Journal of Analytical Chemistry Vol. 55, No. 2, 2000, pp. 191-195. Translated from Zhurnal Analitiche~koi Khimii. VoL 55, No. 2, 2000. pp. 212-21Z Original Russian Text ColLvright 9 2000 by Budniko~; Kazakov.

ANALYTICAL EQUIPMENT

Electroanalytical Instrumentation from Bioanalytical Systems G. K. Budnikov and V. E. Kazakov Department of Chemistry, Kazan State University; Kremlevskava ul. 18, Kazan, 420008 Tatarstan, Russia ReceivedDecember16, 1998

Abstract Electroanalytical instrumentation produced by Bioanalytical Systems Inc. (USA) is discussed in historical and methodological aspects. Attention is given to polarographs and peripheral devices differing in complexity and analytical potentialities. It is noted that the most up-to-date instrumentation designed on the basis of technical innovations has been developed for the use in medicine and environmental analysis. The challenges in the development of instrumentation for electrochemical analytical methods, including voltammetry, were discussed repeatedly at various conferences devoted to these methods in Russia and the former USSR. When foreign development works contributing to the development of new instrumental methods were discussed, names of foreign scientists and engineers as well as trademarks of mainly European companies were mentioned therewith. Though it is likely that the geography of manufacturers of analytical equipment has not changed significantly during the past 10-15 years, nevertheless, new names and companies have appeared. They may be of certain interest for Russian electroanalytical chemists, both the manufacturers and purchasers of equipment for electrochemical analytical methods. Attention is attracted by the history of the advent and evolution of research laboratories in these firms, the history of their scientific and engineering development works, and the currently urgent problems of getting into the market by the most successful market participants. These problems are by far very important for the developers of domestic instrumentation. The US company Bioanalyticai Systems Inc. (BAS) occupies a prominent place among the present-day manufacturers of analytical equipment. In a relatively short time, BAS has gained reputation for its trademark among the analysts all over the world. This has been achieved because of the novelty of technical solutions implemented in output goods, the well-considered nomenclature of products, and the developed service for both potential and regular customers. Nowadays, we can literally state that the analytical instrumentation from BAS compete successfully with the instrumentation produced by such world-famous manufactures as Hewlett-Packard, Metrohm, Princeton Applied Research Corp. (PARC), and others whose production activity had started well before BAS was established. The history of every successful business inevitably becomes surrounded by legends. The history of BAS is no exception. The starting point for the establishment of the company was the development of a thin-layer

flow cell for HPLC detectors by Prof. P. Kissingerfrom the Michigan University [l]. The legend says that the first devices were assembled by the professor of chemistry and two students on a cook table. The above electrochemical detector and a relatively simple CV 1 voltammograph for cyclic voltammetry were the first commercial products of the firm. Both products had gained recognition from specialists: the former because of the lack of commercially available instrumentation of this class and the latter because of the use of then new elements, namely, integrated circuits, which led to a significant decrease in the dimensions and mass of devices [2]. Over the first few years, BAS sold hundreds of products handmade in a garage [2]. However, already in 1975, BAS products were on the market throughout the United States and in most of the West-European countries. It is interesting to note that many leading market participants in America and Europe underwent such metamorphoses: from a small enterprise in a garage to the developed firm or even to a powerful commercial industrial group. For instance, it is well known that the first Henry Ford automobile, which was handmade in a coal shed from improvised materials, was an incitement to the establishment of his "auto empire." The first Walt Disney cartoon was shot also in a garage, and, nowadays, the total revenue of the Walt Disney Company is $22.5 billion. In the 1930s, a garage served as the first office, the booking office, and the waiting room simultaneously for the then young Delta Air Service. Now Delta Airlines is one of the biggest airlines in the USA. Finally, a garage as an industrial research laboratory played an important part in the analyticalinstrument-making industry. In 1938, the history of the Hewlett-Packard Company started in one of the garages in a small town Palo Alto in California. Nowadays, it is the first-rate manufacturer of computers, medical facilities, and chemical analytical equipment. Turning back to the history of Bioanalytical Systems, it is worth noting that the early products of BAS were in such great demand that they are involved in the production program of the firm up to now with modifications but without changing their basic purposes.

