Books

Recruiting CE users

Capillary Electrophoresis in Biotechnology and Environmental Analysis H. Parvez, P. Caudy, S. Parvez, and

P. Roland-Gosselin, Eds. VSP P.O. Box 346 3700 AH Zeist The Netherlands 1997, 484 pp.. $154

Having a single volume on CE is useful be­cause the technology is now accepted and will be around for a long time. However, ,i ts considered new in many circles of biotech­nology and environmental analysis, and therefore, the recruitment of new converts to the field is desirable. This volume also pro­vides a nice reference and well-wriiten re­views of applications for those scientists who already use CE. AH areas of CE are covered. In general, each chapter is well written and concise. The artwork and other graphics are well done and easy to understand.

The section on innovations covers CE in-line with MS (CE/MS), preconcentra-tion techniques, and laser-induced fluores­cence detection. CE/MS has received much attention, and papers dealing with its uses or technological improvements are found throughout the contemporary litera­ture. This treatment is outstanding in giv­ing the reader a basic understanding of CE/MS in terms of what was known up to 1994, but recent novel applications and techniques that pushed CE/MS forward are not described.

The proteins and peptides section con­tains literature citations that, with the ex­amples provided, form logical templates for researchers or quality control managers to develop CE for their own uses. Because every protein differs, however, certain properties of an individual protein will con­tribute to a protein's electrophoretic migra­tion time, which makes it difficult to ade­quately describe in a single chapter the CE options for proteins. Thus there are no sim­ple CE formulas for resolving basic or com­plex mixtures, as there are for proteins us­ing sodium dodecylsulfate polyacrylamide gel electrophoresis (SDS-PAGE).

The section on drug abuse and interac­tions focuses on the use of HPCE for rmall-molecule detection and binding in biological samples. The use of CE for binding studies may be the signature application for CE, be­cause no other technique offers such ease and simplicity for studying binding phenom­ena. This section also describes how CE can be used for separating catecholamines. The chiral separation of enantiomers and the separation of anions and cations also have their own sections.

One challenge in putting this volume together was in selecting the ideal contrib­utors. In addition, it was necessary that the content be as up-to-date as possible to avoid making the volume obsolete before it appears on bookshelves. The first objective was met by the use of first-rate scientists who are truly experts in their respective fields. The second objective, however, was not. The book was published in 1997, and all the references in the book are to papers published in 1994 or before, which ex­cludes of the applications for CE that could enhance its popularity and attract investigators from other research fields. For example there is no description of cap­illary electrophoretic migration shift as­says which are used to monitor the appear­ance or activities of DNA transcription fac­tors in biological cell extracts However

the gap between the 1994 citations and the 1997 publication date does not detract from the many descriptions of the fundamentals of CE, which are very well done.

Having the main sections and the chap­ters numbered for reference would have been helpful.

Reviewed by Frank Robey of the National Institutes of Health

More than a cookbook

Instrumental Methods in Food Analysis J.R.J. Paré and J.M.R. Bélanger, Eds. Elsevier Science P.O. Box 945 New York, NY 10160 1997, 506 pp., $287.50

This multi-author volume covers the most important techniques of food analysis, as well as some emerging techniques. The book is organized into 11 relatively self-contained chapters that can be read and understood without reference to the rest of the book. Four chapters focus on separa­tions by chromatography and CE, two cover sample preparation by supercritical fluid extraction and microwave-assisted processes, and the remaining five deal with spectroscopic (FT-IR, atomic absorption/ emission/fluorescence, and NMR) and electroanalytical techniques.

344 A Analytical Chemistry News & Features, May 1, 1998

A pleasant surprise is the consistent emphasis on fundamentals. Few detailed discussions of applications are included, as might be expected. Chapters open with a brief historical perspective on their respec­tive techniques, usually with citations to some of the seminal early references. Phys­ical and analytical chemical principles un­derlying each technique form the bulk of the text and are covered with remarkable completeness.

