气相色谱法测定茶叶中有机氯农药残留量

Determination of Organochlorine Pesticide Residues in Tea by Gas Chromatography

茶叶中有机氯农药分别经正己烷、石油醚超声、离心、萃取浓缩后,由高纯氮气载入色谱柱进行分离,载有有机氯农药的氮气进入电子捕获检测器后,其出峰顺序为(1)α-HCH;(2)β-HCH;(3)γ-HCH;(4)δ-HCH;(5)ρ,ρ'-DDE;(6)ο,ρ'-DDT;(7)ρ,ρ'-DDD;(8)ρ,ρ'-DDT。测试结果表明,在茶叶中作加标试验时,各种标准物的回收率在88.6%~103.1%之间,相对标准偏差在1.95%~4.53%之间。结果表明,该方法测定茶叶中这8种有机氯农药具有良好的实际应用效果。

Organochlorine pesticides in tea respectively by n-hexane and petroleum ether extraction, ultrasonic,centrifugation and concentration, then high purity nitrogen loading column separation, nitrogen containing organochlorine pesticides into the electron capture detector of gas chromatograph, the peak sequence as follows：（1）α-HCH;（2）β-HCH;（3）γ-HCH;（4）δ-HCH;（5）ρ,ρ＇-DDE;（6）ο,ρ＇-DDT;（7）ρ,ρ＇-DDD;（8）ρ,ρ＇-DDT. The results of this method showed that the recoveries of all standard substances ranged from 88.6% to 103.1%, and the relative standard deviations ranged from1.95% to 4.53%. The results show that the method has a good effect on the determination of these 8 kinds of organochlorine pesticides in tea.