Chlorpyrifos Residue and Behavior in Environment of Peanut Field and Its Safety Evaluation

[Objective]The research aimed to study the residue dynamics of chlorpyrifos in peanut and soil.[Method] Chlorpyrifos in the samples was extracted with organic solvent,purified with colum chromatography of florisil and detected by capillary gas chromatography with electron capture delector.[Result] The average recoveries in plant,peanut kernel,peanut shell and soil were ranged from 80.83% to 96.09%.The standard deviations were from 2.68% to 6.07%,and the coefficients of variation were from 3.05% to 6.90%.The minimum detectable amount of chlorpyrifos standard was 2.0×10-12 g.And the minimum detectable concentrations in plant,peanut kernel,peanut shell and soil were 0.006,0.006,0.006 and 0.003mg/kg,respectively.The test in Anhui and Guangdong Province indicated that the half-lives of chlorpyrifos were from 2.64 to 4.63 days in plant,while in soil were from 6.59 to 7.15 days.The maximum final residues of chlorpyrifos in peanut kernel,shell and plant were 0.02,0.82 and 0.43 mg/kg.[Conclusion] 15% GR of chlorpyrifos could be applied to control soil-insect of peanut with the dosage less than 3 600 ai g/hm2 and used one time,and the safety interval was 28 days.