic acid, 50 mM sodium acetate, pH 4, or 0.14 M acetic acid/0.35 M [3-alanine, pH 4.3. Dot-blot analysis of banana fruit extracts on nitrocellulose filters revealed that a minimum of 5 x 10 .3 units (nmol p-nitrophenyl phosphate hydrolyzed/g, h) of acid phosphatase activity can be detected. This method can be suitable for screening a large number of biological samples for monitoring acid phosphatase activity. -- Anal. Biochem. 179, 194-197 (1989). Dept. Hortieul., Univ., College Park, MD (USA) Dual-enzyme cascade-an amplified method for the detection of alkaline phosphatase. P.D. Mizc, R.A. Hoke, C.P. Linn, J.E. Reardon and T.H. Schulte. A method in which a two-enzyme cascade is used for rapid and sensitive detection of alkaline phosphatase is described. A masked inhibitor, 4-(3-oxo-4,4,4-trifluorobutyl)phenyi phosphate, is dephosphorylated by the action of alkaline phosphatase. The resulting compound, l,l,l-trifluoro-4-(4-hydroxyphenyl)-butan-2-one, acts as a potent inhibitor of the second enzyme, a liver carboxylesterase. A determination of the residual esterase activity provides a highly sensitive indication of the original phosphatase concentration. The sensitivity of this dual-enzyme cascade is approximately 125-fold greater than that observed for the direct detection ofphosphatase activity withp-nitrophenyl phosphate. Anal. Biochem. 179, 229-235 (1989). Becton Dickinson Res. Center, Research Triangle Park, NC (USA) Detection of proteinase inhibitors in fractions after liquid chromatography. I. Safa~ik.

472 A technique for rapid detection of proteinase inhibitors in fractions after liquid chromatography is described. Aliquots of the tested solutions are placed onto a thin layer of gelatin, crosslinked with glutardialdehyde in the presence of water soluble nigrosin, to form small drops. A proteinase solution is added to the above-mentioned drops and the plate is incubated at ambient temperature for approximately 1 5 - 25 min. After the gelatin layer is washed with water the inhibitor negative fractions are visualized as colorless zones on a blue background. With inhibitor positive fractions no change of gelatin layer occurs. - Anal. Biochem. 179, 349-351 (1989). Lab. Anal. Chem., South Bohemian Biol. Centre, Cesk~ Bud~jovice (CS)

An assay for superoxide dismutase activity in mammalian tissue homogenates. D.R. Spitz and L.W. Oberley. During the course of measuring superoxide dismutase (SOD) activity in rat breast tissue, interferences in the nitroblue tetrazolium (NBT) and cytochrome c assay systems were noted. These interferences inhibit accurate measuremer~t of SOD activity in breast tissues, necessitating the development of a new NBT-based assay that includes compounds capable of inhibiting tissue specific interferences. The most effective compounds were metal chelators that were also electron transport chain inhibitors. Bathocuproine sulfonate (BCS) was the most effective of these compounds. The inclusion of BCS in the NBT assay system was shown to make the accurate measurement of SOD activity in tissues with interferences possible. - A n a l Biochem. 179, 8 - 1 8 (1989). Radiation Res. Lab., Med. Labs., Univ., Iowa City, IA (USA) Analysis of urokinase by HPLC. Y. Yamasaki and Y. Kato. Urokinase, ein thrombolytisches Enzym, existiert in hochmolekularer (MW = 54000) und niedermolekularer Form (MW = 32000). Beide Urokinase-Formen werden durch Ionenaustausch-Chromatographie (IEC), Hydroxy-Apatit-Chromatographie (HAC) und Chromatographie mit hydrophoben Wechselwirkungen (HIC) reproduzierbar aufgetrennt, wobei ihre biologische Aktivit/it erhalten bleibt. HAC gibt am besten die Komponenten innerhalb jeder Urokinase wieder. - J. High Resolut. Chromatogr. 12, 2 5 6 - 257 (1989). Central Res. Lab., Tosoh Corp., 4560 Tonda, Shinnanyo-shi, Yamaguchi (J) W. Asche High-performance liquid chromatographic method for a clozapine analogue, CGS 13429, and its N-oxide and desmethyl metabolites. J.P. Chovan and J.D. Vermeulen. CGS 13429, ein Clopazinanaloges, welches zur Zeit als antipsychotischer Wirkstoff klinische Versuche durchlfiuft, kann aus Ratten- und Hundeplasma nach Zusatz eines strukturverwandten internen Standards fiber eine BondElut Cts-S/iule extrahiert werden. Nach Waschen mit Wasser und Wasser/Methanol (8:2) wird mit Methanol eluiert. Der Rfickstand des eingedampften Extraktes wird in mobiler Phase aufgenommen und auf einer Supelcosilsfiule unter Vorschaltung einer analogen Schutzsfiule mit einem linearen Methanolgradienten in Wasser/Methanol + 5 mmol/1 Natriumheptansulfonat, 0,5% Eisessig und 0,5% Triethylamin (pH 4) als mobiler Phase chromatographiert. Der Nachweis kann bei 280 nm im UV ausgeffihrt werden. Im Bereich von 1 0 0 5000 ng/mI erh/ilt man eine lineare Eichkurve. Die Nachweisgrenze wird mit 40 ng/ml (S/N = 3) bei Verwendung von 200 gl Extrakt angegeben. J. Chromatogr. 494, 413-419 (1989). Preclin. Drug Metabolism, Res. Dept., Pharm. Div., Ciba-Geigy Corp., Ardsley, NY (USA) R.H.S. Determination of alprazolam in serum by adsorptive stripping voltammetry. A.H. Rajab Habeeb, J. Rodriguez Procopio and L. Hernandez Hernandez. The surface-active properties of alprazolam at a hanging mercury drop electrode allow their sensitive determination by differential-pulse adsorptive stripping voltammetry. Detection limits are 0.07 ng/ml for accumulation in water (accumulation time 240 s) and 0.3 ng/ml for accumulation in serum extract (accumulation time 30 s). Coefficients of variation at 5 ng/ml (10 determinations) were typically < 2 % . Microchem. J. 39, 247-252 (1989). Dept. Chem., Anal. Chem., Fac. Sci., Univ. Autdnoma, Madrid (E) Determination of an oxadiazole-substituted 1,4-benzodiazepine in plasma by high-performance liquid chromatography with ultraviolet detection and by radioreceptor assay. L. Nordholm and H. Mengel.

