Educational trends? What they are and what they should be

Analytical chemistry has come a long way from ... there has been a growing recognition of the value and ... keeping up with the times and meeting the ...
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James S. Fritz

Iowa State

University Ames

Educational Trends? What They Are and What They Should Be

Analytical chemistry has come a long way from the "cookbook" subject it used to be. Also. there has been a growing recognition of the value and importance of analytical chemistry and analytical chemists. Analytical chemistry is important to chemistry students not only for its practical value, but also because more than any other subject it brings together the chemical reactions and principles learned in inorganic, organic, and physical chemistry. In recent years there has been a tremendous development of analytical methods and techniques. This makes it desirable for us to take a critical look a t instruction in analytical chemistry to see whether we are keeping up with the times and meeting the challenge that such rapid change brings. At the same time it is important not to neglect the discipline that quantitative analysis has traditionally demanded, or to be carried away with novel methods of analysis that in retrospect are only of trivial value. Survey of Educational Trends

In order to discover some of the existing trends in teaching analytical chemistry, a questionnaire was sent to 50 analytical chemistry professors in various colleges and universities throughout the United States. Information was requested on the present content of undergraduate courses and on recent changes in the emphasis given to various topics. Comment was invited regarding the professors' attitudes on educational trends. Replies were received from 79% of the professors. Approximately 73% of the replies received were from medium-sized or large schools, and the remaining 27% were from small schools. In replies from 33 schools, a majority of students had only freshman chemistry (usually with some qualitative analysis) before taking the elementary quantitative analysis course or course sequence. However, 21% of the replies reported that most or all of their students had taken some organic chemistry before quantitative analysis, and 9% reported that their students had some physical chemistry before quantitative analysis. In virtually all elementary quantitative analysis courses, either 2 or 3 hours per week are spent in classroom work, the average being 2.5 hours. An average of 7.0 hours per week is devoted to laboratory work. The average duration of the elementary analytical course sequence is 75% of the regular school year. Table 1 lists some of the topics included in elementary Presented as part of the Symposium on Educational Trends in Analytical Chemistry, sponsored jointly by the Divisions of Analytical Chemistry and Chemical Education, at the 136th Meeting of the America Chemical Society, Atlantic City, N. J., September. 1959.

Table 1. Study o f Topics Included in Elementary Quantitative Analvsis a t 28 Schools

Tonic

O/, of schools including t,nnir

Complex formation titrations Statistical treatment of errors Electrodeposition Colorimetry, photometric methods Colorimetry, vlsual methods Instrumental analvsis Ion-exchange in aklysis Solvent extraction Chromatography Gas analysis Organic functional group methods Other

96 93 89

68 50 43 36 25 36

quantitative analysis courses. It is interesting to note that a larpe majority of courses include complexformation titrations, statistical treatment of errors, electrodeposition, and colorimetry. I n Table 2 the average time spent on various topics in elementary quantitative analysis is tabulated. In most courses not more than one class period is spent on each of the newer techniques such as EDTA titrations, ion-exchange, and solvent extraction. The advanced course offerings in analytical chemistry Table 2. Average Time Spent an Various Topics in Elementaw Quantitative Analvsis Courses a t 29 Schools

Tooio

O/n of Course*

The balance and weighing Calibration of weights or glassware Gravimetrio analysis Titrat.ions involving precipitate formation Acid-base methods of analysis Oxidation-reduotion methods Complex formstion titrations Colorimetric methods Separations using solvent extraction Ion erchanxe in analytical chemisbry Chromatography Instrumentd analysis (polarography, speetrography, etc ) Gas analysis Statistical treatment of errors

4 3 23 6 18 18 4 7 3 3 2

5 3 4

* O/o of oourse wae cltlculated only for wurses that include the

topic. Few courses included all of the above topios.

are tabulated in Table 3. Of the schools surveyed, all but three small schools offered a course in instrumental analysis. A majority of the universities also offer at least one other advanced analytical course. Although fewer schools offer separate courses in organic quantitative analysis, emission spectroscopy, and the like, a larger number consider these topics in other advanced courses. An idea of some of the trends in teaching elementary quantitative analysis can be obtained by noting some of the topics that have recently been added or given Volume 37, Number 6, June 1960

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Table 3.

Advanced Analytical Course Offerings of 32 Schools

O/o of schools offering course

Course area Instrumental malyais Advanced anal. chemistry including special topics courses Micro analysis Emission spectroscopy Organic cluantitative analysis

91

81 34 16 9

increased emphasis, and also the topics that have been dropped or de-emphasized. This information is summarized in Table 4. These data show that in most courses less time is now being spent than formerly on gravimetric analysis and certain other "classical" methods of analysis. Increased attention is being paid to the use of instruments in analysis, complexometric titrations, colorimetry, and the like. Table 4.

