TRACE RESIDUE ANALYSIS OF THE HERBICIDE CHLORSULFURON IN SOIL BY GAS-CHROMATOGRAPHY ELECTRON-CAPTURE DETECTION

A capillary column gas chromatographic method is described for the determination of chlorsulfuron, 2-chloro-iV-[[(4-methoxy-6-methyl-l, 3, 5-triazin-2-yl)amino]carbonyl]benzenesulfonamide, in soil. The soil sample is extracted with aqueous sodium bicarbonate solution by sonic extraction. The aqueous extract is washed with dichloromethane, acidified with hydrochloric acid, and extracted with dichloromethane. The organic extract is dried with anhydrous sodium sulfate and concentrated. The chlorsulfuron in the extract is derivatized with diazomethane to its monomethyl derivative. After Florisil cleanup, the monomethylchlorsulfuron in the sample is analyzed by capillary column gas chromatography-electron capture detection. The recovery of chlorsulfuron from soil samples is greater than 80%. The experimental detection limit of the method is 1 ng/g (1 ppb). © 1990, American Chemical Society. All rights reserved.