Abstract: A method has been developed for monitoring DA-6 in water using the solid phase extraction(SPE) method combined with gas chromatography.Three different SPE cartridges(C₁₈,florisil and Oasis^R HLB)were tested in extracting DA-6,showing a recovery rate of 8%,13% and 96%,respectively.The solid phase extraction method using an Oasis^R HLB cartridge was further studied for its optimal operating conditions,which were found to be 4-8 mL dichloromethane as eluting solvent;the reserved capacity of an Oasis^R HLB cartridge(60 mg) reaches as high as 200 μg·cartridge^-1.This method was applied to a photochemical degradation test of DA-6,with results showing that the photolysis of DA-6 in water followed the first order reaction,and its half-life was 82 min under xenon lamp.