Preparation Of Monodisperse Polymeric Microspheres By Precipitation Polymerization And Their Appliacations In High-Performance Liquid Chromatography

Several Monodisperse Micron-size Microspheres were prepared by precipitation polymerization with divinylbenzene as crosslinker. The Microspheres were modified or used directly as Stationary Phase, and the chromatography performances of the phases were tested in different Chromatographic Separation modes.This thesis major consists several parts as follows:1. Poly Divinylbenzene, Poly(Divinylbenzene-co-Methyl methacrylate) and Poly(Divinylbenzene-co-Butyl methacrylate) monodisperse micron-size microspheres were prepared by precipitation polymerization with acetonitrile as solvent, divinylbenzene as crosslinker, methyl methacrylate(MMA) and butyl methacrylate(BMA) as functional monomer. The contents of initiator, the dosage of monomer and the reaction temperature of the system were changed. Influence of the conditions on morphology of the microspheres was experimented and discussed. FT-IR and SEM were applied to character the microspheres, and some data analysis discussions were carried out on the results, which showed that functional monomer copolymerized with crosslinker during the precipitation polymerization process and the monodisperese-sized micropheres were nonporous. The chromatographic columns were charged with the micropheres and the pressure tests were carried out. The results showed that shrinkage or swelling behavior of the micropheres were not exist in the organic solvents, and the physical properties were satisfied the requirements of the packing material for reversed phase chromatography. The chromatographic performance of the microspheres was evaluated by reversed-phase liquid chromatography mode. The results showed that the microspheres had comparable hydrophobicity. Neutral, basic and acidic aromatic hydrocarbons could be separated adequately, which indicated that the stationary phase based on the microspheres prepared by precipitation polymerization had high column efficiency.2. Poly(Divinylbenzene-co-Glycidyl Methacrylate) monodisperse crosslinked microspheres with lively epoxy group on the surface were prepared by precipitation polymerization. The chiral ligand-exchange stationary phases were synthesized by grafting modification with L-hydroxyproline and L-proline. Some common amino acid enantiomers were used to evaluate the chromatographic performance of the microspheres by chiral separation mode and the influencing factors were discussed. The results showed that enantioseparation of some D,L-amino acids was performed on this chiral stationary phases and achieved satisfactory results. To improved its performance, the stationary phases need to be studied further.3. A weak cation-exchange chromatography stationary phase with carboxyl group on the surface was prepared by modification with the epoxy groups on the P(GMA-co-DVB) microspheres which been modified by triethylene tetramine and succinic anhydride. The chromatographic performance of the microspheres was evaluated by ion-exchange liquid chromatography mode. The experimental conditions were optimized and the separating effects of glycated hemoglobin(HbAlc) was compared with commercially apparatus. The results show that, with the chromatographic columns charging with the microspheres, the effect of the determination of the HbAlc is good, and the methods were simple, rapid and accurate. The human blood samples were tested and test results show that the chromatography performance of the weak cation-exchange microspheres achieved the same type of commercial chromatographic Packing Material.