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
L-proline was linked onto cross-linked polystyrene to give chiral chelating resin (1). The copper (Ⅱ) chelate of resin (1) was used as the chiral stationary phase for the chromatographic resolution of DL-amino acids....L-proline was linked onto cross-linked polystyrene to give chiral chelating resin (1). The copper (Ⅱ) chelate of resin (1) was used as the chiral stationary phase for the chromatographic resolution of DL-amino acids. However, the hydrophobicity of polystyrene causes an amino acid to transfer slowly during chromatographic process so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
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
The enantioseparation of dencichine and its D-isomer was achieved on a novel chiral stationary phase via coating N-（2-hydroxyl-3-octoxyl） propyl-S-benzyl-（L）-cysteine on YWG-C18 phase by ligand exchange chromatogr...The enantioseparation of dencichine and its D-isomer was achieved on a novel chiral stationary phase via coating N-（2-hydroxyl-3-octoxyl） propyl-S-benzyl-（L）-cysteine on YWG-C18 phase by ligand exchange chromatography.展开更多
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L-proline was linked onto cross-linked polystyrene to give chiral chelating resin (1). The copper (Ⅱ) chelate of resin (1) was used as the chiral stationary phase for the chromatographic resolution of DL-amino acids. However, the hydrophobicity of polystyrene causes an amino acid to transfer slowly during chromatographic process so
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]
文摘The enantioseparation of dencichine and its D-isomer was achieved on a novel chiral stationary phase via coating N-（2-hydroxyl-3-octoxyl） propyl-S-benzyl-（L）-cysteine on YWG-C18 phase by ligand exchange chromatography.
