INDIRECT VISIBLE SPECTROPHOTOMETRIC METHOD FOR THE DETERMINATION OF PENICILLINS WITH PERIODATE, p-N, N-DIMETHYLPHENYLENEDIAMINE AND SULPHANILAMIDE

摘要

The acid hydrolyzed product of penicillins (penicillamine) is oxidized with sodium metaperiodate. The iodate, so formed is determined at pH 3.0 with p-N, N-dimethylphenylenediamine (DMPD) and sulphanilamide masking the excess periodate with sodium molybdate. The absorbance of the p-N, N-dimehylbenzoquinonemonoimine – sulphanilamide charge-transfer complex is measured at 520nm. This proposed method is simple, rapid and sensitive with reasonable precision and accuracy. The precision of the method was found by analyzing a set of eight solutions, each containing a final concentration value approximately in the middle of the Beer’s law range. The percent relative standard deviation in this method is presented in table-4.5. The accuracy of the method was determined by taking different known amounts (with in Beer’s law limits) of the drug and analyzing them by proposed method. The results are given in table-4.4. In the determination of penicillins the excipients usually present in formulations (glucose, starch, sodium hexa phosphate) and the other antibiotics did not interfere.