Aflatoxin B1 and M1 in milk

The aflatoxin M-1 (AFLAM(1)) is a mycotoxin that results from the hydroxylation of the aflatoxin B-1 (AFLAB(1)). It contaminates the milk of animals fed with a diet containing its precursor. In this work, we determined the occurrence of AFLAB(1) and AFLAM(1) in milk, as well as the chromatographic conditions to quantify these mycotoxins. The extraction and quantification of AFLAB(1) and AFLAM(1) in naturally contaminated and artificially spiked milk samples which are produced and marketed in the state of RS were performed using the AOAC official method and UHPLC with fluorescence detection. We obtained a separation factor of 2.3 for AFLAB(1) and AFLAM(1) using a mobile phase consisting of 1% acetic acid: acetonitrile: methanol (55: 10: 35). The analytical curves had a wide linearity range and the limit of quantification (LOQ(m)) concentrations of AFLAB(1) and AFLAM(1) were equal to 0.5 and 0.25 mu g L-1, respectively. Samples of pasteurized and ultra-high-temperature processed (UHT) milk showed natural contamination, and the levels for both aflatoxins ranged from 0.7 to 1.5 mu g L-1. Raw and concentrated milk samples only contained AFLAM(1), with a maximum average concentration of 1.7 mu g L-1. These concentrations, higher than permitted by legislation, confirm the existence of a health risk, as well as highlight the relevance of searching for alternatives to reduce this contamination. (c) 2014 Elsevier B.V. All rights reserved.