非衍生化结合液相色谱-串联质谱技术测定茶叶中氯酞酸、茅草枯和草芽畏

Determination of chlorthal-diacid, dalapon and trysben in tea by non-derivatization coupled with liquid chromatography-tandem mass spectrometry

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  trysben  tea  non-derivatization  liquid chromatography-tandem mass spectrometry

中文摘要:

      目的 建立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-串联质谱技术(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 mL 1%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0.01~2.00 μg/mL范围内线性良好(r2>0.998), 在0.05、0.25、0.50和1.00 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%, 相对标准偏差为3.3%~18.3%。3种除草剂在茶叶中的检出限在0.002~0.009 mg/kg之间, 定量限在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 To establish a non-derivatized extraction method for the simultaneous determination of chlorthal-diacid, dalapon and trysben in tea by liquid chromatography-tandem mass spectrometry (LC-MS/MS) combined with hydrophile-lipophile balance (HLB) clean-up. Methods Tea samples were extracted by 20 mL of 1% acetic acid in water and 10 mL of methylene chloride; clean-up by HLB (300 mg/3 mL) filtration. Separation of the target analytes was achieved on an octadecylsilane (C18) chromatographic column, and quantitation was performed by LC-MS/MS in negative ion mode. Results The 3 kinds of herbicides were effectively separated on the C18 column with good linearity in the range of 0.01–2.00 μg/mL (r2>0.997). At 4 spiked levels of 0.05, 0.25, 0.50 and 1.00 mg/kg, the average recoveries of the 3 kinds of pesticides in the blank matrix of tea ranged from 71.1% to 119.2%, with the relative standard deviations between 3.3% and 18.3%. The limits of detection were ranged from 0.002–0.009 mg/kg, and the limits of quantitation were ranged from 0.008–0.029 mg/kg of the 3 kinds of herbicides. Conclusion The developed method offers a simple and rapid pretreatment procedure, eliminating the need for derivatization. It is friendly to the inspectors and the environment, and can be used as a method for large-scale detection of chlorthal-diacid, dalapon and trysben residues in tea.