Product-specific sample clean-up and HPLC analysis of aflatoxins for a dietary product.

ABSTRACT

INTRODUCTION: A sample clean-up procedure has been developed for a complex dietary ingredient, Unigen Inc. (Lacey, WA, USA) product A (a proprietary mixture of Scutellaria baicalensis and Acacia catechu extracts), for the determination of aflatoxins by HPLC. OBJECTIVE: To develop an appropriate sample specific clean-up procedure that removes interferences from the sample for the determination of total aflatoxins B(1), B(2), G(1) and G(2) at or lower than 20 ppb by HPLC. METHODOLOGY: The sample specific clean-up procedure was developed based on the modification of AOAC method 990.33. RESULTS: Coextract interferences were removed with the clean-up procedure. The recovery of total aflatoxins was 70% with RSD about 2%; the LOD and LOQ were 1.6 and 5.2 ppb, respectively, for total aflatoxins; the linearity R(2) > 0.99. None of the samples tested showed the presence of detectable aflatoxins. CONCLUSION: The modified clean-up method was effective to remove coextract interferences from Unigen product A samples.