Teaching of analytical chemistry in the U.S.

Analytical chemistry has long heen, and continues to he, an important component of the undergraduate Bachelor of Science Chemistry degree in most colleges and universities in the U.S. It typically occupies the position in the curriculum where the student first encounters lecture and laboratory instruction in quantitative measurements of chemical materials, and sometimes is the student’s first quantitative experimentation of any form. The skills and attitudes developed in this course in quantitative measurements are underpinnings of subsequent stages of the curriculum, including experimental physical chemistry. Analytical chemistry plays a second important role by introducing the undergraduate student to the principles and applications of chemical transducers, I will refer to chemical transducers in this article in the sense of devices and means by which chemists convert chemical structural and compositional information into recordable electrical and optical phenomena, e.g., a molecular absorption spectrum, a mass spectrum, a cyclic voltammogram, a chromatogram, a pH reading, or a change in molecular conductivity. The chemist’s transducer is in many ways an interface between chemistry and physics in the student’s training, albeit not often mentioned as such by the professor (I use “professor” in the U.S. sense: a teacher). Chemical transducers are pervasive in instruments found in undergraduate organic and physical chemistry and biochemistry laboratory courses. These inst~ments are often used on an empifical basis, preceding explanation of their principles in an analytical course in the terminal year of the curriculum. Chemical transduce& are employed by nearly all chemists who continue further study and/or pursue a professional career in science. Hence, an appreciation of chemical transducers is perhaps the broadest and most lasting contribution that analytical chemistry plays in undergraduate education in the U.S. Analytical chemistry also plays an important role in Bachelor of Science and Bachelor of Arts undergraduate degree programs undertaken by students aiming at careers in the health sciences (medicine, dentistry, pharmacy, nursing, public health). Individuals in health science and health care professions frequently need to seek or use research or clinical diagnostic information derived from analytical chemical experiments and tests. An appreciation, even if only in general terms, of the basis and limitations of such tests, is critical in the use of the scientific approach needed in many elements of the heafth science and health care professions. An understanding of chemical transducers, and particularly of their limitations, could plausibly be a component of Bachelor of Engineering curricula, but with the exception of Chemical Engineering this is seldom the case. The principal thrust of this article will be the history of the analytical chemisty component of the modern B.S. chemistry curriculum offered in the U.S. to those students planning professional careers in chemistry. A historical perspective often yields a better understanding of the present; since the elements of older approaches to chemical education are usually strongly filtered by events of subsequent years, the most essential tenets are those that survive. I will begin my “history” in the 195Os, since this was the beginning both of a period of great change in analyti~l chemistry, and of my own professional exposure to analytical chemistry. Any article on chemical education, especially one with a historical intent, must come with caveats. The most important here is that there is considerable (for better or worse) diversity in the U.S. undergraduate educational system. B.S. chemistry degrees are offered by four-year colleges where the faculty, and hence also the students, often have little if any research involvement, and by large universities where the faculty are deeply committed to chemical research and where undergraduates meet graduate students who serve as teachers as well as role models. There is a continuum of institutions between these extreme types. Because of this diversity, I will inevitably but unintentionally miss elements of analytical chemistry as taught in some institutions. My second caveat is that, to avoid an entirely anecdotal approach, I will engage in a “textbook archaeoIogy”, using the contents of textbooks in analytical chemistry published at different points in time, to document various points of emphasis in analytical chemistry as they were taught on a national scale. Of course many professors, including probably the pioneer teachers, choose to use their own notes for their lectures rather