提出了同位素稀释高效液相色谱-串联质谱法测定植物性食品中的杂色曲霉素。植物性食品样品经乙腈-水混合液提取,提取液通过HLB SPE小柱净化并浓缩后,样品溶液在反相液相色谱柱上分离。MS/MS分析中采用电喷雾离子源离子化和多反应离子监测(MRM)检测,并用同位素稀释内标法定量。杂色曲霉素的线性范围在0.5~100 μg·L-1之间,其线性相关系数大于0.999。小麦和玉米样品的测定下限(10S/N)为0.5 μg·kg-1,花生和黄豆样品的测定下限(10S/N)为0.8 μg·kg-1。以不同的植物性食品作为基体,分别加入不同浓度水平的杂色曲霉素标准液,按方法进行回收试验,测得回收率在88.2%~105%之间;测定值的日内相对标准偏差(n=6)小于7.5%,日间相对标准偏差(n=3)小于9.0%。

A method was proposed for the determination of sterigmatocystin in plant food with isotope diution internal standard by HPLC-MS/MS. Sample of plant food was extracted with a mixture of acetonitrile and water. The extract was purified on HLB SPE microcolumn. The purified extract was concentrated and then separated on RP-LC column. ESI and MRM were adopted in MS/MS analysis and isotope dilution internal standard was used for quantification. Linearity range for sterigmatocystin was found between 0.5-100 μg·L-1 with correlation coefficient greater than 0.999. Values of lower limits of determination (10S/N) found for wheat and maize were same to be 0.5 μg·kg-1, and for peanut and soybean were same to be 0.8 μg·kg-1. Standard sterigmatocystin of different concentration levels was added to various matrixes of plant food, and tests for recovery were made, giving values of recovery in the range of 88.2%-105%. Values of intra-day RSDs (n=6) found were less than 7.5% and of inter-day RSDs (n=3) found were less than 9.0%.