Occurrence of aflatoxin M1 in raw milk in South Korea using an immunoaffinity column and liquid chromatography

The level of aflatoxin M1 (AFM1) contamination in raw milk produced in South Korea was investigated using immunoaffinity column chromatography and high performance liquid chromatography with fluorescence detector. A total of 100 raw milk samples were collected from 100 cattle ranches located in three different provinces of South Korea. Forty eight out of 100 raw milk samples contained AFM1 at low level (0.002–0.08 μg/L) with mean value of 0.026 μg/L. Among the AFM1 contaminated samples, 29 raw milk samples contained only traceable amount of AFM1 below the limit of LOQ, 0.02 μg/L. None of samples exceeded the maximum level (0.5 μg/L) of Korean regulation for AFM1 in milk. The limit of detection was 0.002 μg/L. The result of recovery test with 0.5 μg/L AFM1 in raw milk sample was 96.3% (SD 3.6, n = 5). This is the first pioneering study to investigate the level of AFM1 in raw milk used in dairy industries in South Korea.