The Experts below are selected from a list of 41757 Experts worldwide ranked by ideXlab platform
Hanfa Zou - One of the best experts on this subject based on the ideXlab platform.
-
recent development of hybrid Organic Silica monolithic columns in cec and capillary lc
Electrophoresis, 2015Co-Authors: Hui Lin, Jing Dong, Zhongshan Liu, Hongwei Wang, Hanfa ZouAbstract:As an attractive alternative to Organic and Silica monoliths, hybrid Organic–inOrganic monolith somewhat combines the advantages of them, such as high surface area, excellent mechanical strength, and thermal stability. We have reviewed the preparation and application of hybrid monoliths in 2011 and 2013. The preparation approaches have been mainly summarized into three categories: (1) common sol–gel process using trialkoxysilanes and tetraalkoxysilanes as precursors; (2) “one-pot” process of alkoxysilanes and Organic monomers simultaneously via sol–gel chemistry and free radical polymerization; and (3) other polymerization of silane-containing monomers. Herein, we would focus on the recent progress and development of preparation approaches, mainly covering the literatures since July of 2012. First, the direct synthesis approach of hybrid monoliths via sol–gel chemistry and following postmodification was an important route to fabricate various monolithic stationary phases, particularly, to modify the hybrid monoliths containing amino, epoxy, vinyl, and other groups. Second, “one-pot” process, as a novel preparation approach of hybrid monoliths, was further developed in the past 2 years, in which various Organic functional monomers, not only water-soluble monomers, but also hydrophobic monomers could be added in the preparation system. Other polymerization techniques in the preparation of Organic monolithic materials, particularly, free radical polymerization and ring-opening polymerization, were successfully transferred to fabricate the hybrid monoliths by using silane-containing monomers including POSS monomers or other self-synthesized monomers.
-
recent advances in preparation and application of hybrid Organic Silica monolithic capillary columns
Electrophoresis, 2013Co-Authors: Zhenbin Zhang, Jing Dong, Hui Lin, Guang Huang, Hanfa ZouAbstract:Hybrid Organic-Silica monolithic columns, regarded as a second generation of Silica-based monoliths, have received much interest due to their unique properties over the pure Silica-based monoliths. This review mainly focuses on development in the fields of preparation of hybrid monolithic columns in a capillary and their application for CEC and capillary liquid chromatography separation, as well as for sample pretreatment of solid-phase microextraction and immobilized enzyme reactor since July 2010. The preparation approaches are comprehensively summarized with three routes: (i) general solgel process using trialkoxysilanes and tetraalkoxysilanes as coprecursors; (ii) one-pot process of alkoxysilanes and Organic monomers concomitantly proceeding solgel chemistry and free radical polymerization; and (iii) other polymerization approaches of Organic monomers containing silanes. The modification of hybrid monoliths containing reactive groups to acquire the desired surface functionality is also described.
-
facile preparation of zwitterionic Organic Silica hybrid monolithic capillary column with an improved one pot approach for hydrophilic interaction liquid chromatography hilic
Analytical Chemistry, 2012Co-Authors: Hui Lin, Zhenbin Zhang, Jing Dong, Hanfa ZouAbstract:A simple single-step thermal-treatment "one-pot" approach for the preparation of Organic-Silica hybrid capillary monolithic columns is described. In this improved method, the cross-linker vinyltrimethoxysilane (VTMS) was replaced by 3-methacryloxypropyltrimethoxysilane (γ-MAPS), which is more active in polymerization reactions, and only one thermal treatment step was required in the preparation of hybrid monoliths. Two zwitterionic Organic-Silica monolithic columns were successfully synthesized by using [2-(methacryloyloxy)ethyl]dimethyl-(3-sulfopropyl)ammonium hydroxide (MSA) and 2-methacryloyloxyethyl phosphorylcholine (MPC) as the Organic monomers. The effects of the tetramethoxysilane (TMOS)/γ-MAPS molar ratio, content of monomer, composition of porogenic solvent, and reaction temperature on the morphologies of the hybrid monoliths were investigated. The MSA-Silica and MPC-Silica hybrid monolithic columns exhibited good permeability and good mechanical stability. The monolithic columns were used for the separation of polar compounds by capillary hydrophilic-interaction chromatography (cHILIC). A typical HILIC retention mechanism was observed at higher Organic solvent contents (>50% ACN). The MSA monoliths were further investigated in the separation of various neutral, basic, and acidic analytes, as well as small peptides, by capillary liquid chromatography (cLC), and high efficiency and satisfactory reproducibility were achieved. In addition, the analysis of a tryptic digest of bovine serum albumin (BSA) by cLC tandem mass spectrometry (cLC-MS/MS) with an MSA monolith further demonstrated its potential in the separation of biological samples.
