Determination of aflatoxins B1, B2, G1, G2 and ochratoxin A in animal feed by ultra high-performance liquid chromatography-tandem mass spectrometry

A rapid and simple method was developed to determine aflatoxins B1, B2, G1, G2 and ochratoxin A in animal feed and pet foods by UHPLC-MS/MS. Because the complexity of the evaluated matrices, the proposed method is based on sonication extraction using an ACN/water mixture (80:20 v/v) followed by a clean-up step utilising C-18 as sorbent. Performance parameters of the method were evaluated, including linearity, trueness, precision and LOQ. Good linearity was found for all mycotoxins, with determination coefficients higher than 0.99 in the range considered, using matrix-matched calibration for quantification purposes. Recoveries ranged from 84 to 113%, with RSD lower than 20%, whereas LOQs were 5 mu g/kg for the assayed mycotoxins. Finally, the method was successfully applied to the analysis of 19 real samples, detecting aflatoxin G2 in two samples at 13 and 17 mu g/kg respectively, whereas the other mycotoxins were detected at trace levels (< LOQ) in five samples.