Three chiral stationary phases（CSPl, CSP2 and CSP3） for ligand-exchange chromatography were prepared by firstly using dimethylchlorosilane as an endcapping reagent for decreasing residual silanol groups on the surfa...Three chiral stationary phases（CSPl, CSP2 and CSP3） for ligand-exchange chromatography were prepared by firstly using dimethylchlorosilane as an endcapping reagent for decreasing residual silanol groups on the surface of silica gel, and then modifying the surface of silica gel with allyl glycidyl ether and alkenes through the hydrosilation reaction, and lastly introducing L-proline as a chiral selector. The enantiomer resolutions of 14 amino acids and 2 hydroxyl acids were completed on the CSPs by using an aqueous solution of Cu（Ac）2 as mobile phase at a flow rate of 1.0 mL/min and column temperature of 40 ℃ with detection at UV 254 nm. In terms of enantioseleetivity a, column efficiency and resolution Rs, the chromatographic behaviors of the analytes on the CSPs were discussed via comparing them to those on the CSP4 prepared via the reference method. The results show that enantioselectivity a, column efficiency and resolution Rs of the analytes on the CSPs could be improved by using the above modifying method.展开更多
Click chemistry was applied to immobilize L-proline derivative onto azide-modified silica gel to give a novel chiral stationary phase （denoted as click-CSP） for ligand exchange chromatography. The developed protocol...Click chemistry was applied to immobilize L-proline derivative onto azide-modified silica gel to give a novel chiral stationary phase （denoted as click-CSP） for ligand exchange chromatography. The developed protocol combines the benefits of operational simplicity, exceptionally mild conditions and high surface loadings. The enantioselectivity α of some DL-arnino acids on the click- CSP were found to be in the range from 1.13 to 3.46. The chromatographic resolutions of some DL-amino acids and the stability study firmly illustrate the potential of click chemistry for preparation chiral stationary phase for ligand exchange chromatography.展开更多
Three new hybrid organic/inorganic polymeric ligand-exchange chiral stationary phases were developed by radical chain transfer reaction and surface grafting on silica gel, and successfully used for the enantioseparati...Three new hybrid organic/inorganic polymeric ligand-exchange chiral stationary phases were developed by radical chain transfer reaction and surface grafting on silica gel, and successfully used for the enantioseparations of DL-amino acids and DL-hydroxyl adds. The resolutions were achieved by using water containing 2.0 × 10^-4 mol/L of CuAc2 as a mobile phase, column temperature of 40 ℃, flow rate of 1.0 mL/min and detection at UV 254 nm. The elution order of D-isomer before L-isomer was observed for all DL-amino acids resolved except DL-Pro.展开更多
A novel chiral stationary phase （CSP1） for ligand-exchange chromatography （CLEC） was prepared by firstly using dimethylchlorosilane as an endcapping reagent for decreasing residual silanol group on the surface of ...A novel chiral stationary phase （CSP1） for ligand-exchange chromatography （CLEC） was prepared by firstly using dimethylchlorosilane as an endcapping reagent for decreasing residual silanol group on the surface of silica gel, and then introducing L-Pro as a chiral selector and hydrophobic octyl group to the silica gel surface simultaneously. The enantioseparations of 14 DL-amino acids on CSP1 were achieved with the enantioselectivity α ranging from 1.09 to 2.44 and the resolution Rs being between 0.8 and 6.3. The chromatographic performances of CSP1 with the bonded phase （CSP2） prepared using reference method were compared. The results showed that the column efficiency and resolution Rs of chiral stationary phase could be improved by using the above modifying method.展开更多
Excellent resolution of racemic 2-phenyl-1,1-cyclopropanedicarbonitrile and its nine analogues was accomplished using 100-5CH1-TBB chiral stationary phase under normal-phase HPLC conditions. The influence of mobile ph...Excellent resolution of racemic 2-phenyl-1,1-cyclopropanedicarbonitrile and its nine analogues was accomplished using 100-5CH1-TBB chiral stationary phase under normal-phase HPLC conditions. The influence of mobile phase and the optimum conditions for the resolution of optically active enantiomers were investigated.展开更多