-
preparation and application of Organic Silica hybrid monolithic capillary columns
ChemInform, 2011Co-Authors: Zhenbin Zhang, Hanfa ZouAbstract:Organic-Silica hybrid monolithic columns have drawn more and more attention due to the ease of preparation and good mechanical stability in recent years. Many synthetic approaches have been developed and a variety of hybrid monolithic capillary columns have been prepared. The sol-gel process is well recognized in the fabrication of hybrid monolithic columns, which can be mainly classified as one-step, acid/base two-step procedures. The new approaches such as the " one-pot'' and nano-scaled inOrganic-Organic hybrid reagent of polyhedral oligomeric silsesquioxane used as a cross-linker have also emerged for the preparation of hybrid monolithic columns. The applications of the Organic-Silica hybrid monolithic capillary columns for capillary electrochromatography, micro high-performance liquid chromatography, solid-phase microextraction and enzymatic reactor etc. are included in this review.
-
one pot process for fabrication of Organic Silica hybrid monolithic capillary columns using Organic monomer and alkoxysilane
Analytical Chemistry, 2009Co-Authors: Fangju Wang, Jing Dong, Zhe Liu, Hanfa ZouAbstract:A “one-pot” process for the preparation of Organic-Silica hybrid capillary monolithic columns by concurrently using Organic monomers and alkoxysilanes was described. In this process, the hydrolyzed alkoxysilanes of tetramethoxysilane (TMOS) and vinyltrimethoxysilane (VTMS) as precursors for the synthesis of a Silica-based monolith using the sol−gel method and the Organic monomer (allyldimethyldodecylammonium bromide (ADDAB) or acrylamide (AA)) with vinyl groups for free radical polymerization along with the initiator of azobisisobutyronitrile (AIBN) were concurrently introduced into a pretreated capillary; after that, the polycondensation of alkoxysilanes and the copolymerization of Organic monomers and as-precondensed siloxanes were subsequently carried out within the confines of a capillary at the proper reaction conditions. Two types of Organic-Silica hybrid capillary monolithic columns with hydrophobic and hydrophilic properties have been fabricated, respectively, by this “one-pot” process using two d...
Jing Dong - One of the best experts on this subject based on the ideXlab platform.
-
recent development of hybrid Organic Silica monolithic columns in cec and capillary lc
Electrophoresis, 2015Co-Authors: Hui Lin, Jing Dong, Zhongshan Liu, Hongwei Wang, Hanfa ZouAbstract:As an attractive alternative to Organic and Silica monoliths, hybrid Organic–inOrganic monolith somewhat combines the advantages of them, such as high surface area, excellent mechanical strength, and thermal stability. We have reviewed the preparation and application of hybrid monoliths in 2011 and 2013. The preparation approaches have been mainly summarized into three categories: (1) common sol–gel process using trialkoxysilanes and tetraalkoxysilanes as precursors; (2) “one-pot” process of alkoxysilanes and Organic monomers simultaneously via sol–gel chemistry and free radical polymerization; and (3) other polymerization of silane-containing monomers. Herein, we would focus on the recent progress and development of preparation approaches, mainly covering the literatures since July of 2012. First, the direct synthesis approach of hybrid monoliths via sol–gel chemistry and following postmodification was an important route to fabricate various monolithic stationary phases, particularly, to modify the hybrid monoliths containing amino, epoxy, vinyl, and other groups. Second, “one-pot” process, as a novel preparation approach of hybrid monoliths, was further developed in the past 2 years, in which various Organic functional monomers, not only water-soluble monomers, but also hydrophobic monomers could be added in the preparation system. Other polymerization techniques in the preparation of Organic monolithic materials, particularly, free radical polymerization and ring-opening polymerization, were successfully transferred to fabricate the hybrid monoliths by using silane-containing monomers including POSS monomers or other self-synthesized monomers.
