Aflatoxin M1 concentration in raw milk produced in the cities of Semnan province – Iran

Introduction: Aflatoxin M1 is a hydroxylated metabolite of Aflatoxin B1. It has toxic and carcinogenic effects. So monitoring of its concentration in milk is a very important health concern. The purpose of this study was to determine the concentration of aflatoxin M1 in raw milk produced in the cites of Semnan province, Iran. Materials and Methods: This descriptive–analytical study was done during the 2009-2010, and a total of 311 samples were collected from raw milk collection centers and analyzed by HPLC-fluorescence detection after immunoaffinity purification. Results: The mean concentration and standard deviation of aflatoxin M1 in the raw milk samples was 55.1±80.1 (ng/kg). The lowest and the highest levels of Aflatoxin M1 were zero (undetectable) and 743ng/kg, respectively. Also, the average concentration and standard deviation of aflatoxin M1 in the raw milks produced in Damghan, Shahrood, Semnan and Garmsar (cities of the province) were 25.8±17.1, 47.5±36.5, 62.2±106.3 and 79.4±62.5 ng/kg, respectively. Conclusion: In overall, 15.8% of the raw milk samples had the aflatoxin M1 concentration higher than the 100 ng/kg (Iranian standard). The differences of aflatoxin M1 levels between the cities were statistically significant (P