Determination of ascorbic acid in food by column liquid chromatography with electrochemical detection using eluent for pre-run sample stabilization

Abstract

Determination of ascorbic acid (AA) in food was performed by column liquid chromatography with electrochemical detection using an eluent (100 m M KH 2PO 4 (pH 3) with 1 m M ethylenediaminetetraacetic acid disodium dihydrate) for pre-run sample stabilization. The applied potential was set at 400 mV vs. an Ag/AgCl reference electrode. The proposed method was simple, rapid (analysis time: ca. 8 min). sensitive (detection limit: ca. 0.5 ng per injection (20 μl) at a signal-to-noise ratio of 3), highly selective and reproducible [relative standard deviation: ca. 1.8% ( n=5)]. The calibration graph for AA was linear in the range 0.1–16 ng per injection (20 μl). Recovery of AA was over 90% by the standard addition method.