DETERMINATION OF SORBIC ACID IN FOOD-PRODUCTS BY CAPILLARY ZONE ELECTROPHORESIS IN A HYDRODYNAMICALLY CLOSED SEPARATION COMPARTMENT

A simple, selective and rapid capillary zone electrophoresis method for the determination of sorbic acid in food products is described. The determination was carried out in a hydrodynamically closed separation compartment at pH 5.2 and for the samples taken into this study (soft drinks, wine, fruit and juice concentrates, margarine and marmalade) only simple sample preparation procedures were needed. A very good reproducibility in the migration time of the analyte (R.S.D. = 0.61%) was achieved and as could be expected no negative effect of matrix constituents on this performance parameter was detected. The recoveries of sorbic acid in the spiked samples ranged from 98-102% and 2-3% R.S.D.s in parallel determinations of the acid were typical.