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目的建立茶叶中溴虫腈、啶虫脒、茚虫威、三氯杀螨醇及拟除虫菊酯类等11种农药的气相色谱-质谱(GCMS)分析方法。方法采用乙腈萃取待测组分,萃取液经过氮吹浓缩至1 ml左右;固相萃取净化后,样品经过DB-17MS毛细管色谱柱程序升温分离,质谱选择离子监测模式(SIM)检测,外标法定量。结果所测11种农药的浓度为0.05 mg/L~10 mg/L时,线性关系良好,相关系数(r)≥0.997 3,平均回收率为72%~114%,相对标准偏差≤16.7%。方法的检出限(LOD)为0.001 mg/kg~0.01 mg/kg,定量限(LOQ)为0.004 mg/kg~0.040 mg/kg。结论方法简单、准确、灵敏度高,适用于茶叶中农药多残留同时检测的要求。
Objective To establish a gas chromatography-mass spectrometry (GC-MS) method for the determination of 11 pesticides including chlorfenapyr, acetamiprid, indoxacarb, dicofol and pyrethroid in tea. Methods Acetonitrile was used to extract the components to be tested. The extract was concentrated to about 1 ml by nitrogen blowing. After purification by solid-phase extraction, the sample was subjected to temperature-programmed separation by capillary column chromatography (DB-17MS), ion-selective mass spectrometry (SIM) Legal quantity. Results When the concentration of 11 pesticides was between 0.05 mg / L and 10 mg / L, the correlation coefficient (r) was 0.997 3, the average recovery was 72% -114% and the relative standard deviation was less than 16.7%. The limit of detection (LOD) was 0.001 mg / kg ~ 0.01 mg / kg, and the limit of quantification (LOQ) was 0.004 mg / kg ~ 0.040 mg / kg. Conclusion The method is simple, accurate and sensitive. It is suitable for the simultaneous detection of pesticide residues in tea.