QuEChERS-气相色谱-三重四极杆质谱法测定植物源性食品中砜吡草唑残留量

Determination of pyroxasulfone residues in plant derived foods by QuEChERS combined with gas chromatography-triple quadrupole mass spectrometry

目的建立植物源性食品中砜吡草唑残留量的QuEChERS-气相色谱-三重四极杆质谱检测方法。方法稻谷、小麦、高粱、玉米、大豆、花生、甘薯、马铃薯和葵花籽中的砜吡草唑残留用乙酸乙酯提取,经乙二胺-N-丙基硅烷化硅胶、十八烷基键合硅胶和无水硫酸镁去除杂质,离心过滤后经气相色谱-三重四极杆质谱仪检测,基质匹配外标法定量。实验对提取溶剂、提取方式、净化方式和仪器条件进行了优化,考察了基质效应的影响,确定出最优的前处理方法和仪器条件。结果在优化实验条件下,目标化合物在0.0005~0.05 mg/L范围内的线性关系良好,相关系数大于0.999。空白样品在4个添加水平下的平均回收率为83.8%~104.3%,相对标准偏差(n=6)为2.6%~6.7%,方法定量限为0.001 mg/kg。结论本方法操作简单、快速、灵敏,能满足植物源性食品中砜吡草唑的检测要求。

Objective To develop a method for the determination of pyroxasulfone residue in plant derived foods by QuEChERS combined with gas chromatography-triple quadrupole mass spectrometry.Methods Pyroxasulfone in rice,wheat,sorghum,corn,soybean,peanut,sweet potato,potato and sunflower seeds were extracted with ethyl acetate,and cleaned up with primary-secondary amine,stearyl bonded silica gel and anhydrous magnesium sulfate as dispersive solidphase extraction sorbent.After centrifugation and filtration,the target compound was analyzed by gas chromatography-triple quadrupole mass spectrometry,and quantified by matrix matching external standard method.The extraction solvents,extraction method,purification method and instrument conditions were optimized.The matrix effect was investigated and the optimal pretreatment method and instrument conditions were determined.Results Under the optimal conditions,the calibration curves were linear in the range of 0.0005-0.05 mg/L with correlation coefficients above 0.999.The recoveries were 83.8%-104.3%at four concentration levels with relative standard deviations(RSDs,n=6)of 2.6%-6.7%.The quantitation limit of pyroxasulfone was 0.001 mg/kg.Conclusion The method is simple,rapid and sensitive,and could meet the requirements for the detection of pyroxasulfone residue in plant derived foods.