JOURNAL O F CHEMICAL EDUCATION
ORGANIC ANALYSIS IN THE CHEMISTRY CURRICULUM PHILIP 1. ELVING The Pennsylvania State College, State College, Pennsylvania
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present symposium has as its purpose the discussion of the extent to which organic analytical methods can be and should be included in the undergraduate and graduate curricula in chemistry. The proper discussion of this topic is not an easy one. The very idea of the introduction of more course work into the already crou.ded curriculum will fill the average teacher of chemistry with a certain feeling of horror. The teacher is apt to feel that any additional course might well be the proverbial straw that will break the student's back. In view of this, I shall attempt in this discussion to indicate how some of the material now covered in the customary chemistry courses may be altered or replaced to include more material on organic analysis. As a concrete example of substitution of training in, or a t least an introdurtion t.0. organic analysis in the
undergraduate curriculum, one might consider the elementary course in quantitative analysis. In many institutions the first semester of this course includes as part of the work in titrimetry or volumetric analysis the Kjeldahl method for the determination of nitrogen. The Kjeldahl method not only serves as an illustration of ultimate or elemental organic analysis but it can also be used as a good example of the use of back-titration in titrimetric methods. An example of a method for the determination of organic functional groups that is included in some elementary courses in quantitative analysis is the determination of the neutralization equivalent of an organic acid. I t might well be possible to substitute for some of the inorganic determinations more examples of quantitative organic methods. In addition, the connection between the work done in the course and the methods of organic analysis might well
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be emphasized. Thus, in discussing the determination of sulfur as the sulfate, it would require but little extra time to describe how sulfur in organic compounds can be converted to sulfate by various oxidation methods and determined as such. The determination of certain functional groups in organic compounds by titrimetric methods is well within the capabilities of the students in the elementary quantitative course. The averagestudentwould profit by being taught, for example, the esterification procedure for determining hydroxyl group content. More in this direction could probably be done if it would be possible to teach quantitative analysis following the course in organic chemistry instead of preceding it. I feel that serious consideration should be given to the possibility of giving the course in organic chemistry during the sophomore year with quantitative analysis following it, or a t least following the first semester of organic chemistry. Most teachers of quantitative analysis, when asked to include the determination of organic entities in the elementary quantitative course will raise the problem of obtaining samples. In the case of the Kjeldahl method and the determination of neutralization equivalent, suitable samples are available from the usual suppliers of samples for quantitative analysis. A multitude of samples containing varying amounts of any given organic functional group can be obtained from the catalog of the Eastman Kodak Company and of the other dealers in organic chemicals. It should be noted that in the usual introductory course in biochemistry, which is taken in many universities by undergraduate majors in chemistry, a considerable portion of the laboratory work may be devoted to methods of organic analysis. It would probably be profitable, where curricula are specified for chemistry majors, for the existing courses to be surveyed to see what material pertaining to both qualitative and quantitative organic analysis is now presented and how much more might be introduced. It should be possible to indicate in courses in analytical and in physical chemistry how techniques such as radiant energy absorption are used in the identification and determination of organic compounds. A possible change that might profitably be made in the elementary course in organic chemistry is the introduction of more quantitative experiments based on the reactivity of various functional groups. It should be possible to introduce quantitative experiments in esterification, saponification, or addition to unsaturated bonds with a minimum of difficulty in teaching or cost. It may be possible to make a more extensive use in the elementary organic chemistry course of qualitative organic analysis as a means of teachiig the principles of organic chemistry. In particular, I would like to see more emphasis placed in organic courses on the analytical uses of the properties and reactions of organic compounds for the identification of structural entities in molecules as well as some indication of which of the reactions and tests used in synthetic organic chemistry
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or in organic qualitative analysis could serve as the basis for quantitative methods. It should be possible in the elementary courses in organic chemistry to emphasize, or a t least to indicate, reactions of possible analytical importance or application, that is, to note reactions of 95 per cent or greater yield which can be used for identification and determination. It would seem to me that undergraduate courses in organic analysis, either qualitative or quantitative, should have as their primary function mental training. The acquirement of manipulative skills should be a secondary feature. On the other hand, courses in organic analysis on the graduate level should have different objectives. Graduate courses in chemistry are usually both fundamental and vocational, in that they aim to train in specific areas. Accordingly, graduate courses in qualitative and quantitative analysis should have as their function not only training in the theory of chemistry and increasing mental discipline but also the imparting of certain manipulative skills. Courses in organic analysis at both the undergraduate and graduate levels should emphasize the acquirement of certain habits which can probably best be developed in such courses, especially if they are taught on the basis of semimicro or micro scale laboratory operations. These worth-while habits include those of vigilant observation, preciseness in mental and physical manipulation, rigid observation of cleanliness, and an attitude of skepticism toward reagents, results, and rumors. I believe that it would be justified if more instruction and practice in micromanipulation mere introduced into the existing courses in organic analysis, particularly the preparation, separation, and purification of materials preliminary to analysis. Textbooks covering such microscale operations are available and it is to be hoped that courses embodying such material will increase in number. Courses in organic analysis can be used to great advantage in the training of graduate students in chemistry. The value of training in organic qualitative analysis as fundamental to study and research in organic chemistry has long been recognized. I believe that an analogous case can be made for the value of micro or semimicro organic quantitative analysis as the basis for an introduction to precise chemical technique. Greater emphasis could be placed on the uniqueness of the problems of organic analysis as compared to the problems wbich are customarily encountered in the analysis of inorganic materials. If one compares the large number of elements wbich are commonly determined with the relatively small number which are usually encountered in organic analysis, one is forced to consider why the determination of the six to ten elements which usually require the attention of the organic analyst is so difficult. As is probably obvious, the difficulty in elemental organic analysis is in the nature of the chemical bonds which these various elements form. In inorganic analysis, one is concerned to a large extent with ionic reactions which are virtually complete. This is in contrast to the situation in organic analysis
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where the elements must first he converted to an inorganic form, ionic or otherwise, before they can be measured. Similarly thenumber of functional groupings of atoms which the organic analyst is called upon to identify or to determine is relatively small. The principal ones are: active hydrogen, acyl, alkimide, alkoxyl, amine amino acid, carbonyl, carhoxyl, C-methyl, hydroxyl, isopropylidene, and unsaturation. The difficulty in the detection
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and estimation of these groups is due to the stability of bonds in organic compounds and to the almost infinite variety of compounds possible with a carbon skeleton. Because of the diierences just indicated between inorganic and organic analysis, I do not consider as entirely valid the argument which is often made that training the methods of inorganic analysis is adequate preparation for any analytical work, organic or inorganic.
