[A环-U-^14C]丙酯草醚在土壤中的吸附与解吸特性研究

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

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。

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-^14 C6]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 Linearmodel 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 KF 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.