Books Interfacing and Programming An Introduction to Microcomputers, xix + 394 pages. Adam Osborne and Asso ciates, Inc., 2950 Seventh St., Berke ley, Calif. 94710. 1975. $7.50
Reviewed by Raymond E. Dessy, Dept. of Chemistry, Virginia Poly technic Institute & State University, Blacksburg, Va. 24061 With the current craze in micro computers, a plethora of material is being published concerning them. Aimed a t the hobbyist or technician, this material purports to teach the skills of interfacing and programming, a task which it usually fails in. W h a t the scientist has needed is a text which intends from the very beginning to convey the philosophies of this rap idly changing area to the well-educat ed but computer-illiterate persons and to present generalized concepts for the majority of the text, rather t h a n pro viding a shop manual on one micro computer. This attitude is of extreme importance at the low end of the power spectrum of microcomputers, where the devices will largely substi tute for hard-wired implementation of logic. This area is, and will remain, in an extreme state of flux. Continuous changes in product nature and config uration will occur until no further price reductions are possible. There fore, it is important t h a t the inter ested scientist be exposed to general ized information explaining bus archi tecture, instruction sets, and data handling characteristics. Then, when he is actually exposed to new ma chines in the next few years, he can easily adapt to the subset of opera tional characteristics t h a t it repre sents. For example, exhaustive exami nation of the instruction set of the Intel 8000 series CPU's, with three rather primitive modes of addressing, does not make adequate foundation for utilization of the Motorola 6800, which has a far superior repertoire of commands. T h e present text is an ideal source book serving the needs indicated. Its introductory chapters make it suitable for use by individuals who have had NO programming or hardware experi ence. And the BOLD-FACE/light face format makes it possible for the more advanced reader to skim until he finds material which is new or (and this is perhaps its unique point) material presented in a very novel manner. T h e last pages of the text introduce
the specific architecture of the most popular microcomputers. Browsing in this area makes it possible for a poten tial user to formulate questions t h a t will help in deciding which micropro cessor will be suitable for his task— even if the changing technology intro duces new CPU's. This capability is developed by the continuous use of bench marks and architectural com parisons, allowing the reader to devel op his skill in evaluating the needs of his instrument, and the powers of var ious hardware configurations and soft ware command sets. And the price is delightful. A Textbook of Pharmaceutical Analy sis, 2nd Ed. Kenneth A. Connors, χ + 611 pages. John Wiley & Sons, Inc., 605 Third Ave., New York, N.Y. 10016. 1975. $18.95
Reviewed by Gary D. Christian, Dept. of Chemistry, University of Washing ton, Seattle, Wash. 98195 T h e organization of this second edi tion of Professor Connors' text is basi cally the same as the original. Its first three parts (18 chapters, about 80% of the text) deal with principles of vari ous analytical techniques, and the sec ond three (nine chapters) deal with applications of these techniques in typical pharmaceutical analyses. There are new chapters on magnetic resonance spectroscopy, mass spec trometry, and analytical toxicology and new sections on ion selective elec trodes, ORD and CD, and high-pres sure liquid chromatography. An organic chemistry course is a necessary prerequisite since structures of pharmaceutical compounds are fre quently given. Also, a physical chemis try or physical pharmacy course would be helpful, since the mathematical treatments are frequently quite rigor ous. T h e appendix presents a short sec tion on volumetric techniques and cal culations for those who have not had an introductory quantitative analysis course. This coverage is probably in adequate for most beginning students. T h e chapters on titrimetric analysis treat primarily the equilibria involved. Gravimetric analysis is not covered, nor is the use of analytical balances. T h e emphasis in chapters regarding instrumental techniques is on princi ples and pharmaceutical applications, rather than on instrumentation. This
approach has advantages in a text of limited space. Although careful attention is given to equilibrium principles, less care is shown in discussing applications. For example, on page 70, the action of the Mohr titration indicator is described qualitatively with no quantitative in dication of its limitations regarding concentration required for silver chromate to precipitate at the equivalence point. On page 71 the text states t h a t most halide titrations require nonacidic conditions, but no reason is given. On page 97, the use of stannous chlo ride to reduce iron(III) to iron(II) prior to titration with an oxidizing agent is described, but no mention is made t h a t the excess stannous chlo ride must be destroyed. On pages 99 and 104, precautions in using a starch indicator are not listed. Also, some de tails in experiments are omitted. In Experiment 1.1, for example, direc tions are given for preparing a dilute carbonate-free sodium hydroxide solu tion from a saturated solution, b u t nothing is said of how to separate the insoluble sodium carbonate before dilution. In Experiment 1.2 the solu tion is boiled near the end point in ti trating potassium bicarbonate, but no purpose is given. In general, however, selection of experiments is good throughout. Electrode potentials are introduced in the potentiometry chapter fol lowing the chapter on oxidation-re duction titrations. Hence, redox titra tions are discussed qualitatively. This is quite well done except in spots, for example, when the function of manga nous ion in the Zimmerman-Rheinhart reagent is described as preventing "consumption of permanganate by chloride". Indicator theory could not be given as in previous chapters. P a r t Two on physical and instru mental methods is at a uniformly com prehensive level. In the spectral meth ods chapters, particularly, excellent discussions are given correlating mo lecular structure to spectra. T h e chap ter on voltammetry is less rigorous. T h e residual current in polarography is said to be due primarily to impuri ties, and the charging current is not even mentioned. Hence, when describ ing modern, more sensitive polarographic techniques, the reason for their improved sensitivity is not given. Coulometric titrations are mentioned only briefly in a summary of P a r t
