Pulsed Electrochemical Detection in High-Performance Liquid

Eastman Chemical Company, Kingsport, TN 37662. J. Chem. Educ. , 1998, 75 (12), p 1555. DOI: 10.1021/ed075p1555.2. Publication Date (Web): December 1, ...
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Book & Media Reviews Pulsed Electrochemical Detection in High-Performance Liquid Chromatography William R. LaCourse. Techniques in Analytical Chemistry Series. Wiley-Interscience: New York, 1997. 420 pp. Figs and tables. ISBN 0-471-11914-8. $69.95.

This book, the latest in a series covering contemporary analytical techniques published by Wiley Interscience, is the most thorough review of this important high-performance liquid chromatography (HPLC) detection technique to date. Although it affords a very thorough background and introduction to the basic science behind the technique that could be used for an advanced undergraduate or graduate studies course, it is written with the chromatographic practitioner in mind. Pulsed electrochemical detection (PED) is the generic name given to a set of electrochemical detector operating modes in which a pulse program is applied to a noble-metal working electrode to bring about continuous electrode surface regeneration, in order to overcome deactivation by surface fouling. This method of detection in HPLC has become indispensable in many applications in which the analyte of interest is weakly absorbing in the UV but does possess an electroactive polar constituent such as a hydroxyl, amine, or sulfur-containing group. PED techniques have seen particular use for the selective and sensitive detection of carbohydrates and small amine compounds. Organization of the book is logical and flowing. The first few chapters introduce the history of the detection technique and impart the fundamental electrochemical knowledge necessary for the reader to understand how and why the technique works the way it does. The second chapter, Electrochemical Fundamentals, is an especially impressive review of fundamental electrochemistry, presenting as it does a selective review of pertinent background information. Rather than weaving a tortuous path through the entire field of electrochemistry, LaCourse steers a straight and narrow course that touches upon only those areas that are important for the understanding of the PED techniques presented in later chapters. With the basic information dealing with electrochemical science out of the way, the book then reviews the interface between electrochemistry and high-performance liquid chromatography. After reviewing amperometric electrochemical detection and cell design considerations, the author takes up the topic of using pulsed waveform programs during detection

Edward J. Walsh Allegheny College Meadville, PA 16335

to overcome the shortfalls of nonpulsed detection. He explains in detail the mechanistic differences between the three major modes of detection in PED, namely, (i) direct detection at oxide-free surfaces, (ii) direct oxide-catalyzed detection, and (iii) indirect detection at oxide surfaces. From a fundamental knowledge of the state of the working electrode surface as a function of potential, LaCourse guides the reader to an understanding of which mode of detection works best for what compound. Turning to the more practical aspects of using PED in HPLC, the author includes a very useful discussion of waveform optimization using pulsed voltammetry (PV). In this technique, parameters such as pulse duration and potential can be varied in an automated fashion while monitoring the background-corrected response towards the analyte. As the author points out, using this technique to optimize waveform parameters can save the analyst significant amounts of time, effort, and sample when compared to the more common practice of recording the magnitude of the detector response by repeatedly making injections while manually adjusting the parameter undergoing optimization. Because of the absence of commercial PV instrumentation, LaCourse includes details on the instrumental aspects of performing PV experiments, including an ASYST Scientific Software program for generating the PV waveforms. The next portion of the book provides detailed information on the specific applications of PED, by compound class, published to date. This section is immensely informative as a guidepost to those with a specific application in mind. The last sections of the book deal with instrumental aspects of PED and the author’s perception of where the technique will go in the future. In summary, this is an excellent review of pulsed electrode techniques of detection in HPLC. It is thorough and well written, serving as an outstanding review of the theoretical aspects of the technique while simultaneously being a useful, practical guide for the HPLC practitioner wishing to make immediate use of the technique. John K. Sanders Eastman Chemical Company Kingsport, TN 37662

JChemEd.chem.wisc.edu • Vol. 75 No. 12 December 1998 • Journal of Chemical Education

1555