固相萃取/气相色谱法测定新会陈皮及其制品中8种有机磷农药

Determination of 8 Organophosphorus Pesticides in Xinhui Dried Orange Peel and Its Products by Gas Chromatography with Solid Phase Extraction

建立了固相萃取/气相色谱同时测定新会陈皮及其制品中8种有机磷农药的分析方法,并对影响提取、净化、检测效率的因素进行优化。样品用乙酸乙酯提取,自制改性多壁碳纳米管和N-丙基乙二胺2种填料分层填装的双层固相萃取小柱净化,Shimadzu Rtx-1701毛细管色谱柱分离,火焰光度检测器检测,外标法定量。在优化实验条件下,8种有机磷农药在0.020~1.0μg/m L范围内具有良好的线性关系,相关系数为0.997 0~0.999 2,检出限（S/N=3）为3.6~8.8μg/kg。3个加标水平下的平均回收率为72.5%~106%,相对标准偏差为2.8%~8.7%。该法准确、快速、灵敏﹑操作简单,可满足新会陈皮及其制品中多种有机磷农药残留同时测定的要求。且自制柱的成本低,能够大幅度减低使用成本,值得推广应用。

A method of gas chromatography（GC） coupled with solid phase extraction was established for the simultaneous determination of 8 kinds of organophosphorus pesticide residues, including etho- propophos, sulfotep, terbufos, monocrotophos, parathion methyl, fenitrothion, isofenphos methyl and isocarbophos in xinhui dried orange peel and its products. The factors affecting extraction, puri- fication and detection efficiency were optimized, and the optimal conditions were as follows： the sam- ples were extracted with ethyl acetate, and purified on a homemade double solid phase extraction col- umn packed with N-propylethylenediamine and multi-walled carbon nanotubes. The separation of tar- get compounds were performed on a film thickness of Shimadzu Rtx- 1701 capillary column（30 m x 0. 25 mm x 0.25 ixm）, and the quantitative analysis of organophosphorns pesticides was carried out by GC with flame photometric detector and the external standard method. Under the optimized condi- tions, the calibration curves of 8 organophosphorus pesticides were linear in the range of 0. 020 - 1.0 Ixg/mL with correlation coefficients of 0. 997 0 -0. 999 2. The detection limits （S/N = 3 ）were in the range of 3.6 - 8.8 txg/kg. The recoveries of the pesticides in Xinhui dried orange peel and its prod- ucts at three spiked levels ranged from 72.5% to 106% , with relative standard deviations of 2. 8% - 8.7%. With the advantages of accuracy, sensitivity, easy operation and rapidness, the method is applicable in the simultaneous determination of 8 kinds of organophosphorus pesticides in Xinhui dried orange peel and its products. The homemade column is worthy of popularization and application as it is inexpensive, and could largely reduce the detection cost.