Residue Dynamics of Chlorsulfuron in Soil Determined byAntibody Immobilized Direct Competitive ELISA

A highly specific and sensitive direct competitive (immobilized antibody, enzyme tagged hapten) ELISA was developed to rapidly monitor the residue dynamics of chlorsulfuron in potted soil and cropland soil. The limit of detection was lower than 0.1 ng/g, the recoveries were 85.4%～118%, the CVs(%) were 8.95%~16.14% and the half lives were 22, 26 days for chlorsulfuron in potted soil at 10, 1000 ng/g spiking levels. The residues, at the time of wheat harvest, were 0.24 ng/g and 0.56 ng/g in sandy soil from nonirrigated cropland, 0.30 ng/g and 0.96 ng/g in sandy loam from wheat rice land for the first year, 0.28 ng/g and 0.67 ng/g, 0.38 ng/g and 1.09 ng/g for second year when 22.5g /hm 2 and 45g /hm2 of chlorsulfuron had been used to control wheat land weed for two years. The results from ELISA were well correspondent with that from HPLC and bioassay.