SIDNEY SlGGlA Department of Chemistry, University of Massachusetts, Amherst, Mass. 01002
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HREE PARAMETERS DEFIXE the efTEectiveness of any teaching program: (1) the population of students which must be taught; (2) the mood of the times during which the teaching is done; and ( 3 ) the teacher, teaching program, and facilities with which the teaching is carried out. T h e purpose of this paper is to discuss these three parameters; the subject thus becomes three-dimensional. Any program a t any school then is a defined point in “curricular space,” fixed by these three parameters.
Students
Consider first the students : what are their goals in coming to a college or university? Their motivating goals fall into two categories: (1) T o increase their value in our society. They want to be admired and respected by the people around them. While achieving admiration and respect, they also wish a comjortable degree of materiul s e c u k t y and seek careers where the financial returns are more certain and more sizeable. (2’1 To do interesting, challenging, and useful w o r k . Students set their goals higher than doing just any job; they waiit t o enjoy their jobs and they want to do a complete, rewarding job. T o reach students with analytical chemistry it must be made evident to them t h a t they can achieve their goals with a career in the field. Good analytical chemists are highly esteemed and highly paid members
of any group involved in the teaching and practice of chemistry. In addition, the analytical chemist has more opportunities available to him than most chemists, since the analytical chemist can operate outside of the sphere formally defined as chemistry. The analytical chemist can work in the areas of food science, materials science, archeology, geology, law, international affairs. space, oceanography, environmental problems, biomedicine, and other areas involving the elucidation of matter. Hence, there is all manner of interesting, challenging, and useful work in this field. The student should also be made aware that the job market is better for the analytical chemist than for most chemists. This appeals to the student’s desires for security and material comfort. The above items indicate the compatibility of analytical chemistry with student goals. However, to reach the widest spectrum of student types, we must present the subject such t h a t there is appeal to each type. The various student types are: (1) Knovdedge oriented: This student is generally motivated toward theory, research. and teaching. H e is scholarly and wishes t o pursue a career in basic research, either by teaching or work in a research institute. There is basic science in analytical chemistry. (2) Practical oriented: This student wants to Ivork 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 to: why did the plant explode; wily did the catalyst die; hou’ polluted is the river; w h a t is the competitor using; of tchat did this person die; w h a t corroded this vessel ; and niany other chemical “Sherlock Holmes” situations. Chemical detective Tyork is exciting to this type of student and analytical chemistry consists, to a large extent, of chemical detective work. 13) People oriented: Many students want v o r k which brings them in contact with people. Analytical chemistry is a field where the “people factor” rates high. An analytical chemist must work with lawyers, other chemists. salesmen, customers, plant people, archaeologists, geologists, farmers (pesticides) federal officials IFDX, Dept. of Agriculture, Kational Research Council, etc.), and many others. Hence analytical chemistry suits this people-oriented segment of the student population. T o be eff’ective, a program for teaching analytical chemists must shov that it can fulful! students’ goals. It must also be made t o appeal to the spectrum of personalities which exists in any population of students. Once the student is interested in a subject, you have reached him; the teaching of that subject then becomes easy. ~
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The mood during certain periods will also dictate the way in u-hich 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- 1960’9, 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. I n times of monetary constraint, analytical chemistry thrives because it is an applied science and essential t o basic operations. Even the research done in the field is done n.ith 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.” 50A
A n 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: ( I ) 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. (21 Modern us. 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 t o be thorough. HoLYever, since students, being young, lean tom-ard 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 .Ir-idely used; pollution a n a l p i s again is a good example. Many of the “modern” instrumental methods rely on v e t 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 us. applied: I n 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). 14) 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 G.S., Paris, Sicily, and Australia, without ever seeing a map of the world shoving the relationship of these areas to each other. I n analytical chemistry, \%-eteach 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: T o be effecti7.e in reaching students, a teacher of analytical chemistry should, as should a1117 teacher, be a sort of missionary. H e should loye 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. I n 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 ribrnting that are in tune with what he is teaching. If the teacher vibrates a t only one frequency-i.e., theory-he mill reach only those students in his class who are in tune with that material. T o reach the largest member of students. the teacher must “make music”, striking responsive chords throughout the entire class as he speaks. H e can only do this by knowing his material, loving his subject, and recognizing the abore discussed parameters and students, moods of the times, and his own views.
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At the Vniversity of AIassachusetts the following approaches are effective in teaching the subject. i l i Complete coverage of the basics of analytical chemistry from the classical gravimetric approach to the digitized, instruniental appro a c h es. 121 "Real" experiments in the laboratory. These have been described i l l , but now have been extended to the instrumental analysis course. (3) Connected, interrelated experiments ; the cyclamate analysis discussed below is such a n 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 ;\In in river water (pollution) colorimetrically and yolumetrically Jvhile 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-level 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. I n 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 52A
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goals in our instrumental analysis course. I n the first, elemental analysis of metals in local mater sources is accomplished by a variety of spectroscopic techniques. First the sample is studied qualitatiyely 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 spectrofluorescence. The results are statistically evaluated and used in conjunction with other classwork for anions. etc. for an overall view of the sample. I n 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. hIolecular food additives permit the use of a variety of techniques Lyhich 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 t h a t 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. I n one case, preliminary study of the reaction kinetics of one cyclamate determination was undertaken. I n 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. T o 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 nieasuring 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 coniputational 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 reyision of equipment and introduction of new experiments. For example, automated analog and digital reaction rate methods for cyclamates have been developed for classroom work t o improve the available methods. I n the graduate program a t the Lniversity 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 : iidvanced Analytical Chemistry Theory of hnalytical Processes Electroanalytical Processes Analytical Spectroscopy Analytical Separations Chemical hlicroscopy Electronics for Scientists Ucroanalytical 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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