荧光猝灭滴定法研究土壤腐殖质与氨基甲酸酯类农药相互作用  

Study on the Interaction between Humic Substances in Soil and Carbamate Pesticides Using Fluorescence Quenching Titration Method

作　　者：施国兰[1,2] 郑博福[1] 白英臣[2] 吴丰昌[2] 吴代赦[1] 

机构地区：[1]南昌大学环境与化学工程学院,鄱阳湖环境与资源利用教育部重点实验室,江西南昌330031 [2]中国环境科学研究院,环境基准与风险评估国家重点实验室,北京100012

出　　处：《环境科学研究》2012年第12期1404-1409,共6页Research of Environmental Sciences

基　　金：国家自然科学基金项目(40873080;41173084;40903036)

摘　　要：为研究氨基甲酸酯类农药在溶解有机质参与下的迁移转化过程,利用荧光猝灭滴定法研究了土壤HS(腐殖质)与氨基甲酸酯类农药的相互作用.结果表明,呋喃丹和西维因的荧光都能不同程度地被FA(富里酸)和HA(腐殖酸)猝灭,主要猝灭机理为静电结合猝灭.采用静态猝灭模型计算出氨基甲酸酯类农药与HS的K(结合常数),lg K由大到小为呋喃丹-HA(4.96)>西维因-HA(4.93)>呋喃丹-FA(4.72)>西维因-FA(4.68).HA与氨基甲酸酯类农药的lg K明显大于FA与氨基甲酸酯类农药,表明HS与氨基甲酸酯类农药间的作用力有疏水作用.进一步研究表明,氢键作用对HS与氨基甲酯类农药结合有一定的影响.To reveal the mechanisms of transport and conversion of carbamate pesticides in the presence of dissolved organic matters, the fluorescence quenching titration method was applied to investigate the interactions between carbamate pesticides and humic substances in soil. The results showed that the intrinsic fluorescence of carbofuran and carbaryl was quenched by the fulvic and bumic acids to varying degrees. Static quenching was the primary mechanism during this process. The binding constants （K） of carbamate pesticides and humic substances were estimated using the fluorescence static quenching model. The order of lg K were： those of carbofuran and humic acid （4.96） 〉 those of carbaryl and humic acid （4.93） 〉 those of carbofuran and fulvic acid （4.72） 〉 those of carbaryl and fulvic acid （4.68）. The values of lg K of carbamate pesticides and humic acids were clearly higher than those of carbamate pesticides and fulvic acids. This result indicated that the hydrophobic force is one of the main interactions between carbamate pesticides and humic substances, and further proved that hydrogen bonding could slightly affect the bonding of carbamate pesticides and humic substances.

关 键 词：结合常数 荧光猝灭滴定 腐殖质 呋喃丹 西维因 

分 类 号：X592[环境科学与工程—环境工程]