Preparation Of New Type Of Hydrophilic Monolithic Column And Its Application In Pressurized Capillary Electrochromatography

Hydrophilic interaction liquid chromatography(HILIC) has many specific advantages over conventional normal phase liquid chromatography (NP-LC) and reversed phase liquid chromatography (RP-LC). For example, HILIC column is suitable for analyzing polar compounds and can be conveniently coupled to mass spectrometry (MS) without using expensive ion pair reagents. Therefore, it has attracted many people's attention in recent years. When compared to a packed column, monolithic column has better characteristics such as its uniform and stable bed. It also overcomes the frits effect of a packed column. Besides, it has varied?flexibility by introducing various functional groups and is beacoming a hot field in chromatography. Combining the advantages of HILIC and monolithic column, hydrophilic monolithic column has been frequently used to separate polar compounds and has broad prospect in the analysis of traditional Chinese medicine, proteomics and food safty in the future.The preparation of hydrophilic polymer-based monolithic columns were catalyzed by azodiisobutyronitrile(AIBN) in situ copolymerization with {[2-(Methacryloyloxy)ethyl]dimethyl-(3-sulfopropyl)ammonium hydroxide, SPE}, {[3-(methacryloylamino)propyl]dimethyl (3-sulfopropyl) ammonium hydroxide inner salt, SPP} and pentaerythritol triacrylate (PETA) as monomers in three kinds of porogenic agents consisting of cyclohexanol-ethylene glycol, ethanol--ethylene glycol and methanol--1,4-butanediol.This thesis was mainly divided into three parts as follows.The first part introduced a polymer-based monolithic column which was prepared by in situ copolymerization with SPE and PETA in porogenic agent consisting of cyclohexanol and ethylene glycol, with VS and AIBN as EOF provider and initiator, repectively. The pressurized capillary electrochromatography(pCEC) system using hydrophilic monolithic column showed better separation of the mixture consisted of toluene, phenol, catechol, thymine, resorcinol, uracil and thiourea compared to capillary liquid chromatography (cLC);At the same time, the selectivity of the mixture of toluidine, thymine, uracil, and benzoic acid in pCEC can be tuned by simply adjusting the voltages/pressure ratio.In the second part, new hydrophilic monolithic columns were prepared with SPP and PETA in two different porogenic agents consisting of ethanol--ethylene glycol and methanol--1,4-butanediol, with azobisisobutyronitrile (AIBN) as initiator. In order to obtain monolithic columns with satisfactory efficiency, electroosmotic flow (EOF) velocity and permeability, the composition of the polymerisation mixture were investigated and optimized. The columns were used in cLC and pCEC for the separation of a test mixture of amine, phenols and nucleosides, and satisfactory separations for these samples were achieved.In the last part, the performance of two series of columns was compared in permeability and separation performance. It was found that the monolithic column prepared with ethanol--ethylene glycol had a better column efficiency and selectivity than the monolithic column prepared with methanol--1,4-butanediol , but inferior to the latter in permeability.