-
recent advances in preparation and application of hybrid Organic Silica monolithic capillary columns
Electrophoresis, 2013Co-Authors: Zhenbin Zhang, Jing Dong, Hui Lin, Guang Huang, Hanfa ZouAbstract:Hybrid Organic-Silica monolithic columns, regarded as a second generation of Silica-based monoliths, have received much interest due to their unique properties over the pure Silica-based monoliths. This review mainly focuses on development in the fields of preparation of hybrid monolithic columns in a capillary and their application for CEC and capillary liquid chromatography separation, as well as for sample pretreatment of solid-phase microextraction and immobilized enzyme reactor since July 2010. The preparation approaches are comprehensively summarized with three routes: (i) general solgel process using trialkoxysilanes and tetraalkoxysilanes as coprecursors; (ii) one-pot process of alkoxysilanes and Organic monomers concomitantly proceeding solgel chemistry and free radical polymerization; and (iii) other polymerization approaches of Organic monomers containing silanes. The modification of hybrid monoliths containing reactive groups to acquire the desired surface functionality is also described.
-
facile preparation of zwitterionic Organic Silica hybrid monolithic capillary column with an improved one pot approach for hydrophilic interaction liquid chromatography hilic
Analytical Chemistry, 2012Co-Authors: Junjie Ou, Jing Dong, Zhenbin Zhang, Minghuo WuAbstract:A simple single-step thermal-treatment “one-pot” approach for the preparation of Organic-Silica hybrid capillary monolithic columns is described. In this improved method, the cross-linker vinyltrimethoxysilane (VTMS) was replaced by 3-methacryloxypropyltrimethoxysilane (γ-MAPS), which is more active in polymerization reactions, and only one thermal treatment step was required in the preparation of hybrid monoliths. Two zwitterionic Organic-Silica monolithic columns were successfully synthesized by using [2-(methacryloyloxy)ethyl]dimethyl-(3-sulfopropyl)ammonium hydroxide (MSA) and 2-methacryloyloxyethyl phosphorylcholine (MPC) as the Organic monomers. The effects of the tetramethoxysilane (TMOS)/γ-MAPS molar ratio, content of monomer, composition of porogenic solvent, and reaction temperature on the morphologies of the hybrid monoliths were investigated. The MSA-Silica and MPC-Silica hybrid monolithic columns exhibited good permeability and good mechanical stability. The monolithic columns were used for t...
