Advance in the research on the mechanism of degradation of sulfonylurea herbicides in soils

The sulfonylurea herbicides，an important and new type of herbicides for weed control in agronomic crops，such as rice，wheat and maize，are characterized by high activity low toxicity and low application rates(10～40g／hm²)．When entering the soil，the sulfonylurea herbicides can be degraded by photolysis，alcoholysis，hydrolysis and microbial transformations，and then produce different metabolites．People often select the gas chromatography(GC)，high-performance liquid chromatography(HPLC)，enzyme-linked immunosorbent assay and bioassay to detect the residues of the sulfonylurea herbicides．Standard analytical methods such as HPLC and GC require complicated cleanup procedures to reach the detection limit of 0.1ug／kg，the bioassay and immunoassay procedures are all the rapid，cost-effective and sensitive methods，but are lack of selectivity and specificity．With the research on the model of biodegradation of organic pollutants，the mechanism of degradation of sulfonylurea herbicides in soils is reviewed．