Application of polarography and voltammetry to drug analysis in industry.

Essential to the renewal of interest in polarography and voltammetry in the 1970s were the availability of reliable polarographs offering the pulse mode, with sensitivity down to lo-‘-lo-* M and h’gh 1 er resolving power; a better understanding of the electrode processes of compounds of pharmaceutical interest (active agents, excipients, additives, antioxidants, etc.); and the application of oxidation waves, making the technique available to a wide range of pharmaceuticals. Davidson [l] has surveyed the use of the voltammetric oxidative mode. Few modern books [2-41 but several recent review articles [5-101 discuss the electrochemistry (polarography and voltammetry) of drugs. According to Fogg [ll] the answer to the question: “Voltammetry, is it worth considering?” is an emphatic “yes” for the determination of drugs in biological materials. VirC and Patriarche [12] comment: “ . . . among modem analytical techniques the application of differential pulse polarography in the pharmaceutical sciences is well justified with regard to accuracy and sensitivity, and it is shown to be of use for rapid investigation of complex media . . .” and they conclude: “it is reasonable to think that this technique will be applied more and more in biological and pharmaceutical analysis in the future.” The literature of the last few years shows that polarography and voltammetry are particularly applied in pharmaceutical and biological chemistry. The USP XX quotes 16 drugs and formulations assayed by polarography. Does all this activity mean that polarography and voltammetry are, or will be, used in industry? Osteryoung and Osteryoung [13] note that “The use of electroanalytical methods in industry obviously depends on the availability of individuals knowledgeable in the area, the applicability of methods to solve real problems, and the instrument available. ” One of the main objections to polarography and voltammetry advanced by analysts in industry is that both methods are purely academic; polarography is mostly encountered in basic electrochemical courses. Both are more demanding than most other instrumental techniques used in industrial laboratories 113-17, 681, and they are mostly practised in