A novel chiral bonded stationary phase(CBSP) for ligand exchange chromatography was prepared by bonding ( S ) 1,2,3,4 tetrahydro 3 isoquinoline carboxylic acid prepared from L Phe to YWG 80 silica gel via 3 glycidylox...A novel chiral bonded stationary phase(CBSP) for ligand exchange chromatography was prepared by bonding ( S ) 1,2,3,4 tetrahydro 3 isoquinoline carboxylic acid prepared from L Phe to YWG 80 silica gel via 3 glycidyloxypropyltrimethoxysilane as a coupling agent. Chromatographic resolutions of some DL amino acids were achieved on the CBSP by using an aqueous solution of 2 mmol/L N(C 2H 5) 3, 2 mmol/L HAc and 0 2 mmol/L Cu(Ac) 2 as the mobile phase with a flow rate 1 0 mL/min, column temperature 50 ℃ and detection at 254 nm. The enantioselectivity α of the DL amino acids on the CBSP was found to be between 1 11 and 1 51. The elution order of D isomer before L isomer on the CBSP was observed for all the DL amino acids resolved except DL Val. For DL Pro, DL Val and DL Leu the elution order through the CBSP was different from that through the chiral ligand exchange phases prepared from L Pro or L hydroxyl proline with a five\|membered ring structure. [WT5HZ]展开更多
文摘Three chiral stationary phases（CSPl, CSP2 and CSP3） for ligand-exchange chromatography were prepared by firstly using dimethylchlorosilane as an endcapping reagent for decreasing residual silanol groups on the surface of silica gel, and then modifying the surface of silica gel with allyl glycidyl ether and alkenes through the hydrosilation reaction, and lastly introducing L-proline as a chiral selector. The enantiomer resolutions of 14 amino acids and 2 hydroxyl acids were completed on the CSPs by using an aqueous solution of Cu（Ac）2 as mobile phase at a flow rate of 1.0 mL/min and column temperature of 40 ℃ with detection at UV 254 nm. In terms of enantioseleetivity a, column efficiency and resolution Rs, the chromatographic behaviors of the analytes on the CSPs were discussed via comparing them to those on the CSP4 prepared via the reference method. The results show that enantioselectivity a, column efficiency and resolution Rs of the analytes on the CSPs could be improved by using the above modifying method.
文摘Click chemistry was applied to immobilize L-proline derivative onto azide-modified silica gel to give a novel chiral stationary phase （denoted as click-CSP） for ligand exchange chromatography. The developed protocol combines the benefits of operational simplicity, exceptionally mild conditions and high surface loadings. The enantioselectivity α of some DL-arnino acids on the click- CSP were found to be in the range from 1.13 to 3.46. The chromatographic resolutions of some DL-amino acids and the stability study firmly illustrate the potential of click chemistry for preparation chiral stationary phase for ligand exchange chromatography.
文摘Three new hybrid organic/inorganic polymeric ligand-exchange chiral stationary phases were developed by radical chain transfer reaction and surface grafting on silica gel, and successfully used for the enantioseparations of DL-amino acids and DL-hydroxyl adds. The resolutions were achieved by using water containing 2.0 × 10^-4 mol/L of CuAc2 as a mobile phase, column temperature of 40 ℃, flow rate of 1.0 mL/min and detection at UV 254 nm. The elution order of D-isomer before L-isomer was observed for all DL-amino acids resolved except DL-Pro.
文摘A novel chiral stationary phase （CSP1） for ligand-exchange chromatography （CLEC） was prepared by firstly using dimethylchlorosilane as an endcapping reagent for decreasing residual silanol group on the surface of silica gel, and then introducing L-Pro as a chiral selector and hydrophobic octyl group to the silica gel surface simultaneously. The enantioseparations of 14 DL-amino acids on CSP1 were achieved with the enantioselectivity α ranging from 1.09 to 2.44 and the resolution Rs being between 0.8 and 6.3. The chromatographic performances of CSP1 with the bonded phase （CSP2） prepared using reference method were compared. The results showed that the column efficiency and resolution Rs of chiral stationary phase could be improved by using the above modifying method.
文摘Excellent resolution of racemic 2-phenyl-1,1-cyclopropanedicarbonitrile and its nine analogues was accomplished using 100-5CH1-TBB chiral stationary phase under normal-phase HPLC conditions. The influence of mobile phase and the optimum conditions for the resolution of optically active enantiomers were investigated.
文摘A novel chiral bonded stationary phase(CBSP) for ligand exchange chromatography was prepared by bonding ( S ) 1,2,3,4 tetrahydro 3 isoquinoline carboxylic acid prepared from L Phe to YWG 80 silica gel via 3 glycidyloxypropyltrimethoxysilane as a coupling agent. Chromatographic resolutions of some DL amino acids were achieved on the CBSP by using an aqueous solution of 2 mmol/L N(C 2H 5) 3, 2 mmol/L HAc and 0 2 mmol/L Cu(Ac) 2 as the mobile phase with a flow rate 1 0 mL/min, column temperature 50 ℃ and detection at 254 nm. The enantioselectivity α of the DL amino acids on the CBSP was found to be between 1 11 and 1 51. The elution order of D isomer before L isomer on the CBSP was observed for all the DL amino acids resolved except DL Val. For DL Pro, DL Val and DL Leu the elution order through the CBSP was different from that through the chiral ligand exchange phases prepared from L Pro or L hydroxyl proline with a five\|membered ring structure. [WT5HZ]