3

Biochemical and clinical analysis

Ein HPLC-Verfahren zur Bestimmung eines neuen Oxadiazol-substituierten 1,4-Benzodiazepins [3-(5-Cyclopropyl-l,2,4-oxadiazol-3-yl)-5,6dihydro-5-methyl-6-oxo-4H-imidazo[1,Sa]-[1,4]benzodiazepin], welches eine bessere Trennung zwischen anxiolytischen Eigenschaften nnd Nebeneffekten als bisher bekannte Benzodiazepine aufweist, wird entwikkelt. Zur Bestimmung in Plasma wird nach Zusatz eines internen Standards auf einer Bond-Elut C1 s-Extraktionss/iule extrahiert. Es wird mit Methanol eluiert, die Extrakte werden mit Wasser verdfinnt und auf einer Lichrospher RP-18-S/iule mit 30 % AcetonitriI in 0,013 moI/1Natriumphosphatpuffer (pH 7,0) bei 55°C analysiert. Der Nachweis erfolgt bei 244 nm im UV. Die Ergebnisse werden mit solchen verglichen, die mit einem Radioreceptor-Verfahren nach J. Lund [Scand. J. Clin. Lab. Invest. 41,275 (1981)] erhalten wurden. Die Ergebnisse beider Verfahren stehen in guter Ubereinstimmung. Die Nachweisgrenzen werden mit ca. i ng/ml (S/N = 3) angegeben. Das HPLC-Verfahren kann in einem gr613eren Konzentrationsbereich eingesetzt werden, w/ihrend das Radioreceptorverfahren ffir toxikologische Untersuchungen bevorzugt wird. - J. Chromatogr. 494, 257-265 (1989). Dept. Drug Metabolism Pharmacokin., Ferrosan Res. Div., DK-2860 Soeborg (DK) R.H.S.

Determination of buspirone and 1-(2-pyrimidinyl)piperazine in plasma samples by high-performance liquid chromatography. A. Diaz-Marot, E. PuigdellivoI, C. Salvatella, L. Comellas and M. Gassiot. Das dibasische psychotrop wirkende Buspiron, welches gegen Angstzustfinde eingesetzt wird, sowie sein wichtigstes Stoffwechselprodukt, das 1-(2-Pyrimidinyl)piperazin, k6nnen gleichzeitig mit Hilfe eines HPLC-Verfahrens bestimmt werden. Dazu werden die Plasmaproben mit 1-Phenylpiperazin als internem Standard und Boratpuffer (pH 10) versetzt. Dann wird mit Chloroform/Acetonitril (8:2) extrahiert. Die abzentrifugierte organische Phase wird eingedampft, in mobiler Phase aufgenommen und auf einer 5 gm Spherisorb CN-S~iule unter Vorschaltung einer CN/Corasil-S~iule mit Methanol/KH=PO4-Puffer (5 raM) pH 7,4 (35:65) chromatographiert. Der Nachweis wird bei 254 nm durchgeffihrt. Die Wiederfindungsraten liegen in 100 ng/ml Bereich ffir Buspiron bei 73 __4%. Eichkurven sind yon 5 - 5 0 0 ng/ml linear. Die Nachweisgrenze wird ffir beide Verbindungen ffir S/N = 10 mit 5 ng/mI angegeben. Die Methode wird ffir pharmakokinetische Untersuchungen eingesetzt. - J. Chromatogr. 490, 470-473 (1989). Secc. Anal. Dept. Invest., Lab. FIDES, Barcelona (E) R.H.S. High-performance liquid chromatographic determination of trans-doxepin and desmethyldoxepin. C. Dilger, Z. Salama and H. Jaeger. Zur HPLC-Bestimmung der o.g. Substanzen aus Humanplasma wird 1 ml von diesem nach Auftauen bei 21°C mit 100 gl 1N NaOH-L6sung, 100 pl Perazin-L6sung (Promonta, Hamburg) als interner Standard und 3 ml n-Hexan/Ether (50: 50) versetzt, 30 rain lang geschfittelt und 30 min lang mit 4000 g zentrifugiert. Die organische Phase wird bei 40°C im N2-Strom evaporiert, der Trockenriickstand in 75 pl der mobilen Phase (400 g H20, 1200 g Acetonitril und 1,2 g Tetramethylammoniumperchlorat, auf pH 8,4 eingestellt), aufgenommen. 50 gl dieser L6sung werden in das HPLC-System (Ausrfistung s. Text) injiziert und mit 0,95 ml/min Durchlauf fiber eine Shandon Hypersil-Kolonne Si 100 5 g entwickelt (Diagramme, Chromatogramme, Wertetabelle im Original). - Arzneim.-Forsch./Drug Res. 38(II), 1525-1528 (1988). Anal. Res. Centre, LAB GmbH, Neu Ulm (D) K. S611ner Determination of meprobamate in serum by alkaline hydrolysis, trimethylsilyl derivatization and detection by gas chromatography-mass spectrometry. J. Stidman, E.H. Taylor, H.F. Simmons, J. Gandy and A.A. Pappas. Meprobamat, ein mildes Beruhigungsmittel, kann nach alkalischer Hydrolyse aus Serumproben gaschromatographisch bestimmt werden. Mebutamat wird als interner Standard zugesetzt. Die Extraktion wird mit Methylenchlorid durchgeffihrt. Der Rfickstand des eingedampften Extraktes mit 5 tool/1 KOH hydrolysiert, erneut eingedampft, der R/ickstand mit BSTFA + 1%TMS durch 20 rain Erhitzen auf 70°C derivatisiert und die Trimethylsilylderivate gaschromatographisch auf einer 12 m x 0,2 mm Quarzcapillarsfiule mit Methylsiliconbeschichtung mit einem Temperaturprogramm yon 100-270°C analysiert. Der massenspektrometrische Nachweis wird in SIM-Arbeitsweise bei m/z = 143, 103 und 147 durchgeffihrt. Variationskoeffizienten um 6% werden gefunden. Die Wiederfindungsrate aus Humanserum wird mit 95% im 20 p.g/

3

Biochemical and clinical analysis

473

ml Bereich angegeben, und die Eichkurven sind von 1 - 50 gg/ml linear, wobei 1 gg/ml auch die untere Nachweisgrenze darstellt. - J. Chromatogr. 494, 318-323 (1989). Dept. Pathol., Univ. Arkansas Med. Sci., Little Rock, AR (USA) R.H.S.

