title: Preparation and characterization of monodisperse large-porous silica microspheres as the matrix for protein separation.
abstract: High performance liquid chromatography (HPLC) is a kind of efficient separation technology and has been used widely in many fields. Micro-sized porous silica microspheres as the most popular matrix have been used for fast separation and analysis in HPLC. In this paper, the monodisperse large-porous silica microspheres with controllable size and structure were successfully synthesized with polymer microspheres as the templates and characterized. First, the poly(glycidyl methacrylate-co-ethyleneglycol dimethacrylate) microspheres (PGMA-EDMA) were functionalized with tetraethylenepentamine (TEPA) to generate amino groups which act as a catalyst in hydrolysis of tetraethyl orthosilicate (TEOS) to form Si-containing low molecular weight species. Then the low molecular weight species diffused into the functionalized PGMA-EDMAmicrospheres by induction force of the amino groups to form polymer/silica hybrid microspheres. Finally, the organic polymer templates were removed by calcination, and the large-porous silica microspheres were obtained. The compositions, morphology, size distribution, specific surface area and pore size distribution of the porous silica microspheres were characterized by infrared analyzer, scanning-electron microscopy, dynamic laser scattering, the mercury intrusion method and thermal gravimetric analysis, respectively. The results show that the agglomeration of the hybrid microspheres can be overcome when the templates were functionalized with TEPA as amination reagent, and the yield of 95.7% of the monodisperse large-porous silica microspheres can be achieved with high concentration of polymer templates. The resulting large-porous silica microspheres were modified with octadecyltrichlorosilane (ODS) and the chromatographic evaluation was performed by separating the proteins and the digest of BSA. The baseline separation of seven kinds of protein standards was achieved, and the column delivered a better performance when separating BSA digests comparing with the commercial one currently available. The high column efficiency and good reproducibility present that the large-porous silica microspheres obtained can be used as a matrix for peptide and protein separation.
authors.affiliation: Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, Institute of Modern Separation Science, Key Lab of Modern Separation Science in Shaanxi Province, Northwest University, Xi'an 710069, China.
authors.forename: Hongjun
authors.initials: H
authors.lastname: Xia
authors.affiliation: Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, Institute of Modern Separation Science, Key Lab of Modern Separation Science in Shaanxi Province, Northwest University, Xi'an 710069, China.
authors.forename: Guangping
authors.initials: G
authors.lastname: Wan
authors.affiliation: Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, Institute of Modern Separation Science, Key Lab of Modern Separation Science in Shaanxi Province, Northwest University, Xi'an 710069, China.
authors.forename: Junlong
authors.initials: J
authors.lastname: Zhao
authors.affiliation: Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, Institute of Modern Separation Science, Key Lab of Modern Separation Science in Shaanxi Province, Northwest University, Xi'an 710069, China.
authors.forename: Jiawei
authors.initials: J
authors.lastname: Liu
authors.affiliation: Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, Institute of Modern Separation Science, Key Lab of Modern Separation Science in Shaanxi Province, Northwest University, Xi'an 710069, China. Electronic address: baiquan@nwu.edu.cn.
authors.forename: Quan
authors.initials: Q
authors.lastname: Bai
mesh_terms: D002623:Chemistry Techniques, Analytical / Q000379:methods*; D002851:Chromatography, High Pressure Liquid; D004852:Epoxy Compounds / Q000737:chemistry; D008689:Methacrylates / Q000737:chemistry; D008855:Microscopy, Electron, Scanning; D008863:Microspheres; D008970:Molecular Weight; D016062:Porosity; D011506:Proteins / Q000302:isolation & purification*; D015203:Reproducibility of Results; D012822:Silicon Dioxide / Q000737:chemistry*
chemical_list: D004852:Epoxy Compounds; D008689:Methacrylates; D011506:Proteins; D012822:Silicon Dioxide; C004919:ethylene dimethacrylate; C007870:glycidyl methacrylate
keywords: Monodisperse silica microspheres; Polymer microspheres; Protein separation; Template method