Brown R S, Szolar O H, Luong J H
Biotechnology Research Institute, National Research Council Canada, Montreal, Quebec, Canada.
J Mol Recognit. 1996 Sep-Dec;9(5-6):515-23. doi: 10.1002/(sici)1099-1352(199634/12)9:5/6<515::aid-jmr294>3.0.co;2-5.
Two neutral cyclodextrins (CDs), hydroxypropyl-beta-CD (HP beta OD) and methyl-beta-CD (M beta CD), and two negatively charged forms, carboxymethyl-beta-CD (CM beta CD) and sulfobutylether-beta-CD (SB beta CD), were used to demonstrate the principle of separation of hydrophobic and non-charged polynuclear aromatic hydrocarbons (PAHs) by capillary electrophoresis (CE) based on differential partitioning of analytes between the CDs. The estimation of the partition coefficient (Ki) confirmed that the PAH components which partitioned most to the negative cyclodextrin (i.e. with the highest Ki) exhibited the longest migration time. The Ki values obtained for the CM beta CD-HP beta CD system are all below 1, indicating that the PAHs prefer to remain in the neutral HP beta CD. The Ki values for the SB beta CD-M beta CD buffer are all greater than 1, and cover a wider range, indicating preference of the PAHs for the anionic derivative. Methods were applied for separation of a PAH mixture containing various important PAHs on the US Environmental Protection Agency priority list. This novel procedure provided much better separation of PAH isomers, including benzo[a]pyrene and benzo[e]pyrene, than has been reported previously using CE. The system was applied to the sensitive determination of nanomolar levels of PAHs in contaminated soil.
使用了两种中性环糊精（CDs），即羟丙基-β-环糊精（HPβCD）和甲基-β-环糊精（MβCD），以及两种带负电荷的形式，羧甲基-β-环糊精（CMβCD）和磺丁基醚-β-环糊精（SBβCD），来证明基于分析物在环糊精之间的差异分配，通过毛细管电泳（CE）分离疏水性和不带电荷的多环芳烃（PAHs）的原理。分配系数（Ki）的估算证实，在负性环糊精中分配最多（即具有最高Ki值）的PAH组分迁移时间最长。CMβCD - HPβCD系统获得的Ki值均低于1，表明PAHs更倾向于保留在中性的HPβCD中。SBβCD - MβCD缓冲液的Ki值均大于1，且覆盖范围更广，表明PAHs更倾向于阴离子衍生物。所采用的方法用于分离含有美国环境保护局优先清单上各种重要PAHs的混合物。与之前报道的使用CE的方法相比，这种新方法对PAH异构体（包括苯并[a]芘和苯并[e]芘）的分离效果要好得多。该系统被应用于灵敏测定受污染土壤中纳摩尔水平的PAHs。