-
facile preparation of zwitterionic Organic Silica hybrid monolithic capillary column with an improved one pot approach for hydrophilic interaction liquid chromatography hilic
Analytical Chemistry, 2012Co-Authors: Hui Lin, Zhenbin Zhang, Jing Dong, Hanfa ZouAbstract:A simple single-step thermal-treatment "one-pot" approach for the preparation of Organic-Silica hybrid capillary monolithic columns is described. In this improved method, the cross-linker vinyltrimethoxysilane (VTMS) was replaced by 3-methacryloxypropyltrimethoxysilane (γ-MAPS), which is more active in polymerization reactions, and only one thermal treatment step was required in the preparation of hybrid monoliths. Two zwitterionic Organic-Silica monolithic columns were successfully synthesized by using [2-(methacryloyloxy)ethyl]dimethyl-(3-sulfopropyl)ammonium hydroxide (MSA) and 2-methacryloyloxyethyl phosphorylcholine (MPC) as the Organic monomers. The effects of the tetramethoxysilane (TMOS)/γ-MAPS molar ratio, content of monomer, composition of porogenic solvent, and reaction temperature on the morphologies of the hybrid monoliths were investigated. The MSA-Silica and MPC-Silica hybrid monolithic columns exhibited good permeability and good mechanical stability. The monolithic columns were used for the separation of polar compounds by capillary hydrophilic-interaction chromatography (cHILIC). A typical HILIC retention mechanism was observed at higher Organic solvent contents (>50% ACN). The MSA monoliths were further investigated in the separation of various neutral, basic, and acidic analytes, as well as small peptides, by capillary liquid chromatography (cLC), and high efficiency and satisfactory reproducibility were achieved. In addition, the analysis of a tryptic digest of bovine serum albumin (BSA) by cLC tandem mass spectrometry (cLC-MS/MS) with an MSA monolith further demonstrated its potential in the separation of biological samples.
-
one pot process for fabrication of Organic Silica hybrid monolithic capillary columns using Organic monomer and alkoxysilane
Analytical Chemistry, 2009Co-Authors: Fangju Wang, Jing Dong, Zhe Liu, Hanfa ZouAbstract:A “one-pot” process for the preparation of Organic-Silica hybrid capillary monolithic columns by concurrently using Organic monomers and alkoxysilanes was described. In this process, the hydrolyzed alkoxysilanes of tetramethoxysilane (TMOS) and vinyltrimethoxysilane (VTMS) as precursors for the synthesis of a Silica-based monolith using the sol−gel method and the Organic monomer (allyldimethyldodecylammonium bromide (ADDAB) or acrylamide (AA)) with vinyl groups for free radical polymerization along with the initiator of azobisisobutyronitrile (AIBN) were concurrently introduced into a pretreated capillary; after that, the polycondensation of alkoxysilanes and the copolymerization of Organic monomers and as-precondensed siloxanes were subsequently carried out within the confines of a capillary at the proper reaction conditions. Two types of Organic-Silica hybrid capillary monolithic columns with hydrophobic and hydrophilic properties have been fabricated, respectively, by this “one-pot” process using two d...
Zhenbin Zhang - One of the best experts on this subject based on the ideXlab platform.
-
recent advances in preparation and application of hybrid Organic Silica monolithic capillary columns
Electrophoresis, 2013Co-Authors: Zhenbin Zhang, Jing Dong, Hui Lin, Guang Huang, Hanfa ZouAbstract:Hybrid Organic-Silica monolithic columns, regarded as a second generation of Silica-based monoliths, have received much interest due to their unique properties over the pure Silica-based monoliths. This review mainly focuses on development in the fields of preparation of hybrid monolithic columns in a capillary and their application for CEC and capillary liquid chromatography separation, as well as for sample pretreatment of solid-phase microextraction and immobilized enzyme reactor since July 2010. The preparation approaches are comprehensively summarized with three routes: (i) general solgel process using trialkoxysilanes and tetraalkoxysilanes as coprecursors; (ii) one-pot process of alkoxysilanes and Organic monomers concomitantly proceeding solgel chemistry and free radical polymerization; and (iii) other polymerization approaches of Organic monomers containing silanes. The modification of hybrid monoliths containing reactive groups to acquire the desired surface functionality is also described.
-
facile preparation of zwitterionic Organic Silica hybrid monolithic capillary column with an improved one pot approach for hydrophilic interaction liquid chromatography hilic
Analytical Chemistry, 2012Co-Authors: Junjie Ou, Jing Dong, Zhenbin Zhang, Minghuo WuAbstract:A simple single-step thermal-treatment “one-pot” approach for the preparation of Organic-Silica hybrid capillary monolithic columns is described. In this improved method, the cross-linker vinyltrimethoxysilane (VTMS) was replaced by 3-methacryloxypropyltrimethoxysilane (γ-MAPS), which is more active in polymerization reactions, and only one thermal treatment step was required in the preparation of hybrid monoliths. Two zwitterionic Organic-Silica monolithic columns were successfully synthesized by using [2-(methacryloyloxy)ethyl]dimethyl-(3-sulfopropyl)ammonium hydroxide (MSA) and 2-methacryloyloxyethyl phosphorylcholine (MPC) as the Organic monomers. The effects of the tetramethoxysilane (TMOS)/γ-MAPS molar ratio, content of monomer, composition of porogenic solvent, and reaction temperature on the morphologies of the hybrid monoliths were investigated. The MSA-Silica and MPC-Silica hybrid monolithic columns exhibited good permeability and good mechanical stability. The monolithic columns were used for t...
