Superficially porous core-shell silica microspheres （CSSMs） have been a great success for the fast separation of small molecules and proteins in recent years. In this paper, the CSSMs were synthesized by an improved...Superficially porous core-shell silica microspheres （CSSMs） have been a great success for the fast separation of small molecules and proteins in recent years. In this paper, the CSSMs were synthesized by an improved polymerization-induced colloid aggregation （PICA） method using urea-formaldehyde polymers as the templates. The agglomeration of the functionalized silica core was avoided by the surface modification through reflux with ureidopropyltrimethoxysilane in the neutral ethanol solution at 80 ~C, and the secondary nucleation of the silica nanoparticles during the preparation process could also be inhibited via the optimization of the reaction conditions, such as pH, temperature, colloidal silica sol concentration and the reaction time. The controllable shell thickness and pore size of the synthesized monodisperse CSSMs were successfully obtained by adjusting the weight ratio of silica core/colloidal silica sol and the particle size of colloidal silica sol, respectively. The C18-modified CSSMs with different pore sizes were used to separate small solutes and proteins. The higher efficient separation and relatively low back pressure of the synthesized core-shefi column demonstrate that the CSSMs have a great ootential aoolication for fast HPLC展开更多
Recombinant human granulocyte colony-stimulating factor （rhG-CSF） in inclusion bodies was solubilized by 8 mol/L urea solution and subsequently precipitated by acetone to improve its purity. After that, the precipit...Recombinant human granulocyte colony-stimulating factor （rhG-CSF） in inclusion bodies was solubilized by 8 mol/L urea solution and subsequently precipitated by acetone to improve its purity. After that, the precipitates were solubilized by sodium hydroxide solution containing 2 mol/L urea. Then the solubilized rhG-CSF was passed through a size exclusion chromatography for refolding and extensive purification, and further purified by a weak anion exchange chromatography. The purity and mass recovery of refolded rhG-CSF were 96.5% and 75.6%, respectively. The bioactivity was 8.4x10^7 IU/mg.展开更多
Based on the fact that the first set of the linear relationship between z and lg/ ofstoichiometric displacement model for retention in reversed-phase liquid chromatography is separatelyproportional to contact surface ...Based on the fact that the first set of the linear relationship between z and lg/ ofstoichiometric displacement model for retention in reversed-phase liquid chromatography is separatelyproportional to contact surface area,a linear relationship between z and lg/ for both of polar and apolarsmall solute molecules was theoretically derived and experimentally tested.The j obtained,one of the secondset of the linear parameters,is a characterization parameter for organic solvent strength and the column phaseratio(?)is defined as the value of k’ when the partition coefficient of solute in two phases is unity.展开更多
A unified retention equation of proteins was proved to be valid for a mixed-mode interaction mechanism in ion exchange chromatography (IEC) and hydrophobia interaction chro-matography (HIC). The reason to form a '...A unified retention equation of proteins was proved to be valid for a mixed-mode interaction mechanism in ion exchange chromatography (IEC) and hydrophobia interaction chro-matography (HIC). The reason to form a 'U' shape retention curve of proteins hi both HIC and IEC was explained and the concentration range of the strongest elution ability for the mobile phase was determined with this equation. The parameters in this equation could be used to characterize the difference for either HIC or IEC adsorbents and the changes in the molecular conformation of proteins. With the parameters in this equation, the contributions of salt and water in the mobile phase to the protein retention in HIC and IEC were discussed, respectively. In addition, the comparison between the unified equation and Melander' s three-parameter equation for mixed-mode interaction chromatography was also investigated and better results were obtained in former equation.展开更多
基金supported by the National Natural Science Foundation of China(Nos.21545007,21605122)the Foundation of Key Laboratory in Shaanxi Province(Nos. 2010JS103, 11JS097, 15JS115)
文摘Superficially porous core-shell silica microspheres （CSSMs） have been a great success for the fast separation of small molecules and proteins in recent years. In this paper, the CSSMs were synthesized by an improved polymerization-induced colloid aggregation （PICA） method using urea-formaldehyde polymers as the templates. The agglomeration of the functionalized silica core was avoided by the surface modification through reflux with ureidopropyltrimethoxysilane in the neutral ethanol solution at 80 ~C, and the secondary nucleation of the silica nanoparticles during the preparation process could also be inhibited via the optimization of the reaction conditions, such as pH, temperature, colloidal silica sol concentration and the reaction time. The controllable shell thickness and pore size of the synthesized monodisperse CSSMs were successfully obtained by adjusting the weight ratio of silica core/colloidal silica sol and the particle size of colloidal silica sol, respectively. The C18-modified CSSMs with different pore sizes were used to separate small solutes and proteins. The higher efficient separation and relatively low back pressure of the synthesized core-shefi column demonstrate that the CSSMs have a great ootential aoolication for fast HPLC
基金This work is supported by the National Natural Science Foundation of china （No. 20175016 and No. 20475042） the Foundation of Key Laboratory of Modem Separation Science in Shaanxi Province （No. 05JS61）.
文摘Recombinant human granulocyte colony-stimulating factor （rhG-CSF） in inclusion bodies was solubilized by 8 mol/L urea solution and subsequently precipitated by acetone to improve its purity. After that, the precipitates were solubilized by sodium hydroxide solution containing 2 mol/L urea. Then the solubilized rhG-CSF was passed through a size exclusion chromatography for refolding and extensive purification, and further purified by a weak anion exchange chromatography. The purity and mass recovery of refolded rhG-CSF were 96.5% and 75.6%, respectively. The bioactivity was 8.4x10^7 IU/mg.
基金the National Natural Science Foundation of China
文摘Based on the fact that the first set of the linear relationship between z and lg/ ofstoichiometric displacement model for retention in reversed-phase liquid chromatography is separatelyproportional to contact surface area,a linear relationship between z and lg/ for both of polar and apolarsmall solute molecules was theoretically derived and experimentally tested.The j obtained,one of the secondset of the linear parameters,is a characterization parameter for organic solvent strength and the column phaseratio(?)is defined as the value of k’ when the partition coefficient of solute in two phases is unity.
基金Project (Nos. 296750l7 and 39880003) supported by the National Natural Science Foundation of China.
文摘A unified retention equation of proteins was proved to be valid for a mixed-mode interaction mechanism in ion exchange chromatography (IEC) and hydrophobia interaction chro-matography (HIC). The reason to form a 'U' shape retention curve of proteins hi both HIC and IEC was explained and the concentration range of the strongest elution ability for the mobile phase was determined with this equation. The parameters in this equation could be used to characterize the difference for either HIC or IEC adsorbents and the changes in the molecular conformation of proteins. With the parameters in this equation, the contributions of salt and water in the mobile phase to the protein retention in HIC and IEC were discussed, respectively. In addition, the comparison between the unified equation and Melander' s three-parameter equation for mixed-mode interaction chromatography was also investigated and better results were obtained in former equation.
