[Determination of zearalenone and related mycotoxins in grain and its products by solid-phase extraction coupled with ultra performance liquid chromatography-tandem mass spectrometry].

A method was established for the determination of 6 zearalenonic compounds (alpha-zearalanol, beta-zearalanol, alpha-zearalenol, beta-zearalenol, zearalanone and zearalenone) in grain and its products based on solid-phase extraction coupled with ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The samples was extracted by 84% (v/v) acetonitrile-water solution and further purified by an ENVI-Carb graphite carbon black (GCB) cartridge, which was eluted by 6 mL dichloromethane-methanol (7:3, v/v) solution. The target compounds were assayed by UPLC-MS/MS. The chromatographic separation was performed on an ACQUITY UPLC BEH C18 column with gradient elution using acetonitrile and water as mobile phases. The mass spectrometric acquisitions were carried out by means of multiple reaction monitoring (MRM) in electrospray negative ionization mode. The good linearities (R2 > 0.99) were achieved for the 6 compounds over the range of 0.1-50 microg/L based on the internal standard calibration of a-zearalenol-d4. The detection limits of the method were 0.1-0.2 microg/kg. The mean recoveries of the 6 target compounds (spiked at three concentration levels) ranged from 79.9% to 104.0%, with the relative standard deviations (RSDs) no more than 10%. It has been applied in the analysis of grain and related products taken from Beijing. As a result, zearalenone presented a highest detectable frequency, with a concentration range of 0.42-220.7 microg/kg. In addition, alpha-zearalenol and beta-zearalenol were also detected in this survey. This proposed method is simple, sensitive, reproducible, and complied with the regulations for the determination of trace contaminants residues in food matrices.