Determination of Benzoates and Hydroxybenzoates in Foods

Abstract A method has been devised for the qualitative and quantitative determination of benzoates and hydroxybenzoates in foods. The qualitative procedure is based on the TLC separation of benzoic acid, the hydroxybenzoates, and sorbic acid, using kieselguhr G-silica gel GF 254 as the absorbent and hexane:acetic acid as the mobile solvent. The separated preserving acids are identified under UV radiation and by specific chromogenic reagents. Benzoic acid in foods was determined quantitatively by steam distillation, extraction, and TLC separation. The benzoic acid was removed from the chromatographic plate, extracted with ethanol, and determined in the UV region with a recording spectrophotometer and 5 cm micro cells. These procedures should be subjected to collaborative study.