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The company management explains this fact by the sentimental weakness of the founders. However, besides personal predilections, there is well-grounded market decision for such an extraordinary step. An upgrade of the first CV 1B polarograph and an up-todate modification of a flow electrochemical detector (produced now under the brand name Petite Ampere) are offered at a low price basically for training purposes. The partly "handicraft character" of early BAS products and the total absence of service at first resulted in that fact that the first purchasers bought equipment inevitably at their own risk. The lack of wide publicity and after-sale service reduced the prices significantly [2]. Later, the company management made proper conclusions from the experience and developed an original system of service and scientific support along with the bright image of the company and its own publicity style. To confirm and develop the first success, the company management declared the concept of the production program that determined the principal idea: the advancement of the present-day technologies to those scientists who were not analysts themselves but needed analytical chemistry as a research method. BAS promoted present-day HPLC to neurochemistry and neuromedicine, where it had not been applied yet [2]. Cyclic voltammetry was proposed to organic chemists and biochemists, that is, to all those who had never heard about this method before but felt an actual need for information about the redox properties of systems [2]. This approach was expressed by a single phrase that became a motto of the company: "Helping Scientists Do Science." The motto has not remained only words, and, nowadays, the company developed an interesting system of the scientific maintenance of its development works. It covers all steps from the publicity to after-sale service. The BAS managers emphasize repeatedly that the collaboration of the company and a customer does not stop after purchasing but only begins at this moment. They probably keep in mind the market law saying that getting a new customer is several times more expensive than retaining an old one in the sphere of own attraction. Several succeeding years were of crucial importance in forming the present-day production profile and, consequently, the following existence and development of the firm. This period was characterized by a qualitative leap in the concept of the production program: from single, relatively simple devices that were more likely accessories or components of voltammetric and HPLC systems, the company turned to the design of integrated systems for voltammetry and chromatography and entered, by doing so, into a direct competition with the largest manufactures of analytical equipment. At that time, almost all chromatographers bought equipment produced by such famous companies as Waters or DuPont. Electrochemists preferred equip-

ment produced by PARC, Metrohm, or Tacussel. Some specialists working in the fields of both electroanalytical chemistry and HPLC designed at times their own devices [2]. Having entered into competition with famous manufacturers of analytical equipment, BAS in a short period of time worked up its own sector of the market, because it offered production with the performance characteristics and functional capabilities that competitors could not offer. The circumstance that voltammetry and chromatography, which had already become the analytical practice, were proposed for solving analytical problems in the fields where they were not used before, enhanced the competitive ability of BAS products. A typical example is the development of BAS analytical equipment for biochemistry, neurochemistry, and neurobiology, as well as pioneering developments of HPLC applications in these fields [3]. The situation at the market of analytical equipment in the days when BAS was growing as a manufacturer, the correct marketing analysis, and the resulting commercial success determined the production profile of the company for many succeeding years. Thus, the branch of industry in which the company achieved significant advances, namely, the development of analytical equipment for biochemistry and related sciences, gave the name of the company itself. Since its establishment, BAS has become one of the leading manufacturers of analytical equipment for HPLC and, somewhat later, for electrochemistry and voltammetry. The beginning of the latest electrochemical history of BAS can be attributed to the early 1980s. It is intimately related to the development of microelectronics, which took place then. After the sensational digital boom in the middle seventies, which resulted in the large-scale production, availability, and low price of microprocessors ("single-chip microcomputers" as they were named at that time). Engineers and designers of various apparatus began to think seriously about imparting intelligent potentialities to their products. In the early 1980s, microprocessors were tried to be applied everywhere: from kitchen units and electronic watches to armament-control systems. In Foreword and Editorial of the BAS journal Current Separations (1983), it was mentioned that microprocessors are used everywhere and that, today, microprocessors control even mixers and heaters. This phrase opened the presentation of the first microcomputer-controlled polarograph [4]. Before this device became a finished commercial product, its prehistory had involved numerous amateurish attempts of different research teams to develop a computer-controlled electrochemical complex. Thus, already in the preceding decade, Perones, Osteryoung, Smith, and their colleagues had developed and assembled instruments controlled by minicomputers. As a rule, every research team developed equipment designed for its own needs that can be used in electrochemical experiments of rather limited types. The con-

