【作者】 王珊珊；

【导师】 冯流；

【作者基本信息】 北京化工大学 ， 环境工程， 2005， 硕士

【摘要】 有机锡化合物主要用于塑料工业生产的稳定剂和催化剂以及防污涂料,使用范围非常广泛。但是,目前已经证实世界各地海域的有机锡含量超标,严重破坏了海洋生态系统。因此研究有机锡化合物的生物毒性对于探讨其致毒机理以及进行生态风险评价具有重要的意义。 本论文以斜生栅藻（Scenedesmus obliquus）和大型蚤（Daphnia magna）为受试生物,采用静水试验法评价了五种有机锡化合物的毒性效应,并初步探讨了化合物结构和性质对其毒性效应的影响。结果表明,有机锡化合物对两种水生生物均显示出较强的毒性,且具有相同的变化规律,即毒性效应均为三丁基锡>四丁基锡>二丁基锡>一丁基锡,但由于种间差异及外部因素的影响,同一有机锡化合物对两种水生生物的毒性作用差异明显。同时,有机锡化合物自身的理化性质和分子结构也影响着它们对水生生物的毒性效应,在同一取代系列中,取代烷基数目越多,其疏水性越大,毒性也越大,但是当取代烷基数增加到一定程度后,由于分子体积过大,毒性反而降低。 接着以实验得出的有机锡对生物毒性数据lgEC₅₀为因变量,一阶价电连接性指数¹x^V,辛醇—水分配系数lgK_ow为自变量进行了定量结构—活性相关（QSAR）研究,通过分析认为¹x^V与-lgEC₅₀正相关,说明在同一取代基系列中,取代基越多,其毒性也越大。lgK_ow与-lgEC₅₀正相关,说明分子的疏水性越强,有机锡化合物越容易与生物体结合,更多还原

【Abstract】 Organotin compounds (OTCs) are extensively used in polymer stabilizers, fungicides, antifoulants, insecticides, organic catalysts, oil additives and so on. Due to the wide industrial applications considerable amounts of OTCs have entered various ecosystems, and destroy the aquatic environment. Therefore, research on their aquatic toxicity is of great significance to discussing toxic mechanism and ecological risk assessment.In this article, in order to assess the toxic effects of organotin compounds, with the method of static toxicity test, the acute toxicity of five organotin compounds to Scenedesmus obliquus and Daphnia magna was determined, and the influence of organotin compounds’ structure and physicochemical properties on their toxic effects was elementarily discussed. The results indicated that all the organotin compounds had relatively strong toxicity to the two aquatic organisms with similar sequence of toxic action, viz. tri-n-butyltin>tetra-n-butyltin>di-n-butyltin >butyltin, on the other hand, due to species difference and influences of environmental factors such as degradation, the toxicity of the sameorganotin compound to the two aquatic organisms was greatly different. In the same time, the organotin compounds’ physicochemical properties and molecular structure also affected their toxicity to the two aquatic organisms. In the same series, the more substituted alkyl was, the stronger the organotin compound’s hydrophobicity was, and the higher toxicity was. However, when the number of substituted alkyl increased to more than enough, the toxicity became lower because of the bigger molecular volume.Moreover, the QSAR study was carried between toxicity data lgEC50 obtained by experiments and lgK0W, ’%V. The results showed that in the same series, the more substituted alkyl was, the higher toxicity was, because the value of -igECso became bigger and bigger with lgKow fO ’%v. However, when the volume of organotin was big enough, the toxicity became low. The reason was that organotin was difficult to penetrate the cell membrane and arrive at the center of active sites because of the large spatial resistance. Therefore, the toxicity of TeBT is similar to TBT.Finally, the QSAR between the acute toxicity of Scenedesmus obliquus and Daphnia magna by 16 organotin compounds and molecular structure parameters were established, like dipole(a), core-core repulsion(CC7￡), total energy(7F), LUMO energies^UMo), net atomic charges(g). The result showed that the toxicity of the organotin compounds to the aquatic organisms was related to the quantum chemical descriptors which characterized the molecular volume. When the values of Mr , CCR更多还原