Preparation And Appilication Of Novel Polymer-Based Capillary Monolithic Columns

Monolithic columns,defined as "continuous stationary phases that can be prepared by in-situ polymerization or sol-gel process inside the capillary",have been widely used in the field of separation science due to the merits of simple preparation,fast mass transfer rate,low back pressure and high column efficiency.Nevertheless,expoloring novel monomers,developing new preparation methods of monolithic column and expanding new appilication areas are popular in the analysis of chromatography field in recent years.Based on these issues,we devoted to developed three novel capillary monolithic columns.Accordingly,their chromatographic retention mechanisms were systematically evaluated in detail.The thesis consists of four chapters as following:In chapter 1,a general review of the definition and classification of monolithic columns,as well as their appilications in biomolecule separation was described in detail.Furthermore,the present preparation method of monolithic columns,how to improve novel monoliths and exploring new method to prepare monoliths were mainly introduced.Besides,the aim and significance of this thesis were also briefly presented.In chapter 2,combining free radical polymerization with click chemistry via CuAAC click chemistry in a "one-pot" process,a facile approach was developed for the preparation of a polymer monolithic column carrying 6-azidohexanoic acid(AHA),which was applied in capillary liquid chromatography(cLC)separations in the mixed-mode.Different rations of monomers,cross-linker and porogens were used for optimizing the properties of monolithic column.A series of alkylbenzenes,phenols and anilines were used to evaluate the chromatographic properties of the polymer monolith in terms of reverse phase,hydrophilic and cation-exchange interactions.In addition,the poly(AHA-co-PMA-co-EDMA)monolithic column could be successfully applied to the separation of polycyclic aromatic hydrocarbons,nucleosides and nucleobases,alkaloids,peptides and proteins.In chapter 3,preparation of nucleoside-bases polymer monolithic column by the combination of free radical polymerization and CuAAC click chemistry was described.In this process,3'-azido-3'-deoxythymidine(AZT)and propargyl methacrylate(PMA)were used as functional monomers,and pentaerythrityl triacrylate(PETA)was introduced as a hydrophilic cross-linker.The different ratios of AZT was optimized in detail as to the selectivity and chromatographic property of monolithic column.The optimal monolith showed a mixed mode chromatography including hydrophilic,reverse phase and cation-exchange interaction.Compared with the AZT-modified monolith,this monolithic column presented better separation and efficiency performance when separating hydrophilic solutes.The purposed monolith was also applied to efficient separation of sulfonamides,nucleobases and nucleosides,anesthetics and proteins for demonstrating its potential.In chapter 4,a novel dual-funcational protein affinity capillary monolithic column was developed.The monolith was synthesized by in situ copolymerization of 4-vinylphenylboronic acid(VPBA)and vinylphosphonic acid(VPA)as bifunctional monomers in a binary porogenic solvent(diethylene glycol and ethylene glycol).The morphology,permeability and pore property of the resultant monolithic column were characterized.The retention behaviors of small molecules have been investigated.Efficient separations of glycoproteins and non-glycoproteins,phosphorylated proteins and non-phosphorylated proteins were be obtained under the optimized conditions.