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目的建立应用QuEChERS前处理法处理样品,采用气相色谱电子捕获检测器测定蔬菜水果中7种拟除虫菊酯类农药残留量的分析方法。方法样品经乙腈均质提取,氮吹浓缩至近干,加入丙酮定容至3.0 mL后,过QuEChERS柱进行分散固相萃取,净化液用GC-ECD进行分析测定。结果 7种拟除虫菊酯类农药在0.10~1.00μg/mL浓度范围内,标准曲线线性关系良好,相关系数r为0.9985~0.9995,最低检出质量浓度0.0010~0.0023mg/kg,在3个浓度水平上对方法的回收率进行测定,回收率78.1%~97.4%,相对标准偏差(RSD)1.9%~8.4%。结论该方法具有净化效果好、选择性好、精密度和准确好等优点,且操作简单、快捷,适合对蔬菜水果中7种拟除虫菊酯类农药残留量定性定量分析。
Objective To establish a method for the determination of seven pyrethroid pesticide residues in vegetables and fruits by using QuEChERS pretreatment method and gas chromatography electron capture detector. Methods The samples were homogenized with acetonitrile and concentrated to near dryness by nitrogen. After acetone was added to 3.0 mL, QuEChERS column was used to carry out dispersive solid-phase extraction. The purified liquid was analyzed by GC-ECD. Results The calibration curve of seven pyrethroid pesticides showed a good linearity in the range of 0.10-1.00 μg / mL with a correlation coefficient of 0.9985-0.9955 and a minimum detectable concentration of 0.0010-0.0023 mg / kg. At the three concentration levels The recovery rate of the method was determined, the recovery rate of 78.1% to 97.4%, the relative standard deviation (RSD) of 1.9% to 8.4%. Conclusion The method has the advantages of good purification effect, good selectivity, precision and accuracy, and is simple, fast and suitable for the qualitative and quantitative analysis of seven kinds of pyrethroid pesticide residues in vegetables and fruits.