Occurrence of aflatoxin M-1 in Korean dairy products determined by ELISA and HPLC

The occurrence of aflatoxin M-1 (AFM(1)) in pasteurized milk and dairy prod ucts was investigated by using direct competitive enzyme-linked immunosorbe nt assay (ELISA) and high-performance liquid chromatography (HPLC). The rec overies of AFM(1) from the samples spiked at levels between 5 and 500 pg/ml were 88.0-106.5% for pasteurized milk and 84.0-94.0% for yoghurt by ELISA. By HPLC, the recoveries were 103-120% for pasteurized milk and 87.0-93.0% for yoghurt. The limits of detection were found to be 2 pg/ml by ELISA and 10 pg/ml by HPLC. Among a total of 180 samples collected in Seoul, Korea, t he incidence of AFM(1) in pasteurized milk, infant formula, powdered milk a nd yoghurt was 76, 85, 75, and 83%, respectively, with a mean concentration of 18, 46, 200, and 29 pg/g, respectively, when determined by ELISA. These results obtained by ELISA were closely related to those by HPLC for AFM(1) (r(2) = 0.9783).