Anal Bioanal Chem (2004) 378 : 1401–1402 DOI 10.1007/s00216-003-2482-0

E D I TO R I A L

Cynthia K. Larive

Bioanalytical Nuclear Magnetic Resonance Spectroscopy

Published online: 4 February 2004 © Springer-Verlag 2004

This special issue on analytical and bioanalytical applications of Nuclear Magnetic Resonance Spectroscopy (NMR) includes a selection of reviews, original papers and ‘Trends’ articles that have been accepted for publication following peer-review. Although this selection of papers cannot constitute a comprehensive review of an area as diverse as NMR, it does highlight many of the current trends of this field. NMR is arguably the premiere analytical method for the structure elucidation of organic molecules. Functional group analysis for an unknown compound can often be accomplished by simple inspection of chemical shifts and relative integrals. Spin-spin coupling information, especially when accessed through 2D NMR experiments, can be used to stitch together the various functional groups to define the structure of the molecule. NMR characterization of phytochelatin peptides, natural organic matter and pharmaceutical solids is discussed in several manuscripts. In an accelerated publication, the use of a novel isotopic labeling scheme along with multidimensional NMR analysis is introduced as a new strategy for polymer characterization. A ‘Trends’ article discusses instrumental developments for high throughput analysis of combinatorial libraries. The analysis of paramagnetic hemes and hemoproteins is also reviewed in this issue. NMR is also an important analytical method for quantitative analysis because the intensity of the response depends only on the molar concentration of the analyte and the number and type of nuclei producing the spectral response. This means that a pure standard of the analyte is not required and analyte signals can be quantified using any standard that has the appropriate chemical and spectral properties. This feature of NMR is widely used for comparative quantitation in the emerging field of metabonomics, as illustrated in an article in this issue. The dynamic properties of chemical reactions can also be studied by NMR. Indeed, a large number of NMR paC. K. Larive (✉) Department of Chemistry, University of Kansas, 1251 Wescoe Hall Dr., Lawrence, KS 66045, USA e-mail: [email protected]

rameters have been used to study dynamic processes, including chemical shift, line width, dipolar relaxation rates and diffusion coefficients. This issue includes articles using relaxation rates and NOEs to study molecular dynamics and solvation. NMR diffusion measurements are an important analytical tool since they can relate chemical shifts to molecular size. Several manuscripts report on developments related to diffusion NMR. A significant contribution of NMR to analytical chemistry has been the determination of equilibrium constants, including acidity constants, binding constants and partition coefficients. In addition to these macroscopic equilibrium constants, NMR has been used to evaluate microscopic equilibria, as described in two reviews. Chiral recognition of crown ethers and their ytterbium complexes has been studied using conventional NMR methods, while the chiral separation of nanomole quantities of atenolol has been accomplished using on-line isotachophoresis-NMR using microcoil detection. Another article reports a novel probe with dual Helmholz microcoils designed for difference spectroscopy, and the use of this probe for the detection of ligand-protein binding. The incorporation of NMR into undergraduate research is discussed in a ‘Trends’ article. One limitation for investigators who may wish to make use of this technique in their research is the expense of modern NMR spectrometers, especially those operating at very high fields. As described in another ‘Trends’ feature, the establishment of a collaborative NMR laboratory at the Pacific Northwest National Laboratory allows investigators access to stateof-the-art instrumentation that can even be accessed remotely, allowing investigators to perform experiments from their own laboratory over the internet. In conclusion, it is my privilege, as Guest Editor of this special issue on analytical and bioanalytical applications of NMR spectroscopy, to present this collection of articles. I would especially like to thank all of the authors for the time and effort spent in the preparation of their papers. I would also like to thank the Editors for the opportunity to provide the Journal with important contributions in the field of NMR spectroscopy.

1402 Cynthia Larive is Professor of Analytical Chemistry at the University of Kansas. Her research involves the application of NMR spectroscopy to problems in bioanalytical and environmental analytical chemistry. Current areas of research focus include the development and application of microcoil NMR probes, the use of NMR diffusion measurements to study ligand-protein binding, structure elucidation of metabolites and transformation products of pesticides and pharmaceuticals using LC/NMR, cITP/NMR and LC/MS/MS, and the functional group characterization, metal complexation and aggregation properties of humic substances. For additional information about her research, please visit http://www.chem.ku.edu/CLarive/.