Determination of total vitamin C in fruits by capillary zone electrophoresis

A simple capillary zone electrophoretic (CZE) method is described for the rapid determination of ascorbic acid and dehydroascorbic acid, the physiologically active forms of vitamin C, in fruits. The electrophoretic run was accomplished in 9 min on a coated capillary column using 20 mM phosphate buffer (pH 7.0). Total ascorbic acid was determined by first reducing the dehydroascorbic acid to ascorbic acid by treatment with DL-homocysteine. This reaction was complete in 15 min and total ascorbic acid determination was performed immediately. The data obtained by CZE were in good agreement with HPLC data.