title: An insight into the mechanism of CEC separation of template analogues on a norepinephrine-imprinted monolith.
abstract: A monolith molecularly imprinted polymer (MIP) column was prepared from template (-)-norepinephrine, functional monomer (itaconic acid), and a cross-linker (either ethylene glycol dimethacrylate or divinylbenzene) in porogen N,N-dimethylformamide. Understanding the molecular recognition of a template using an MIP seems feasible. However, it is hard to explain the recognition properties of their analogues on an MIP. The separation mechanism was investigated with the addition of charged surfactants, native and derivatised β-cyclodextrin (β-CD), achiral crown ether, etc. to determine the retention behaviour of the template analogues. The addition of organic modifiers and the adjustment of separation conditions were used to manipulate the selectivity. No chiral recognition was observed under most of the test conditions except the experiment with the charged β-CD on the divinylbenzene-MIP column. The different experimental conditions led to differences in the mobilities of the analytes and resulted in remarkable enantiomeric separation of the template. We confirmed the presence of mixed-mode selectivity of the stationary phase based on hydrogen bonding, hydroelectric and hydrophobic interactions, and the electrophoretic mode.
authors.affiliation: Department of Chemistry, National Taiwan University, Taipei, Taiwan.
authors.forename: Bao-Yu
authors.initials: BY
authors.lastname: Huang
authors.forename: Yu-Cheng
authors.initials: YC
authors.lastname: Chen
authors.forename: Chuen-Ying
authors.initials: CY
authors.lastname: Liu
mesh_terms: D053801:Capillary Electrochromatography / Q000295:instrumentation / Q000379:methods*; D006860:Hydrogen Bonding; D057927:Hydrophobic and Hydrophilic Interactions; D054802:Molecular Imprinting; D009638:Norepinephrine / Q000031:analogs & derivatives / Q000302:isolation & purification*; D011108:Polymers / Q000138:chemical synthesis / Q000737:chemistry*
chemical_list: D011108:Polymers; D009638:Norepinephrine