SIDNEY SIGGIA Department of Chemistry, University of Massachusetts, Amherst, Mass. 0 1 0 0 2
Reaching S t u d e n t s w i t h
FT1HREE PARAMETERS D E F I N E t h e
ef-
-*- fcctiveness of a n y teaching program: (1) the population of students which must be t a u g h t ; (2) the mood of the times during which the teaching is done; and (3) t h e teacher, teaching program, and facilities with which the teaching is carried out. T h e purpose of this paper is to discuss these three p a r a m e t e r s ; the subject thus becomes three-dimensional. A n y program a t a n y school then is a defined point in "currioular space," fixed by these three p a r a m e t e r s . Students
Consider first t h e students : w h a t are their goals in coming to a college or university? Their m o t i v a t i n g goals fall into two categories: (1) To increase their value in our society. T h e y w a n t to be admired and respected b y t h e people around them. While achieving admiration and respect, they also wish a comfortable degree of material security and seek careers where the financial returns are more certain and more sizeable. (2) To do interesting, challenging, and useful work. Students set their goals higher t h a n doing just a n y j o b ; t h e y w a n t to enjoy their jobs and they w a n t to do a complete, rewarding job. T o reach students with a n a l y t i c a l chemistry it must be m a d e evident to t h e m t h a t t h e y can achieve their goals with a career in the field. Good analytical chemists are highly esteemed and highly paid members
of a n y group involved in the teaching and practice of chemistry. I n addition, the analytical chemist has more opportunities available to him t h a n most chemists, since t h e analytical chemist can operate outside of the sphere formally defined as chemistry. T h e analytical chemist can work in t h e areas of food science, materials science, archeology, geology, law, international affairs, space, oceanography, environmental problems, biomedicine, and other areas involving the elucidation of m a t t e r . Hence, there is all manner of interesting, challenging, and useful work in this field. T h e student should also be m a d e aware t h a t t h e j ob m a r k e t is better for the a n a l y t i cal chemist t h a n for most chemists. T h i s appeals to the student's desires for security and material comfort. T h e above items indicate t h e compatibility of analytical chemistry with student goals. However, to reach the widest spectrum of student types, we m u s t present the subject such t h a t there is appeal to each t y p e . T h e various student types a r e : (1) Knowledge oriented: This s t u d e n t is generally motivated t o w a r d theory, research, and teaching. H e is scholarly and wishes to pursue a career in basic research, either b y teaching or work in a research institute. T h e r e is basic science in analytical chemistry. (2) Practical oriented: This student wants to work in an area where specific, applied scientific
goals are sought. H e is applied-science oriented, and since analytical chemistry is an applied science, this field suits this personality. H e likes problem solving, and seeking answers t o : why did the plant explode; why did the catalyst die; how polluted is the river; what is the competitor using; of what did this person die ; what corroded this vessel; and m a n y other chemical "Sherlock Holmes" situations. Chemical detective work is exciting to this t y p e of student and a n a l y t i cal chemistry consists, to a large extent, of chemical detective work. (3) People oriented: M a n y students w a n t work which brings t h e m in contact with people. Analytical chemistry is a field where the "people factor" rates high. An a n a l y t i cal chemist must work with lawyers, other chemists, salesmen, customers, p l a n t people, archaeologists, geologists, farmers (pesticides), federal officials ( F D A , D e p t . of Agriculture, N a t i o n a l Research Council, etc.), and m a n y others. Hence analytical chemistry suits this people-oriented segment of the student population. T o be effective, a program for teaching analytical chemists must show t h a t it can fulfull students' goals. I t must also be made to a p peal to t h e spectrum of personalities which exists in a n y population of students. Once t h e student is interested in a subject, you have reached h i m ; , t h e teaching of t h a t subject then becomes easy.
