title: Spectrophotometric determination of some penicillins with ammonium vanadate.
abstract: A spectrophotometric method for determining some penicillins has been developed. A known volume of the penicillin solution-in phosphate buffer of pH 6.8 is boiled with ammonium vanadate solution-in sulphuric acid medium-for 10 min and the absorbance of the colour formed is measured at 750 nm. The excess of vanadate can also be determined volumetrically. The method has been successfully applied for the determination of penicillin G sodium, phenoxymethyl penicillin, ampicillin sodium, phenethicillin potassium, cloxacillin sodium and methicillin sodium. The procedure is also used for analysing some pharmaceutical preparations of these drugs, e.g., injections. The results obtained are in agreement with those of the B P 1973 methods.
authors.affiliation: Pharmaceutical Chemistry Department, Faculty of Pharmacy, University of Alexandria, Alexandria, Egypt.
authors.forename: el-S A
authors.initials: el-SA
authors.lastname: Ibrahim
authors.forename: Y A
authors.initials: YA
authors.lastname: Beltagy
authors.forename: M M
authors.initials: MM
authors.lastname: El-Khalek