Nachweis erfolgt spektralfluorimetrisch bei 610/685 nm. Im Bereich yon 0,i - 10 gg/ml wird eine lineare Eichkurve erhalten, die Nachweisgrenze liegt bei 0,5 ng/ml. - J. Chromatogr. 433, 367-372 (1988). Dept. Animal Med., Cell. Veterinary Med., North Carolina State Univ. Raleigh, NC (USA) R.H.S.

High-performance liquid chromatographic determination of mianserin in plasma and brain and its application of pharmacokinetic studies in the rat. K. Kurata, M. Kurachi and Y. Tanii. Das tetracyclische Antidepressivum Mianserin kann mit Hilfe eines einfachen HPLC-Verfahrens in Plasmaproben und Hirngewebe bestimmt werden. Dazu werden die Proben nach S.H. Preskorn und R.H. Glotzbach [Psychopharmacology 78, 23 (1982)] extrahiert. Imipramin wird als interner Standard zugesetzt. Die Hexan/Isoamylalkohol-Extrakte werden angesfiuert und rfickextrahiert und die wfigrige Phase auf einer Zorbax ODS-Reversed-Phase Sfiule mit 1% Triethylamin/ Acetonitril (pH 3,5) (680:320) chromatographiert. Der Nachweis erfolgt im UV bei 215 nm. Mit dem Verfahren kann Mianserin gut von seinen Stoffwechselprodukten getrennt werden. Die Wiederfindungsraten liegen um 80% ffir Mianserin und um 93% fiir den internen Standard. Ffir S/N = 2 erhfilt man eine Nachweisgrenze yon 3 ng. Die Standardabweichung liegt bei 1,7%. - J. Chromatogr. 434, 278-282 (1988). Dept. Neuropsych., Fac. Med., Med. Pharm., Univ., Toyoma (J) R.H.S.

Reversed-phase liquid chromatographic determination of idarubicin and its 13-hydroxy metabolite in human plasma. S. Eksborg and B. Nilsson. A method is given for the determination of idarubicin and its main metabolite, idarubicinol, in plasma from cancer patients, ldarubicin and idarubicinol are extracted from 2-ml samples of buffered plasma (pH 8.1) using chlorolbrm/1-heptanol (9: 1). After reextraction into phosphoric acid (0.1 M), separation is performed by RP-LC on a LiChrosorb RP-2 column (5 pro) with a mobile phase of acetonitrile/water, acidified with phosphoric acid. The absolute recovery in the range 5 - 1 0 0 ng/ml was greater than 83% with a precision better than 8% (relative standard deviation), using photometric detection at 484 nm. Proper handling of whole blood samples containing idarubidin is essential to avoid metabolic conversion into idarubicinol. Prolonged storage of the drug and its main metabolite under alkaline conditions should be avoided to prevent chemical degradation. - J. Chromatogr. 488, 427-434 (1989). Karolinska Pharm., Stockholm (S)

Simple high-performance liquid chromatographic method for the measurement of toloxatone in rabbit cerebrospinal fluid and plasma. B. Vistelle, D. Lamiable and M. Zinzou. Ein vereinfachtes, schnelles HPLC-Verfahren zur Bestimmung des antidepressiv wirkenden Monooxidaseinhibitors Toloxaton in Kaninchenplasma und Cerebrospinalflfissigkeitwird beschrieben. Das Verfahren ben6tigt nut einen einstufigen Extraktionsschritt der alkalisch gemachten Probe mit Diethylether. Die HPLC-Analyse des in Methanol aufgenommenen eingedampften Extraktes erfolgt auf einer Cs-S~-ulemit Acetonitril/0,01 M Phosphatpuffer (pH 3) (60:40) + 0,02 M Tetramethylammonium als mobiler Phase. Die UV-Detektion wird bei 240 nm durchgeffihrt. Die Bestimmung dauert bei Durchflugraten yon 1 ml/min nur 8 min. Die Nachweisgrenze wird mit 70 ng Toloxaton pro ml (S/ N = 3) in Kaninchenplasma und -cerebrospinalflfissigkeit angegeben. Das Verfahren wird zur Bestimmung von Wirkstoffkonzentrations/ZeitProfilen und zur Bestimmung nach intraven6ser Injektion eingesetzt. J. Chromatogr. 490, 387-394 (1989). Lab. Pharmacol., U F R Pharm., Reims (F) R.H.S. Simultaneous determination of trimipramine and its demethylated metabolites in plasma by gas chromatography-mass spectrometry. A.M. Bougerolle, J.L. Chabard, M. Jbilou, H. Bargnoux, J. Petit, J.A. Berger and G. Dordain. Das tricyclische Antidepressivum Trimipramin kann aus alkalischen Plasmaproben nach Zusatz eines strukturanalogen internen Standards mit Isoamylalkohol/Heptan (1,5:98,5) extrahiert werden. Dann wird in 0,05 M Schwefelsfiure rfickextrahiert und nach Alkalisierung erneut in Isoamylalkohol/Heptan extrahiert. Der Rfickstand dieses eingedampften Extraktes wird in Methanol aufgenommen und gaschromatographisch auf einer SE-30 Quarzcapillars~iule mit einem Temperaturprogramm yon 80 270°C analysiert. Der Nachweis wird massenspektrometrisch durchgeffihrt. Die Nachweisgrenze Iiegt bei 1 ng/ml bei der Verwendung yon 1 ml Plasmaproben. Im Bereich von 0 - 1 0 0 ng/ml erhfilt man eine lineare Eichkurve. Dieses schnelle Verfahren kann bei pharmakokinetischen Experimenten zur gleichzeitigen Bestimmung von Trimipramin und zwei seiner desmethylierten Metab01ite eingesetzt werden. J. Chromatogr. 434, 232-238 (1988). Lab. Chim. Anal. Spectrom. Masse, Fac. Pharm., Clermont-Ferrand (F) R.H.S. Reversed-phase liquid chromatographic determination of chloraluminium phthalocyanine tetrasulfonate in canine tissues and fluids. M.M. Zuk, K. Tyczkowska, E. Ben-Hur, H.C. Newmafl, I. Rosenthal and S.W. Crane. Ein empfindliches HPLC-Verfahren zur Bestimmung des bei der photodynamischen Krebstherapie getesteten Chloraluminiumphthalocyanins in Kaninchen-Gewebe, -Serum oder -Urin wird beschrieben. Dazu werden die Proben mit 0,2 M NaOH versetzt, 1 h auf 60°C inkubiert, zentrifugiert und die 1]berstfinde auf einer Ultrasphere CN-S/iule mit Methanol/0,05 M NaH2PO4/Eisessig (60 : 39 : 1) chromatographiert. Der

