GC-MS/MS法测定鳄梨中拟除虫菊酯类农药残留

Determination of Pyrethroid Pesticide Residues in Avocado by GC-MS/MS

采用改良QuEChERS前处理技术联合气相色谱-串联质谱法(gas chromatography-tandem mass spectrometry,GC-MS/MS)同时检测鳄梨中8种拟除虫菊酯类农药残留。样品经乙腈提取,乙二胺-N-丙基硅烷化硅胶(primary secondary amine,PSA)、石墨化炭黑(graphitized carbon black,GCB)、十八烷基键合硅胶固定相(octadecylsilane,C18)联合净化,采用GC-MS/MS多反应监测模式(multiple reaction monitoring,MRM)分析测定,基质匹配标准曲线内标法定量。结果表明,8种拟除虫菊酯类农药在质量浓度10~300 ng/mL范围内,线性关系良好,相关系数(R2)在0.9961~0.9996,检出限(limit of detection,SLOD)范围为0.00040~0.0030 mg/kg,定量限(limit of quantitation,SLOQ)范围为0.0010~0.0096 mg/kg。在0.01,0.03和0.1 mg/kg添加水平下的回收率为71.0%~92.6%,相对标准偏差(n=6)在1.4%~13.4%。该方法的精密度、灵敏度、准确度均能满足8种拟除虫菊酯类农药残留测定要求,可用于实际样品的分析。

Establish an analitical method for simultaneously analyzing eight pyrethroid pesticide residues in avocado by the gas chromatography-tandem mass spectrometry(GC-MS/MS)combined with QuEChERS.The samples were extracted by acetonitrile,purified with primary secondary amine(PSA),graphitized carbon black(GCB)and octadecylsilane(C18),and determined by GC-MS/MS with multiple reaction monitoring(MRM).Quantify by matrix-matched internal standard method.The results showed that about 8 pyrethroids with the mass concentration range of 10-300 ng/mL had good linear relationship,and the correlation coefficient(r2)was 0.9961-0.9996.The limit of detection(SLOD)was 0.00040-0.0030 mg/kg,and the limit of quantification(SLOQ)was 0.0010-0.0096 mg/kg.The average recovery rates were between 71.0%and 92.6%at fortifification levels of 0.01,0.03 and 0.1 mg/kg,and relative standard deviation(SRSD)was 1.4%-13.4%.The method was accuracy,precision and sensitivity,which could meet the requirements for the determination of pyrethroid pesticide residues to analyze authentic samples.