-
facile preparation of zwitterionic Organic Silica hybrid monolithic capillary column with an improved one pot approach for hydrophilic interaction liquid chromatography hilic
Analytical Chemistry, 2012Co-Authors: Hui Lin, Zhenbin Zhang, Jing Dong, Hanfa ZouAbstract:A simple single-step thermal-treatment "one-pot" approach for the preparation of Organic-Silica hybrid capillary monolithic columns is described. In this improved method, the cross-linker vinyltrimethoxysilane (VTMS) was replaced by 3-methacryloxypropyltrimethoxysilane (γ-MAPS), which is more active in polymerization reactions, and only one thermal treatment step was required in the preparation of hybrid monoliths. Two zwitterionic Organic-Silica monolithic columns were successfully synthesized by using [2-(methacryloyloxy)ethyl]dimethyl-(3-sulfopropyl)ammonium hydroxide (MSA) and 2-methacryloyloxyethyl phosphorylcholine (MPC) as the Organic monomers. The effects of the tetramethoxysilane (TMOS)/γ-MAPS molar ratio, content of monomer, composition of porogenic solvent, and reaction temperature on the morphologies of the hybrid monoliths were investigated. The MSA-Silica and MPC-Silica hybrid monolithic columns exhibited good permeability and good mechanical stability. The monolithic columns were used for the separation of polar compounds by capillary hydrophilic-interaction chromatography (cHILIC). A typical HILIC retention mechanism was observed at higher Organic solvent contents (>50% ACN). The MSA monoliths were further investigated in the separation of various neutral, basic, and acidic analytes, as well as small peptides, by capillary liquid chromatography (cLC), and high efficiency and satisfactory reproducibility were achieved. In addition, the analysis of a tryptic digest of bovine serum albumin (BSA) by cLC tandem mass spectrometry (cLC-MS/MS) with an MSA monolith further demonstrated its potential in the separation of biological samples.
-
preparation and application of Organic Silica hybrid monolithic capillary columns
ChemInform, 2011Co-Authors: Zhenbin Zhang, Hanfa ZouAbstract:Organic-Silica hybrid monolithic columns have drawn more and more attention due to the ease of preparation and good mechanical stability in recent years. Many synthetic approaches have been developed and a variety of hybrid monolithic capillary columns have been prepared. The sol-gel process is well recognized in the fabrication of hybrid monolithic columns, which can be mainly classified as one-step, acid/base two-step procedures. The new approaches such as the " one-pot'' and nano-scaled inOrganic-Organic hybrid reagent of polyhedral oligomeric silsesquioxane used as a cross-linker have also emerged for the preparation of hybrid monolithic columns. The applications of the Organic-Silica hybrid monolithic capillary columns for capillary electrochromatography, micro high-performance liquid chromatography, solid-phase microextraction and enzymatic reactor etc. are included in this review.
Yuqi Feng - One of the best experts on this subject based on the ideXlab platform.
