Determination of kojic acid in various commercial foods by HPLC.

Abstract

A simple method for the determination of kojic acid in various commercial foods by HPLC was developed. The kojic acid was extracted from the various commercial foods with 50% methanol solution. The extract was centrifuged, then the supernatant fluid was filtered through a 0.45 im membrane filter. The HPLC separation was performed on an RP-18 column with 0. 1 mol/L sodium dihydrogenphosphate-methanol (97 : 3) as the mobile phase. The recoveries of kojic acid spiked into foods at the level of 0. 10 g/kg were 7396%, and the detection limit was 0. 005 g/kg. The proposed method was applied to the determination of kojic acid in 92 commercial foods. Kojic acid was detected in 1 sample of crab and 2 samples of beverages at the levels of 0. 03 g/kg, 0. 20 g/kg and 0. 03 g/kg, respectively. The identity of kojic acid in these foods was confirmed using a photodiode-array detector. (Received August 9, 1999)