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Books Two. Professor G. Patriarche and coworkers have demonstrated the utility of this technique in pharmaceutical analysis. Likewise, atomic absorption spectroscopy receives brief attention, and this is surely one of the methods of choice for trace metal analysis in pharmaceutical preparations. The solvent extraction chapter emphasizes the separation of organic substances but does not discuss the extraction of metal chelates. The chapters on functional group analysis are very appropriate for a pharmaceutical analysis course and are well presented. From the student's viewpoint, more example calculations throughout would have strengthened the text. By the author's admission, the text sometimes exceeds the undergraduate level. Despite some uneven coverage, this text has much to offer. Except for the deficiencies as pointed out above, it is written with care, is readable, and contains much useful theoretical and practical information. Thin Layer Chromatography. Victor W. Rodwell. Four cassettes (playing t i m e , 4 h and 15 min) + 65-page manual. Educational Activities Dept., A m e r i c a n C h e m i c a l Society, 1155 16th St., N.W., Washington, D.C. 2 0 0 3 6 . 1975. $80
Reviewed by James M. Bobbitt and Sally E. Knowles, Dept. of Chemistry, University of Connecticut, Storrs, Conn. 06268 This audio course is designed as an introduction to the theory and the practical applications of thin-layer chromatographic techniques. Essentially, it consists of a series of lectures (on tapes) and a printed manual containing the slides and tables used in the lectures. Some additional appendices and bibliography are included in the text. We examined the course in two ways. First, one of our senior undergraduate students in biology and chemistry, Sally E. Knowles, "took" the course. Miss Knowles has had some laboratory experience in TLC. She reported that the course was superb and that it had given her a much better understanding of the theory and background involved in the technique. She did feel that at least a small amount of experience was necessary to obtain the full benefit of the course. She also pointed out some errors. Thus, for the student, and therefore for the designed purpose, the course is quite successful. When I listened to the course from a considerably more experienced and
knowledgeable standpoint, the results were somewhat more qualified, albeit still successful. The introduction and the general theoretical background (such as it is in TLC) are very well presented. In particular, the presentations of the strengths and weaknesses of TLC compared with other chromatographic methods, the differentiation between adsorption and partition chromatography, and the discussion of solvent demixing are very good. The course, as would be expected from the background of the author, is strongly slanted toward biochemistry with the accent on qualitative and quantitative aspects of the technique. Very little mention of preparative TLC (of prime interest to the organic chemist) is made. Considering the topics left out, it seems that an inordinate amount of time has been spent describing the structures of the classes of biochemical molecules. There are several errors in the slides in the text and a few in the lecture material. Specific errors can be found in slides 3.3 ("standard" and "sample" reversed), 4.4 (incorrect structure for leucine), 4.2 (increasing, not decreasing polarity), and 9.2 (this is not dichlorofluorescein). From the lecture, most alkaloids do not have a formal positive charge. Only the quaternary ones, a very small number, do. I am disturbed that the author has relied upon, and cited, only secondary references for many of his slides. For example, the multiple spotting device in slide 7.2 was invented by Max Morgan of the University of Connecticut and published in the Journal of Chromatography. The data in slide 6.5 were recorded and published by Stahl. In these cases and others, the people who did the work are not cited. While no two authors would agree on what should be included or excluded from a text or course, it does seem that such techniques as multiple development, theoretical optimum development, and preparative TLC should have been given more attention. Although the differentiation between adsorption and partition TLC is well presented, the author does not state clearly just how the stationary liquid for partition TLC is put in place. As noted above, the course is quite successful for persons with an interest in biochemistry and, to some extent, chemistry. Chromatographic Science Series, Vol. S: Quantitative Analysis by Gas Chromatography. Josef Novak, ix + 218 pages. Marcel Dekker, Inc., 270 Madison A v e . , New York, N.Y. 10016. 1975. $16.75
