官厅水库沉积物极性提取液化学成分分析及基因毒性效应

Chemical analysis and genotoxic effects of polar extracts of sediments from Beijing Guanting reservoir

提取北京市官厅水库表层沉积物极性组分,定量检测了12种硝基芳香烃和5种芳香胺的含量水平;并通过鼠伤寒沙门氏菌回复突变试验(Ames试验)研究沉积物极性提取液的致突变毒性,对官厅水库沉积物的潜在基因毒性效应进行评价.结果表明,官厅水库沉积物中12种硝基芳香烃的总含量为8.4—272 ng·g^(-1),平均值为121 ng·g^(-1);5种芳香胺总含量为5.1—42.8 ng·g^(-1),平均值为4.8 ng·g^(-1).各组沉积物极性提取液对鼠伤寒沙门氏菌(Salmonella typhimurium)TA98及TA100的致突变毒性试验结果均呈阴性,但多个点位沉积物极性提取液导致的细菌突变数随提取液浓度的上升而增加,表明可能存在致突变物质.Pearson相关分析结果表明,2-硝基甲苯、3-硝基甲苯、1,3,5-三硝基苯和联苯胺的含量与TA98的突变效应具有显著相关性,推断其可能是主要的致突变物质,且其可能引起的致突变类型为移码型基因突变.

In this study,polar components were extracted from surface sediments of Beijing Guanting reservoir,and the concentrations of the nitro aromatics and five aromatic amines were determined.The mutagenicity of the polar extracts was investigated by Ames tests with TA98 and TA100 of Salmonella typhimurium for assessing the genetic toxicity of the surface sediments. Results showed that the total concentrations of the nitro aromatics ranged from 8. 4 ng·g^-1 to 272 ng·g^-1 with an average value of 121 ng·g^-1; The total concentrations of aromatic amines ranged from 5.1 ng·g^-1 to42.8 ng·g^-1 with an average value of 4.8 ng·g^-1. The mutation toxicity tests all presented negative results,however,the number of Salmonella typhimurium mutants increased with the increase of the concentration of polar components in some sampling points,indicating that mutagenic compounds might exist in these sediments. In addition,Pearson correlation analysis showed that there was significant positve correlation between the concentrations of 2-nitrotoluene,3-nitrotoluene,1,3,5-trinitrobenzene,benzidine and the number of mutants of TA98. Therefore,it can be inferred that these compounds may be the major mutagenic compounds,and the caused mutation type might be frameshift mutation.