Analytical and preparative high-performance liquid chromatographic separation of the enantiomers of ifosfamide, cyclophosphamide and trofosfamide and their determination in plasma. D. Masurel and I.W. Wainer. A HPLC chiral stationary phase (CSP) based upon cellulose-tris(3,5dimethylphenylcarbamate), the OD-CSP, was used to stereochemically resolve three racemic anticancer drugs; ifosfamide (IFF), cyclophosphamide (CTX) and trofosfamide (TFF). The observed enantioselectivities (~) were 1.45 (IFF), 1.21 (CTX) and 1.10 (TFF). The OD-CSP was also used on a preparative scale to isolate the enantiomers of IFF with an optical purity greater than 97%. In addition, an analytical assay was developed for the determination of the enantiomeric composition of IFF and CTX in plasma using achiral-chiral coupled column chromatography. A racemic form of another CSP, the D,L-naphthylalanine-CSP, was used as the achiral pre-column, The sample clean-up prior to HPLC analysis was realized by liquid-liquid extraction with chloroform. The correlation coefficient was 0.987 for both standard curves (20-130 gg/ ml) and the controls were within 10% of the real value. The analysis time for each serum sample was less than 30 rain. - J. Chromatogr. 490, 133 143 (1989). St. Jude Children's Res. Hosp., Pharm. Div., Memphis, TN (USA) A fluoreseein-methotrexate-based flow cytometric bioassay for measurement of plasma methotrexate and trimetrexate levels. Y.G. Assaraf, A. Molina and R.T. Schimke. This assay is based on the intracellular saturation of dihydrofolate reductase with fluorescein-methotrexate (F-MTX) and its dose-dependent displacement by methotrexate or trimetrexate as monitored by flow cytometry. Serially diluted methotrexate-containing plasma, representing a wide chemotherapeutic range, produces F-MTX displacement curves similar to those of standard methotrexate solutions. There is no interference by normal plasma components such as folate and its reduced forms. Plasma methotrexate or trimetrexate concentration is the product of the 50% displacing concentration of standard antifolate (ICso) and the reciprocal of the plasma dilution which yields the same displacement. F-MTX competition with standard methotrexate displayed linear displacement from 18.0 _+ 3.1 to 33.7 ___ 1.5 nM (n~10). The standard trimetrexate calibration curve was linear from 0.28 _+ 0.03 to 1.5 _+ 0.33 nM (n=8). Thus, the bioassay sensitivities for methotrexate and trimetrexate are at least 18 and 0.3 nM, respectively. Comparison of methotrexate levels in l0 plasma specimens from cancer patients determined by the clinical enzyme inhibition assay and by our bioassay showed a high degree of correlation (r = 0.987). - Anal. Biochem. 178, 287-293 (1989). Dept. Biol. Sci. Med., Univ., Stanford, CA (USA) Analytical methods for the determination of terbinafine and its metabolites in human plasma, milk and urine. F. Schatz and H. Haberl. Analytical procedures have been developed for the determination of the allylamine antimycotic terbinafine (1) and its demethylderivate (2)

474 in plasma, milk and urine, and the metaboiite carboxy-terbinafine (3) in plasma and urinel as well as the further metabolites demethyl-carboxyterbinafine (4) and naphthoic acid (5) in urine. HPLC-methods for plasma analysis employed either electrochemical detection (for I and 2) or UV-detection (for 3) following a protein precipitation step with methanol or sample extraction with hexane as appropriate. For quantitative urine analysis of substances 1 - 4 native urine samples were deconjugated, mixed with internal standard and injected by an autosampler into a microprocessor controlled HPLC-system. The substances were monitored by UV-absorption. The metabolite 5 was determined in urine after deconjugation, sample preparation with commercially available cartridges and silylation by automatized GC with fused silica capillary column and FID-detectiofi. - Arzneim.-Forsch./Drug Res. 30, 527-532 (1989). Sandoz Forsch.inst., Vienna (A)

