Determination of ascorbic acid in food by column liquid chromatography with electrochemical detection using eluent...

Determination of ascorbic acid (AA) in food was performed by column liquid chromatography with electrochemical detection using an eluent (100 mM KH2PO4 (pH 3) with 1 mM 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 microliters) 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 microliters). Recovery of AA was over 90% by the standard addition method.