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Reviewed by Csaba Horvath, Dept. of Engineering and Applied Science, Yale University, New Haven, Conn. 06520 It is saddening to see the decline of the "Chromatographic Science Series" that has claimed such outstanding pieces of the chromatographic literature as Giddings' "Dynamics of Chromatography", Snyder's "Principles of Adsorption Chromatography", and "Multicomponent Chromatography" by Helfferich and Klein. This reviewer feels that the last volume, which deals with quantitative analysis by gas chromatography, compares very poorly with the previous ones and wonders why it has been included in the series. The author states that "quantitative analysis by gas chromatography can be looked upon as a self-contained analytical discipline having its own consistent theory". Whereas the subject is of great analytical significance, the reader of the book who wants to take advantage of this theory in practical applications will find the statement grossly exaggerated. We are confronted with a host of relatively simple equations owing to the author's quodlibetic effort to compound a theoretical framework for the treatment of chromatographic signals under certain ideal conditions. Those who would benefit from the quantitative discussion of a number of techniques employed in practice will likely be confused by the abstract approach of the author; those who are seriously interested in the subject will find the treatment trivial and of little value in view of the complexity of the overall chromatographic process. It is disappointing that the two detectors that are the workhorses of gas chromatography, the catharometer and the flame ionization detector, have received relatively little attention. The importance of sample introduction has not been given sufficient weight. The outstanding work by Guiochon on the precision attainable in GC is scarcely mentioned. In view of the recent developments in computerization of gas chromatography, particularly in the field of quantitative analysis, the meager treatment of this area renders the book largely obsolete. Despite all of this, the author's effort to organize the problems encountered when dealing with detector responses and sample preparations with standards and deriving the pertinent equations is not without merits. The book can be used as a reference by those few who do further research in this area or intend to use gas chromatography for physicochemical mea-
surements. More importantly, how ever, it focuses our attention on the difficulties in achieving high precision in chromatography which begins with the sample preparation and ends with the quantitative evaluation of the chromatographic data. Yet, many problems such as the effect of derivatization and the evaluation of radioac tive peaks which have not been treat ed in this book are of great importance in life sciences. Thus, this book's main contribution is to emphasize the need for a treatise which deals in depth with the quanti tative aspects of both gas and liquid chromatography and can guide the vast number of practicing chromatographers in both fields. T h a t approach should not look upon the subject as a self-contained analytical discipline b u t as the essence of chromatographic analysis which involves much more than what the present book offers. T h e last thing we need is trying to force this multifarious subject into the Procrustean bed of a "consistent theo ry", which is very limited at this state of art, and ignoring the convoluted na ture of the chromatographic method that is still an art when it comes to the quantitative analysis of complex sam ples the analytical chemist has to cope with day by day.
TWO TEKMAR ANALYTICAL WILLS, Two Sizes Your Choice The Model A-20 can handle samples up to 300 ml/volume. The stainless steel chamber is 3" in diameter and 23Λ" deep. The power ful 550W motor prepares hard, brittle sam ples in seconds. Comes with a built-in 15 minute timer. The A-10 can handle samples up to 50 grams. Built-in on/off switch, or use it with its accessory timer. Also available is a cryogenic attachment for milling of heat sensitive materials. Both units have a closed loop tube around the chamber for temperature control. Chamber and cutter are easily dissembled for autoclaving and cleaning. To learn about Tekmar Analytical Mills, use the reader service card, or call Tekmar collect.
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New Books Resinography. T. G. Rochow and E. G. Rochow. xiv + 1 9 3 pages. Plenum Pub lishing Corp., 227 West 17th St., New York, N.Y. 10011. 1976. $25 The contents of this book are selfevident from the subtitle, "An Intro duction to the Definition, Identifica tion, and Recognition of Resins, Poly mers, Plastics, and Piberts". T h e text is derived from the resinography course taught by the senior author at the School of Textiles, North Carolina State University in Raleigh, over a five-year period beginning in 1970. T h e intended audience is graduate level chemists with some knowledge of macroscopy and microscopy. The plan of instructional material is simple. First, the student is introduced to the descriptive characteristics of known samples of resins, polymers, and plas tics, and then the student is encour aged to identify unknown specimens. Although the emphasis is on macroscopical and microscopical descrip tions of structure and morphology, other analytical techniques such as x-ray diffraction, electron and N M R spectroscopy, and absorption spec troscopy are also discussed.
Now... ^ a continuously var iable fluorescence detector for = „ liquid chromatography monochromator and readily adjustable emission wavelength in conjunction with a very accessible 5 ul flow through cuvette makes detection at picogram levels possible. The 970 Spectrofluro monitor can be attached and operated in conjunction with existing HPLC systems. Write today for complete technical literature. Schoeffel Instrument Corporation 24 B o o k e r Street, W e s t w o o d , N. J. 07675 · 201-664-7263
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CIRCLE 190 ON READER SERVICE CARD ANALYTICAL CHEMISTRY, VOL. 4 8 , NO. 9, AUGUST 1976 · 779 A