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ELECTROANALYTICAL INSTRUMENTATION FROM BIOANALYTICAL SYSTEMS cept of "an instrument for the electrochemistry of the eighties" proposed by BAS involved the task of designing a hardware and software complex. This complex should provide a wide range of currently known methods of polarizing the working electrode and methods of recording the analytical signal (alternating current voltammetry (ACV), differential pulse voltammetry (DPV), normal pulse voltammetry (NPV), cyclic voltammetry (CV), and others) and routine techniques (stripping voltammetry (SV), voltammetry, and polarography). These methods and techniques were incorporated in a unified program of instrument control, data acquisition, and data treatment (data converted to a digital form). A BAS 100 cybernetic potentiostat appeared to be very successful. It was a combination of three principal units: (1) the main unit without control devices, (2) a cathode-ray tube monitor, and (3) a PC keyboard. It provided performance of as much as 25 most widely used operation modes of an electrochemical experiment. The choice of a mode was performed by means of a standard IBM PC keyboard using simple and clear commands of the control language. For instance, entering a "CV" abbreviation meant the choice of cyclic voltammetry. The heart of a BAS 100 analyzer was a Zilog Z80A microprocessor, which was widespread in the early eighties [5]. In several succeeding years, new modifications named BAS 100A/BAS 100B were developed. They kept the main design solutions and performance characteristics of their predecessor, but they were improved significantly by increasing the number of available modes of an electrochemical experiment and by improving the possibilities of data processing. A Z80A processor was coupled with a 9511 arithmetic co-processor. This coupling transformed a microprocessorcontrolled device to more or less valuable computer and made it possible to efficiently use sophisticated algorithms of data processing, namely, background subtraction, automatic determination of electrochemical peak parameters, Fourier transform, and others. BAS 100A and BAS 100B models were completed with functional peripheral devices: a C I A voltammetric cell stand with stationary electrodes, an RDE 1 rotating-disk electrode, a current preamplifier for ultramicroelectrodes, and a preparative electrolysis module. Control over the operational parameters of add-on devices could be performed both conventionally, i.e., with the use of a control panel on the corresponding device, and with the aid of the macro-command language of the BAS 100A or BAS 100B software. On the edge of the nineties, the users' view of how and what one should do with personal computers changed suddenly [6]. This influenced significantly the production program of the firm. The revolution in the way of thinking bf PC users was in fact a consequence of the advent of Intel 80386 enhanced-mode microprocessors. However, it was incited by the emergence of JOURNAL OF ANALYTICALCHEMISTRY

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the only program product, Windows 3. !, developed by Microsoft in 1991. After that, virtually all PC users turned from a conventional command-character interface to a full-value ergonomic graphical interface. The real support of multitasking and new information technologies gained a wide popularity of Microsoft Windows and made it an actual standard for the user environment. In 1991-1992, the competition for the capacious and promising market of Windows applications resulted in the development of radically new versions of the known software products, whose names included the words for Windows. The methodology of user's work on PCs itself underwent revision. After getting into the market of Windows applications, BAS engineers proposed their own original concept of integrating modern information technologies and analytical equipment. This concept was implemented in a BAS 100B/W Electrochemical Workstation. The new version of an electrochemical analyzer of the nineties was developed based on the previous BAS 100B model. The main obstacle for the upgrade of this kind must seemingly be the Zilog microprocessor. It became out of date already in the middle eighties and held out little or no hope of upgrading the BAS 100B hardware-software complex so as to change over to a new, modern user interface. At the same time, the capacities of Z80A were sufficient to provide high performance characteristics of the instrument itself. It was generally accepted that the implementation of Windows technologies in full measure required a 386SX processor or better, that is, the capacities of a then quite powerful computer. Based on this fact, BAS engineers proposed an original architecture of analytical equipment implemented in a BAS 100B/W voltammograph. The microprocessor in 100B was now controlled by an external microprocessor, i.e., functioned as a slave device. The practical implementation of this approach resulted immediately in several advantages. First, the elaborated technology of BAS 100B production was only slightly updated with respect to hardware, and the main efforts went into the development of the software. Second, "the division of labor" provided by such a dual-processor architecture allowed the best use of the advantages of Microsoft Windows and, at the same time, retained the high performance characteristics achieved in BAS 100B with a Zilog microprocessor. Being developed for BAS 100B/W, the control BAS Windows program places at user's disposal a standard set of functions of Windows applications (user-friendly "point-and-click" interface, support of a mouse, possibility of using color graphics of high resolution, and access to "object linking and embedding" technology for linking experimental data to other applications, e.g., to a text processor). As compared to BAS 100B, this software provided enriched functionality for data processing (background subtraction, differentiation and integration, construc-

