THE DETERMINATION OF FOOD COLORS BY HPLC WITH ONLINE DIALYSIS FOR SAMPLE PREPARATION

A simple method is reported for the determination of synthetic dyes in sugar rich foods. Extraction of the dyes is achieved with water at room temperature. The extract is then centrifuged or filtered prior to dialysis using an ASTED system. A portion of the dialysate is transferred directly to the HPLC column without further concentration, where adequate sensitivity is achieved for the determination of dyes in a range of foods. Samples studied include boiled sweets, fruit gums, lemon curd, jelly, blancmange and soft drinks.