A PAPER CHROMATOGRAPHIC METHOD FOR THE QUANTITATIVE ESTIMATION OF PENICILLIN ENTITIES

In research and in commercial penicillin production, there has been an ever-increasing demand for a rapid and accurate method for estimating penicillin entities in broth, in processing streams, and in final products. Several methods have been proposed. The differential microbiological assay procedures reported by Schmidt, Ward, and Coghill (1944) and by Higuchi and Peterson (1947) are susceptible to possible additive errors of the multiple microbiological assays em-ployed and are applicable, respectively, only to mixtures of two or three peni-cillin entities. The Craig (1944) countercurrent distribution method, although suitable for a detailed examination of a limited number of selected samples, is time-consuiming and is not practicable for the routine analysis of a large number of samples. The Goodall and Levi (1946, 1947) paper chromatograph method, based on the difference in distribution of the various penicillins between ether and phosphate buffer, provides a direct, analytical method for both qualitative and quantitative evaluation of the composition of penicillin mixtures. However, it too is time-consuming (72 hours) and involves cumbersome apparatus an