Books Encyclopedia of Instrumental Methods Instrumental Methods of Analysis. 6th ed. Hobart Willard, Lynne Merritt, John Dean, Frank Settle, xxiv + 1030 pp. Van Nostrand Company, 125 West 50th St., New York, N.Y. 10020.1981. $29.95
Reviewed by William Gutknecht, Environmental Chemistry Department, Research Triangle Institute, P.O. Box 12194, Research Triangle Park, N.C. 27709 Without intending a value judgment, I would say this book can best be called an encyclopedia of contemporary methods of instrumental analysis. In 936 pages of text (excluding experiments and answers to problems) essentially all instrumental methods relevant to present-day analytical chemistry are covered, including atomic absorption and emission spectroscopy, UV, VIS, and IR spectrophotometry, Raman, NMR, and ESR spectroscopy, X-ray methods, mass spectrometry, chromatography, electrochemistry, electronics, computer applications, and automation. The amount of discussion given to each topic is generally in proper proportion to its importance in the field of analytical chemistry; that is, there is no apparent bias toward a particular area as seen in many other texts. Topics discussed that are particularly relevant now include GC/MS, LC/MS, surface characterization techniques including ESC A, SIMS, and Auger spectroscopy, ion chromatography, and use of microcomputers. Within each area, the authors have generally been quite successful in choosing appropriate subtopics. In the area of mass spectrometry, for example, ionization methods discussed include electronimpact ionization, chemical ionization, field ionization and desorption, spark source ionization and thermal ionization. In the area of NMR, subtopics include magic angle spinning, the nuclear Overhauser effect, and spin tickling. In these and other cases, the discussion is much more than minimal, with nearly a page often given to the subtopic. Most discussions are well written and (necessarily) concise. Examples of topics presented with special clarity include the Fourier transform interferometer, the van Deemter relationship, Raman spectroscopy, GC/MS
and LC/MS interfacing, and optimization of liçtuid chromatography. A few, such as discussion of NMR spin-spin splitting and mass spectral fragmentation, are weak in relation to their relative importance. One aspect of the text that is a source of moderate frustration is occasional use of terms not previously defined, for example, angle of specular reflection, Tenax GC, Brewster's angle window, and cryosorption pumping. Discussions of method limitations and applications are generally limited in scope, except in the areas of separations and electrochemistry. Such is the price to pay for being especially comprehensive in equipment descriptions. This weakness will lead to some frustration for undergraduates not especially motivated. This text is well suited, however, for advanced undergraduate courses and graduate courses. Even in these courses though, the student will often need to consult other texts for details, which the authors apparently intended. Indeed, comprehensive bibliographies and literature citings are included with each chapter. Also, problems are provided at the end of each chapter; many of these are quite difficult, however, and require both analytical insight and additional reading. As noted, this reviewer has some reservations about using this text for undergraduate students lacking a sincere interest in chemistry, though not for those who are more highly motivated. The book is, however, an excellent reference source for biologists, engineers, and others who occasionally need to refresh their memories about a method or need to gain a basic understanding of some of the newest methodologies, for example, LC/MS. The text is certainly an excellent starting point for identifying the latest instrumental methodologies that might prove suitable for solving an analytical problem. Espectroscopla de Absorcion Atomica. Vol. I. Introduccion (in Spanish). Luis Ximenez Herraiz. 387 pp. Publicaciones Analiticas, Apartado 2417, Madrid-2, Spain. 1981. $33. 3000 pesetas
Reviewed by Miguel Montaguit-Buscas and Jose Obiols-Salvat, Institute Quimico de Sarria, Barcelona-17, Spain
This book is a collection of practical advice resulting from the author's experience with AA. As announced in the foreword, the book is intended for the uninitiated and, as such, the technique is introduced without complicated equations. This is an ambitious plan, however, given the considerable effort involved in the simplification of something that is inherently complex. The author attempts to present the material so that it can be comprehended intuitively with the help of diagrams, schematics, and examples. Yet even in the first few chapters, which are dedicated to fundamental principles, there is a certain lack of precision in the way terms are used. This makes it difficult to gain a thorough understanding of the concepts that are treated. The book's very title seems somewhat inappropriate since AA is a spectrophotometric method (measuring the intensity of spectral lines) and not spectroscopic (studying the distribution in the spectrum). Another error is the author's use of the term "transmittance" instead of "transmission," the latter being more suited to the ratio of intensities. This results in a confusion of the terms "absorption" and "absorbance." This lack of precision results in absorption being defined as a difference (I 0 -I) and to the use of absorbance units without any indication of their character as logarithmic operators. The way in which the concepts of sensitivity and detection limit are explained is misleading since, after devoting three pages to the calculation of the detection limit, it is said that it is of no practical interest and refers to the tabulated sensitivity values. It is also remarkable that certain important topics, such as the difference between the intensity, or brightness, and the radiative energy are not mentioned. Incomprehensibly, there is no mention of photons in the whole text. In the chapter devoted to instrumentation, greater emphasis is placed on justifying matters of instrument layout (mirrors instead of lenses or safety devices in the burners) than on describing the physical/chemical phenomena occurring in AA so that the analyst can better understand the various types of interferences—as well as the chances of optimizing the analytical results obtained by AA. There are also important omissions in this chapter, such as the correction
ANALYTICAL CHEMISTRY, VOL. 54, NO. 2, FEBRUARY 1982 · 353 A
Books of nonspecific absorption by Zeeman effect and the determination of mercury by the cold vapor technique through a reduction with NaBH 4 . There are important subjects that do not receive the attention they deserve, such as atomization with graphite furnaces and the utilization of deuterium background correctors. Thirty percent of the book is devoted to presenting (in the form of file cards) the conditions for each element—information that can be found in any of the manuals usually provided by the makers of spectrophotometers. This, together with the many shortcomings in the chapters devoted to the preparation of samples, working techniques, installation and auxiliary materials, as well as the difficulty in broadening the text, due to the fact that it is not correlated with the bibliography, makes it unlikely that the reader will be interested in the next three volumes. Several important journals and annual reviews that are devoted exclusively to atomic absorption spectrometry and that provide all the available information on applications and advances are already in existence.