Rapid and sensitive method for the determination of 5-fluorocytosine in human plasma by ion-pair high-performance liquid chromatography. H. Hosotsubo. Ein einfaches, genaues, selektives und empfindliches Verfahren zur Bestimmung des antifungal wirkenden fluorierten Pyrimidins, dem 5Fluorocytosin, durch Ionenpaar Reversed-Phase HPLC wird beschrieben, das weder interne Standards noch ein Extraktionsverfahren ben6tigt. Zur Analyse von Plasmaproben werden diese mit Acetonitril zentrifugiert und der/.)berstand direkt auf einer Shim-Pack CLC-C8 S/iule mit 5 mM Natriumoctansulfonat/Methanoi/Essigs/iure (70: 30:1) (pH 3) chromatographiert. Der UV-Nachweis wird bei 280 nm durchgefiihrt. Eine vollstfindige Analyse dauert weniger als 15 min. Die Nachweisgrenze wird mit 0,1 gg/ml (S/N = 2) angegeben. Die Wiederfindungsraten liegen zwischen 98 und 101%. Andere fungizid wirkende Substanzen, Antibiotika und andere pharmazeutische Wirkstoffe st6ren die Bestimmung nicht. - J. Chromatogr. 487, 183-188 (1989). Centr. Lab. Clin. Invest., Univ. Hosp., Osaka (J) R.H.S. Determination of cephalexin in human plasma and rabbit serum by automated column-switching HPLC. K. Hikida, Y. Inoue, T. Okuura, T. Miyazaki, N. Kojima and Y. Ohkura. An automated method for the determination of cephalexin in human plasma and rabbit serum has been developed by means of columnswitching HPLC with UV detection (260 am). A TSK precolumn BSAODS-120A and a TSK gel ODS-80TM were used as the sample preparation column and analytical column, respectively. Plasma or serum sample (20 ~L1)was directly injected onto the sample preparation column. The recovery of cephalexin from human plasma was complete (approximately 100%) with good reproducibility (R.S.D. less than 3%). This method could be successfully used for the determination of cephalexin in plasmas and sera from humans and rabbits receiving oral doses of cephalexin preparations. The values of cephalexin concentrations obtained by this method correlated well with those obtained by a bioassay method. - Bunseki Kagaku 38, 135--139 (1989) (Japanisch, mit engl. Zus.fass.). Yoshitomi Pharm. Ind., Chikujyo-gun, Fukuoka (J) Determination of cyclosporin A in the serum of kidney transplant patients by rapid-flow fractionation and normal-phase high-performance liquid chromatography. K. Oka, K. Hosoda, T. Hirano, E. Sakurai and M. Kozaki. HPLC was used to determine cyclosporin A (CsA) concentrations in the serum of kidney transplant patients by rapid-flow fractionation (RFF) followed by silica gel normal-phase HPLC. The extraction of CsA from serum was achieved by RFF using a short diatomaceous earth column eluted with diethylether/n-hexane (50:50). The recovery was more than 80% at concentrations of 5 0 - 1 5 0 gg/1. The concentration of this compound was determined by HPLC using a conventional silica gel column with 3.3 M ammonia solution/ethanol/n-hexane (0.31 : 10.69:89) as eluent. Concentration calibration was made on the basis of the peakheight ratio of CsA to CsD as the internal standard. The coefficient of variation of this assay was less than 6.5% and the results were used for the therapeutic drug monitoring of CsA administered to kidney transplant patients. Measurements of the CsA concentrations in 160 serum specimens were also made by conventional radioimmunoassay (RIA) using commercial kits. The data obtained by RIA were on average 2.5 times those obtained by HPLC. Higher values in RIA were observed characteristically with patients with severe disfunction resulting from

3

Biochemical and clinical analysis

CsA hepatotoxicity. From the results, it appeared that HPLC rather than RIA provides more precise and reliable values for the concentration of this drug. - J. Chromatogr. 490, 1 4 5 - / 5 4 (1989). Div. Clin. PharmacoI., Tokyo Coll. Pharm., Hachioji, Tokyo (J)

Reversed-phase high-performance liquid chromatographic assay for the determination of mezlocillln in human and rat biological samples. G.L. Jungbluth, D.M. Janicke and W.J. Jusko. Das halbsynthetische Breitband Antibioticum Mezlocillin kann mit Hilfe eines isokratischen Reversed-Phase HPLC-Verfahrens aus kleinen Probevolumina bestimmt werden. Das Verfahren kann auf 50 gl-Proben oder weniger von Serum, Urin oder GalIe von Mensch oder Ratte angewandt werden. Ffir die Serumanalyse werden die Proteine durch Zentrifugation mit AcetonitriI abzentrifugiert, Piperacillin in Phosphatpuffer als interner Standard zugesetzt und mit 1,2-Dichlormethan extrahiert. Die w/il3rige Phase wird auf einer Ultrasphere oder einer Econosphere ODS-S~iule unter Vorschaltung einer C18-Bondapak SchutzsS.ule mit einer mobilen Phase aus 23% Acetonitril in 0,1 mol/1 Phosphatpuffer (pH 7,0) chromatographiert. Der Nachweis wird mit einem 214 nm Filter im UV ausgeffihrt. Im Bereich von 1,25-80 gg/ml erh/ilt man lineare Eichkurven, die Nachweisgrenze wird ffir S/N= 3 mit 0,1 ~tg/ml, die untere Grenze f/Jr die quantitative Auswertung mit 1,25 gg/ml angegeben. Eine Bestimmung mit diesem einfachen und selektiven Verfahren dauert nur 10 min. - J. Chromatogr. 494, 376-380 (1989). Dept. Pharm., School Pharm., State Univ. New York, Buffalo, NY (USA) R.H.S. Determination of mizoribine in plasma using ion-pair high-performance liquid chromatography. G.R. Erdmann, S.A. Gruber, M.M. McGuiggan, R.J. Cipolle and D.M. Canafax. Das Nucleosid-Antibioticum Mizoribin aus Eupenicillium brefeldianum, welches als immunosuppressives Agens eingesetzt wird, kann mit Hilfe eines HPLC-Verfahrens aus Plasmaproben bestimmt werden. Dazu wird den Proben 3-Methylxanthin als interner Standard zugesetzt, die Proteine mit Perchlors/iure abgef/illt und fiberschfissige S/iure mit KC1 entfernt. Nach Zentrifugation wird der l~lberstand mit 10 tool/1 NaOH alkalisch gemacht und mit Dichlormethan extrahiert, die w/il3rige Phase wird mit 2 mol/1 HC1 neutralisiert und durch HPLC auf einer Hypersil ODS-S/iule mit Methanol/20 retool/1 Natriumphosphat (2:98) (pH 3) unter Zusatz von 0,04% Octansulfons~ure chromatographiert. Zur Elution des internen Standards wird der Methanolgehalt auf 6% erh6ht. Der Nachweis wird bei 275 nm im UV ausgef/ihrt. Im Bereich yon 0,25 10 ~tg/ml wird eine lineare Eichkurve erhalten, die Nachweisgrenze liegt bei 0,1 gg/ml. - J. Chromatogr. 494, 354-360 (1989). Dept. Pharm., Coll. Pharm., Health Sci. Unit F, Univ. Minnesota, Minneapolis, MN (USA) R.H.S. Micro-method for the determination of roxithromycin in human plasma and urine by high-performance liquid chromatography using electrochemical detection. F.M. Demotes-Mainaird, G.A. Vingon, C.H. Jarry and H.C. Albin. A dichloromethane extract of the sample was chromatographed on a C18 reversed-phase column with acetonitrile/83 mM ammonium acetate/ methanol (55:23:22) adjusted to pH 7.5 with acetic acid as the mobile phase. Roxithromycin and the internal standard, erythromycin, were detected by dual coulometric electrodes operated in the oxidative screen mode. The appIied cell potential of the screen electrode was set at +0.7 V and the sample electrode at +0.9 V. The intra- and inter-assay coefficients of variation were ~<7.0%. The detection limit (signal-tonoise ratio = 3) was 0.l Ixg/mi for both plasma and urine. A study of drug stability during sample storage at 4, 20 and 37°C showed no degradation of roxithromycin. The method is convenient for clinical monitoring and pharmacokinetic studies. - J. Chromatogr. 490, 1 1 5 123 (1989). Dept. Clin. Pharmacol., H6pital Pellegrin, Bordeaux (F) Automated high-performance liquid chromatographic analysis of tetracycline in urine. B.W. LeDuc, D.J. Greenblatt and H. Friedman. Ein einfaches, billiges HPLC-Verfahren zur Bestimmung yon Tetracyclin in Urin, welches kaum Probenvorbereitung erfordert und mit einem internen Standard arbeitet, wird beschrieben. Dabei werden die Probeu mit interner Standardl6sung (Demeclocyclin als freie Base in 0,1 M HC1) verdtinnt und dann direkt auf eine PLRP-S 5 ~tm-Sfiule injiziert, die

