A
SYMPOSIUM
T e a c h i n g of A n a l y t i c a l C h e m i s t r y Introduction
Undergraduate course work in analytical chemistry, likc that in the chemistry curriculum as a whole, is undergoing thorough reexamination and experimentation. Earlier analytical symposia, chaired by Laitinen and Bowers, respectively, featured instrumental analysis,' and the movement of "quant" from its traditional place in the second year to either the first year or the third.% The papers selected for the present symposium all share one point in common-they attempt to illustrate basic analytical principles using currently interesting chemistry and modern instruments for physical measurements. The present symposium deals primarily with quantitative aspects of analysis though this does not imply that the qualitative and structural aspects are not important. Largely, it reflects the fact that limitation of the scope would permit a more leisurely and more thorough discussion. Discussion of quantitative measurements in first-year chemistry has been omitted because the trend in that direction seems to he approaching general acceptance. At the same time, there is a growing realization that, although quantitative measurements are a necessary part of quantitative analysis, there should be a place where analysis, i.e., the making of analytical decisions, is required of the student. Such decisions imply that a critical evaluation has been made of a variety of possible procedures for solving a problem, and that matrix effects and other possible interferences have been taken into account. It also implies that the student has checked the calibrations of his instrument and has standardized his reagents. Finally, it implies that due consideration has been given to two hallmarks of a good analysis: The selected procedure will give no more or no less than the desired accuracy and precision, and the conditions for the procedure will be optimized so as to permit the analysis to be completed in a minimum of time. Those demands, when properly satisfied, require much more than the purely mechanical performance of a quantitative cookbook procedure selected at random from a compilation of methods. The papers that follow represent different approaches to the presentation of modern quantitative analysis of chemical systems. An approach that can be undertaken without revision of the overall curriculum is one in which the experiments are changed within a given course. Professor Dilts has Presented at the Joint Symposium on The Teaching of Analytical Chemistry a t the 152nd Meeting of the American Chemical Society, New York City, Sept,ember, 1966. 'LAITTNEN,15. A., J. CHEM.EDUC.,33,422 (1955). 'BOWERS,R. C., J. CHEM.EDUC., 37,276 (1960).
greatly modified the sophomore course in quantitative analysis to include a variety of quantitative separation techniques. In addition, he plans in the future to incorporate experiments involving organic analyses as well as inorganic. Certainly the omission of organic analyses from most classical quantitative courses might well have led the studentas to infer that quantitative analysis was limited to inorganic systems. To facilitate the introduction of quantitative organic experiments, some schools have moved analytical to the junior year. For a junior-year course, Professor Rechnitz makes a case for incorporating kinetic experiments so as to introduce the student to their utility for quantitative purposes, and also to emphasize the fact that quantitative analyses can be made under other than equilibrium conditions. Certainly an outstanding example of the quantitative application of kinetic measurements is the determination of enzymes in biochemistry. In another approach, the combination of analytical with either physical or organic chemistry has been explored. The combination with physical reported by Professors Diefenderfer and Daen (not printed with this symposium) represents an economical way to discuss a basic physical phenomenon, the principles (and limitations) of the instruments, and the types of errors encountered in quantitative applications. The corresponding combination with organic, described by Professor Grob, has the advantage that students are analyzing compounds they have synthesized, thereby gaining a real appreciation for sampling errors and the need for high purity before starting to characterize a compound. In addition, they realize the need for a variety of approaches, both chemical and instrumental, to prove the existence of a compound. An even more ambitious reorganization has been attempted at UCLA. Professor Pecsok reports the efforts of that faculty to revise the entire laboratory program so as to incorporate modern instruments from the first year. In addition biochemistry is made an integral part of the basic curriculum at an early stage, thereby making the chemistry program more attractive for biology and premedical students. Analytical is presented as a laboratory that accompanies the lectures in organic and biochemistry. The "basic core" of courses requires only three years and allows one year for advanced electives. The Hammond Curriculum (not reported at this symposium) proposes a more drastic revision along lines on which the Westheimer Report was based, i.e., "Chemical Dynamics," "Structural Chemistry," eto. I t is possible that such a sharp departure from convention
may encounter a practical, but not insurmountable, problem such as explaining to medical schools how their specific requirements (defined in tenns of classical courses) have been met. By retaining classical names for their courses, the UCLA faculty have avoided that problem. The final paper in the symposium approaches the teaching of instrumental analysis in a way different from that used in most places. Professor Morgenthaler emphasizes the functions of components, including electrical circuits, by having the students assemble working instruments from available modules. The use of modules minimizes the length of time required to assemble a working instrument and yet appears to provide the student with a better understanding of its operation
(and limitations) than if he had used a commercial instrument. Professor Morgenthaler also used a blockdiagram approach to electronics which is basically similar to his overall approach to instrumentation. His experiences confirm and extend the suggestions made a few years ago by C. F. Morrison, Jr., while he was teaching at Washington State University. One thing that this symposium should emphasize is that there is no single "correct" approach to the t ~ a c h ing of the principles of quantitative analysis of chemical systems. At the same time, it should emphasize that there is a great deal of leeway for the exercise of imaginative approaches to quantitative analysis in the undergraduate courses. I..0. Rogers Purdue University Lafayette, Indiana 47907
Volume
44, Number 6, June 7967
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