QuEChERS-气相色谱法检测苎麻及其土壤中8种有机磷农药残留

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。

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

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.