Quan Bai

Name: 白泉

Organization: Northwest University , China

Department: Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of the Ministry of Education

Title: NULL(PhD)

Chemicals
References

Preparation of a weak anion exchange/hydrophobic interaction dual-function mixed-mode chromatography stationary phase for protein separation using click chemistry

Co-reporter:Kailou Zhao;Fan Yang;Hongjun Xia;Fei Wang;Qingguo Song

Journal of Separation Science 2015 Volume 38( Issue 5) pp:703-710

Publication Date(Web):

DOI:10.1002/jssc.201401020

In this study, 3-diethylamino-1-propyne was covalently bonded to the azide-silica by a click reaction to obtain a novel dual-function mixed-mode chromatography stationary phase for protein separation with a ligand containing tertiary amine and two ethyl groups capable of electrostatic and hydrophobic interaction functionalities, which can display hydrophobic interaction chromatography character in a high-salt-concentration mobile phase and weak anion exchange character in a low-salt-concentration mobile phase employed for protein separation. As a result, it can be employed to separate proteins with weak anion exchange and hydrophobic interaction modes, respectively. The resolution and selectivity of the stationary phase were evaluated in both hydrophobic interaction and ion exchange modes with standard proteins, respectively, which can be comparable to that of conventional weak anion exchange and hydrophobic interaction chromatography columns. Therefore, the synthesized weak anion exchange/hydrophobic interaction dual-function mixed-mode chromatography column can be used to replace two corresponding conventional weak anion exchange and hydrophobic interaction chromatography columns to separate proteins. Based on this mixed-mode chromatography stationary phase, a new off-line two-dimensional liquid chromatography technology using only a single dual-function mixed-mode chromatography column was developed. Nine kinds of tested proteins can be separated completely using the developed method within 2.0 h.

Preparation of weak cation exchange packings for chromatographic separation of proteins using ``click chemistry''

Co-reporter:Kailou Zhao;Chao Song;Fei Wang ;Fan Yang

Journal of Separation Science 2012 Volume 35( Issue 8) pp:907-914

Publication Date(Web):

DOI:10.1002/jssc.201101097

“Click chemistry” is defined as a class of robust and selective chemical reactions affording high yields and is tolerant to a variety of solvents (including water), functional groups, and air. In this study, click chemistry was used as an effective strategy for coupling three alkyne-carboxylic acids onto the azide-silica to obtain three novel stationary phases of weak cation exchange chromatography, which were characterized with FTIR and elemental analysis. Six kinds of standard proteins, such as myoglobin, RNase A, RNase B, cytochrome C, α-chymotrypsin A, and lysozyme, were separated completely with the three novel weak cation exchange chromatography stationary phases. Compared with commercial weak cation exchange chromatography columns, the three kinds of novel weak cation exchange chromatography packings prepared by click chemistry approach have better resolution and selectivity. The mass recovery of more than 97% was obtained for all the tested proteins, and the bioactivity recovery of lysozyme on the prepared column was determined to be 96%. In addition, lysozyme was purified successfully from egg white with the novel weak cation exchange chromatography column by one step. The purity was more than 97% and a high specific activity was achieved to be 81 435 U/mg. The results illustrate the potential of click chemistry for preparing stationary phase for ion-exchange chromatography.

“Click chemistry” preparation of WCX packings for protein separation

Co-reporter:Kai Lou Zhao, Chao Song, Fei Wang, Quan Bai

Chinese Chemical Letters 2012 Volume 23(Issue 3) pp:305-308

Publication Date(Web):March 2012

DOI:10.1016/j.cclet.2012.01.010

Click chemistry was applied to immobilize three kinds of alkyne-carboxylic acids onto azide-modified silica gel to prepare three novel stationary phases for weak cation exchange chromatography (WCX). The developed protocol combines the benefits of operational simplicity, exceptionally mild conditions and high surface loadings. Six kinds of standard proteins were separated completely on the novel packings. Compared with commercial WCX columns, the three kinds of novel WCX packings prepared by click chemistry approach have better resolution and selectivity. Lysozyme was purified successfully from egg white with the novel WCX column by one step. The purity was more than 97% and a high specific activity was achieved to be 81,435 U/mg. The results illustrate the potential of click chemistry for preparation of stationary phase for IEC.

