加速溶剂萃取-固相萃取小柱净化-气相色谱法测定土壤中有机磷农药

Determination of 12 Organophosphorus Pesticides in Soil by Gas Chromatography with Accelerated Solvent Extration and Solid Phase Extration

建立了加速溶剂萃取-固相萃取小柱净化-气相色谱法测定土壤中12种有机磷农药的方法。推荐了12种有机磷农药快速分离的色谱条件。采用加速溶剂萃取技术实现了对土壤中有机磷农药残留的提取,选取最佳条件参数,减少了组分的损失,提取回收率达88%～108%。选择不同填料的SPE小柱和洗脱溶剂形成3种方案法进行净化实验,结果表明,方案2采用混合溶剂(正己烷、丙酮、二氯甲烷体积比为1∶1∶1)洗脱上样后的硅胶SPE小柱的净化效果好,回收率为91%～121%。方法检出限为0.000 1～0.000 2 mg/kg,石英砂基体和实际污染土壤样品加标回收率为62%～112%,相对标准偏差为0.7%～8.6%。该方法操作简便,快捷,灵敏度高,检出限低,试剂用量少,准确度和精密度符合质量控制要求。

This paper established the method for determination of 12 organophosphorus pesticides by gas ghromatography（GC） combinated with accelerated solvent extration （ASE） and solid phase Extration （ SPE）. The condition parameters of GC were recommended. The technology of ASE was applied with optimized parameters to reduce the loss of target compounds to obtain better recoveries of 88%-108%. Three purification experiments with different SPE columns and solvents were discussed,and the results showed that the experiment eluting silicone SPE columns with mixed elution solvent （hexane：aeeone：dichloromethane = 1：1：1 ）obtained a high purification efficiency with recoveries of 91%-121%. Detection limits of the average organophosphorus pesticides were in the range of 0. 000 1-0. 000 2 mg/kg,and the spiked recoveries of 12 compents in the quartz sand and polluted soil samples were between 62% and 112% with precision of relative standstard deviations（RSD, n = 7） of 0.7% -8.6%. This method had the advantage of rapid sample analysis , simple operation, highsensitivity, low detection limits and little toxic and hazardous reagents, also ,the detection precision and accuracy could meet with the requirements of laboratory quality control.