THE DETERMINATION OF SORBIC ACID AND BENZOIC-ACID IN A VARIETY OF BEVERAGES AND FOODS BY MICELLAR ELECTROKINETIC CAPILLARY CHROMATOGRAPHY

A rapid method for the identification and quantitation of sorbic acid and benzoic acid in a variety of beverages and foods by micellar electrokinetic capillary chromatography (MECC) is described. Dehydroacetic acid was used as the internal standard. The separations were achieved using a 68 cm fused silica capillary column with a buffer comprising 0.05 M sodium dodecylsulphate and 0.02 M disodium hydrogen phosphate, pH 9.2. The amounts of preservatives determined by MECC were in good agreement with those determined by the high-performance liquid chromatographic (HPLC) procedure currently used in the authors' laboratory. The MECC procedure has the same order of repeatability as the HPLC method and is also faster, more efficient and less costly to operate. This procedure can also be used for the screening of sorbic acid, benzoic acid and dehydroacetic acid in beverages using phthalate as the internal standard.