【作者】 董向宜；

【导师】 李效宇；

【作者基本信息】 河南师范大学 ， 水生生物学， 2012， 硕士

【摘要】 离子液体的化学组成仅有离子，是在室温条件下呈熔融状态的盐。它们具有一系列典型的特征，如：几乎不蒸发不挥发，高热且不可燃，有较高的溶解度且化学性质稳定，这些特征使得它们将来可以被用于有机物合成，催化，化学分离和电化学。尤其是在近几年，离子液体有望被用于环境保护和对生物资源的再利用，例如吸收有害气体CO2，降解作物茎秆中的纤维素等。而且，由于其几乎可以忽略的蒸发性，离子液体可以减少空气污染的风险。因此离子液体被认为是环保的“绿色溶剂”，化学家强烈推荐用它来作为传统有机溶剂的替代物。然而，大部分离子液体是水溶性的，它们在生产和应用的过程中被排放到水环境中可能会对水生生物产生危害。因此，离子液体可能会对水生生态系统产生环境风险，正是如此近几年离子液体对水生生物的毒性研究被热切关注。咪唑类离子液体不仅被广泛的应用在化学工业，而且它们与传统的有机溶剂相比具有明显的优势；它们通常对生物具有中等或者相对较低的毒性。更重要的是，根据之前我们的研究，生物对该类离子液体的毒性反应严格符合剂量依赖反应，而且这个毒性检测的结果可以代表常见的离子液体。因此，咪唑类离子液体被用于目前的研究中以确定其对Physa acuta的胚胎毒性和胚后发育毒性，并且通过测定暴露在[C₈mim]Br离子液体中的Physa acuta内脏团抗氧化系统和脂质过氧化水平来阐述离子液体的生化毒性机制。胚胎毒性试验结果表明[C₈mim]Br离子液体可抑制螺胚胎的孵化率，提高胚胎的死亡率。同时，[C₈mim]Br离子液体更敏感，这也表明[C₈mim]Br离子液体的毒性是阶段敏感的，而且，我们还发现幼螺和成螺比螺胚胎对离子液体的抵抗性强。另外，这项研究还表明较长的碳链能够增加咪唑类离子液体对螺的毒性。研究还发现，暴露96h后，[C₈mim]Br离子液体抑制SOD和GST的活性，同时提高CAT的活性和增加谷胱甘肽的含量。与对照组相比，所有处理组中MDA的含量都有所提高，这表明[C₈mim]Br离子液体可导致脂质过氧化。这些结果表明活性氧和脂质过氧化可能与[C₈mim]Br离子液体对螺的毒性机制有关。最后，根据目前的研究结果，认为P.acuta可能是一个比较好的毒理学实验模型并且可作为水污染的一个有效的指示生物。更多还原

【Abstract】 Ionic liquids(ILs)are room-temperature molten salts which chemically consist only of ions. They possess a series of preponderant properties, such as almost no vapour pressure and nonvolatility, high thermal and non-flammability, and high solvent capacity and chemical stability, which promote them to be used in organic synthesis, catalysis, chemical separation, and electrochemistry in the future. Especially in the recent years, ILs have been promised to be used in environmental protection and the utilization of biotic resources, for example, absorption of harmful gas CO2, and degradation of cellulose from the crop stalks. Furthermore, ILs may reduce the risk of air pollution due to their negligible vapor pressure. Therefore ILs have been claimed to be environmentally benign "green solvent" strongly recommended to be the substitutes for conventional organic solvents by chemists. However, most ILs are hydrosoluble and they may be released to water and cause damage to aquatic organisms during the generation and application. Therefore, ILs may pose environmental risks to aquatic ecosystems, and thus IL-toxicity on aquatic organisms is much concerned in the near years.The imidazolium-based ILs have been not only widely applied in the chemical industry, they also possess the excellent and advantageous properties over the conventional organic solvents. Moreover, they usually have moderate or relatively lower toxicity on organisms. The most important is that the toxic response of organisms to the exposure of imidazolium-ILs is in a remarkable dose-dependent manner according to our previous studies and the result of toxicity-testing can be the representation for the common ILs. Therefore the imidazolium-based IL was adopted in the present study to evaluate their embryonic and post-embryonic developmental toxicities on the snail Physa acuta and to elucidate the biochemical mechanism of IL-toxicity by determining the responses of the antioxidant system and the level of lipid peroxidation in the viscera of Physa acuta exposed to1-octyl-3-methylimidazolium bromide([C8mim] Br)in the present study.The results of embryonic toxicity tests showed that[Csmim]Br inhibited the hatching rate of snail embryos while promote the embryonic death rate. Meanwhile, the results reveal that the stage veliger is more sensitive to[Csmim]Br than the stages of blastula and gastrula, indicating that[Csmim]Br-toxicity is stage-sensitive. Moreover, we also find that the juvenile or adult snail is more resistant to the ionic liquids than snail embryo. In addition, this study also indicates that longer alkyl chains can increase the toxicity of the imidazolium ionic liquids on snails.We also find that[Csmim]Br inhibits the activities of superoxide dismutase and glutathione S-transferase while promotes the activity of catalase and increases glutathione content after96h of exposure. Malondialdehyde levels increase in all treatment groups compared to the control, indicating that[C8mim]Br induce lipid peroxidation. These results suggest that reactive oxygen species and lipid peroxidation may involved in the toxicity mechanism of[Csmim]Br for the snail.Finally, we suggest that P. acuta may be a good model of toxicity tests and a valuable indicator of water pollution according to the results of the present study.更多还原