气相色谱-串联质谱法快速检测玉米粉中乙草胺、异丙甲草胺和三唑酮残留
Simultaneous determination of acetochlor, metolachlor and triadimefon residue in corn flour by gas chromatography-tandem mass spectrometry

建立了玉米粉中乙草胺、异丙甲草胺和三唑酮残留检测的气相色谱-串联质谱(GC-MS/MS)分析方法。样品采用乙腈浸提3 h、过两次0.22μm尼龙66微孔过滤膜后,以气相色谱-串联质谱EI离子源,多反应监测模式(MRM)检测。结果表明:在0.005~1 mg/L范围内,3种供试农药的质量浓度与其相应的峰面积间呈良好的线性关系,决定系数(R2)均大于0.999。在0.025、0.050和0.25 mg/kg 3个添加水平下,3种农药的平均回收率为95%~101%,相对标准偏差(RSD)为0.7%~2.2%(n=6)。3种农药在玉米粉中的定量限(LOQ)分别为0.05、0.05和0.2μg/kg。该方法准确、灵敏、简单,适用于同时快速检测玉米粉中乙草胺、异丙甲草胺和三唑酮的残留量。
A gas chromatography-tandem mass spectrometry(GC-MS/MS) method was established for the simultaneous determination of acetochlor, metolachlor and triadimefon residue in corn flour. The samples were extracted with acetonitrile for 3 h, and the upper acetonitrile layer was filtered with 0.22μm nylon membrane.The samples were then determined by GC-MS/MS. The results showed that the calibration curve was linear in the range of 0.005-1.0 mg/L. The determination coefficients(R2) was higher than 0.999. When the spiked levels were 0.025, 0.050 and 0.25 mg/kg, the average recoveries of the three pesticides were between 95%-101%, with relative standard deviation(RSD) between 0.7% and 2.2%(n=6). The limits of quantitation(LOQ) for the three pesticides were 0.05, 0.05 and 0.2μg/kg, respectively. This new method is accurate, sensitive, simple and suitable for the simultaneous determination of the above mentioned three pesticide residues in corn flour.