Quantification of L-ascorbic acid and total ascorbic acid in fruits and spinach by capillary zone electrophoresis

A standard curve for the quantification of L-ascorbic acid (L-AA) by capill ary zone electrophoresis (CZE) was established, and the quantification of a scorbic acid and total ascorbic acid in fruits (lemon, Sunkist, and pineapp le) and spinach were performed using D-isoascorbic acid (D-IAA) as an inter nal standard. The minimum detection limits (MDLs) for L-AA and D-IAA were d etermined to be 1 and 2 mug/mL, respectively, at 265 nm. Dehydroascorbic ac id (DHAA) in fruits and spinach was quantified in the presence of DL-homocy steine. The recoveries for L-AA in these juices were between 95 and 105%.