茶叶中10种农药残留的液相色谱-串联质谱法和气相色谱-串联质谱法测定

建立了茶叶中啶虫脒、乐果、吡虫啉、灭多威、甲基嘧啶磷、腐霉利共6种农药残留的液相色谱-串联质谱(LC-MS/MS)测定方法和溴氰菊酯、乐果、高效氯氟氰菊酯、p,p'-滴滴伊、甲基嘧啶磷、腐霉利、哒螨灵共7种农药残留的气相色谱-串联质谱(GC-MS/MS)测定方法。其中,乐果、甲基嘧啶磷和腐霉利三种农药均能通过两种方法测定。LC-MS/MS法测定的6种农药,在5~200 μg/L范围内线性关系良好(R2>0.995),在10、50、100 μg/kg加标水平下的回收率为70.0%~105.0%,相对标准偏差为0.3%~18.7%。GC-MS/MS法测定的7种农药,在10~500 μg/L范围内线性关系良好(R2>0.996),在10、50、300 μg/kg加标水平下的回收率为82.0%~110.0%,相对标准偏差为1.8%~12.0%。该方法完善了茶叶中10种农药残留检测方法针对实际样品的检测,灵敏度满足国外限量标准要求,适合出口茶叶中农药残留的测定。

Determination of Ten Pesticide Residues in Tea by Liquid Chromatography-Tandem Mass Spectrometry and Gas Chromatography-Tandem Mass Spectrometry

The method was developed for the determination of six pesticide residues (acetamiprid, dimethoate, imidacloprid, methomyl, pirimiphos-methyl and procymidone) in tea by liquid chromatography-tandem mass spectrometry (LC-MS/MS) and another method was developed for the determination of seven pesticide residues (deltamethrin, dimethoate, lambda-cyhalothrin, p, p'-DDE, pirimiphos-methyl, procymidone and pyridaben) in tea by gas chromatography-tandem mass spectrometry (GC-MS/MS).Dimethoate, pirimiphos-methyl and procymidone were suitable for determination by both methods. The calibration curves showed good linearity in 5~200 μg/L for the six pesticides by LC-MS/MS (R2>0.995). The average recoveries ranged from 70.0%~105.0% with the relative standard deviations of 0.3%~18.7% at the spiked levels of 10, 50, 100 μg/kg. The calibration curves showed good linearity in 10~500 μg/L for the seven pesticides by GC-MS/MS (R2>0.996). The average recoveries ranged from 82.0%~110.0% with the relative standard deviations of 1.8%~12.0% at the spiked levels of 10, 50, 300 μg/kg. The method improved the detection of 10 pesticide residues in tea, and the sensitivity met the requirement of foreign limit standard, which was suitable for the determination of pesticide residues in tea.