Enantiomers of a-substituted-(2-pyridyl)-methylarfdnes uere separated on SC -7 gas chromatograph with a 20m×0.25mm Chirasil-Val capIlary column,Carrier gas was nitro- gen or hydrogen.The resolution factors(ri.s) ...Enantiomers of a-substituted-(2-pyridyl)-methylarfdnes uere separated on SC -7 gas chromatograph with a 20m×0.25mm Chirasil-Val capIlary column,Carrier gas was nitro- gen or hydrogen.The resolution factors(ri.s) were 1.02 to 1.06.Enantiomers of pyridyl anines were separated to and near to base line.展开更多
Silica gel thin-layer plates covered with L-arginine and copper acetate were used for the separation of amino acid enantiomers, The chromatographic selectivity and the effects of plate different preparation methods, s...Silica gel thin-layer plates covered with L-arginine and copper acetate were used for the separation of amino acid enantiomers, The chromatographic selectivity and the effects of plate different preparation methods, sample molecular structure and solvent compositions on resolution performance were also discussed.展开更多
A β-cyclodextrin derivative, perbenzyl-β-cyclodextrin, was prepared and used as a chiral stationary phase for capillary gas chromatography. Using FID detector and the column temperature between 70 and 80℃, the chir...A β-cyclodextrin derivative, perbenzyl-β-cyclodextrin, was prepared and used as a chiral stationary phase for capillary gas chromatography. Using FID detector and the column temperature between 70 and 80℃, the chiral separations of racemic 3-phenyl-1, 2-epoxyethane and 1-phenyl-1-propanol on a 14m×0.23mm I. D. fused silica column with the β-cyclodextrin derivative were carried out and the optical purities of optically active 1-phenyl-1-propanol samples prepared by asymmetric synthesis were determined.展开更多
Direct enantiomeric separation of all four optical isomers of 2-phenylcyclopropane carboxylate ester was first achieved on each of the three different beta-cyciodextrin chiral stationary phases (CSPs) in GC. Using the...Direct enantiomeric separation of all four optical isomers of 2-phenylcyclopropane carboxylate ester was first achieved on each of the three different beta-cyciodextrin chiral stationary phases (CSPs) in GC. Using these CSPs, enantiomeric excess of the products of enantioselective cyclopropanation can be determined directly, conveniently and fast.展开更多
Using two b-cyclodextrin derivatives (CDs) with long chain of acyl groups as chiral stationary phases (CSPs) of capillary gas chromatography (CGC), the enantiomers of racemic allethrone and propargyllone were well res...Using two b-cyclodextrin derivatives (CDs) with long chain of acyl groups as chiral stationary phases (CSPs) of capillary gas chromatography (CGC), the enantiomers of racemic allethrone and propargyllone were well resolved after derived with acetyl chloride. The enantiomer excess values (e.e.%) of 1S-allethrone and 1S-propargyllone were also determined successfully using these CDs.展开更多
Crosslinking experin(?)tnts for the chiral stationary phase OV-225-L-Val-t-butylamide within both fused silica and glass capillary columns have been carried out.Amino acid enantiomers were separated on crosslinked col...Crosslinking experin(?)tnts for the chiral stationary phase OV-225-L-Val-t-butylamide within both fused silica and glass capillary columns have been carried out.Amino acid enantiomers were separated on crosslinked columns by、both GC and SFC methods.In SFC,the α values of amino acid enantiomers are independent of the density of the mobile phase,and they are hig her than those obtained by GC for the tested enantiomers with the same column due to the lower column tempera- ture used in SFC.展开更多
Chromatographic substrate material,as a carrier of chromatographic stationary phases,plays a vital role in defining its chromatographic characteristics,including column efficiency,stability,peak capacity and so on.In ...Chromatographic substrate material,as a carrier of chromatographic stationary phases,plays a vital role in defining its chromatographic characteristics,including column efficiency,stability,peak capacity and so on.In recent years,superficially porous silica(SPS)was widely valued for its excellent performance in improving the column efficiency due to its special structural properties,which was considered as a real substitute for fully porous SiO_(2)(FPS)and had been used to develop a new generation of highly efficient stationary phase.To help researchers better understand the SPS and further promote its application and development in the field of chromatography,the rapid separation mechanism,preparation method and its applications in the rapid separation and analysis of enantiomers were systematically introduced,and the development prospects of SPS were also prospected in this paper.展开更多
