Analysis and Monitoring of Aflatoxin M 1 in Milks

Raw milk samples (n=28) obtained from milk tanks in 3 dairy plants of different regions and commercial milks (n=100) were collected from six cities. These samples were analyzed for the level of aflatoxin M1 contamination using immunoaffinity columns and high performance liquid chromatography coupled with fluorescent detectors. Confirmation of aflatoxin M1 (AFM1) identified in positive samples was based on the formation of the hemiacetal derivative (AFM2a) after derivatization with trifluroacetic acid. The average concentrations of aflatoxin M 1 in the raw milks were 25.1 ng/kg, and those values in commercial milks were 29.8 ng/kg. The highest level of aflatoxin M1 in milk was 72.7 ng/kg. These results showed that the contamination of aflatoxin M 1 in milks consumed in the Korea was quite low compared to the standard in Korea Food Code (aflatoxin M1 500 ng/kg).