Chromatography occupies Chapters 1-3 (92 pages total), with the first chapter on general fundamentals, the second on HPLC, and the third on GC. The 100-page chapter on electrochemical methods, by J. G. Dick, is particularly detailed. The MS chapter (28 pages) focuses on magnetic sector instruments and does a good job of introducing basic principles as well as more advanced techniques, such as linked scans. There is little mention of quadrupole and ion-trap mass analyzers, both of which are far more prominent than magnetic sec­tor instruments in contemporary laborato­ries. The omission of high-precision iso­tope techniques that are used to detect food adulteration is disappointing.

The reader interested in learning basic principles or looking for a reference to rein­force them would profit most from this vol­ume, but those looking for an analytical protocol or detailed instructions on meth­ods for analysis of a particular sample will find this book less helpfull The index is only two and a half pages. It is likely that the editors have succeeded in at least one of the goals mentioned in the preface—the monograph "will act as a mentor to all those graduate students in food science that have an inclination toward the analyti­cal side of their field." Unfortunately, the extraordinarily high price compared with established texts will that few stu­dents will it It can be recommended confidently to analytical chemists working in food-related fields who desire a scholarly

treatment of relevant modern instrumental methods.

Reviewed by J. Thomas Brenna of Cornell University

One molecule at a time

Single-Molecule Optical Detection, 11 i I.;;;!.;.'

and Spectroscopy

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Single-Molecule Optical Detection, Imaging, and Spectroscopy T. Basché, W. E. Moerner, M. Orrit, and

U. P. Wild, Eds. VCH Postfach 10 11 61 D-69451 Weinheim Federal Republic of Germany 1997, 250 pp.. DM 198

Single-molecule detection (SMD) is clearly one of the most fascinating and potentially evolutionary tools for studying molecular behavior and for sensitive analytical mea­surements. In the first chapter of this mono­graph, the author gives an excellent survey of the various considerations that opened the door for single-fluorophore detection. Al­though the discussion centers around solids, the criteria readily extend to liquid samples. It is a must-read summary for anyone who wants to learn about this research field and compares favorably with the best A-page articles in Analytical Chemistry.

The next three chapters describe specific solid-state systems in which SMD has pro­vided unique insights into molecular dynam­

ics. For the more physically incllned, ,he chapter that follows reviews some of the the­oretical framework relevant to SMD. We often hear about homogeneous and inhomo-geneous line widths. SMD actually reveals the inhomogeneity among a population of molecules. For ordered media, this feature becomes a sensitive probe of the local micro-environment. Other effects such as satura­tion in absorption, fluorescence lifetimes, and polarization show discrete behavior that is not observed in bulk experiments. Under certain conditions, one can select a molecule and probe its properties over the period of weeks which may represent the ultimate in high-density optical storage. As for sensitive analytical applications we need 1~0 WOt*TV

about the concept of selectivity Different spectral features lifetimes polarization and so forth need not come from structurally different molecules Normally we think of NMR and electron paramagnetic resonance (EPR) as spectroscopies that are completely separate from optical techniques; but the next chapter describes results from ODtically detected magnetic resonance which is NMR of individual molecules C ranted the s heme relies on having p-ood onriral m bores for excitation and detection How

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tails of selected molecules is exciting. Near-field optical microscopy is a tool for

achieving spatial resolution below the dif­fraction limit of light waves. Combining this with single-molecule studies is natural. Al­though one need not rely on near-field mi­croscopy to isolate single molecules for study, the superior spatial resolution is find­ing use in subcellular structures, molecular aggregates, and nanoscale heterogeneities.

The book concludes with a chapter on liquid-phase measurements, a topic related to most analytical chemistry practice. Nu­merous schemes are surveyed, including sheath flow, confocal microscopy, micro-droplets, total internal reflection, and capil­laries. An intriguing question is what hap-

Analytical Chemistry News & Features, May 1, 1998 345 A