Chromatographic techniques for PCB and dioxin problems.

(1)在填充了十八烷基硅烷化二氧化硅颗粒的石英柱中，利用紫外光照射降解了多氯联苯和多氯二苯并对二恶英(PCDDs)。捕获在消耗臭氧层物质-二氧化硅上的高氯化多氯联苯从水溶液中连续光解也是可能的。含有2至8个氯的多氯联苯的光解使得能够检查影响反应途径的因素。空间位阻和分子对称性被发现是主要因素，解释了各种同系物看似复杂的分解途径，这些途径不太受光源、汞灯或阳光的影响。结果表明，在光解条件下，以邻位脱色为主的产物不仅具有较高的热释电常数，而且具有更长的寿命。在H给体存在的情况下，…优先从2378位失去一个氯原子，而在没有增加TEQS的情况下，则优先从1469位失去一个氯原子，这表明PCDDs具有潜在的危险(2)从二氧化硅颗粒中制备了电子受体键合固定相3-(对-硝基苯氧基)丙基硅基(NPO)和电子键合相3-(N-咔唑基)丙基硅基(CZP)、2-(1-吡咯烷基)乙基硅基(PYE)和5-冠烯基戊基硅基(COP)，并考察了它们对PCDD异构体、六氯萘(HxCNs)、平面和非平面多氯联苯(PCBs)的选择性。虽然没有一个固定相能够分离PCDDs和HxCNs合成过程中共生成的所有异构体对，但可以通过选择合适的固定相和溶剂来分离它们。用PYE和NPO相分离PCDD异构体效果最好。对于作为混合物产生的每个异构体对，这两个相产生相反的洗脱顺序。对于在Pye和CZP相上分离的HxCN异构体也得到了类似的结果。基于平面性，COP相比PYE相更容易将非邻位取代和单邻位取代的多氯联苯与其他多氯联苯分开。这些固定相能够完全分离二恶英的所有同系物以及多氯二苯并二恶英、多氯联苯和多环芳烃之间的组分离。(3)在血清样品脱蛋白后将多氯联苯和多氯二苯并多氯联苯分离到有机溶剂中，然后将多氯二苯并二恶英与多氯联苯进行分类分离的可能性，除了使用限制进入的反相柱外，还使用了填充在外表面具有二醇官能团的十八烷基硅烷化二氧化硅的反相柱。第一步从脂蛋白中溶解多氯联苯和二恶英，第二步提供基团分离。这种血清样品处理方法可以将制备时间从24小时缩短到大约1小时，避免了几个层析步骤，从而降低了GC/MS分析的成本和时间效率。结果表明，已经释放到环境中的多氯联苯和多氯二苯并二恶英在阳光下的光解对生物物种具有潜在的危险，适当的管理和处置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、更灵敏和更快速的分析方法对这些污染物进行分析是很重要的，这种方法需要最少的劳动力来处理生物样品。利用层析技术，或使用固体表面分离和分解二恶英和多氯联苯，预计将导致更快的分析和更安全的环境污染物分解。较少

(1)PCBs and polychlorodibenzo-p-dioxins (PCDDs) were decomposed in a quartz column packed with octadecylsilylated silica particles (ODS-silica) by external UV irradiation. Continuous photolysis of highly chlorinated PCBs trapped on ODS-silica from aqueous solution was also possible. The photolysis of PCBs having two to eight chlorines allowed the examination of the factors that affect the reaction pathway. Steric congestion and molecular symmetry were found to be the major factors, explaining the seemingly complicated decomposition pathways of various congeners that were not much affected by the light source, a mercury lamp or sunlight. The results indicate that the predominant ortho-dechiorination leads to products having not only higher TEFs but also much longer life under photolysis conditions. PCDDs lose a chlorine atom preferentially from 2378-positions in the presence of H-donor, but preferentially from 1469-positions in the absence increasing TEQs, suggesting potential danger of … More sunlight photolysis of contaminated soil in the absence of H-donor.(2)Electron-acceptor-bonded stationary phase, 3-(p-nitrophenoxy)propylsilyl (NPO), and electron-bonded phases, 3-(N-carbazolyl) propylsisly (CZP), 2-(1-pyrenyl) ethylsilyl (PYE), and 5-coronenylpentylsilyl (COP), were prepared from silica particles, and their selectivities were examined for PCDD isomers, hexachloronaphthalense (HxCNs), and planar and nonplanar PCB congeners. Although no single stationary phase was able to separate all the isomer pairs that are coproduced during the synthesis of the PCDDs and HxCNs, they can be separated by selecting a suitable stationary phase and solvent. The separation of PCDD isomers were found to be most successful with PYE and NPO phases. The two phases yielded the opposite elution orders for each isomer pair that is produced as a mixture. Similar results were obtained for the HxCN isomers that were separated on PYE and CZP phases. The COP phase provided easier separation of non-ortho-substituted and mono-ortho-substituted PCBs from the other PCBs based on the planarity than PYE phase. These stationary phases enabled total separation of all congeners of dioxins as well as group separation between PCDDs, PCBs, and PAHs.(3)The possibility of isolating PCBs and PCDDs into an organic solvent upon deproteinization of a serum sample followed by the class separation of PCDDs from PCBs was shown by using a PYE silica column in addition to a restricted-access reversed-phase column packed with octadecylsilylated silica having diol functionality at the external surfaces. The first step solubilizes PCBs and dioxins from lipoproteins, and the second step provide group separations. The serum sample treatment method will allow shortening the preparation time from 24 h to about 1 h, by avoiding several chromatographic steps leading to cost and time efficient analysis by GC/MS.The results suggest that sunlight photolysis of PCBs and PCDDs already released to the environment is potentially dangerous to living species, and that proper management and 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 pollutants that needs minimum labor for the treatment of biological samples. The utilization of chromatographic techniques, or the use of solid surfaces for separation and decomposition of dioxins and PCBs is expected to lead to faster analysis and safer decomposition of environmental contaminants. Less