QuEChERS-气相色谱-质谱法检测洋葱中20种农药残留

Determination of 20 pesticides residues in onions by QuEChERS method coupled with gas chromatography-mass spectrometry

中文关键词:  QuEChERS  气相色谱-质谱法  洋葱  农药残留

英文关键词:QuEChERS  gas chromatography-mass spectrometry  onions  pesticide residues

中文摘要:

      目的 建立洋葱中20种农药残留的气相色谱-质谱(gas chromatography-mass spectrometry, GC-MS)分析方法。方法 样品前处理采用QuEChERS方法, 用乙腈溶液进行提取, 经N-丙基乙二胺(primary secondary amine, PSA)、十八烷基硅烷键合硅胶(C18)和无水硫酸镁固相分散净化, 浓缩定容后用GC-MS在选择离子监测模式(select ion monitoring, SIM)下进行测定, 外标法定量。结果 20种农药在0.1~0.5 μg/mL范围内线性关系良好, 相关系数均大于0.99。方法检出限为0.0003~0.0222 mg/kg, 方法定量限为0.0009~0.0741 mg/kg, 加标回收率为87.9%~110.0%, 相对标准偏差(relative standard deviation, RSD)为0.4%~3.8%。结论 该方法前处理过程简单、快速, 灵敏度高, 重现性好, 适用于洋葱中20种农药残留的测定。

英文摘要:

      Objective To establish a rapid method for the simultaneous determination of 20 pesticide residues in onions by gas chromatography-mass spectrometry (GC-MS). Methods The samples were prepared by the modified QuEChERS method, extracted with acetonitrile, and cleaned up by adding primary secondary amine (PSA), octadecyl silane chemically bonded silica (C18) and anhydrous magnesium sulfate. After concentration and dissolution, the compounds were analyzed by GC-MS under selected ion monitoring (SIM) mode. The external standard method was used for quantitative analysis. Results The 20 pesticides had good linear relationships in the range of 0.1?0.5 μg/mL, and the correlation coefficients were larger than 0.99. The limits of detection of the method were 0.0003?0.0222 mg/kg, the limits of quantitation were 0.0009?0.0741 mg/kg, and the recoveries ranged from 87.9% to 110.0% with the relative standard deviations of 0.4%?3.8%. Conclusion The method is simple, accurate, and sensitive, which is suitable for the determination of 20 pesticide residues in onions.