高效液相色谱-串联质谱法测定大米与小米中柄曲霉素残留

Determination of Sterigmatocystin in Rice and Millet by High Performance Liquid Chromatography-Tandem Mass Spectrometry

通过优化提取溶剂及其体积、超声时间及吸附剂,建立了一种快速、简单、准确测定大米和小米中柄曲霉素的分析方法。以乙腈为提取溶剂,乙二胺-N-丙基硅烷（PSA）吸附剂净化,上清液过膜后进行分析,在电喷雾电离（ESI）模式下,采用多反应监测（MRM）模式进行测定。结果表明,柄曲霉素在0.1～100.0μg/L范围内呈良好的线性,相关系数不低于0.999 0。大米中柄曲霉素的检出限为0.03μg/kg,定量下限为0.1μg/kg,回收率为88.3%～91.5%,相对标准偏差（RSD）为2.3%～6.0%;小米中柄曲霉素的检出限为0.1μg/kg,定量下限为0.3μg/kg,回收率为92.7%～103.8%,RSD为2.2%～6.9%,符合痕量分析的要求。采用该方法分析收集的大米和小米样品,均未检出柄曲霉素。

Sterigmatocystin, a mycotoxin produced by fungi and widely distributed in cereal food, has a potential toxic effect to hmnan and animals with risk on food safety. In this study, a rapid, simple and accurate high performance liquid chromatography -tandem mass spectrometric （HPLC - MS/MS） method was established for the analysis of sterigmatocystin in rice and millet by optimizing extraction solvent and its volume, ultrasonic time and adsorbent. The samples were extracted with acetonitrile, and cleaned up with PSA, then detected after the supernatant was filtered through nylon filter. The detection was performed in the electrospray ion （ESI） positive mode and multiple reaction monitoring（MRM） mode. The sterigmatocystin showed good linear relationships in the range of O. 1 - 100.0 μg/L with correlation coefficients not less than 0. 999 0. The limit of detection（LOD） and the limit of quantitation（LOQ）for sterigmatocystin in rice were 0.03 μg/kg and 0. 1μg/kg, re- spectirely, the recoveries ranged from 88.3% to 91.5% with relative standard deviations（RSDs） of 2. 3% -6. 0%,6. The LOD and LOQ for sterigmatocystin in millet were 0.1 μg/kg and 0.3 μg/kg, re- spectively, and the recoveries were 92. 7% - 103.8% with RSDs of 2. 2% - 6. 9%. The proposed method could meet the requirement for trace analysis. The method was applied in the the detection of the collected rice and millet samples, and no sterigmatocystin was detected.