提出了气相色谱-串联质谱法(GC-MS/MS)测定牛肉中4种琥珀酸脱氢酶抑制剂类杀菌剂(吡噻菌胺、氟唑菌苯胺、氟唑菌酰羟胺和苯并烯氟菌唑)残留量的方法。取5 g绞碎的牛肉样品,以10 mL体积比1∶1的环己烷-乙酸乙酯混合溶液提取两次,2.0 mL乙腈净化。分取1.0 mL乙腈层,于40 ℃水浴氮吹至近干,用1.0 mL正己烷溶解残渣,过0.22 μm有机滤膜,滤液按照仪器工作条件进行测定。4种琥珀酸脱氢酶抑制剂类杀菌剂在柱升温程序下分离,在多反应监测模式下检测,基质匹配法绘制工作曲线,外标法定量。结果显示:4种琥珀酸脱氢酶抑制剂类杀菌剂工作曲线的线性范围均为0.2~20.0 μg·L^-1,检出限(3S/N)均为0.08 μg·kg^-1;对空白样品进行3个浓度水平的加标回收试验,回收率为89.8%~105%,测定值的相对标准偏差(n=6)为0.74%~4.5%;方法用于12份实际样品分析,均未检出目标物。

A method for the determination of residues of four succinate dehydrogenase inhibitor fungicides including penthiopyrad, penflufen, pydiflumetofen and benzovindiflupyr in beef by gas chromatography-tandem mass spectrometry (GC-MS/MS) was proposed. The ground beef sample (5 g) was extracted twice with 10 mL of cyclohexane and ethyl acetate mixed solution at volume ratio of 1∶1, and purified with 2.0 mL of acetonitrile. An aliquot (1.0 mL) of acetonitrile layer was taken, and blown to nearly dryness in water bath by nitrogen at 40 ℃, and the remaining residue was dissolved with 1.0 mL of n-hexane. The obtained solution was filtrated by 0.22 μm organic filter membrane, and the filtrate was determined according to the operating conditions of the instrument. Four succinate dehydrogenase inhibitor fungicides were separated by column temperature program, and detected by multiple reaction monitoring mode. The working curves were drawn by matrix matching method, and external standard method was used for quantitative analysis. It was shown that the linear ranges of four succinate dehydrogenase inhibitor fungicides were 0.2-20.0 μg·L^-1, with detection limits (3S/N) of 0.08 μg·kg^-1. Test for recovery was made on the blank sample by standard addition method at 3 concentration levels, giving results in the range of 89.8%-105%, and RSDs (n=6) of the determined values ranged from 0.74% to 4.5%. The method was used to analyze 12 actual samples, and the targets were not detected.