Determination of saccharin in soft drinks by a spectrophotometric method.

Abstract

Saccharin reacts quantitatively with phenothiazine (thiodiphenylamine) and copper(II) acetate dissolved in 50%V/V ethanol at 70 °C. The reaction product can be dissolved in an organic solvent and has a characteristic colour. The colour reaction is sensitive and the absorbance, at 510 nm, of the extract in 5 ml of xylene obeys Beer's law at saccharin concentrations between 20 and 400 µg ml–1. Cyclamates, sorbic acid, benzoic acid, 4-hydroxybenzoic acid and dehydroacetic acid do not interfere. Recoveries of saccharin from soft drinks were satisfactory. A procedure suitable for routine use is proposed.