在线凝胶渗透色谱-二维气相色谱/质谱法测定鲫鱼样品中的14种农药残留

Determination of 14 pesticide residues in crucian carp using on-line gel permeation chromatography-multi gas chromatography/mass spectrometry

建立了在线凝胶渗透色谱-二维气相色谱/质谱（GPC-MDGC/MS）测定鲫鱼样品中14种农药残留的方法.样品用环己烷/乙酸乙酯（1∶1,v/v）提取两次,合并提取液.提取液冷冻、过膜后,经在线凝胶渗透色谱净化后直接进行MDGC/MS分析,通过中心切割的方式将农药组分选择性切割进入二维色谱柱进行进一步分离分析,采用内标法进行定量.实验结果表明：14种农药在0.01～0.9 mg/L范围内具有较好的线性关系,相关系数均大于0.99.14种农药在3个添加水平（0.01、0.05、0.1 mg/kg）的加标回收率为83.0％～ 112.9％,相对标准偏差为3.2％～12.0％.该方法前处理简单,实现了在线GPC和MDGC的有效结合,准确度好、精密度高,具有很好的推广性.

A new method was developed for the determination of pesticide residues in crucian carp using on-line gel permeation chromatography-multi gas chromatography/mass spectrome- try （GPC-MDGC/MS）. The pesticide residues were extracted with cyclohexane-ethyl acetate （1：1, v/v） for twice. After being frozen, the extract was filtered by 0.22 μm member, and then cleaned up and analyzed by online GPC-MDGC/MS. The pesticides were selectively trans- ferred from the lst column to the 2nd column by means of heart cutting. As a result, selective transfers of some pesticides from the first to the second dimension were at times essential to avoid overlapping. The selected separation conditions from the study with standards were applied to crucian carp spiked with some pesticide standards. The performance of this method was examined by recovery, linearity and precision. Inter-standard quantitative method was used for calculation. Good linear relationship was achieved in the range of 0.01-0.9 mg/L for the 14 pesticides with correlation coefficients above 0.99. The recoveries of the method ranged from 8.3.0% to l l2.9% with the relative standard deviations （RSDs） among 3.2%-12.0% at 3 spiked levels of 0.01, 0.05 and 0. 1 mg/kg. This is a simple, rapid method for the analysis of multiple pesticide residues in crucian carp with high accuracy and sensitivity. The results prove that the employment of a multidimensional analysis technique permits to avoid interferences of the ana- lyres with matrix components.