SOLID-PHASE EXTRACTION AS A CLEANUP PROCEDURE FOR THE LIQUID-CHROMATOGRAPHIC DETERMINATION OF BENZOIC AND SORBIC ACIDS IN FRUIT-DERIVED PRODUCTS

A liquid-chromatographic procedure is proposed for the simultaneous de termination of benzoic and sorbic acids in fruit-derived products. Pri or to the chromatographic separation, a clean-up pre-treatment of the sample is carried out off-line, using successively an anionic resin an d a C-18 stationary phase as sorbent beds. After elution from the cart ridges, the acids are separated and quantitated by LC with UV-absorban ce detection. The validation tests show that the technique can be appl ied to different types of fruit-derived products (i.e. jams, dried fru its and almond paste).