Residue Determination of Prochloraz and Its Major Metabolites by HPLC in Paddy Water and Soil

Prochloraz(1-[N-propyl-N-2-(2,4,6-trichlorophenoxy)ethyl carbamoyl] imidazole)is a new broad-spectrum imidazole fungicide applied in many crops.There are three major metabolites(BTS44595,BTS44596 and BTS45186)when it is used in the environment.In this study,a high-performance liquid chromatography(HPLC)method for the quantitative determination of the residues of prochloraz and its metabolites in paddy water and soil was developed.Soil sample was extracted with acetone and condensed to dry,and then the extracted soil sample and paddy water sample were adjusted pH approximate to 9.0 with NaHCO3-Na2CO3 buffer solution,respectively.Prochloraz was extracted from the two solutions with petroleum ether∶acetone(9∶1,V/V)and its metabolites were extracted by petroleum ether from aqueous phases which pH were adjusted to 2～3 using HCl solution.Determinations of analytes were completed using HPLC with UV detection at 210 nm.Under HPLC conditions,prochloraz retain time was 5.384 min and the detection limit was 3.5×10-10 g.BTS44595,BTS44596 and BTS45186 retain time were 12.365,10.678 and 8.074 min,respectively,and their detection limits were 5.0×10-10,3.0×10-10 and 6.0×10-10 g,respectively.The average recoveries from untreated control samples fortified with these four compounds at rates of 0.1,0.5 and 5.0 mg·kg-1 ranged from 76.74 % to 105.72 %,and relative standard deviations were 2.08%～12.35 %.Sensitivity,accuracy and repeatability of the method were fitted for the demand of pesticide residue analysis and detection,and it was easy to perform in practice.