Assay of p-aminobenzoic acid with aromatic N-haloamines

Abstract

The organic sulphonyl haloamines chloramine-T, bromamine-T and bromamine-B were used for the determination of p-aminobenzoic acid in aqueous solution. The proposed back-titration methods, which are based on the oxidation of p-aminobenzoic acid, are simple, fairly rapid and reproducible with an error of ±1%. The reactions involve a four-electron change and the oxidation products were identified. The effects of pH and the presence of some foreign ions, and also pyridoxine, pyridoxalamine, glycerol and alcohol, on the oxidation were studied.