-
profiling of cis diol containing nucleosides and ribosylated metabolites by boronate affinity Organic Silica hybrid monolithic capillary liquid chromatography mass spectrometry
Scientific Reports, 2015Co-Authors: Hanpeng Jiang, Bifeng Yuan, Chubo Qi, Yuqi FengAbstract:RNA contains a large number of modified nucleosides. In the metabolic re-exchange of RNA, modified nucleosides cannot be recycled and are thus excreted from cells into biological fluids. Determination of endogenous modified nucleosides in biological fluids may serve as non-invasive cancers diagnostic methods. Here we prepared boronate-affinity Organic-Silica hybrid capillary monolithic column (BOHCMC) that exhibited excellent selectivity toward the cis-diol-containing compounds. We then used the prepared BOHCMC as the on-line solid-phase microextraction (SPME) column and developed an on-line SPME-LC-MS/MS method to comprehensively profile cis-diol-containing nucleosides and ribosylated metabolites in human urine. Forty-five cis-diol-containing nucleosides and ribosylated metabolites were successfully identified in human urine. And five ribose conjugates, for the first time, were identified existence in human urine in the current study. Furthermore, the relative quantification suggested 4 cis-diol-containing compounds (5′-deoxy-5′-methylthioadensine, N4-acetylcytidine, 1-ribosyl-N-propionylhistamine and N2,N2,7-trimethylguanosine) increased more than 1.5 folds in all the 3 types of examined cancers (lung cancer, colorectal cancer, and nasopharyngeal cancer) compared to healthy controls. The on-line SPME-LC-MS/MS method demonstrates a promising method for the comprehensive profiling of cis-diol-containing ribose conjugates in human urines, which provides an efficient strategy for the identification and discovery of biomarkers and may be used for the screening of cancers.
-
facile preparation of Organic Silica hybrid monolith for capillary hydrophilic liquid chromatography based on thiol ene click chemistry
Journal of Chromatography A, 2013Co-Authors: Mingluan Chen, Jun Zhang, Zheng Zhang, Bifeng Yuan, Qiongwei Yu, Yuqi FengAbstract:Abstract In this work, a one-step approach to facile preparation of Organic–inOrganic hybrid monoliths was successfully developed. After vinyl-end Organic monomers and azobisisobutyronitrile (AIBN) were mixed with hydrolyzed tetramethoxysilane (TMOS) and 3-mercaptopropyltrimethoxysilane (MPTMS), the homogeneous mixture was introduced into a fused-Silica capillary for simultaneous polycondensation and “thiol-ene” click reaction to form the Organic-Silica hybrid monoliths. By employing this strategy, two types of Organic-Silica hybrid monoliths with positively charged quaternary ammonium and amide groups were prepared, respectively. The functional groups were successfully introduced onto the monoliths during the sol–gel process with “thiol-ene” click reaction, which was demonstrated by ζ-potential assessment, energy dispersive X-ray spectroscopy (EDX), and Fourier transform infrared (FT-IR) spectroscopy. The porous structure of the prepared monolithic columns was examined by scanning electron microscopy (SEM), nitrogen adsorption–desorption measurement, and mercury intrusion porosimetry. These results indicate the prepared Organic-Silica hybrid monoliths possess homogeneous column bed, large specific surface area, good mechanical stability, and excellent permeability. The prepared monolithic columns were then applied for anion-exchange/hydrophilic interaction liquid chromatography. Different types of analytes, including benzoic acids, inOrganic ions, nucleosides, and nucleotides, were well separated with high column efficiency around 80,000–130,000 plates/m. Taken together, we present a facile and universal strategy to prepare Organic-Silica hybrid monoliths with a variety of Organic monomers using one-step approach.
Hui Lin - One of the best experts on this subject based on the ideXlab platform.
