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

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。

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

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: aceone: 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.