Determination of reducing sugars in selected beverages by capillary electrophoresis

A method for the analysis of reducing sugar enantiomers in beverages using capillary zone electrophoresis is presented. Based on previous results, a resolution of all aldo-hexoses, -pentoses, -tetroses and trioses is achieved. Additional separation of uronic acids, deoxy and amino sugars in different buffer systems is demonstrated. Derivatives of sugar enantiomers change their migration order if derivatized with the phenylethylamine enantiomer. Thus, the use of a chiral derivatizing agent leads to simpler peak validation and opens new opportunities for the development of new applications. Screening of pharmaceutical drugs or food for rare sugar enantiomers with a detection limit of 25 fmol (5 μM) is feasible. Adaptation of the general method to wine, juice and instant coffee is demonstrated. The aldose, uronic acid and deoxy aldose enantiomer composition of the presented beverages is obtained in a single run.