Occurrence of aflatoxin M1 in commercial pasteurized milk determined with ELISA and HPLC

Eighty-one samples of commercial pasteurized milk from Athens market were analysed for the presence of aflatoxin M1 (AFM1). A combination of a commercial ELISA kit and a modified HPLC method was applied for the rapid and reliable determination of AFM1. AFM1 concentrations in milk extracts were initially estimated by ELISA. Samples found to contain more than 5 ng/l were further quantitated by HPLC. Determination was performed after derivatization of AFM1 to its hydroxylated product AFM2a. The recovery of the HPLC method used was found to be close to 100%. Thirty-two samples contained aflatoxin M1 at levels of 2.5-5 ng/l, none contained more than 5 ng/l, while 31 contained only traces of aflatoxin (0.5-1 ng/l). In nine samples no AFM1 was detected. There was no seasonal influence on the aflatoxin content of the milk samples analysed.