液相色谱串联质谱法快速测定油茶籽中9种农药残留量

Fast simultaneous determination of nine kinds of pesticides in camellia seed by liquid chromatography-tandem mass spectrometry

建立了高效液相色谱串联－质谱法同时检测油茶籽中吡虫啉、乐果、甲胺磷、马拉硫磷、三唑酮、对硫磷、毒死蜱、丁草胺、噻嗪酮9种农药的残留量。样品经乙腈提取后，取上清液直接过膜后进行液相色谱串联质谱分析。采用 Agilent SB—C18色谱柱分离，用4 g／L 甲酸铵水溶液－乙腈作为流动相进行梯度洗脱，电喷雾正离子（ESI ＋）模式电离，多反应监测（MRM）模式检测。结果表明：各物质峰面积与样品浓度在0.001～0.5 mg／L 范围内呈良好的线性关系，线性回归系数大于0.9990。在添加浓度0.01～1.0 mg／kg 范围内，9种农药的平均添加回收率在64.2％～114.1％范围内，变异系数在1.2％～9.4％之间，该方法能满足油茶籽中9种农药残留量分析的要求。

A method was developed for determining 9 pesticides residues in camellia seed using liquid chromatography tandem mass spectrometry.Samples were extracted with acetonitrile.Then,the upper supernatant was directly analyzed by LC —MS /MS on an Agilent SB—C18 column with a mixture of 4g/L formic acid ammonium solution （A）and acetoni-trile （B）as mobile phase under gradient elution conditions.The mass spectrometer operated in multiple reaction monito-ring （MRM）mode with the positive mode.There is a good linear correlation （all of the calibration coefficients are above 0.9990）between the peak areas and concentration of sixteen amide fungicides in the range of 0.001 ～0.5 mg/L.The average recoveries of 9 pesticides in camellia seed were 64.2% ～114.1%.The relative standard deviations were between 1.2% and 9.4%.The method is demonstrated to be suitable for the determination of the 9 kinds of pesticides in camellia seed.