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The mood during certain periods will also dictate the way in which material must be presented for optimum impact. The post-war period, for example, was the era of "Big Science" when theory was the fashion. During this period physical chemistry assumed a top position among the chemists, as physics did among the sciences. Analytical chemistry, as an applied science, was moved into the background. Since the mid-1960's, however, money has become tight, and the scientist has had to justify his financial support. A theoretical scientist finds it difficult to justify his efforts because the results are often unknown; and even if known, either the time of their fruition is not known, or their utility to man is unknown. In times of monetary constraint, analytical chemistry thrives because it is an applied science and essential to basic operations. Even the research done in the field is done with distinct practical goals in mind—i.e., more sensitive methods can be applied to environmental or biochemical problems; better methods yield better results; faster methods yield prompter answers. Also, because of its ambivalence, analytical chemistry fits significantly into almost any program at any one time. For example, the problems of the environment, of public health, of oceanography, and of space are all timely. Analytical chemistry is applicable in all these areas. The students want to work on timely programs. With a little preparation, it is easy to present the subject of analytical chemistry in tune with almost any period. Teaching (Teacher-Curriculum-Facilities)
The teaching function is to confront the student with the subject matter, so that he can acquire an adequate background to perform effectively when he leaves school. However, as the old adage states: "You can bring the horse to water, but you cannot make him drink it." 50 A
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An effective teaching program is one that not only presents the material but makes it appetizing to the students, in the mood of the prevailing times. Below are some teaching aspects and the analysis thereof: (1) What is "good for the student"; Each teacher feels he knows what is good for the student. However, he must be sure that it is, and, that it will be accepted by the student. Unless ingested and digested, the knowledge is no good to the student. Course material must be valuable and attractively presented. (2) Modern vs. classical material: The young teacher of analytical chemistry accents the modern instrumental approaches while the older faculty members accent the classical chemical approaches. Either alone is inadequate. Both must be covered for a course to be thorough. However, since students, being young, lean toward the modern, the course must be modern. Classical chemistry can be dressed in modern clothes and taught accordingly—e.g., statistics can be taught with instrumental data from a pollution program. Also, wet methods are still widely used ; pollution analysis again is a good example. Many of the "modern" instrumental methods rely on wet methods for calibration. With this type of indoctrination, the students see that the material being taught him is important and is not just an exercise in analytical history. Updating the classical material is easy, especially since it is still used to a large extent and is not obsolete. Its place in today's analytical scheme of things need only be shown. (3) Pure vs. applied: In most curricula, only the basics of analytical chemistry are accented, the applied aspects are left for the students to presume or to learn later on. However, as was discussed above, many students are oriented toward applied subjects. Methods are available for teaching the applied aspects of analytical chemistry without sacrifice of the teaching of the theory (1 ). (4) Presenting the "broad-view" as well as the details: Teachers
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tend to present a course in increments of the subject and often fail to show the student how these details fit together to make up the field they are studying. This is like studying the earth by studying maps of the U.S., Paris, Sicily, and Australia, without ever seeing a map of the world showing the relationship of these areas to each other. In analytical chemistry, we teach volumetric, gravimetric, atomic absorption, molecular absorption, optical emission, and other methods of analysis but seldom show how these approaches fit together in the attack and solution of analytical problems. Once the student sees the broad view, he can better appreciate the details. Alone, the details just hang. (5) The teaching position: To be effective in reaching students, a teacher of analytical chemistry should, as should any teacher, be a sort of missionary. He should love his subject with such zeal that he "feels" his material. If his feeling is sufficiently intense, he stands a good chance of putting across his material. In some schools the teaching of analytical chemistry is considered as nonessential and is relegated to a faculty member in physical, inorganic, or other chemistry. This course is then a "chore" and the teaching will reflect this attitude, which will be absorbed by the student. This is unsatisfactory for propagation of the discipline. A teacher and his students can be compared to tuning forks. If the teacher "vibrates" in teaching his subject, he will start students vibrating that are in tune with what he is teaching. If the teacher vibrates at only one frequency—i.e., theory—he will reach only those students in his class who are in tune with that material. To reach the largest member of students, the teacher must "make music", striking responsive chords throughout the entire class as he speaks. He can only do this by knowing his material, loving his subject, and recognizing the above discussed parameters and students, moods of the times, and his own views.
