title: Determination of ascorbic acid with o-iodosobenzoate: analysis of mixtures of ascorbic acid with methionine and cysteine or glutathione.
abstract: Ascorbic acid has been determined in pure solutions, pharmaceutical preparations, food-stuffs and biological fluids by titration with o-iodosobenzoate, with visual or photometric detection of the end-point, with leuco-2,6-dichlorophenolindophenol plus potassium iodide as indicator. Cysteine and glutathione, which interfere quantitatively, are masked by cyanoethylation; the cyanoethylated product and methionine have been determined with o-iodosobenzoate in the presence of acidified potassium bromide, with Methyl Red as indicator. Procedures are given for the analysis of mixtures of ascorbic acid with sulphur-containing amino-acids.
authors.affiliation: Department of Chemistry, University of Jabalpur, Jabalpur 482001, India.
authors.forename: K K
authors.initials: KK
authors.lastname: Verma