四溴双酚-A的光化学反应和毒性研究

【作者】 晋艺聪；

【导师】 焦玉国；

【作者基本信息】 中央民族大学 ， 环境科学， 2011， 硕士

【摘要】 四溴双酚-A (TBBP-A)主要应用于印刷线路板及ABS、HIPS等多种材料的阻燃,是目前全球用量最大的溴代阻燃剂。由于它的大量使用和生物富集性,已经在多种环境介质和生物样品中被检测到,对生态环境及人体健康造成危害,如肝肾毒性、免疫毒性、神经毒性和内分泌干扰特性等多方面,因而受到人们的广泛关注。但是目前关于TBBP-A光化学反应降解途径和毒性评价的报道比较有限,因此考察TBBP-A的光降解机理以及遗传毒性对其环境迁移归趋和毒性评价具有指导意义。本论文的工作主要包括三个部分：第一部分是TBBP-A光化学降解反应研究：(1)选择5种性质不同的溶剂和1种添加剂,用氙灯和紫外灯作为光源,分别进行TBBP-A的光化学反应实验。研究结果表明：TBBP-A在5种溶剂中的光解反应都遵循一级反应动力学规律,而光解速率有所不同。TBBP-A在正己烷中的降解速率明显大于其他4种溶剂,光解速率大小顺序为正己烷>DMSO>甲醇>乙腈>水,速率常数分别为K1=0.0478 min-1, K2=0.035 min-1, K3=0.0294 min-1, K4=0.0195min-1, K5=0.014min-1。光解速率大小与溶剂极性呈反向相关关系,极性小的溶剂有利于TBBP-A的光解反应,相反,极性大的溶剂则不利于光解反应的发生。(2)在TBBP-A的正己烷溶液中加入二氧化钛,随着添加剂的加入光解速率大大增加,其光解速率大小顺序为添加二氧化钛>空白溶剂,速率常数分别为0.1624min-1和0.0498min-1。实验结果表明：TBBP-A在添加二氧化钛的条件下,光解速率大大增加,说明催化剂的添加有利于光解反应的发生,加入二氧化钛时的降解速率是空白的3.26倍。(3)利用液质联用技术分析降解产物,得出光化学反应主要是溴的丢失和苯环的断裂,生成一种主产物三溴双酚一A和两种副产物。第二部分和第三部分分别用彗星方法和DNA凝胶电泳方法研究TBBP-A及其光解产物遗传毒性,研究结果表明：TBBP-A具有细胞毒性和遗传毒性,在相同的实验条件下,随着染毒浓度的增大,TBBP-A的细胞毒性和遗传毒性也随之增大。TBBP-A光解产物的细胞毒性和遗传毒性随着光照时间的增加发生改变,毒性先增大后减小。更多还原

【Abstract】 Tetrabromobisphenol-A(TBBP-A) is widely used throughout the world as flame retardant,which is covalently bound to plastic and electronic circuit boards, and has additive applications in several types of polymers. Due to TBBP-A extensive use and bioconcentration potential in aquatic organisms,it has been found in environmental and biological specimen,which might render the damage to ecological environment and health,such as kidney toxicity, immune toxicity, neurotoxicity and endocrine disturbance characteristics and so on.However, the reports about study of degradability and ecotoxicology of Tetrabromobisphenol A are very limited,so it is meaningful for to do this field of study.The dissertation consists of three parts.In the first part,the works mainly on analysis of influencing factors like solvent, light-source (xenon lamp, uv lamp), on degradation of TBBP-A. The result shows that, in 5 kinds of solvent, the photochemical reactions are primary reaction and the reaction rate order is hexane > DMSO>methanol>acetonitrile>water, rate constant is K1=0.0478 min-1, K2=0.035 min-1, K3=0.0294 min-1, K4=0.0195min-1, K5=0.014 min-1 respectively. The photolysis rate decreased as the polarity of solvents increased. Small polar solvent is favorable to the photodissociation reaction.With additives, the degradation rates of TBBPA are obviously improved.The reaction rate order is titanium dioxide>hexane and the rate constant is 0.1624min-1,0.0498min-1 respectively. We also find that the photochemical reaction is mostly lost bromine and the breaking of benzene ring, finally one main product and 2 by-products by LC-MS analysis.In the second and third part,we study the ecotoxicology of TBBP-A and degradation products by using single cell gel electrophoresis assay and agarose gel electrophoresis.The results show that:The cytotoxicity and genetic toxicity of TBBP-A increased as the concentration increased.With the change of the light, The cytotoxicity and genetic toxicity of degradation product increased at first and then decreased.更多还原