THE DETERMINATION OF SUGARS IN BEVERAGES AND MEDICINES USING ONLINE DIALYSIS FOR SAMPLE PREPARATION

A method is described for the analysis of sugars in beverages and medi cines using on-line dialysis for sample preparation. The design, const ruction and method development for the on-line dialysis is described. The dialysis is carried out using a novel polypropylene membrane treat ed for wettability (Celgard 3401) which is mechanically strong and sol vent resistant when compared to traditional cellulose acetate membrane s. Counter-current dialysis was used at a flow rate of 0.8 ml min(-1), with a recipient stream of water and the dialysate was then analysed by high-performance liquid chromatography. Fructose, glucose, lactose, maltose and sucrose were determined in a range of samples. The % RSD of the method was shown to be below 5% and the recoveries above 90% fo r all samples.