| γ-辐照对敌草隆的降解过程及毒性变化分析 |
| 摘要点击 1688 全文点击 1264 投稿时间：2007-05-25 修订日期：2007-08-06 |
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| 中文关键词 γ-辐照 敌草隆 降解过程 毒性 |
| 英文关键词 γ-irradiation diuron degradation process toxicity |
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| 中文摘要 |
| 采用γ-辐照技术降解水中敌草隆，考察了辐照降解敌草隆的过程以及通过Ames实验和发光细菌实验考察了敌草隆溶液降解前后的毒性变化.结果表明，·OH自由基、·H自由基和e-aq自由基对辐照降解水中敌草隆贡献大小依次为：·OH>e-aq>·H；·OH自由基、e-aq自由基和·H自由基在辐照降解敌草隆过程中量子效率的比例为：3∶1∶2.e-aq自由基、·H自由基和敌草隆及降解产物主要发生脱氯反应和加成反应.随辐照时间的增加，致突变性先增加然后减少；在考察的辐照时间里，敌草隆水溶液辐照前后没有表现出移码型致突变性；但是在辐照时间为22.2 min时，表现出碱基置换型致突变性.随着辐照时间的延长，敌草隆溶液对发光细菌的急性生物毒性先减小然后增加，敌草隆降解后生成了急性毒性更强的物质. |
| 英文摘要 |
| The radiation-induced degradation process of diuron and change of toxicity by γ-irradiation were investigated. The contribution to diuron degradation by the radicals is in the order of: ·OH>e-aq>·H. The quantum efficiency ratios of ·OH, e-aq and ·H for the degradation of diuron are calculated as 3∶1∶2. e-aq and ·H could reduce diuron and its degradation product by loss of the chlorine atoms and the addition reaction. Both the shift and alkaline substitute mutations firstly increase and then decrease with the increase of irradiation time. But, the sample only shows mutagenic potential in Ames assay (TA100 strain) when 22.2 min is selected as the irradiation time. The acute toxicity firstly decreases and then increases with the increase of irradiation time and the more toxic substances are produced. |
