Fabrication And Evaluation Of Immobilized Ionic Liquid Functionalized Organic Polymer-based Monoliths

Fabrication of ionic liquid functionalized organic ploymeric monoliths by using a direct bonding of desired pyridines or imidazoles on the monolithic surface is facile and has being become a hot topic. In this work, an organic monolith with epoxy groups has been prepared by one-step in-situ thermal initiated polymerization, then a novel immobilized ionic-liquid functionalized monolithic has been prepared through the post column modification of epoxy groups with alkaloids. Various characteristics of the resulant monolithic column have been well investigated, which might be favourable to develop new mediums for efficient electrochromatographic technology.This thesis is composed of four sections as following:In chapter 1, review. A detailed introduction on ionic liquid polymer-based monoliths, including the types, preparation techniques and the interaction mechanisms between analyte and stationary phases, has been provided. Based on these, the aim and design of this thesis have been briefly presented.In chapter 2, a hydrophobic monolith with epoxy groups on the surface has been prepared by the in-suit thermally initiated polymerization. Characteristics including polymerization mixture composition, mechanical stability, morphology and chromatography performance were investigated in the obtained monolith. A good mechanical stability was gained with the permeability increasing from 0.98×10-13m2 to 1.35×10-13m2 when the mobile phase changed from water to ACN. At the same time, the influence of mobile phase with various buffer concentrations on the retention factors of alkyl benzene were explored, and the RP mode was also discussed. By using the resultant monolith, the neutral polycyclic aromatic and polar alkaline aniline could be efficiently separated.In chapter 3, a pyridine-based immobilized ionic liquids (ILs)-type polymeric monolith has been developed via the post-column modification of the epoxy groups with quinines. Effects of the concentration of quinine, reaction temperature and reaction time have been investigated for achieving the optimum reaction factors. A strong and stable reversed electroosmotic flow (EOF) under a broad pH range could be observed, and the mixed-model separation mechanism including hydrophobic, anion-exchange, π-π interactions could be well presented in this prepared monolith. Neutral polycyclic aromatic hydrocarbons, negatively charged acidic compounds and positively charged alkaline aniline such as p-agonists compounds were also efficiently separated.In chapter 4, Based on the π-π interactions and ionic repulsion between the stationary phase and analyte which containing aromatic and alkaline amine, the separation of corydalis were established under the mode of CEC. The chromatographic separation conditions were investigated detailly. The retention behavior of alkaloids (berberine, protopine, tetrahydropalmatine) was discussed. Under the optimal conditions, these alkaloids could be separated in baseline within 8 minutes. the intra RSD of migration time was less than 1.2% and tanht of inter RSD was less than 2.8%. Applied to Rhizoma Corydalise, three active alkaloids extracted from the real samples were well separated, which might be provided as a new electrokinetic microseparation technology for analysis Chinese herbal medicine.