-
recent development of hybrid Organic Silica monolithic columns in cec and capillary lc
Electrophoresis, 2015Co-Authors: Hui Lin, Jing Dong, Zhongshan Liu, Hongwei Wang, Hanfa ZouAbstract:As an attractive alternative to Organic and Silica monoliths, hybrid Organic–inOrganic monolith somewhat combines the advantages of them, such as high surface area, excellent mechanical strength, and thermal stability. We have reviewed the preparation and application of hybrid monoliths in 2011 and 2013. The preparation approaches have been mainly summarized into three categories: (1) common sol–gel process using trialkoxysilanes and tetraalkoxysilanes as precursors; (2) “one-pot” process of alkoxysilanes and Organic monomers simultaneously via sol–gel chemistry and free radical polymerization; and (3) other polymerization of silane-containing monomers. Herein, we would focus on the recent progress and development of preparation approaches, mainly covering the literatures since July of 2012. First, the direct synthesis approach of hybrid monoliths via sol–gel chemistry and following postmodification was an important route to fabricate various monolithic stationary phases, particularly, to modify the hybrid monoliths containing amino, epoxy, vinyl, and other groups. Second, “one-pot” process, as a novel preparation approach of hybrid monoliths, was further developed in the past 2 years, in which various Organic functional monomers, not only water-soluble monomers, but also hydrophobic monomers could be added in the preparation system. Other polymerization techniques in the preparation of Organic monolithic materials, particularly, free radical polymerization and ring-opening polymerization, were successfully transferred to fabricate the hybrid monoliths by using silane-containing monomers including POSS monomers or other self-synthesized monomers.
-
recent advances in preparation and application of hybrid Organic Silica monolithic capillary columns
Electrophoresis, 2013Co-Authors: Zhenbin Zhang, Jing Dong, Hui Lin, Guang Huang, Hanfa ZouAbstract:Hybrid Organic-Silica monolithic columns, regarded as a second generation of Silica-based monoliths, have received much interest due to their unique properties over the pure Silica-based monoliths. This review mainly focuses on development in the fields of preparation of hybrid monolithic columns in a capillary and their application for CEC and capillary liquid chromatography separation, as well as for sample pretreatment of solid-phase microextraction and immobilized enzyme reactor since July 2010. The preparation approaches are comprehensively summarized with three routes: (i) general solgel process using trialkoxysilanes and tetraalkoxysilanes as coprecursors; (ii) one-pot process of alkoxysilanes and Organic monomers concomitantly proceeding solgel chemistry and free radical polymerization; and (iii) other polymerization approaches of Organic monomers containing silanes. The modification of hybrid monoliths containing reactive groups to acquire the desired surface functionality is also described.
-
facile preparation of zwitterionic Organic Silica hybrid monolithic capillary column with an improved one pot approach for hydrophilic interaction liquid chromatography hilic
Analytical Chemistry, 2012Co-Authors: Hui Lin, Zhenbin Zhang, Jing Dong, Hanfa ZouAbstract:A simple single-step thermal-treatment "one-pot" approach for the preparation of Organic-Silica hybrid capillary monolithic columns is described. In this improved method, the cross-linker vinyltrimethoxysilane (VTMS) was replaced by 3-methacryloxypropyltrimethoxysilane (γ-MAPS), which is more active in polymerization reactions, and only one thermal treatment step was required in the preparation of hybrid monoliths. Two zwitterionic Organic-Silica monolithic columns were successfully synthesized by using [2-(methacryloyloxy)ethyl]dimethyl-(3-sulfopropyl)ammonium hydroxide (MSA) and 2-methacryloyloxyethyl phosphorylcholine (MPC) as the Organic monomers. The effects of the tetramethoxysilane (TMOS)/γ-MAPS molar ratio, content of monomer, composition of porogenic solvent, and reaction temperature on the morphologies of the hybrid monoliths were investigated. The MSA-Silica and MPC-Silica hybrid monolithic columns exhibited good permeability and good mechanical stability. The monolithic columns were used for the separation of polar compounds by capillary hydrophilic-interaction chromatography (cHILIC). A typical HILIC retention mechanism was observed at higher Organic solvent contents (>50% ACN). The MSA monoliths were further investigated in the separation of various neutral, basic, and acidic analytes, as well as small peptides, by capillary liquid chromatography (cLC), and high efficiency and satisfactory reproducibility were achieved. In addition, the analysis of a tryptic digest of bovine serum albumin (BSA) by cLC tandem mass spectrometry (cLC-MS/MS) with an MSA monolith further demonstrated its potential in the separation of biological samples.