基于分散固相萃取液相色谱-串联质谱法测定大米中8种真菌毒素

摘要

建立了大米中HT-2毒素、T-2毒素、伏马毒素B1、伏马毒素B2、玉米赤霉烯酮、赭曲霉毒素A、脱氧雪腐镰刀菌烯醇和黄曲霉毒素B1共8种真菌毒素的快速测定方法.比较了3种基于分散固相萃取原理的样品前处理方法(即QuEChERS方法、EMR-lipid方法以及DisQuE方法)对8种真菌毒素的回收率;以提取后加标法考察大米基质中各目标物LC-MS/MS分析的基质效应.结果表明,QuEChERS样品前处理方法不适于伏马毒素B1、伏马毒素B2和赭曲霉毒素A分析;而EMR-lipid样品前处理方法无法消除玉米赤霉烯酮和赭曲霉毒素A在大米中的基质效应.据此采用DisQuE方法并优化LC-MS/MS分析参数,一次进样监测16对离子对(每个化合物2对离子对)分析大米中的8种真菌毒素残留量.8种真菌毒素在3个添加水平下的回收率为70.0％ ～ 124.1％,相对标准偏差为0.9％ ～ 16.9％,检出限(S/Ⅳ≥3)为1.2～ 60.0 μg/kg.该方法准确、灵敏,适用于大米中多种真菌毒素的快速分析.%A rapid method was developed for the determination of HT-2 toxin,T-2 toxin,fumonisin B1,fumonisin B2,zearalenone,ochratoxin A,deoxynivalenol and aflatoxins B1 in rice.Three dispersive solid phase extraction sample preparation methods,including QuEChERS method,EMR-lipid method and DisQuE method,were compared for the determination of 8 mycotoxins in rice.The recoveries of the three extraction methods for the toxins were studied.The method of afterextraction addition was used to evaluate the matrix effects for mycotoxins in rice by liquid chromatography-tandem mass spectrometry(LC-MS/MS).As a result,the QuEChERS method was not suitable for the analysis of fumonisin B1,fumonisin B2 and ochratoxin A.The EMR-lipid methods could not overcome the matrix effects of zearalenone and ochratoxin A in rice.In this study,mycotoxins were extracted by DisQuE method,and analysed by LC-MS/MS under the optimized condition with monitoring 16 pairs of MS/MS transitions of precursor ions(two for each mycotoxin) in one single run.Recoveries at three fortified levels in rice ranged from 70.0％ to 124.1％ with relative standard deviations of 0.9％-16.9％.The limits of detection(S/N≥3) were in the range of 1.2-60.0 μg/kg.The method was proved to be highly efficient,robust and sensitive,and was suitable for the simultaneous analysis of mycotoxins in rice.