The Preparation And Evaluation Of Organic Copolymer Capillary Columns

Capillary chromatography micro-column is a new manufacturing technology of chromatographic column. It is based on the miniaturization of conventional chromatographic column and carried out with the advancement of precision manufacturing technology and the emergence of new materials.Using new Capillary chromatography micro-column to replace the conventional chromatographic column has the following advantages:decreasing the consumption of stationary phase and mobile phase, small sample volume, less environmental pollution, low backpressure, good permeability, using smaller stationary phase particles and suitability to other detector(for example:mass-spectrometry) coupling.In this thesis, the organic copolymer capillary chromatography micro-columns were prepared in situ polymerization and high pressure slurry packing. Then the prepared columns were evaluated by the commercial capillary electrochromatography (CEC) instrument and self-installed capillary liquid chromatography (LC) system, respectively.This thesis consists of five chapters.In chapter 1, a review on the recent advances in capillary electrochromatography and capillary liquid chromatography were presented.In chapter 2, the polystyrene-based monolithic column and packed column were prepared by microwave irradiation and high pressure slurry packing. The key parameters such as column efficiency, column life, column reproducibility were evaluated by means of CEC and capillary-LC. The results showed that this method of column prepared was fast, simple and easy to realize.In chapter 3, The methacrylic acid based monolithic column was prepared by in-situ photopolymerization, using methacrylic acid (MAA) as a functional monomer as well as electroosmotic flow modifier, ethylene glycol dimethacrylate (EDMA) as a cross-linking agent, toluene and isooctane as porogenic solvents and Irgacure 1800 as an initiator. On this basis, the capillary tandem column and packed column were prepared with high pressure slurry packing. The chromatographic behavior of those column were studied, all of which exhibited reversed-phase character.In chapter 4, the preparation of acrylamide-based entrapping of octadecylsilane(ODS) microsphere Column were realized by ultraviolet light initiation for capillary LC separation and analysis. At first a porous temporary frit in fused silica capillary was fabricated, after the slurry packing of C18 particles, the acrylamide-based copolymer solution were pumped for immobilizing ODS microspheres. The experiment result demonstrates excellent chromatographic performance, baseline separation of the model analytes was achieved including thiourea, benzene, naphthalene and biphenyl with the largest theoretical plate number up to 39260/m for the retained component.In chapter 5, the influence of an improvement of the splitting device of the self-installed capillary LC system was investigated. A T-piece connector replaced by four-way valve can effectively avoid the damage to the pump caused by a blockage in splitting capillary more accurately adjust the velocity of the mobile phase in microlitre grade, improve stability of the system. Compare with commercial capillary column, the quality of the self-prepared capillary column is qualified and satisfies the requirement of experiment.