不同形态磺胺类药物在根-土界面的空间分布及毒性评价

Forms Distribution and Ecotoxicity of Three Forms of Sulfonamides in Root-Soil Interface of Maize

采用化学分析和发光细菌检测相结合的方法,研究了磺胺类药物在作物根-土界面的形态分布及生态毒性.结果表明,磺胺类药物在根际土壤中主要以水溶态的形式存在,远根区则以有机溶剂可提取态为主要形态.3种形态磺胺类药物对明亮发光细菌的相对发光抑制率均小于30%,表现为低毒性.不同形态磺胺类药物对明亮发光菌表现的生态毒性不同,有机溶剂可提取态对明亮发光细菌的毒性最大,水溶态次之,结合态毒性最小.根际区水溶态的含量及其对明亮发光细菌的相对毒性抑制率大于远根区,而有机溶剂可提取态和结合态的含量及其对明亮发光细菌的相对毒性抑制率则小于远根区.

Forms distribution and ecotoxicity of sulfonamides in root-soil interface of maize were studied by chemical analysis and luminescent bacteria toxicity assay.The results indicated that the water soluble residues were the main form in rhizosperic soils,and the organic solvent extractable residues were the main form in far-rhizosperic soils.The three forms of sulfonamides showed relatively lower toxicity to luminescent bacteria with the relative inhibition rates less than 30%.The toxicity of water soluble residues was lower than that of the organic solvent extractable residues,and the bound residues showed the lowest toxicity to luminescent bacteria.The contents and relative inhibition rates of water soluble residues in rhizosperic soils were higher than those in far-rhizosperic soils,while the contents and relative inhibition rates of organic solvent extractable and bound residues in rhizosperic soils were lower than those in far-rhizosperic soils.