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tion of Cottrell and Tafel plots, automatic determination of peak and wave parameters, etc.), which made it possible to automate the selection of analytical signals and to reduce the influence of the human factor. The software supports 38 most widely used modes of an electrochemical experiment, including CV, NPV, DPV, square wave and AC voltammetry, tast polarography, galvanostatic and potentiostatic electrolysis, phaseselective polarography and voltammetry, and AC impedance measurements. The BAS 100B/W software-hardware complex was developed ten years after the development of the first BAS 100 instrument of the 100 series,. It became the first commercially available instrument for electrochemistry that used Windows applications for data treatment. BAS counted on the new information technology just in the first months of its appearance on the market. Considering the significant and growing popularity of this environment among scientists and other computer users, this step was fully rewarding. Bioanalytical Systems was again able to develop a device most innovative for its time, and did it far in advance of its competitors. The widespread use of Windows-compatible programs, including those used in analytical instrument making [7, 8] gives a user the assurance that the Windows information technologies will remain very popular in the future. The review of the present-day electroanalytical instrumentation produced by BAS would be incomplete without mentioning the devices that are relatively inexpensive, are more readily available for customers, and possess less functionality than a BAS 100B/W Electrochemical Workstation. Peripheral equipment produced by the firm should be described as well. A cheaper and somewhat simplified version of BAS 100B/W is sold under the brand name CV 50W. It is a modification of the Electrochemical Workstation controlled by the similar Windows interface. The reduced price of this device is the result of the reduction of the number of modes of an electrochemical experiment available for a user (12 instead of 38 provided by BAS 100B/W; CV, chronoamperometry and chronocoulometry, NPV, DPV, and square wave and AC voltammetry/polarography are available). Designers considered that the commercial availability of this device should correspond to the concept of an efficient instrument for routine analyses and tests [9]. However, it is worth noting that these limitations (including those for peripheral devices) do not affect the main performance characteristics of the device concerning the reliability of measurements and the representation of analytical signals. In these cases, a CV 50W power polarograph for routine analyses is identical with a BAS 100B/W Electrochemical Workstation. CV 27 and CV 37 cyclic voltammographs are the cheapest instruments produced by BAS. These are recommended for use in research and training [10]. Besides the main CV mode, CV 27 can be used for

chronoamperometric, potentiostatic, and amperometric experiments. The modes of SV and potentiostatic preparative electrolysis with simultaneous coulometric measurements are also available. A CV 37 model was designed as the cheapest instrument for studies in a relatively new branch of electrochemistry, namely, voltammetry with ultramicroelectrodes. The problem of recording very small currents (picoamperes), arising in these studies, is solved in CV 37 by using a highly efficient amplifier and a highly sensitive current-voltage transducer. Both devices provide an analog representation of analytical signals. Unlike BAS 100B/W and CV 50W, these are controlled in a more conventional way by commutation of controls on a front panel. An XY-recorder from BAS is provided for recording signals [l 1]. The peripheral equipment currently produced by BAS is primarily characterized by their versatility in the use both with hardware-software complexes (BAS 100B/W or CV 50 W) and with polarographs (CV 27 or CV 37). This versatility has been achieved by using a duplicate control system that implements two basic modes: local and remote control. The local control mode is performed by commutation of controls of the peripheral device itself, and the remote control is performed by using the software of BAS 100B/W and CV 50W instruments. Nowadays the product range of the firm includes a C 2 modified cell stand with stationary electrodes, a PA 1 preamplifier unit for work with ultramicroelectrodes, a module for measuring the AC impedance, a CGME stationary dropping mercury electrode, an RDE 1 rotating-disk electrode, and a PWR 3 preparative electrolysis module [ 12]. The computer-aided operation of peripheral devices demonstrates well that the production program of the firm has been carefully thought up. Thus, the hardware-software complex of the most expensive and sophisticated BAS 100B/W instrument provides control over all the working modes of the peripheral equipment mentioned above. The concept of a powerful polarograph for routine analyses implemented in CV 50 W provides this possibility only for modules of a C 2 cell of stationary electrodes and a CGME stationary dropping mercury electrode. The program of manufacturing electrochemical detectors for HPLC and flow-injection analysis is a boundary field between two major lines of activities of the firm, namely, the production of equipment for electrochemistry and liquid chromatography [13]. As a continuation of developments made by E Kissinger, the founder and president of BAS, the firm traditionally produces thin-layer flow cells completed with glassy carbon, platinum, gold, silver, and nickel working electrodes and an Ag/AgCI reference electrode. The layer thickness can be varied within 0.002-0.015 in. and larger by setting Teflon gaskets of various thickness. To minimize pickups and noises, the whole cell is placed into a Faraday cage.

