[A环-U-~(14)C]丙酯草醚在土壤中的吸附与解吸特性研究

丙酯草醚(ZJ0273)是我国拥有自主知识产权的新型高效油菜田除草剂。本文以A环-U-14C]丙酯草醚为示踪剂,在实验室模拟条件下,采用液体闪烁测量技术对其在7种土壤中的吸附和解吸特性进行了研究。结果表明:(1)丙酯草醚在7种土壤中的吸附等温线均能极显著符合Freundlich、Langmuir和线性模型,相对而言,前两种模型的相关系数R2(0.9883~0.9998)明显高于线性模型(R2=0.9173~0.9593);(2)丙酯草醚在7种土壤中的解吸等温线能被Freundlich模型和线性模型很好地描述;(3)丙酯草醚极易被土壤吸附,不同类型的土壤对其吸附的差异较大,吸附常数KF与土壤有机质含量呈显著正相关,与之对应的解吸率极低。丙酯草醚吸附解吸过程存在明显的滞后现象,应科学合理地在有机质丰富的土壤中使用。

SORPTION AND DESORPTOIN OF [A ring-U-~(14)C] ZJ0273 IN SOILS

ZJ0273,propyl 4-(2-(4,6-dimethoxypyrimidin-2-yloxy)benzylamino)benzoate,is a novel herbicidal ingredient obtained temporary registration in China for weed control in oilseed rape field.In this study,A ring-U-14C]ZJ0273,propyl 4-(2-(4,6-dimethoxypyrimidin-2-yloxy)benzylamino)phenyl-U-14C_6]benzoate,were applied in 7 soils to investigate sorption and desorption of ZJ0273.The results revealed for all soils studied that(1) Freundlich-model,Langmuir-model and Linear-model fit the sorption isotherm of ZJ0273 well,and the correlation coefficient of the two former models(R 2=0.9883～0.9998) were better than that of linear-model(R 2=0.9173～0.9593);(2) Desorption isotherm was better described by using Freundlich-model and linear-model;(3) A ring-U-14C]ZJ0273 was ready to be sorbed,the constant K_F was positively related to soil organic matter(SM),the desorption ratios of A ring-U-14C]ZJ0273 was extra low,and obvious hysteresis could be found in the sorption and desorption of A ring-U-14C]ZJ0273 in the tested soils.