Preparation Of Magnetic Microparticle And Its Application In Bio-separation And Concentration Fields

Magnetic microparticles with magnetism and special structure are composed of polymer or functional materials and inorganic magnetic materials. Since the introduction of magnetic microparticles in 1970s, they provide with many functional groups (-COOH、-COH、-NH2、-OH, etc.) by the modification of the surface. The microparticles can be oriented and separated conveniently under applied magnetic field. Compared with conventional separation methods, the magnetic separation technique has the advantages of high efficiency, rapidity and cleanness. The high surface area of the magnetic microparticles improved the kinetic velocity of the interaction between the analytes and the magnetic microparticles. Hence, the magnetic microparticles have been widely applied in various fields, such as magnetic material, biotechnology, biomedical engineering, organic chemistry and catalysts, etc.. Recently, the preparation of various magnetic microparticles and their applications in different fields has become one of research hotspots.Preparation of the Fe3O4 magnetic fluids and magnetic microparticles having functional groups are the keystone of this thesis. Co-precipitation procedure of phase transformation at low temperature was used for the synthesis of Fe3O4 magnetic fluids with the structure of spinel, which was used for the preparation of the magnetic microparticles with functional groups. In this study, magnetic ODS microparticles were prepared using silanizational method, and magnetic NH2 microparticles were prepared using sol-gel silanizational method. The properties of these magnetic microparticles including diameter distribution, apparent shape, magnetic responsiveness, and functional groups were characterized. In the end, they were applied in the bioseparation and concentration field.The main research in this thesis is as follows:1. The optimization of the preparation method for the synthesis of Fe3O4 magnetic fluids;2. The characterizaton of Fe3O4 magnetic fluids and the investigation of the relationship between the structure of the magnetic microparticles and their property;3. The optimization of the preparation method for the synthesis of magnetic ODS microparticles and magnetic NH2 microparticles;4. The characterizaton of the properties of the prepared magnetic microparticles and the investigation of the relationship between the structure of the magnetic microparticles and their property; 5. Magnetic ODS microparticles were used to extract trace amounts of hydrophobic compounds in the environmental samples. Combining the magnetic ODS microparticles extraction and sweeping micellar electrokinetic chromatography (MEKC) analysis can enhance the detection sensitivity and eliminate the interferences from other substances in the sample matrices.