土壤中磺酰脲除草剂降解机制研究进展

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

磺酰脲除草剂是一种高效、低毒、低用量(10～40g/hm^2)的新型除草剂,广泛应用于水稻、小麦和玉米等田间杂草的控制,在土壤中降解途径主要为水溶性光分解、醇解、化学水解和微生物分解,且4种降解途径下各自产生不同的降解产物。对土壤中磺酰脲除草剂降解产物的测定多采用气相色谱、液相色谱、酶连免疫吸附和生物检测,各测定方法均有利弊,色谱法需繁琐的纯化程序提纯样品以达到检测极限0.1μg/kg,生物检测和免疫吸附法测定快速、灵敏度高但缺乏专一性。结合生物降解模型研究,阐述了磺酰脲除草剂的降解机制。

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 0.1μg/kg,the bioassay and immunoassay procedures are all the rapid,cost-effective and sensitive methods,but are lack of selectivity and specificity.With (he research on the model of biodegradation of organic pollutants,the mechanism of degradation of sulfonylurea herbicides in soils is reviewed.