Preparation of a novel dual-function strong cation exchange/hydrophobic interaction chromatography stationary phase for protein separation

Co-reporter:Kailou Zhao, Li Yang, Xuejiao Wang, Quan Bai, Fan Yang, Fei Wang

Talanta 2012 Volume 98() pp:86-94

Publication Date(Web):30 August 2012

DOI:10.1016/j.talanta.2012.06.050

We have explored a novel dual-function stationary phase which combines both strong cation exchange (SCX) and hydrophobic interaction chromatography (HIC) characteristics. The novel dual-function stationary phase is based on porous and spherical silica gel functionalized with ligand containing sulfonic and benzyl groups capable of electrostatic and hydrophobic interaction functionalities, which displays HIC character in a high salt concentration, and IEC character in a low salt concentration in mobile phase employed. As a result, it can be employed to separate proteins with SCX and HIC modes, respectively. The resolution and selectivity of the dual-function stationary phase were evaluated under both HIC and SCX modes with standard proteins and can be comparable to that of conventional IEC and HIC columns. More than 96% of mass and bioactivity recoveries of proteins can be achieved in both HIC and SCX modes, respectively. The results indicated that the novel dual-function column could replace two individual SCX and HIC columns for protein separation. Mixed retention mechanism of proteins on this dual-function column based on stoichiometric displacement theory (SDT) in LC was investigated to find the optimal balance of the magnitude of electrostatic and hydrophobic interactions between protein and the ligand on the silica surface in order to obtain high resolution and selectivity for protein separation. In addition, the effects of the hydrophobicity of the ligand of the dual-function packings and pH of the mobile phase used on protein separation were also investigated in detail. The results show that the ligand with suitable hydrophobicity to match the electrostatic interaction is very important to prepare the dual-function stationary phase, and a better resolution and selectivity can be obtained at pH 6.5 in SCX mode. Therefore, the dual-function column can replace two individual SCX and HIC columns for protein separation and be used to set up two-dimensional liquid chromatography with a single column (2DLC-1C), which can also be employed to separate three kinds of active proteins completely, such as lysozyme, ovotransferrin and ovalbumin from egg white. The result is very important not only to the development of new 2DLC technology with a single column for proteomics, but also to recombinant protein drug production for saving column expense and simplifying the process in biotechnology.Highlights► We explored a bifunctional column with ligand containing sulfonic and benzyl groups. ► This column can provide two operation modes (HIC and SCX). ► High resolution and selectivity are obtained in both SCX and HIC modes, respectively. ► This column can replace two corresponding single mode (SCX and HIC mode) columns. ► Based on this bifunctional column, 2DLC was established using only a single column.

Refolding of reduced/denatured bovine pancreatic insulin with ion-exchange chromatography coupled with MALDI-TOF MS

Co-reporter:Cui E. Lin, Quan Bai

Chinese Chemical Letters 2009 20(12) pp: 1487-1490

Publication Date(Web):

DOI:10.1016/j.cclet.2009.07.005

Preparation and characterization of monodisperse large-porous silica microspheres as the matrix for protein separation

Co-reporter:Hongjun Xia, Guangping Wan, Junlong Zhao, Jiawei Liu, Quan Bai

Journal of Chromatography A (4 November 2016) Volume 1471() pp:138-144

Publication Date(Web):4 November 2016

DOI:10.1016/j.chroma.2016.10.025

Preparation and characterization of monodisperse large-porous silica microspheres as the matrix for protein separation

Co-reporter:Hongjun Xia, Guangping Wan, Junlong Zhao, Jiawei Liu, Quan Bai

Journal of Chromatography A (4 November 2016) Volume 1471() pp:138-144

Publication Date(Web):4 November 2016

DOI:10.1016/j.chroma.2016.10.025

•The monodisperse silica was obtained with controllable morphology and structure.•The agglomeration could be overcome with TEPA as amination reagent.•The yield of 95.7% was achieved with high concentration of templates.•The synthesized silica can be used as an excellent matrix for protein separation.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-EDMA microspheres 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.

