Chromatographic Approach to Environmental Science of Dioxins

本项目的目标包括：(1)开发水中二恶英和多氯联苯的光解方法；(2)开发高效液相色谱高选择性分离二恶英异构体和多氯联苯的方法；(3)开发一种新型的拟固定相，用于环境污染物(即疏水性碳氢化合物和卤代芳香族化合物)的高速高选择性EKC分离。(1)将水溶液中的多氯联苯成功地吸附在石英柱中的疏水固定相上，通过柱外紫外光照射光解。所有的多氯联苯都可以在几个小时内在异丙醇-水混合物中完全光解，而只有亲水性的产品离开色谱柱。毒性较大的共面多氯联苯的光解速度慢于邻位取代的多氯联苯。然而，毒性较小的邻位取代多氯联苯的快速光解优先产生更有毒的共面…通过在未混合的有机溶剂中使用基于硅胶的各种电子供体和电子受体键合的固定相，实现了标准物质合成过程中产生的所有二恶英异构体的分离，以及共面和邻位取代多氯联苯的基团分离。以星形树枝状大分子和聚烯丙基胺为载体，通过烷基化和羧酸基的连接制备了拟固定相。EKC的拟固定相，特别是那些具有长烷基链的拟固定相，在水-甲醇或水-乙腈混合物中表现出非常高的性能，在不到20分钟的时间内完成了对16种优先污染物多环芳烃的分离。结果表明，假设在阳光下也有类似的光解，已经释放到环境中的多氯联苯的光解对生物物种可能是非常危险的，控制和适当处理剩余的多氯联苯是非常重要的。结果还表明，开发一种更具选择性、更灵敏、更快速的环境污染物分析方法是重要的，这种方法需要最少的劳动力来处理生物样品。较少

The objectives of this project include (1) the development of a photolysis method of dioxins and PCBs in aqueous waste, (2) the development of a high selectivity separation method of dioxin isomers and PCB congeners by HPLC,and (3) the development of a novel pseudo-stationary phase for the high-speed and high-selectivity EKC separation of environmental contaminants, namely hydrophobic hydrocarbons and halogenated aromatic compounds.(1) PCBs were successfully adsorbed from aqueous solution onto the hydrophobic stationary phase packed in a quartz column, the photolyzed by the irradiation with ultra-violet light from outside the column. All the PCBs can be completely photolyzed in a few hours in a stream of 2-propanol-water mixtures, while only hydrophilic products leaving the column. The photolysis of more toxic, coplanar PCBs were slower than ortho-substituted PCBs. The rapid photo-decomposition of less toxic, ortho-substituted PCBs, however, preferentially produced more toxic coplanar … More PCBs as an intermediate, which can potentially provide serious environmental problems, if similar photolysis occurs under sunlight.(2) The separation of all the dioxin isomers coproduced during the synthesis of reference standard and the group separation between coplanar and ortho-substituted PCBs were achieved by using various electron-donor and electron-acceptor bonded stationary phases based on silica gel for HPLC in an unmixed organic solvent. This allows the easy recycle of the organic solvent in preparative operation.(3) Pseudo-stationary phases were prepared by using starburst dendrimers and polyallylamine as supports by alkylation and the attachment of carboxylate groups. The pseudo-stationary phases for EKC,especially those with long alkyl chains, showed very high performance in water-methanol or water-acetonitrile mixtures to result in the complete separation of 16 priority pollutant polynuclear aromatic hydrocarbons in less than 20 minutes.The results suggest that the photolysis of PCBs already released to the environment is potentially very dangerous to living species, assuming a similar photo-decomposition under sunlight, and that the control and proper disposal of remaining PCBs are very important. The results also suggest that it is important to develop a more selective, sensitive, and rapid analysis method of these environmental pollutants that needs minimum labor for the treatment of biological samples. Less