加速溶剂萃取-气相色谱-串联质谱法测定茶叶中10种吡唑和吡咯类农药的残留量

Determination of ten pesticides of pyrazoles and pyrroles in tea by accelerated solvent extraction coupled with gas chromatography-tandem mass spectrometry

建立了加速溶剂萃取(ASE)-气相色谱-串联质谱(GC-MS/MS)法用于测定茶叶中10种吡唑和吡咯类农药残留。ASE萃取压力为1.03×107Pa,萃取温度为100℃,萃取时间为5 min,萃取溶剂为乙酸乙酯-正己烷(1∶1,v/v)。萃取循环1次,萃取液浓缩后用Envi-Carb/PSA固相萃取小柱净化,乙酸乙酯-正己烷(1∶1,v/v)洗脱。洗脱液浓缩后,用正己烷定容,供GC-MS/MS测定,外标法定量。方法的准确度和精密度均符合残留分析要求。方法的定量限(LOQ)分别为唑螨酯0.003 mg/kg、氟虫腈硫化物0.001 mg/kg、氟虫腈0.002 mg/kg、氟虫腈砜化物0.005mg/kg、溴虫腈0.002 mg/kg、氟硅唑0.006 mg/kg、野燕枯0.001 mg/kg、吡草醚0.001 mg/kg、吡螨胺0.000 3 mg/kg、唑虫酰胺0.005 mg/kg。方法的灵敏度能满足各国有关农药的残留限量要求。

An effective method was developed and applied to determine the residues of ten pesticides of pyrazoles and pyrroles in tea by accelerated solvent extraction coupled with gas chromatography-tandem mass spectrometry （ASE-GC-MS/MS）. The samples were extracted with ethyl acetate-hexane（ l： 1, v/v） for5 min at I. 03 x l07 Pa and 100 ℃ for one cycle. Then, they were purified by Envi-Carb/PSA column, and eluted by ethyl acetate-hexane （ 1： 1, v/v）. The analytes were determined by GC-MS/MS and quantified by external standard method. The lim- its of quantification were 0. 003 mg/kg for fenpyroximate, 0.001 mg/kg for fipronil-sulfide, 0. 002 mg/kg for fipronil, 0. 005 mg/kg for fipronil-sulfone, 0. 002 mg/kg for chlorfenapyr, 0. 006 mg/kg for flusilazole, 0. 001 mg/kg for difenzoquat, 0. 001 mg/kg for pyraflufen-ethyl, 0. 000 3 mg/kg for tebufenpyrad and 0. 005 mg/kg for tolfenpyrad. The results show that the proposed method is sensitive and accurate for the determination of the ten pesticide residues.