好氧土壤中[C环-U-^14C]丙酯草醚的结合残留及其在腐殖质中的分布动态

BOUND RESIDUES OF [C ring-U-^(14)C] ZJ0273 IN SOILS AND DYNAMICS DISTRIBUTION IN HUMUS

农药的环境行为与归趋,尤其是结合残留研究,是新农药安全性评价的重要内容之一,这关系到新农药的科学使用。利用14C同位素示踪技术研究了[C环-U-14C]丙酯草醚(ZJ0273)在3种不同类型好氧土壤中的结合残留及其在富啡酸、胡敏酸和胡敏素中的动态分布。结果表明:(1)在整个培养过程中,土壤中的丙酯草醚结合残留量均随时间而递增。培养至75d,红砂土(S1)、黄松土(S2)与淡涂泥田(S3)中的14C-BR最大值分别为引入量的12.55%、20.35%和20.49%,且富含有机质和pH较高的土壤更易与丙酯草醚形成结合残留;(2)丙酯草醚与富啡酸、胡敏酸和胡敏素形成的结合残留,含量大小依次为富啡酸>胡敏素>胡敏酸。因此,丙酯草醚与土壤基质形成结合残留的过程中,富啡酸起主要作用,而胡敏酸的作用最小。

ZJ0273, propyl 4- （2- （4,6-dimethoxypyrimidin-2-yloxy） benzylamino） benzoate, is a newly developed herbicide for pre- and post-emergence weed control primarily in oilseed rape. In this study, bound residues （BR） of [ Cring-U-^14C] ZJ0273 in three kinds of soil and dynamics distribution in humus fulvie acid, humin and humic acid were studied by using ^14C isotope tracer technique. The results presented that, the ^14 C-bound residues of ZJ0273 increased with incubation time in the three tested soils （S1, S2 and S3 ） and reached 12.55%, 20.35% and 20.49% of the applied at the end of incubation, respectively. The soil of rich organic matter and higher pH was easier to form soil-bound residue of ZJ0273. In addition, the distribution of ^14C-BR of [ Cring-U-^14C]ZJ0273 in soils was in the order of fulvic acid 〉 humin 〉 humic acid.