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.