固相萃取-气相色谱-三重四极杆串联质谱法测定茶叶中45种有机磷农药残留

采用气相色谱-三重四极杆串联质谱(GC-MS/MS)技术建立了茶叶中45种有机磷农药残留的检测方法。茶叶样品加水浸泡后采用乙腈提取，经TPT固相萃取柱净化，用V (乙腈) : V (甲苯) ＝ 3 : 1混合溶液洗脱，采用GC-MS/MS检测，基质匹配标准溶液外标法定量；分析了加水对茶叶中有机磷类农药提取效率的影响。结果表明:45种有机磷类农药在各自质量浓度范围内线性关系良好，相关系数均大于0.993。方法检出限为0.001~0.01 mg/kg，定量限为0.002~0.02 mg/kg。在0.05、0.5和5 mg/kg 3个添加水平下，45种农药平均回收率在71%~102%之间，相对标准偏差均小于9.4%。

Determination of 45 organophosphorus pesticide residues in tea by solid-phase extraction combined with gas chromatography-tandem mass spectrometry

An analytical method for the determination of 45 organophosphorus pesticide residues in tea has been established by gas chromatography-triple quadrupole mass spectrometry (GC-MS/MS). The rehydrated samples were extracted with acetonitrile and purified by Cleanert TPT SPE cartridge, eluted with V(acetonitrile) : V(toluene) = 3 : 1. The target compounds were detected by GC-MS/MS, and quantified by matrix matching external standard method. The effect of water addition on the extraction efficiency of organophosphorus pesticides in tea was discussed in detail. The calibration curves for 45 organophosphorus pesticides showed good linearity in their own ranges with correlation coefficients higher than 0.993.The limits of detection and the limits of quantitation of organophosphorus pesticide residues in tea were in the range of 0.001-0.01 mg/kg and 0.002-0.02 mg/kg, respectively.The average recoveries at spiked levels of 0.05, 0.5, 5 mg/kg ranged from 71% to 102% with relative standard deviations < 9.4%.