The use of HPLC for the analysis of ascorbic acid and dehydroascorbic acid in orange juice and powdered orange drink

Ascorbic acid and dehydroascorbic acid may be separated by High Performance Liquid Chromatography (HPLC) after pre-column reaction of dehydroascorbic acid with 1,2-phenylenediamine. Two methods are described, viz. reversed-phase ion-pairing HPLC, and the use of a CN column for the separation. When both methods were applied to the analysis of orange juice and powdered orande drink, the reversed-phase ion-pairing method was found to be subject to interference problems and variability in retention times. The Cn column method was more successful, particularly for powdered orange drink. Recovery and precision data are presented.