DETERMINATION OF METAMIFOP AND ITS METABOLITES BY A COMBINED APPROACH OF ASE-GPC PURIFICATION AND HPLC

To determine the residues of metamifop and its metabolites in environmental samples,an ASE-GPC/HPLC method was develeped. The samples were extracted with dichloromethane by accelerated solvent extraction (ASE),and cleaned up by auto gel permeation chromatography (GPC).The collected solution was analyzed by high performance liquid chromatography (HPLC) and quantified by PDA detector.The limit of detection of metamifop and its metabolites ranged from 0.001—0.005 mg·kg-1 in soil and rice plant,and from 0.001—0.002 mg·l-1 in water. The recoveries ranged from 80.0% to 97.4 % by fortified with 0.02mg·l-1 to 1.0 mg·l-1 in water and 0.05 mg·kg-1 to 2.0 mg·kg-1 in soils and rice plant.The RSD was less than 20 %.The limit of detection and the recovery of metamifop and its metabolites both meet the analytical requirements of pesticide residues.