固相萃取-气相色谱法测定茶叶中多种有机磷农药残留量

Determination of Multi-Residues of Organophosphorus Pesticides in Tea by Solid Phase Extraction and Gas Chromatography

本文选择石墨碳黑固相萃取小柱对茶叶样品进行净化,样品中残留的农药经过乙腈洗脱,浓缩后采用气相色谱-火焰光度检测器(FPD)测定。研究结果表明,茶叶中添加农药浓度为0.02～1.0 mg/kg时,9种农药的平均回收率为75.76%～107.9%,相对标准偏差为1.38%～8.95%,方法检出限为0.006～0.01 mg/kg。该方法操作简单、净化效果好、准确度和精密度高。

A method for determing multi-residues of organophosphorus pesticides in tea was developed.The sample was purified using ENVI-Carb solid phase extraction which was then eluted with 8 mL actonitrile.9 organophosphorus pesticide residues in tea were separated through a capillary column DB-1,and determined with gas chromatogray-flame photometric detector（GC-FPD）.Under these conditions,the average recoveries ranged from 75.76% to 107.9% at spiked levels of 0.02～1.0 mg/kg,and the relative standard deviations（RSDs） were 1.38%～8.95%.The detection limits were 0.006～0.01 mg/kg.The method has the merits of good purifying effect,high accuracy and precision.