超声波提取-气相色谱法测定农田土壤中有机氯农药残留

目的]有机氯农药(Organochlorine pesticides OCPs)是一类可以在土壤中积累的持久性有机污染物,因生物积累及放大效应会对人类健康引起潜在危害,因此检测农田土壤中的有机氯非常重要。建立超声波提取/气相色谱技术分析农田土壤中8种有机氯农药的新方法。方法]优化后的萃取条件:以乙腈作为萃取溶剂,加氯化钠以盐析,置摇床振摇,再超声提取并放置过夜,次日再次超声提取,弗罗里硅固相萃取小柱净化(Florisil SPE)。结果]色谱条件:使用HP-5色谱柱,在11 min内8种有机氯分离良好。8种有机氯均具有良好的线性关系,相关系数不小于0.999,平均加标回收率为92.1%~105.3%,相对标准偏差为2.7%~6.9%,方法检出限为0.012~0.059 ng/g。结论]该方法适用于农田土壤中有机氯的快速检测。

Determination of OCPs in Farmland Soil by Gas Chromatography & Ultrasonic Wave Extraction

Objective]Organochlorine pesticides(OCPs)were organic pollutants that can be accumulated in soils and cause potential environ-mental hazards.It is very important to determine OCPs in farmland soil testing.A new method was developed for the determination of eight OCPs in farmland soil by ultrasonic wave extraction coupled with gas chromatography-electron capture detector.Method]The extraction conditions were optimized.A good extraction efficiency was obtained by using acetonitrile as extraction solvent,extraction efficiency can be promoted by the addition of sodium chloride,shaken,ultrasonic wave extraction and stay overnight,ultrasonic wave extraction again the next day.The extract was cleaned up by florisil solid phase extraction columns.Result]The gas chromatographic conditions were optimized by used of HP-5 column,eight kinds of OCPs were well separated within 11 minutes.The calibration curves for 8 OCPs all had good linear relationships with correlation coeffi-cients not less than 0.999.The average spiked recoveries ranged from 92.1%to 105.3%with relative standard deviations of 2.7%-6.9%.The limits of detection were in the range of 0.012-0.059 ng/g.Conclusion]The method was applied in the determination for OCPs in farmland soil with satisfactory results.