3

Biochemical and clinical analysis

mit 7,5 mM PhosphorsS.ure/Acetonitril/Methanol (20: 3:3) als mobiler Phase betrieben wird. Der Nachweis erfolgt bei 355 nm im UV. Im Bereich von 1 , 0 - 75 gg Tetracyclin pro ml erhfilt man eine lineare Eichkurve mit einem Korrelationskoeffizienten yon mindestens 0,99. - J. Chromatogr. 490, 474-477 (1989). Div. Clin. Pharmacol., Tufts-New England Med. Center, Boston, MA (USA) R.H.S.

Detection and determination of antimalarial drugs and their metabolites in body fluids. Y. Bergquist and F.C. Churchill. Anhand yon 83 Literaturstellen wird ein Uberblick fiber Verfahren zur Bestimmung yon Antimalariawirkstoffen in biologischen Flfissigkeiten gegeben. Die verschiedenen analytischen Techniken, die in den letzten 10 Jahren durch das verbesserte Angebot chromatographischer Ger/ite einem groBen Wandel unterlegen sind, werden dargestellt. Die Wahl der Methode und damit deren Selektivitfit und Empfindlichkeit richtet sich nach den vorhandenen apparativen M6glichkeiten sowie den analytischen Erfordernissen wie Screening oder metabolisch kinetische Untersuchungen. Besondere M6glichkeiten der Felduntersuchungen, der Probenaufbewahrung und des Transportes sowie deren Adaption an die hochempfindlichenchromatographischen Verfahren werden ffir Chlorochin beschrieben und ffir andere Wirkstoffe in Zukunft erwartet. Im einzelnen wird kapitelweise auf die Bestimmung yon Chlorochin, Amodiachin, Meflochin, Proguanil, Pyrimethamin, Sulfadoxin, Primachin und deren Metabolite eingegangen. - J. Chromatogr. 434, 1 - 20 (1988). Dept. Clin. Chem., Centr. Hosp., Falun (S) R.H.S. Automated high-performance liquid chromatographic method for the determination of iodotyrosines and iodothyronines. P.R. Kootstra, H.H. van den Broek, E.A. Hogendoorn, C.E. Goewie and J.J.M. de Vijlder. Ein Verfahren zur Bestimmung der sechs Iodtyrosine und Iodthyronine im Reaktionsgemisch des Modellsubstrats Tyrosin und ThyroidPeroxidase, welches ffir kinetische Untersuchungen eingesetzt wird, in Urinproben yon Patienten und in Proben yon enzymatisch hydrolysierten Thyroglobulin aus Schilddrfisenmaterial wird beschrieben. Die Methode ist ein vollautomatisiertes Reversed-Phase Ionenpaar HPLC-Verfahren und umfal3t Probenreinigung und Vorkonzentrierung auf einer kleinen C18-Vors/iule. Eine kleine Probenschleife wird zur Beladung der RP-18 Vors/iule verwendet. Die analytische Hypersil ODS-Sfiule wird bei 40°C im Wasserbad betrieben. Ffir die Vorsfiulenkonzentrierungwird 0,03 M Natriumphosphatpuffer (pH 2,2) + 2,5 mM HSA verwendet. Zur Elution auf die analytische Sfiule wird Phosphatpuffer (pH 2,5) + 2,5 mM HSA eingesetzt. Als mobile Phase wird ein Gradient zwischen Methanol/Puffer+HSA (30:70) und Methanol/Acetonitril/Puffer+ HSA (34: 17:49) verwendet. Die Peakh6hen werden bei 230, 240, 254 und 280 nm gemessen. Bei einer spektralphotometrischen Detektion bei 220 nm erhfilt man eine Nachweisgrenze yon 10 ng/ml bei 50 pl Injektionen. Im Bereich yon 25 - 250 ng sind die Eichkurven linear (mit Ausnahme der ffir Thyrosin). - J. Chromatogr. 438, 175-183 Cl988). Exp. Pediatric Endocrinol., Acad. Med. Centre, Amsterdam (NL) R.H.S.

