POLAROGRAPHIC-DETERMINATION OF SOME PENICILLINS THROUGH NITROSATION

Direct current and differential pulse polarography DPP were used for t he determination of three penicillins, namely, ampicillin, benzylpenic illin and carbenicillin, in pure form and in their dosage forms. The m ethod is based upon treatment of penicillins with nitrous acid followe d by polarographic measurement of the produced derivatives polarograph ically. The nitroso derivatives formed exhibited reduction waves over the whole pH range in Britton-Robinson buffers. The waves were charact erized as being diffusion-controlled and free from adsorption phenomen a. The current-concentration plots were rectilinear over the concentra tion range 8-200 and 2-160 mu g ml(-1) for DC, and DPP, respectively, for all the studied compounds. The proposed method was further applied to determine penicillins in pharmaceutical preparations, and the resu lts obtained were in good agreement with those given by the companies. (C) 1998 Elsevier Science B.V. All rights reserved.