title: Indirect spectrophotometric methods for the determination of antibiotics with iodine or periodate, and metol and sulphanilamide.
abstract: Two spectrophotometric methods are described for the determination of antibiotics. In the first method, penicillins, cephalosporins, streptomycin and griseofulvin are estimated by oxidizing them under neutral or slightly acidic conditions, after alkaline hydrolysis, by means of a known and excessive quantity of iodine solution. The excess of iodine is determined at pH 3.0 with metol and sulphanilamide. In the second method, dihydrostreptomycin, framycetin and the acid hydrolysis product of chloramphenicol are determined by a method involving oxidation with sodium metaperiodate, masking the excess of periodate with sodium molybdate, and using metol and sulphanilamide at pH 3.0 to determine the iodate formed. In both methods the absorbance of the resulting p-N-methylbenzoquinonemonoimine sulphanilamide charge-transfer complex is measured at 520 nm.
authors.affiliation: Food and Drug Laboratories, School of Chemistry Andhra University, Waltair 530 003, India.
authors.forename: C S
authors.initials: CS
authors.lastname: Sastry
authors.forename: T E
authors.initials: TE
authors.lastname: Divakar
authors.forename: U
authors.initials: U
authors.lastname: Viplava Prasad