14C-涕灭威在旱田土壤中的降解

研究了¹⁴C-涕灭威在5种土壤中(4ppm,1.22μCi·50g^-1 土壤干重)的生物降解。模拟试验为密闭系统,土壤中水分含量为22%,气温20-30℃在供试的5种土壤中,北京肖家河的土壤降解最快,为施人放射剂量的51.3%,以“¹⁴CO₂ 形式从土壤进出;26.0%与土壤结合,只有21.6%可以被抽出。取自浙江义乌的土壤降解较慢,收集到的¹⁴CO₂ 为施入量的23.3%.土壤中加入杀菌剂红霉素或敌茵丹降解作用明显减慢。土壤提取物中涕灭威亚砜、涕灭威亚砜肟被确认是主要的代谢产物,还发现了少量的涕灭威砜,涕灭威亚砜腈涕灭威砜腈和涕灭威砜肟等降解物。

Biodegradation of 14C-aldicarb in upland soils

Biodegradation of ¹⁴C-aldicarb in five soils is studied.Simulation test carried out in a closed microcosm with 22% of soil moisture content at 20-30℃.Among the soils tested,that from Xiaojiahe, Beijing, has the highest degradation rate of ¹⁴C-aldicarb. After a four-weeks incubation,51.3% of applied radiocarbon are released from it in the form of ¹⁴CO₂,26.0%are bound and only 21.6 % are extractable.In soil from Yiwu, Zhejinag,a decreased degradation of ¹⁴C-aldicarb is observed.The amount of ¹⁴CO₂,collected from it occupies 23.3% of total ¹⁴C applied.The degradation of aldicarb is significantly retarded when sterilizing chemical chloramphenicol or captafol is applied to the soil.Aldicarb sulfoxids and aldicarb sulfoxide oxime are identified as the major metabolites, and trace amounts of aldicarb sulfone,nitrile sulfoxide and nitrile sulfone are also found in soils.