Simultaneous determination of aflatoxin M1, ochratoxin A, zearalenone and α-zearalenol in milk by UHPLC-MS/MS

In this study, a sensitive and rapid method has been developed for the simultaneous determination of aflatoxin M-1, ochratoxin A, zearalenone and alpha-zearalenol in milk by ultra high performance liquid chromatography combined with electrospray ionisation triple quadrupole tandem mass spectrometry (UHPLC-ESI-MS/MS). The milk samples were purified using Oasis HLB cartridge. The matrix effects were evaluated by determining the signal suppression-enhancement (SSE) and corrected by external matrix-matched calibration. The limits of quantity (LOQ) of the mycotoxins were in the range of 0.003-0.015 mu g kg(-1). The high correlation coefficients (R-2 >= 0.996) were obtained in the range of 0.01-1.00 mu g kg(-1) of the mycotoxins, along with good recovery (87.0-109%), repeatability (3.4-9.9%) and intra-laboratory reproducibility (4.0-9.9%) at the concentrations of 0.025, 0.1 and 0.5 mu g kg(-1). The detected rates of the mycotoxins were from 16.7% to 96.7% in raw milk, liquid milk and milk powder samples collected from the dairy farms and supermarkets in Beijing. The method proposed is suitable for the simultaneous determination of aflatoxin M-1, ochratoxin A, zearalenone, and alpha-zearalenol, and could be performed for analysing the mycotoxins in milk. (C) 2013 Elsevier Ltd. All rights reserved.