475 Ein chromatographisches Verfahren zur quantitativen Analyse einzelher Folate in einer durch Affinit~itschromatographie gereinigten Mischung wird entwickelt. Mischungen, die Pteroylglutamate (PteGlul- 7) enthalten, werden zu den Dihydro-(H2PteGlul_ 7) und den Tetrahydro(H4PteGlu~ _ 7)-Formen reduziert. Zur Eichung werden 5-MethylH,PteGlu~ 7- und 10-FormylH,~PteGlu~ _ 7-Formen eingesetzt. Die Trennung erfolgt auf einer C1 s Econosphere S/iule mit einem Gradienten zwischen 5 mmol/1 TBAP, 25 mmol/1 NaC1 und 0,5 mmol/l Dithioerythritol (pH 6,8) in Wasser bzw. Acetonitril/Wasser (65 : 35). Die Folataktivit~it wird im UV bei 280 nm mit einem Diode-Array-Detektor bestimmt, die Absorptionssignale bei 350 und 258 nm werden zur Bestimmung von FoP s~iure und Dehydrofolsfiure bzw. I 0 Formyltetrahydrofolatderivatenverwendet. Das Verfahren wird zur Bestimmung der Folatzusammensetzung in Lebergewebe und in Human- und Kuhmilch eingesetzt. Die strukturellen Grundlagen fiir die Trennungen werden diskutiert. Anal. Biochem. 182, 8 4 - 9 3 (1989). Bioavail. Lab. USDA Human Nut. Res. Center, Tufts Univ., Boston, MS (USA) R.H.S. Anti-T2 monoclonal antibody immobilization on quartz fibers: stability and recognition of T2 mycotoxin. M.L. Williamson, D.H. Atha, D.J. Reeder and P.V. Sundaram. Es werden verschiedene Techniken zur Immobilisierung von monoklonalen Anti-T2-Mycotoxin-Antik6rpern an Quarzfasern beschrieben. Diese werden als optische Sensoren eingesetzt, mit deren Hilfe T2-Mycotoxine untersucht werden k6nnen. Diskutiert werden das Prinzip der Methodik, die verwendeten Materialien, Prfiparation der immobilisierten Antik6rper, deren Lagerungsffihigkeit und schlieBlich die Analyse der Anti-T2-Aktivitfit. Einflfisse yon Spacergruppe auf die Leistung der fasergebundenen Antik6rper, des pH-Wertes aufdie Stabilit/it der immobilisierten Antik6rper und deren thermische Bestfindigkeit sind weitere Punkte, die er6rtert werden. - Anal. Lett. 22, 803 - 8 1 6 (1989). Detect. Technol. Div., US Dept. Defende, Chem. Res., Aberdeen Proving Grounds, MD (USA) W. Czysz

Microcomputer-assisted liquid chromatographic separation system: Application to toxic compounds identification in poisoned human fluids. K. Jinno and M. Kuwajima. The computer-assisted liquid chromatographic system (MCASYST) is developed for automated identification and analysis. The system has six main functions: retention prediction system, liquid chromatographic data base system, automated identification system, optimization of separation conditions, data loading program from UV multichannel detector, and UV spectral data base system. The performance and potential of this MCASYST system is evaluated for toxic compounds identification in poisoned human fluids. - J. Chromatogr. Sci. 27, 5 7 - 6 2 (1989). Sch. Mater. Sci., Univ. Technol., Toyohashi (J) High-performance liquid chromatography of domoic acid, a marine neurotoxin, with application to shellfish and plankton. M.A. Quilliam, P.G. Sire, A.W. McCulloch and A.G. McInnes. Vergiftungen beim Verzehr yon Pfahlmuscheln k6nnen durch die neurotoxische Aminos~iure Domons//ure verursacht werden. Zur Bestimmung dieser Aminosfiure in wfigrigen Muschel- und Phytoplanktonextrakten sowie zur Auftrennung einiger ihrer Isomeren wird ein HPLCVerfahren eingesetzt. Dabei wird der rohe Extrakt aufpH 6 - 7 eingestellt und fiber eine Octadecylsilica LC-18-Extraktionskartusche gereinigt, von der die Probe mit 10%igem w~il3rigenAcetonitril eluiert wird. Die HPLC wird auf einer Vydac 20l TP-ODS Reversed-Phase-Sfiule mit einem linearen Gradienten yon 5 - 2 5 % Acetonitril unter Zusatz von 0,1% Trifluoressigsfiure oder ffir Schnellanalysen isokratisch mit 10% Acetonitril durchgeffihrt. Der UV-Nachweis erfolgt bei 242 nm. Die Trennung dauert bei Verwendung einer Microbore-S/iule (2,1 mm i.D.) nur 5 rain und weist eine Nachweisgrenze von 0,3 ng auf. -- Intern. J. Environ. Anal. Chem. 36, 139-154 (1989). Atlant. Res. Lab., Nat. Res. Council Canada, Halifax, Nova Scotia (CDN) R.H.S.