Special Report
At the University of Massachusetts the following approaches are effective in teaching the subject. (1) Complete coverage of the basics of analytical chemistry from the classical gravimetric approach to the digitized, instrumental approaches. (2) "Real" experiments in the laboratory. These have been described (1), but now have been extended to the instrumental analysis course. (3) Connected, interrelated experiments ; the cyclamate analysis discussed below is such an example. Also, peach brandy is analyzed for aldehydes, precipitating the aldehydes and ketones via the hydrazones to illustrate gravimetry; then chromatographing the hydrazones to illustrate separations ; then isolating the bands and measuring colorimetrically to illustrate colorimetry. The junior class works on determining Ca, Mg, Fe, and Mn in river water (pollution) colorimetrically and volumetrically while the senior class does the same analyses by instrumental methods. Both sets of students are made aware of each other's results and are asked to compare. The chemical measuring principles and exerimental approaches developed during the junior-lçvel analytical course are continued and extended in the senior-level instrumental analysis course. The senior course emphasizes a systematic approach to attacking a single problem through a variety of methods. In approaching a problem, such as the determination of the concentration of additives in foods, students are encouraged to develop a number of avenues: Evaluation of various measuring techniques through intercomparison of results on the same sample; derivation of new or modified procedures based upon published experiments on the same or related materials ; and development of progressive series of increasingly revealing measurements based upon interpretation of results from previous experiments—the research approach. Two problems have been used in the recent past to accomplish these 52 A
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goals in our instrumental analysis course. In the first, elemental analysis of metals in local water sources is accomplished by a variety of spectroscopic techniques. First the sample is studied qualitatively by optical emission, X-ray fluorescence, and combustion flame emission techniques. Quantitative analysis of selected elements is then performed by these techniques as well as by combustion flame absorption, spectrophotometry, and speetrofluorescence. The results are statistically evaluated and used in conjunction with other elasswork for anions, etc. for an overall view of the sample. In the second problem, the determination of cyclamate and saccharin in foods and beverages was used to illustrate the multiple approaches available and the need for intercomparison among published methods. Molecular food additives permit the use of a variety of techniques which often do not overlap those studied for metal analysis. For example, cyclamate is determined by gas chromatography, infrared and visible spectrophotometry, polarography, amperometric, spectrophotometric, coulometric, potentiometric, conductometric, and thermometric titrations, and a kinetic reaction rate method. Students readily learn that published methods are often incomplete, inaccurate, and empirical by experimentally determining the accuracy and precision of analysis on known and unknown samples. They are encouraged to devise further tests and experiments to improve these analysis. In one case, preliminary study of the reaction kinetics of one cyclamate determination was undertaken. In each step of this analysis, unsuspected problems associated with particular food or beverage samples become apparent. Real samples present problems with interferences generally neglected for synthetic samples and offer the opportunity to introduce additional separation or masking procedures. To eliminate interferences from citrate, tartrate, and other interferring additives, cyclamate and saccharin are separated by extraction,
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ion exchange, or gel permeation chromatography. The chemical measuring phase of the problem is also emphasized in obtaining the best possible result. Chemical measuring systems are constructed by individual students using modular equipment. The availability of both modern analog and digital readout and computational systems complements our modern optical, electrochemical, and separation equipment and permits the student great flexibility in independent assembly of quality measuring systems. Up-to-date approaches are encouraged by constant revision of equipment and introduction of new experiments. For example, automated analog and digital reaction rate methods for cyclamates have been developed for classroom work to improve the available methods. In the graduate program at the University of Massachusetts there is also a good mixture of pure and applied analytical chemistry, modern and classical, and specialized topics as well as broad coverage of the field. A listing of the courses is as follows : Advanced Analytical Chemistry Theory of Analytical Processes Elcctroanalytical Processes Analytical Spectroscopy Analytical Separations Chemical Microscopy Electronics for Scientists Microanalytical Chemistry Applied Analytical Chemistry Many of the students take summer jobs in industry to implement their formal course instruction with practical experience. Field trips to industrial laboratories are incorporated in several of the courses listed. The University currently has a faculty of six analytical chemists with approximately 25 graduate students majoring in analytical chemistry. References (1)
S.
Siggia,
(1969).
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CHEM.
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