The quantitative determination of benzoic acid in soft drinks by ion-exchange chromatography

Abstract

A quantitative method for the determination of benzoic acid in soft drinks and their associated bases and compounds is described. The method consists essentially in the isolation of benzoic acid from the sample by means of ion-exchange chromatography on De-Acidite FF anion-exchange resin, and the subsequent estimation of the isolated preservative by ultraviolet spectrophotometry. The separation of benzoic acid from other constituents is discussed and a simple three-point correction formula is proposed to correct for non-specific background absorbance. Recovery of benzoic acid was satisfactory when the method was applied to a wide range of ready-to-drink beverages, concentrated soft drinks, and fruit bases and compounds.