Abstract: A method was developed for the multi-residue determination of 24 mycotoxins including aflatoxin B1 (AFB1), AFB2, AFG1, AFG2, AFM1, ochratoxin A (OTA), zearalanone, zearalenone, α-zearalanol, β-zearalanol, α-zearalenol, β-zearalenol, T-2 toxin, HT-2 toxin, fumonisin B1 (FB1), FB2, FB3, deoxynivalenol (DON), 3-DON, 15-DON, alternariolmethylether, alternariol, tentoxin and tenuazonic acid in milk by ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The sample was extracted with 80% aqueous acetonitrile, the extract was purified by matrix solid-phase dispersion (MSPD) extraction and blown to dryness under nitrogen, and the residue was re-dissolved in 1 ml of 50% aqueous acetonitrile (V/V) and analyzed by UPLC-MS/MS. An acquity UPLC HSS T3 (2.1 mm × 100 mm, 1.8 μm) reversed-phase column was used for the separation with gradient elution. Detection was performed under the multiple reaction monitoring (MRM) mode using electrospray ionization. The correlation coefficients (R2) for all analytes were greater than 0.985, the recoveries for spiked samples ranged from 71.0% to 123.0%, and the relative standard deviation (RSD) was less than 10%. The developed method has the advantages of simple operation, good repeatability, high sensitivity and low impurity interference and can be used for the determination of the 24 mycotoxins in milk.

Key words: matrix solid-phase dispersion extraction; mycotoxins; ultra-high performance liquid chromatography-tandem mass spectrometry; milk