非衍生化结合LC-MS/MS测定茶叶中氯酞酸、茅草枯和草芽畏

Determination of Chlorthal-diacid, Dalapon and Trysben in Tea by Non-derivatization Coupled with LC-MS/MS

中文关键词:  氯酞酸  茅草枯  草芽畏  茶叶  非衍生化  液相色谱-串联质谱法

英文关键词:Chlorthal-diacid  Dalapon and Trysben  tea  non-derivatization  liquid chromatography-tandem mass spectrometry

中文摘要:

      目的 试验建立了一种非衍生化前处理，亲水亲脂平衡柱(Hydrophile-Lipophile Balance，HLB)净化结合液相色谱-串联质谱(liquid chromatography-tandem mass spectrometry，LC-MS/MS)测定茶叶中氯酞酸、茅草枯、草芽畏的检测方法。方法 样品经20 mL1%乙酸水+10 mL二氯甲烷提取，HLB(300 mg/3 mL)滤过净化，十八烷基硅烷(Octadecylsilane，C18)色谱柱分离，液相色谱-串联质谱仪负离子模式测定，外标法定量检测。结果 3种除草剂在色谱柱上分离良好，在0.01-2.0 μg/mL范围内线性良好（R2>0.997），在0.05、0.25、0.50和1.0 mg/kg 4个添加水平下，3种农药在茶叶空白基质中平均回收率为71.1% ~119.2%，相对标准偏差（Relative Standard Deviation，RSD）为3.3%~18.3%。3种除草剂在茶叶中的检出限（Limit of Detection，LOD）在 0.002~0.009 mg/kg之间，定量限（Limit of Quantitation，LOQ）在 0.008~0.029 mg/kg之间。结论 该方法前处理简单快捷，无需衍生化，对检测人员和环境友好，可作为大批量检测茶叶中氯酞酸、茅草枯、草芽畏残留的方法。

英文摘要:

      Objective A non-derivatized extraction method was established for the determination of chlorthal-diacid, dalapon and trysben in tea by liquid chromatography-tandem mass spectrometry (LC-MS/MS) coupled with Hydrophile-Lipophile Balance (HLB) clean-up. Methods The samples were extracted by 20 mL of 1% acetic acid in water+10 mL of methylene chloride, purified by HLB (300 mg/3 mL) filtration, separated on an Octadecylsilane (C18) column, and quantified by LC-MS/MS in negative ion mode. Results The three herbicides were well separated on the column with good linearity in the range of 0.01-2.0 μg/mL (R2>0.997), and the average recoveries of the three pesticides in the blank matrix of tea at three spiked levels of 0.25, 0.50 and 1.0 mg/kg were 74.0%~119.2% with the relative standard deviations(RSD) of 3.3%~10.4%.Results showed that the limits of detection and limits of quantitation were in the ranges of 0.002~0.009 mg/kg and 0.008~0.029 mg/kg. Conclusion The method is simple and rapid in pretreatment, without derivatization, friendly to the detector and the environment, and can be used as a method for the detection of the three herbicide residues in tea in large quantities.