固相萃取-毛细管气相色谱法同时测定黄瓜中23种有机氯和拟除虫菊酯类农药残留量

Determination of 23 Organochlorine and Pyrethroid Pesticide Residues in Cucumber by Solid-Phase Extraction and Capillary Gas Chromatograph

目的:建立了蔬菜中23种有机氯类和拟除虫菊酯类的固相萃取-毛细管气相色谱(SPE-CGC)分析方法。方法:样品以正己烷为提取剂,采用超声波提取黄瓜样品,然后用Florisil固相萃取小柱净化提取物。采用DB-35MS弹性石英毛细管气相色谱柱分离样品,电子捕获检测器检测。结果:23种农药在25min内很好地分离;样品加标回收率(n=3)为76.0%～110.1%,相对标准偏差0.81%～3.28%。最低检出限范围为0.03～2.06μg/kg。结论:该方法的测定结果满足多残留农残的检测要求。

Objective： The solid-phase extraction and capillary gas chromatography were introduced for determining 23 organochlorine and pyrethroid pesticide residues in cucumber. Method： The organochlorine and pyrethroid pesticides were extracted from cucumber samples with n-hexane by ultrasonic method and cleaned up by Florisil solid-phase extraction column. Then, the extract was separated by capillary colartm（30 m × 0.25 mm i.d. × 0.25μm）and detected by ECD（electron capture detector）. Results： The average recoveries for spiked standards are 76.0%- 110.1%. The relative standard deviations are 0. 81%-3.28%. The range of limit of detection（LOD） is 0.03-2.06o g/kg. Conclusion： The method is effective, fast and accurate.