恶唑菌酮在土壤中的移动性研究

Studies on Mobility of Famoxadone in Several Soils

采用土壤薄层层析法研究了杀菌剂恶唑菌酮在土壤中的移动性以及表面活性剂对其移动性的影响。结果表明,在不同性质的土壤中恶唑菌酮的相对移动值Rf在0.089￣0.141之间。恶唑菌酮土壤中移动性的差异主要与土壤有机质和粘粒含量有关,它们之间呈显著的负相关性。通过供试的3种表面活性剂发现,表面活性剂影响恶唑菌酮的移动性主要取决于表面活性剂的临界胶束浓度,在低于表面活性剂临界胶束浓度中恶唑菌酮的移动性受到抑制,而在高于临界胶束浓度下恶唑菌酮的移动性明显增大。恶唑菌酮在表面活性剂中移动性的变化是恶唑菌酮和土壤表面吸附位、表面活性剂分子、胶束之间相互作用的结果。

Laboratory studies using soil thin layer chromatography were conducted to determine mobility of famoxadone （3-anilino-5-methyl-5-（4-phenoxyphenyl）-l,3-oxazolidine-2,4-dione） in selected soils. The observed Rf values- the mobility parameter for famoxadone were from 0.089 （river tidal soil） to 0.141（brown sandy mud soil） in five representative soils of Hunan Province including fiver tidal soil, red earth soil, purple mud soil, gray mud soil, brown sandy mud soil. Linear regression analysis indicated that soil organic matter content and clay mineral content were the most important contributors to the mobility of famoadone in soil. The effect of three different surfactants- sodium dodecylbenzene sulphonate （anionic, cetyltrimethyl ammonium bromide （cationic）and Tween-80 （non-ionic） on the mobility of famoxadone were also studied by the technologyabove. Surfactants can affect the movement of famoxadone in soil. The most important parameter of a surfactant to mobilize famoxadone was the critical micelle concentration （CMC）.Results indicated that the application of surfaetants with a concentration of 2CMC resulted in a significant promotion in mobility of famoxadone in red earth soil ,the Rf values were 0.379 （SDBS）, 0.315（CTAB）, 0.273 （T-80）, respectively; while the surfactants concentration of 0.2CMC and 0.5CMC restrained famoxadone to transfer, the Rf value decreased. The modifications on Rf values caused by three different surfactants were similar. The changing mobility of famoxadone under surfactant solution was due to the results of interactions between famoxadone molecule, adsorption site of soil surface, surfactant molecule and surfaetant micelle.