QuEChERS-气相色谱法检测苎麻及其土壤中8种有机磷农药残留

Determination of 8 organophosphorus pesticide residues in ramie and soil by QuEChERS-gas chromatography

建立了采用QuEChERS-气相色谱快速检测苎麻及其土壤中8种有机磷农药残留的方法。样品用乙腈或乙腈-超纯水提取,苎麻叶样品用N-丙基乙二胺(PSA)配合石墨化炭黑(GCB)净化,土壤和苎麻杆样品经PSA净化,最后用丙酮置换乙腈,气相色谱-FPD检测,外标法定量。结果表明,在0.05～0.5 mg/kg添加水平范围内,8种农药在土壤、苎麻杆和苎麻叶样品中的平均添加回收率在71.1%～114.2%之间,相对标准偏差(RSD)为2.2%～14.6%,检出限(LOD)在0.006～0.016 mg/kg之间,定量限(LOQ)在0.020～0.050 mg/kg之间。该方法准确、快速、方便,适用于有机磷类农药在苎麻叶、苎麻杆和土壤中的残留检测。

A rapid analytical method for simultaneous determination of 8 organophosphorus pesticides in ramie and soil was established based on QuEChERS and GC-FPD detection. The samples were extracted with acetonitrile or acetonitrile-ultrapure water, cleaned up by primary secondary amine （PSA） and graphitized carbon black （ GCB ）, or by primary secondary amine （PSA） for soil and ramie stem. Then use acetone to reconstruct after solvent evaporation under nitrogen. The 8 organophosphorus pesticides residues was analyzed by GC-FPD and quantified with external standards. The results showed that the average recoveries of the 8 pesticides in soil,ramie stem,ramie blade at three levels （0.05,0. 1 and 0.5 mg/kg） were in the range of 71. 1%- 114.2% with relative standard deviations （RSD） ranged from 2.2% - 14.6%. The limits of detection （LOD） of the method were 0.006 -0. 016 mg/kg, and the limit of quantitation were 0. 020 - 0. 050 mg/kg. The method was simple and applicable to determine organophosphorus pesticide residues in ramie blade ,ramie stem and soil.