DETERMINATION OF ASCORBIC-ACID IN FOOD BY COLUMN LIQUID-CHROMATOGRAPHY WITH ELECTROCHEMICAL DETECTION USING ELUENT FOR PRE-RUN SAMPLE STABILIZATION

Determination of ascorbic acid (AA) in food was performed by column li quid chromatography with electrochemical detection using an eluent (10 0 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 li mit: ca. 0.5 ng per injection (20 mu l) 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 mu l). Recovery of AA was over 90% by the st andard addition method. (C) 1998 Elsevier Science B.V.