Wilson and Wilson's Comprehensive Analytical Chemistry. Vol. II. Gu Svehla, Ed. xiv + 407 pp. Elsevier North-Holland, Inc., 52 Vanderbilt Ave., New York, N.Y. 10017. 1981. $119.50
Chapters 1, 2, and 3 reviewed, respectively, by John Mandel, Larry Moore, and Richard Durst, National Bureau of Standards, Washington, D.C. 20234 Chapter 1 This chapter covers basic statistical concepts, the law of propagation of errors with application to a number of chemical situations, and linear and nonlinear regression. Some computer programs are also given. Unfortunately, much of the information provided in this chapter is erroneous. Moreover, the likely impact of this chapter, if it receives wide circulation, would be to generate an attitude of "playing statistics," rather than using statistical methodology to gain better insight into the meaning and reliability of measurements. Space does not permit me to cite in detail all the serious errors found in this chapter. I can merely cite a few examples:
• The definitions for confidence levels and confidence limits (p 17) are totally erroneous. The ensuing confusion is perpetuated through several pages, including Figure 9 which, in spite of its title, has nothing to do with confidence intervals. • On page 35, homogeneity of variance is confused with normality, and then some unintelligible procedure— based on repeated applications of Dixon's test—is given that seems to permit rejection of up to one-half the number of observations! • The analysis of two-dimensional arrays of data (pp 45-51) is treated for the fully general case of unequal frequencies in all cells. The author seems to be totally unaware of the problems inherent in this situation, nor does he seem to be aware of the problems inherent in pooling various sums of squares. Nowhere does he invite the reader to "look at his data," but rather seems to advise him to plunge into complicated calculations and significance testing indiscriminately. • The recommended treatment of straight line fitting when both variables are subject to error (pp 109-113)
Our new multi-syringe six paks.
Take your choice. Our economical C-160 six pak come in both fixed or removable-needle versions for sampling into GC or LC systems. GC or LC Starter Kits are available in selected styles and varying syringe sizes to complement various applications. In addition, our six paksof Heavy-Duty Syringes for Hewlett Packard Automatic Samplers feature double-reinforced Teflon* tipped plungers. Most six paks include two replacement plungers and two needles (RN version) for added value. For more information contact your nearest chromatography supplies dealer or Dynatech Precision Sampling Corporation, P.O. Box 15886, Baton Rouge, Louisiana 70895. DYNATECH Telephone (504) 927-1128. •Dupont TM
PRECISION SAMPLING CIRCLE 59 ON READER SERVICE CARD
354 A · ANALYTICAL CHEMISTRY, VOL. 54, NO. 2, FEBRUARY 1982
CORPORATION
Books is meaningless: There is no such thing as a line of "best fit" without specifi cation of the error structure. Here again, the author seems to be unaware of the deeper conceptual aspects of this problem. These are merely some examples to illustrate the serious inadequacy of this chapter as a guide to chemists in the use of statistical methodology. While some of the information in this chapter may be useful to analyti cal chemists, it, unfortunately, also
contains such a profusion of outright errors and misinformation about even the most basic statistical concepts that it cannot be recommended to chemists as a reliable source of infor mation about statistical methodology. Chapter 2 Mass spectrometry is a broadly de fined and historically rich discipline with many rapidly changing facets. This observation underlines the diffi culty in summarizing succinctly all in
^ ^ P u r g e and Trap Concentrators α Dynamic Headspace Analysis
π Meet or Exceed EPA Requirements for THM and Priority Pollutants • Dry Purge for Reduction of H 2 0 Interference If you are analyzing trace quantities of volatile pollutants m water by gas chromatography, you will want to know about Tekmar*". purge and hap conc-entrtttor-i. We offer a fully automatic mode! and a newlyintroduced serni-dutomatic system, described below
of desorb to start QC programmer and data system ALS • Automatic Sampler for LSC-2. Witi process up to 10 purqe and trap or dynamic headspace samples automatically
Tekmar s LSO> are finding their way info industrial laboratories, too, where they are used by research and cjuahty control people LSC-2 • Fully automatic system Operates as master or siave relative to logic m your QC. bSC-3 « $erm automatic system. Provides contact closure at start
Dynamic Headspace Analysis * Tekmar puige and trap concentrators cars be a very cost-effective addition to rf quality control laboratory foi uses other than priority pollutants and THMs in water For example, the concentration ofvolatileorganlcs outclassing from solid or liquid samples as in aroma dnd flavors analysis.
Dry Piirge • Featured on LSC-2 and LSC3 to reduce water interference with gai chiomaioijraphs utilizing & photoion nation detector Mot only do these purge and trap concentrators feature reliable performance, they are priced within most laboratory budgets The tbC i ts available for less than $3000
For more mforination about hnw the LSC uisti umenis can be used m \our speuFit application, call 800-543-4461. (in Ohio