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ELECTROANALYTICAL INSTRUMENTATION FROM BIOANALYTICAL SYSTEMS The firm has a rather original and developed publicity system that completely corresponds to the main motto "Helping Scientists Do Science" Besides printing catalogs that represent the produced equipment as such (i.e., prices, purposes, and functionality), BAS publishes periodicals, which give an insight into the scientific potentialities of devices in actual experiments. Current Separations is the main research journal of Bioanalytical Systems. It provides an exchange of information among customers, future customers, and other scientists who are interested in studying in vivo sampling, microdialysis, liquid chromatography, electrochemistry, and HPLC with electrochemical detection [14]. Qualified BAS customers are automatically supplied with a subscription for this journal. BAS also published so-called Capsules, which are brief, one- or two-page descriptions of interesting experiments performed with the use of BAS equipment. Any device is certain to be completed with several Capsules, which are guidelines for using this device, coupling it with equipment produced by other firms, and so on. Besides, some Capsules are intended for training purposes and give information about characteristic features of performing experiments, which is useful for novice users. More specific issues are printed using a Capsules format. They are CV Notes, which give experimental conditions and results in cyclic voltammetry, and two requests (CV Request and Chromatography Request) allowing customers to send a request for the examination of a sample to the research laboratory of the firm. In this case, a customer should fill out a form including a post address, assumed molecular structure and empirical formula of the test substance, its molecular mass, solubility, and precautions, and also recommend an analytical method and a device of those produced by BAS. Along with the request, it is proposed that a customer send a sample. The minimal amount is 1 mg, 5 mg is better, 50 mg is desirable, and 100 mg is sufficient for a thorough examination. The results of experiments organized in such a way are fruitful for both sides. Scientists obtain information on the physical and chemical properties of test compounds. If the results appear to be interesting enough, Bioanalytical Systems may publish one more issue of Capsules. The use of scientific achievements for advertising knowledge-intensive production is not restricted to only publishing periodicals. The program of equipping analytical laboratories at the Purdue University (Indiana) with BAS analytical instruments is intended to

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develop practical skills of working with the BAS equipment in students trained in analytical chemistry. These skills may become a habit to work with BAS equipment in future. In this regard, the advertising policy of the firm is similar to the policy of the well-known PC provider, Apple Computer, Inc., which also carries out a wide expansion of supplying its computers to US universities free of charge. To summarize briefly, quite efficient equipment for electrochemical analytical methods is produced nowadays. Its manufactures use the achievements of allied branches of science and technology and take into account the trends in analytical chemistry. The use of new ideas in the design of analytical equipment to advantage combined with the use of successes achieved in this way for advertising its own production is typical not only for Bioanalytical Systems but for all known manufacturers specializing in instrument making [15]. We can state with assurance that the possibilities of using electroanalytical equipment in biology, medicine, and environmental control are the main stimuli for searching new scientific and technological solutions [16].

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REFERENCES Kissinger, P.T., Electroanalysis (N.Y.), 1992, no. 4. p. 359. Curr. Sep., 1994, vol. 13, no. 1, p. 1. Curr. Sep., 1987, vol. 8, no. I/2, p. 30. Curr. Sep., 1983, vol. 5, no. 2, p. 20. Curr. Sep., 1983, vol. 5, no. 2, p. 21. PCMagazine (USSR), 1991, no. 2, p. 37. hit. Lab., 1994, voi. 19, no. 4, p. 13. Int. Lab., 1994, vol. 20, no. 5, p. 17. BAS 1993 Catalog: Electrochemical Products and Services, 1993, p. 9. BAS 1993 Catalog: Electrochemical Products and Set'vices, 1993, p. 1 i. BAS 1993 Catalog: Electrochemical Products and Set'vices, 1993, p. 33. BAS 1993 Catalog: Electrochemical Products and Services, 1993, p. 14. BAS 1993 Catalog: Electrochemical Products and Set'vices, 1993, p. 2 !. Curr. Sep., 1994, vol. 13, no. i, p. 38. Budnikov, G.K., Zh. Anal Khim., 1994, vol. 49, no. 5, p. 540. Hewlett-Packard's Peak. Autumn, 1989, pp. 2-11.

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