Studies Of The Residue Of Chlorimuron-methyl In Soil By Gas Chromatography

A gas chromatographic method had developed for determination of chlorimuron- methyl in soil. GC method was used for residure analsis of pesticides by means of hign sensitive and low detection limit.The paper groped fkr extraction condition of Chlorimuron-methyl in soil and define the conditions of GC. Residue in soil sample was extracted by 0.1 5M aqueous sodium bicarbonate solution. Chlorimuron-methyl which was in ionic state was dissolved in aqueous solution. The aqueous extract was washed with dichiormethane.This path remove the impurity in soil and degradation products. The aqueous was acidified. Chlorimuron-methyl in the acidified water was hydrolyzed at lhour in 80 C to 4-chloro-6-rnethoxy-2-pyridinamine .The aqueous pH was adjusted to 10 with alkalinity solution The hydrolysis product of 4-chloro-6- methoxy-2-pyridinamine was extracted by CH2CL2 and dried with antydrous sodium sulfate and concentrated. Chromatographic column The detector The column temperature The jnjector temperature The detector temperature Nitrogen and rate Make-up gas Air BPX5 capillary column (25mX0.32mmXO. 25um) Nitrogen phosphorus detector Owing to the thermal instability of this compound, it couldnot be directly analysed by gas chromatography. It must be transferred in the thermal stability of compound. The experimental detection limit of the method is 2ppb. Recovery from soil at levels from 2ppbto l00ppb: 75.5 0?7.l8% Student: Zhang shuying Advisor: Professor Sm shaoquan...