Preparation for Determination of Chlorpyrifos and Chlorpyrifos-methyl in Water,Soil and Vegetable

A preparation method for simultaneous determination of pesticides chlorpyrifos and chlorpyrifos-methyl in water,soil and vegetable by high-performance liquid chromatography(HPLC)was developed.Water samples were exacted and collected by solid-phase extraction LC-18 column.Soil samples were extracted by ethyl acetate-petroleum ether(2:1,by vol)and purified and collected by solid-phase extraction LC-18 column.Vegetable sample was extracted by acetonitrile and purified and collected by solid-phase extraction LC-18 column.The calibration curves of the method were determined in the range of 0.1 to 8.0 mg/L both chlorpyrifos and chlorpyrifos-methyl,with the correlation coefficients(r 2 ) were 0.9996 and 0.9994 respectively.With the minimal detection limits being 10 and 5μg/L.The spiked recoveries of chlorpyrifos and chlorpyrifos-methyl in water sample ranged from 80.5 to 81.0%and 88.8 to 92.4%,the soil sample from 80.7 to 98.0%and 85.0 to 95.5%,the vegetable sample from 80.4 to 84.4%and 80.7 to 83.7%,respectively.With the relative standard deviations(RSD)in water,soil and vegetable samples were from 0.5 to 1.4%and 2.1 to 4.6%,0.4 to 1.0% and 1.1 to 3.9%,0.8 to 3.0%and 1.8 to 3.3%respectively.