High-performance liquid chromatographic method for the analysis of benztropine in human plasma. K. Selinger, G. Lebel, H.M. Hill and C. Discenza. Ein einfaches, verlfil31ichesund empfindliches Verfahren zur Bestimmung des anticholinergisch wirkenden Benztropinmesylats, welches bei der Behandlung der Parkinsonschen Krankheit eingesetzt wird, wird beschrieben. Es gestattet die pharmakokinetische Untersuchung nach Eingabe yon einmaligen 2 mg-Dosen Benztropinmesylat. Dazu werden die Plasmaproben mit 200 ng/ml Desipraminhydrochlorid als internem Standard versetzt, mit 5 M NaOH alkalisch gemacht, 1 ml Ethylenglykol zugesetzt und mit Hexan extrahiert. Benztropin wird aus der organischen Phase in 0,1 M HC1 rfickextrahiert. Die saure Phase wird auf einer C8Spherisorb-S~iule mit Triethylamin in Wasser (~,5 ml/1; pH 3) analysiert. Der Nachweis erfolgt bei 199 nm. Die Nachweisgrenze wird mit 0.25 ng/ ml angegeben. Die chromatographische Trennung dauert weniger als 10 rain. Die Extraktionsausbeute wird zu 70% ermittelt. - J. Chromatogr. 491, 248--252 (I989). Bio-Res. Lab., Senneville, Quebec (CDN) " High-performance liquid chromatographic determination of rhodamine B ' R.H.S. "~ in rabbit and human plasma. R.W. Mason and I.R. Edwards. Der vielfach verwendete Farbstoff Rhodamin B, dessen Metabolismus Determination of tissue folate composition by affinity chromatography in Kaninchen und Menschen untersucht wird, kann mit Hilfe eines followed by high-pressure ion pair-liquid chromatography. J. Selhub. einfachen HPLC-Verfahrens bestimmt werden. Dazu werden die mit

476 Phosphatpuffer (pH 5,5) versetzten Plasmaproben mit Ethylacetat extrahiert, die organische Phase eingedampft, der R/ickstand in mobiler Phase aufgenommen und auf einer gBondapak CN-S/iule mit Acetonitril/Wasser (35:65 oder 40: 60) + 0,1% Phosphors/lure chromatographiert. Der Nachweis wird fluorimetrisch bei 261/575 nm ausgeffihrt. Mit dem Verfahren k6nnen Rhodamin B und vier seiner Metaboliten getrennt und bestimmt werden. Im Bereich yon 2 5 - 5 0 0 ng/ml erh/ilt man lineare Eichkurven, die Wiederfindungsraten liegen bei 98 + 5%. Die Nachweisgrenze wird mit 2 ng Rhodamin B (25 ng/ml Plasma) ffir S/N = 4 angegeben. - J. Chromatogr. 4 9 1 , 4 6 8 - 472 (1989). Toxicol. Res. Unit., Med. Res. Council, Univ. Otago Med. School, Dundedin (NZ) R.H.S. Rapid extraction and determination of xylazine in greyhound urine using high-performance liquid chromatography. C.M. Moore and J.S. Oliver. Das in der Veterin/irmedizin als Seditativum, AnaIgetikum und Muskelrelaxans eingesetzte Xylazin [5,6-Dihydro-2-(2,6-xylidino)-4H1,3-thiazin] kann gut mit Hilfe von Feststoffextraktion/HPLC-Analyse im Urin yon Rennhunden nachgewiesen werden. Dazu werden die Proben unter Zusatz von Diazepam in Methanol als interner Standardl6sung fiber eine Bond-Elut CN-Sfiule gegeben, die mit methanolischer HC1/ Acetonitril (] : 1) eluiert wird. Das Eluat wird dann direkt auf einer Hypersil 5 gm Ca 8-S/iule isokratisch mit einer L6sung von 1 g Tetramethylammoniumhydroxid in 250 ml Wasser/Acetonitril/Methanol (250:150:10) chromatographiert. Der Nachweis kann bei 225 nm im UV durchgeffihrt werden. Mit dem Verfahren kann Xylazin noch 8 h nach Eingabe bestimmt werden. Die Wiederfindungsraten liegen um 98%. Die Genauigkeit wird mit 90,3 + 4,6% und die Nachweisgrenze mit 10 ng/ml angegeben. Der Vorteil des Verfahrens wird in seiner schnellen und unkomplizierten Probenvorbereitung gesehen. - J. Chromatogr. 491, 519-524 (1989). Dept. Forens. Med. Sci., Univ., Glasgow (GB) R.H.S.

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Biochemical and clinical analysis

Preparation of fentanyl analogs suitable for immobilization for receptor binding analyses. L.B. Wingard, Jr., K. Narasimhan, T.-C. Cheng, M.L. Casner and W.E. White. Im Zusammenhang mit Untersuchungen fiber die Pharmakon-Rezeptor-Komplexbindung, die bei der Arzneimittelwirkung yon Bedeutung ist, werden Fentanyl-Analoge mit bestimmten funktionellen Gruppen synthetisiert, die es erlauben, die Art der Bindung an einen Rezeptor zu untersuchen. Insbesondere werden Amino- und Azid-Fentanylderivate sowie 3H-markierte Azid-Derivate synthetisiert und charakterisiert. PMR- und andere spektroskopische Analysen besfiitigen die Brauchbarkeit des gew/ihlten Syntheseschemas und die Eignung der Amino- und Azid-Derivate zur IR-spektroskopischen Untersuchung der Bindung an Opioid-Rezeptoren. - Anal. Lett. 22, 1403-1416 (1989). Dept. Pharmacol., Univ. Pittsburgh School Med., Aberdeen Proving Ground, MD (USA) W. Czysz Determination of human toluene metabolites by mass spectrometry using an silicone membrane source. A. Sturaro, L. Doretti, G. Parvoli and P. Traldi. Verff. beschreiben ein schnelles Verfahren zum Nachweis und zur Bestimmung des Toluolmetaboliten p-Kresol in hydrolysiertem Urin (100 ml-Proben, 20 ml HC1, 1,5 h bei 95°C), der nach Abkfihlen mit 2 x 40 ml CHC13 extrahiert wurde. Der unter vermindertem Druck evaporierte Extrakt wurde mit 1-Propanol (unter Zugabe von Phenol als innerem Standard) aufgenommen und dann massenspektrometrisch analysiert. Fiir die Ionisation im Massenspektrometer (VG ZAB-2F) unter Elektronenstol~bedingungen wurde eine Siliconmembran-Ionenquelle benutzt, die speziell ffir dieses Massenspektrometer entwickelt wurde. Bei der Analyse von Urinproben nicht Toluol-exponierter Personen wurde ein Durchschnittswert yon 11 __ 1 gg/ml p-Kresol festgestellt. - Anal. Chim. Acta 224, 119-122 (1989). Serv. Sicur. Lavoro e Prot. Sanit. CNR, Padova (I) W. Czysz