建立了液相色谱-飞行时间质谱(LC-TOF MS)联用技术同时检测小麦和玉米中镰刀菌、曲霉菌和青霉菌产生的13种真菌毒素的分析方法.样品经乙腈-水-乙酸(84∶ 15∶1,体积比)混合溶剂提取,Mycosep 226多功能净化柱和强阴离子交换柱净化后,采用LC-TOF MS检测.在电喷雾正离子模式下,以保留时间和化合物精确分子离子质量对真菌毒素进行识别,以10 ppm为提取离子窗口进行定量.结果表明,13种真菌毒素在一定的线性范围内线性关系良好,相关系数均大于0.99,质量精确度均小于5 ppm,回收率为70％～113％,相对标准偏差为0.2％～14.5％.该方法可用于粮食中多种真菌毒素的同时测定.%Mycotoxins are toxic secondary metabolites produced by filamentous fungi that grow on grain commodities. They have been widely recognized as the main undesirable substances in grain. A method using liquid chromatography - time of flight mass spectrometry( LC - TOF MS) was developed for simultaneous determination of 13 mycotoxins derived from the fungal genera of Fusarium, Aspergil-lus and Penicillum in wheat and maize. The samples were extracted with acetonitrile - water - acetic acid (84 : 15 : 1) , and cleaned up on the Mycosep 226 multifuctional cartridge and the strong ani-on exchange cartridge. The purified extracts were analysed by LC - TOF MS under the mode of positive electrospray ionization, the mycotoxins were identified by the retention time and the mass accuracy of [M + H]+ or [M + NH4] + and quantified in exact mass chromatograms with a mass window width of 10 ppm. The results indicated that 13 mycotoxins had good linear relationships in the certain concentration ranges with their correlation coefficients more than 0.99 and the accurate mass errors less than 5 ppm. The average recoveries of 13 mycotoxins at three spiked levels ranged from 70% to 113% with relative standard deviations of 0. 2% - 14.5% . The method was suitable for the identification and quantification of targeted mycotoxins at trace level in grain.
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