气相色谱法测定结球甘蓝中三氟甲吡醚农药的残留

Determination of Trifluoromethane Pesticide Residues in Cabbage by Gas Chromatography

为建立测定结球甘蓝中三氟甲吡醚农药残留量的气相色谱检测方法,采用加压流体萃取-多功能浓缩技术,利用丙酮进行加压流体萃取,萃取液经脱水、浓缩、溶剂交换后用气相色谱-电子捕获检测器(ECD)检测,以外标法定量。该方法检出限(信噪比法)三氟甲吡醚0.004 mg·kg^(-1);0.1~10 mg·L^(-1)浓度范围内线性关系良好,线性相关系数r>0.990;3个浓度添加水平(低、中、高)加标回收率为85.4%~117.0%;利用建立的方法对结球甘蓝样品进行测定,结果相对标准偏差1.5%。该方法提取效率高,样品提取浓缩后测定准确度高,重现性好,检出限低,适用于结球甘蓝中三氟甲吡醚农药残留量的测定。

In order to establish a gas chromatographic method for the determination of trifluoromethane pesticide residues in cabbage.The pressurized fluid extraction multifunctional concentration technology was adopted,and acetone was used for pressurized fluid extraction.After dehydration,concentration and solvent exchange,the extracted liquid was detected by gas chromatography electron capture detector(ECD)and quantified by external standard method.The detection limit of this method(signal-to-noise ratio method)was 0.004 mg·kg^(-1) for trifluoromethane.The linear relationship was good in the concentration range of 0.1 mg·L^(-1);10 mg·L^(-1),and the linear correlation coefficient was r>0.990.The recoveries of three concentration addition levels(low,medium and high)were 85.4%-117.0%.The relative standard deviation of the results was 1.5%.This method had high extraction efficiency,high accuracy,good reproducibility and low detection limit after sample extraction and concentration.It was suitable for the determination of trifluoromethyl pyridyl pesticide residues in cabbage.