Preparation of polyhedral oligomeric silsesquioxane based cross-linked inorganic-organic nanohybrid as adsorbent for selective removal of acidic dyes from aqueous solution

Co-reporter:Jiawei Liu, Heng Yu, Qingmei Liang, Yanna Liu, Jiwei Shen, Quan Bai

Journal of Colloid and Interface Science (1 July 2017) Volume 497() pp:

Publication Date(Web):1 July 2017

DOI:10.1016/j.jcis.2017.03.028

A cross-linked polyhedral oligomeric silsesquioxane (POSS) nanohybrid is synthesized through Schiff base chemistry by using octa-amino POSS as building blocks and glutaraldehyde as dual functional reagent. The obtained nanohybrid is characterized by FT-IR, solid-state 29Si NMR, SEM, TEM, TGA and N2 adsorption-desorption isotherm, and the results demonstrate the successful cross-linkage between POSS molecules, forming block-like irregular nanoparticles with a specific surface area of 42.8 m2 g−1. As a novel solid-phase adsorbent, cross-linked POSS nanohybrid exhibits selective adsorption properties for acidic dyes, i.e., methyl orange (MO) in the present case. The strong electrostatic interactions between MO species and the nanohybrid are the main driving forces for MO adsorption. The kinetic data are well described by the pseudo-second-order kinetic model. The adsorption isotherm studies demonstrate that the data are well fit with Langmuir model at 293 K and a maximum adsorption capacity of 237.5 mg g−1 is obtained. Thermodynamic studies indicate that the adsorption of MO is spontaneous and exothermal, along with reduced randomness. The adsorbed MO species could be effectively recovered by using methanol/NaOH (9/1, v/v, 0.1 mol L−1 NaOH) as eluent. The practical application for textile wastewater treatment demonstrates that cross-linked POSS nanohybrid appears to be a promising material in dye removal field.Cross-linked polyhedral oligomeric silsesquioxane (POSS) nanohybrid is prepared by using octa-amino POSS as building blocks and glutaraldehyde as dual functional bridge, and further employed as a novel adsorbent for selective adsorption and removal of acidic dyes from aqueous solution.

Preparation of superficially porous core-shell silica particle with controllable mesopore by a dual-templating approach for fast HPLC of small molecules

Co-reporter:Hongjun Xia, Guangping Wan, Gang Chen, Quan Bai

Materials Letters (1 April 2017) Volume 192() pp:

Publication Date(Web):1 April 2017

DOI:10.1016/j.matlet.2017.01.055

•CSSMs were synthesized with a dual-templating approach for the first time.•The pore size of the CSSMs can be enlarged to 10.6 nm with the addition of TOMAB.•The mesopore channels of the CSSMs are perpendicular to the particles surface.•The synthesized CSSMs can be used in fast separation of small molecules.A novel strategy to synthesize the monodisperse superficially porous core-shell silica microspheres (CSSMs) with enlarged mesopore channels perpendicular to the particles surface using a dual-templating approach was presented for the first time. With hexadecyl trimethyl ammonium bromide (CTAB) as the template and trioctylmethylammonium bromide (TOMAB) as an auxiliary chemical to enlarge the size of CTAB micelles, the pore size can be enlarged from 2.6 nm to 10.6 nm, the mesopore channels perpendicular to the surface of CSSMs can be obtained. The particles synthesized in this work have a uniform mesoporous shell of about 198.3 nm in thickness over the silica core and possess a surface area of ca. 85.1 m2/g, and narrow pore size distribution. This preparation method is highly versatile, controllable and easy to operate. The CSSMs obtained were modified with octadecyltrichlorosilane (ODS) to separate the alkyl benzene homologues. The higher efficient separation with fast flow rate and relatively low back pressure of the synthesized column demonstrate that the CSSMs have a great potential application for fast separation and analysis of small solutes with high performance liquid chromatography (HPLC).