Studies on the Analysis of Food Additives by High-Performance Liquid Chromatography (III) The Application of Ion Pair Chromatography to Determination of Saccharin, Benzoic Acid and Sorbic Acid in Foods

Abstract

A rapid and reproducible method for the determination of saccharin (SA), benzoic acid (BA) and sorbic acid (SOA) by high-performance liquid chromatography (HPLC) was established. Ion pair partition system was used for both HPLC separation and sample clean-up. Liquid foods such as soy sauce, soft drinks and lactic acid bacteria beverages were diluted to suitable concentration with water. Hydrochloric acid (1N) and 0.005M cetyltrimethylammonium chloride were added to the dilute sample and the solution passed through SEP-PAK C18 cartridge. After washing the cartridge with water, the three compounds were eluted with a mixture of methanol-0.05M phosphate buffer pH 5.0 (6 : 4). The eluate was diluted with water and 0.05M tetra n-butylammonium bromide (TBA) and injected on a Li Chrosorb RP-18 column by using a mixture of methanol-0.03M phosphate buffer pH 5.0 (7 : 13) containing 0.005M TBA as a mobile phase. The effluent was monitored with a UV detector at a wavelength of 225 nm. The recoveries of SA, BA and SOA from the samples fortified with 0.05g/kg each were 98.0-101.7%, 98.2-101.0% and 94.2-101.0%, respectively. These detection limits were 0.0005g/kg each.