Aflatoxin B1 is often found in animal feeds such as corn, cottonseed cake, groundnut meal, and other agricultural commodities. When these contaminated feeds are ingested by milk-producing animals, such as cattle, aflatoxin B1 can be converted to aflatoxin M1 (a hydroxy derivate of aflatoxin B1) by oxidation metabolism, and then excreted in milk. To protect consumers from the potential toxicity and carcinogenicity of aflatoxin M1, regulatory agencies have established regulatory limits or action levels for aflatoxin M1 in milk products.
In this study, a simple, fast, selective and sensitive LC/MS/MS method for the analysis of aflatoxin M1 is presented, along with the evaluation of three sample preparation methods.