Edwards Selvin H, Shamsi Shahab A
Department of Chemistry, Center of BioTechnology and Drug Design, Georgia State University, Atlanta, GA 30303, USA.
Electrophoresis. 2002 May;23(9):1320-7. doi: 10.1002/1522-2683(200205)23:9<1320::AID-ELPS1320>3.0.CO;2-9.
Chiral separation of moderately to highly hydrophobic polychlorinated biphenyls (PCBs) using a conventional chiral micelle or a polymeric chiral surfactant, as the single chiral selector is very difficult since the hydrophobic interactions between the chiral PCB and the monomeric or polymeric surfactant is very strong. Combined use of a polymeric chiral surfactant, polysodium N-undecanoyl-D-valinate (poly-D-SUV) with hydroxypropyl-gamma-cyclodextrin (HP-gamma-CD) was successful in cyclodextrin modified electrokinetic chromatography (CD-EKC) enantioseparation of PCB congeners. Addition of HP-gamma-CD to the background electrolyte containing poly-D-SUV functioned to improved chiral resolution for the PCBs and reduce the analysis time for these congeners. In addition, concentration of methanol, concentration of 2-(N-cyclohexylamino) ethanesulfonic acid (CHES) buffer and separation voltage was also varied to optimize multicomponent separation of five chiral PCBs. Simultaneous separation and enantioseparation of all five PCBs was possible in less than 50 min under optimized conditions that requires a 5 mM CHES solution buffered at about pH 10 with 1.5% w/v (ca. 60 mM) poly-D-SUV and 16 mM HP-gamma-CD. In addition, 1 M urea and 20% v/v methanol should be added as organic modifier and the capillary temperature maintained at 45 degrees C. As expected the polymeric surfactant showed improved chiral resolution of PCBs over conventional micelles of SUV. Under optimized conditions, when CD-EKC of chiral PCBs using poly-D-SUV was compared to sodium dodecyl sulfate (SDS), better resolution, higher efficiency and shorter analysis time was achieved with poly-D-SUV.
使用传统的手性胶束或聚合手性表面活性剂作为单一手性选择剂，对中度至高度疏水的多氯联苯（PCBs）进行手性分离非常困难，因为手性多氯联苯与单体或聚合表面活性剂之间的疏水相互作用非常强。在环糊精修饰的电动色谱（CD-EKC）中，将聚合手性表面活性剂N-十一烷酰-D-缬氨酸钠（聚-D-SUV）与羟丙基-γ-环糊精（HP-γ-CD）联合使用，成功地实现了多氯联苯同系物的对映体分离。在含有聚-D-SUV的背景电解质中添加HP-γ-CD，可提高多氯联苯的手性分辨率，并减少这些同系物的分析时间。此外，还改变了甲醇浓度、2-（N-环己基氨基）乙磺酸（CHES）缓冲液浓度和分离电压，以优化五种手性多氯联苯的多组分分离。在优化条件下，所有五种多氯联苯在不到50分钟内即可同时分离和对映体分离，该条件需要在约pH 10下用1.5% w/v（约60 mM）聚-D-SUV和16 mM HP-γ-CD缓冲的5 mM CHES溶液。此外，应添加1 M尿素和20% v/v甲醇作为有机改性剂，并将毛细管温度保持在45℃。正如预期的那样，与传统的SUV胶束相比，聚合表面活性剂显示出更高的多氯联苯手性分辨率。在优化条件下，将使用聚-D-SUV的手性多氯联苯的CD-EKC与十二烷基硫酸钠（SDS）进行比较时，聚-D-SUV实现了更好的分辨率、更高的效率和更短的分析时间。