Trends in the Content of 28 Elementary Quantitative Analysis Courses

Topic Instrumental analysis Complexomet.ric titrations Colorimetric methods ~eparations Statistios Ion exchange Solvent extraction Electrode~osition Organic analysis Grivimetric analysis Other "classical" techniques Details of methods

% of schoqls

% qf schools

50 39

.. ..

glvlng toplc added emphasis 36

.. .. ..

giving topic decreased emphasis

..

64 29 14

A number of timely comments were received from professors who replied to the questionnaire. The essence of some of these comments, many of which were repeated by several persons, is given below. For the vast majority of presentday students, the old philosophy of a. rather extensive gravimetrie training is outmoded. Orgsnio chemistry should be taught before analytical. If possible some physical chemistry should also precede analytical. More quantitative analytical measurements should be made in freshman chemistry laboratory. Laboratory skills are being badly neglected. More emphasis should be placed on principles and theory, less on descriptive material. Use more instruments in the elementary quantative analysis course, but keep instrumental analysis as a. separate course. Do not dilute the fundamental analytical course with too much instrumental. Quantitative analysis laboratory should be made more interestinz. Less emphasis should he placed on unknowns with set procedures. Sponsored researoh threatens teaching standards by taking the better graduate students from teaching duties. Qualitative analysis is still an analytical course and should receive more emphasis. There is so much material to cover that it is difficult to know what to emphasize. There is little interest in improving courses in any fundamental way because it is not personally rewarding to do so.

Summary of Trends

Plaee of analytical chernism in the undergraduate curriculum. There is a definite movement toward teaching organic chemistry before quantitative analysis. There is also an inclination to teach some physical 280 / Journd of Chemical Educafmn

chemistry before quantitative analysis. Analytical chemistry is now a more sophisticated subject than it used to be and should be treated as such. There is also a trend toward more quantitative work in the first year of college chemistry. This would be especially helpful if the regular quantitative analysis course is being postponed until the junior year. Content of elementary pantitatiue analysis course or sequence. In most schools there is a definite reduction in emphasis on gravimetric analysis. Many are also devoting somewhat less attention to certain other "classical" techniques. However, all courses are retaining the fundamentals of gravimetric analysis. Many are merely cutting down on the descriptive parts and are reducing repetition. In a majority of cases, topics such as EDTA titrations, colorimetric methods of analysis, statistics, and ion exchange are being added or are being given increased emphasis. There has been a rapid expansion in the theory and methods of analytical chemistry, but the time available in analytical courses has not increased. To combat this problem, the trend is to emphasize principles and to cut down on descriptive and "cookbook" analytical chemistry. There is more discussion of instrumental methods in elementary courses. Use of instruments such as pH meters and photoelectric calorimeters in laboratory is more widespread. Aduanced anulytical cvurses. Except for small schools, virtually all schools offer a course in instrumental analysis. Many schools (81% of those surveyed) also offer a course on advanced chemical methods of analysis or on special topics. Quantitative organic analysis has been largely ignored until recently, but many of the larger universities are now introducing courses on this important aspect of analytical chemistry. Comments on Educational Trends

The dominant trend in analytical chemical instrnction is one of cautious change. These changes, which are summarized above, are in the right direction and are encouraging. However, it is the author's feeling that many professors are being overly cautious and that modernization of undergraduate anal.ytical courses is proceeding too slowly. Writers of textbooks have been especially conservative. In most books, important and proved analytical techniques such as complexometric titrations with EDTA, ion-exchange, and solvent extraction are treated briefly if a t all. Quantitative analy,'-1s remains almost exclusively inorganic in nature. No "boldly dierent" elementary quantitative analysis text has been written. Conformity to convention seems to he the keynote of most authors. Although some progress is being made, inclusion of quantitative organic analysis in course offerings is still lagging. This is an important deficiency, because organic analysis is now of equal or greater practical importance today than inorganic analysis. While some of the principles learned in inorganic analysis are directly applicable to organic analysis, many aspects of organic analysis are unique.

A separate course in organic analysis is one answer to this problem. However, the situation also can he improved by incorporating some organic analysis into existing courses. For example, nonaqueous titrations, quantitative determination of carbonyl compounds by, oxirnation, alcohols by acetylation, and esters by saponification could he discussed with acid-base theory and practice. Ultraviolet spectrophotometric determination of organic compounds could be included when the subject of inorganic spectrophotometry is considered.

Finally it should he recognized that the laboratory part of many quantitative analysis courses should be revised. The unknowns now done in laboratory are repetitious; they bore the students and do not provide very efficient instruction. Each experiment done in laboratory should illustrate a different principle or technique. Laboratory work does not have to consist entirely of analyzing unknowns. Where possible, more emphasis should be placed on the student's finding appropriate procedures for himself and applying them to actual samples.

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