Department of Occupational and Environmental Health, College of Public Health, University of Iowa, Iowa City, IA 52242, USA.
J Chromatogr A. 2013 Feb 22;1278:133-44. doi: 10.1016/j.chroma.2012.12.041. Epub 2012 Dec 26.
Changes in the enantiomeric fraction of chiral polychlorinated biphenyls (PCBs) are a powerful tool to investigate the movement of PCBs in the environment, for example as part of source apportionment and ecological studies. Environmental studies typically employ a series of cyclodextrin-based gas chromatography columns to separate all environmentally relevant PCB congeners. The elution order of most PCB atropisomers has not been established on different enantioselective columns due to the unavailability of analytical standards. To overcome this limitation, the current study generated atropisomerically enriched fractions of chiral PCBs with rat liver microsomes. Subsequently, the enrichment profile of the enriched PCB fractions was used to determine the elution order of PCB atropisomers on selected enantioselective gas chromatography columns. While the elution order of PCB 95, 131, 132, 136, 149 and 176 atropisomers was identical on all enantioselective columns investigated, an inversion of the elution order was observed for PCB 45, 84, 91 and 174 atropisomers on a few columns. These results demonstrate that atropisomerically enriched fractions obtained from microsomal metabolism can be used to unambiguously establish the relative elution order of the atropisomers of PCBs and potentially other environmental pollutant, especially if pure enantiomers are not available.
手性多氯联苯（PCBs）对映体分数的变化是研究 PCBs 在环境中迁移的有力工具，例如作为源解析和生态研究的一部分。环境研究通常采用一系列基于环糊精的气相色谱柱来分离所有与环境相关的 PCB 同系物。由于缺乏分析标准，大多数 PCB 对映异构体在不同的手性柱上的洗脱顺序尚未建立。为了克服这一限制，本研究使用大鼠肝微粒体生成了手性 PCB 的对映体富集馏分。随后，利用富集 PCB 馏分的富集谱来确定在选定的手性气相色谱柱上 PCB 对映异构体的洗脱顺序。虽然在所有研究的手性柱上，PCB 95、131、132、136、149 和 176 对映异构体的洗脱顺序相同，但在少数柱上，PCB 45、84、91 和 174 对映异构体的洗脱顺序发生了反转。这些结果表明，从微粒体代谢获得的对映体富集馏分可用于明确建立 PCB 对映异构体和潜在其他环境污染物的相对洗脱顺序，特别是如果没有纯对映异构体时。