Cellulose tris(4-methylphenylcarbamate), amylosetris(3,5-di-methylphenylcarbamate) and amylose tris (phenylcarbamate) were prepared by the methodreported by Okamoto and were coated onto an aminopropylated mesoporous s...Cellulose tris(4-methylphenylcarbamate), amylosetris(3,5-di-methylphenylcarbamate) and amylose tris (phenylcarbamate) were prepared by the methodreported by Okamoto and were coated onto an aminopropylated mesoporous spherical silica gel. Thesefinal products were used as chiral stationary phases of high performance liquid chromatography forthe eighteen structurally related biphenyl compounds. The resolution was made using normal-phasemethodology with a mobile phase consisting of n-hexane-alcohol (ethanol, 1-propanol, 2-pro-panol or1-butanol). The effects of various aliphatic alcohols in the mobile phase were studied. Thestructural features of the solutes that influence then- k′ were discussed. A dominant effect oftrifluoroacetic acid on chiral separation of acidic solutes was noted.展开更多
Enantiomeric separations of epinephrine and salbutamol, by means of micellar electrokinetic chromatography (MEKC) employing β-cyclodextrin as chiral additive in ammonium chloride-ammonia solution were investigated. ...Enantiomeric separations of epinephrine and salbutamol, by means of micellar electrokinetic chromatography (MEKC) employing β-cyclodextrin as chiral additive in ammonium chloride-ammonia solution were investigated. In this system, the analytes migrated with the micellar phase towards the anode and were detected by electrochem- istry using gold microelectrode at +0.65 V vs. SCE. The success of the chiral separations is strongly dependent on the concentration of β-CD and SDS, and the optimal concentration is 8 mmol?L-1 and 15 mmol?L-1 respectively. The effects of detection potential, pH value of electrolyte and applied voltage were discussed also. Using the pro- posed method, baseline separation of the enantiomers could be accomplished in 6 min. Further, an attempt was made to elucidate the plausible mechanism of the chiral recognition.展开更多
The enantiomers of thirty-nine O-ethyl O-phenyl N-isopropyl phosphoroamidothioates have been separated by high performance liquid chromatography on a Pirkle model chiral stationary phase using ten mobile phase. Chroma...The enantiomers of thirty-nine O-ethyl O-phenyl N-isopropyl phosphoroamidothioates have been separated by high performance liquid chromatography on a Pirkle model chiral stationary phase using ten mobile phase. Chromatographic data are presented for the separation of these organic phosphorus enantiomers on the chiral phase. The influences of molecular structures and compositions of mobile phases have been described.展开更多
基金The project is supported by National Nature science Foundation of China.
文摘Enantiomers of a-substituted-(2-pyridyl)-methylarfdnes uere separated on SC -7 gas chromatograph with a 20m×0.25mm Chirasil-Val capIlary column,Carrier gas was nitro- gen or hydrogen.The resolution factors(ri.s) were 1.02 to 1.06.Enantiomers of pyridyl anines were separated to and near to base line.
文摘Silica gel thin-layer plates covered with L-arginine and copper acetate were used for the separation of amino acid enantiomers, The chromatographic selectivity and the effects of plate different preparation methods, sample molecular structure and solvent compositions on resolution performance were also discussed.
文摘A β-cyclodextrin derivative, perbenzyl-β-cyclodextrin, was prepared and used as a chiral stationary phase for capillary gas chromatography. Using FID detector and the column temperature between 70 and 80℃, the chiral separations of racemic 3-phenyl-1, 2-epoxyethane and 1-phenyl-1-propanol on a 14m×0.23mm I. D. fused silica column with the β-cyclodextrin derivative were carried out and the optical purities of optically active 1-phenyl-1-propanol samples prepared by asymmetric synthesis were determined.
文摘Direct enantiomeric separation of all four optical isomers of 2-phenylcyclopropane carboxylate ester was first achieved on each of the three different beta-cyciodextrin chiral stationary phases (CSPs) in GC. Using these CSPs, enantiomeric excess of the products of enantioselective cyclopropanation can be determined directly, conveniently and fast.
文摘Using two b-cyclodextrin derivatives (CDs) with long chain of acyl groups as chiral stationary phases (CSPs) of capillary gas chromatography (CGC), the enantiomers of racemic allethrone and propargyllone were well resolved after derived with acetyl chloride. The enantiomer excess values (e.e.%) of 1S-allethrone and 1S-propargyllone were also determined successfully using these CDs.
基金the National Natural Science Foundation of China.
文摘Six chiral diamide stationary phases (CSPs), namely N-(3-carbobenzoxypropionyl)-L- Val-tert-butylamide (CSP-1), N-undecenoyl-L-Val-S-α-phenylethylamide (CSP-2), N-undecenoyl-L- Val-R-α-phenylethylamide (CSP-3), OV-225-L-Val-tert-butylamide (CSP-4), XE-60-L-Val-tert- butylamide (CSP-5) and polycyanoethyl vinyl siloxane-L-Val-tert-butylamide (CSP-6), were inves- tigated and CSP-6 was crosslinked within narrow bore (70 μm) fused silica capillary columns. The separation of amino acid enantiomers on this narrow bore column by gas chromatography (GC) is illustrated.
基金This work was supported by the National Natural Science Fundation of China.
文摘Crosslinking experin(?)tnts for the chiral stationary phase OV-225-L-Val-t-butylamide within both fused silica and glass capillary columns have been carried out.Amino acid enantiomers were separated on crosslinked columns by、both GC and SFC methods.In SFC,the α values of amino acid enantiomers are independent of the density of the mobile phase,and they are hig her than those obtained by GC for the tested enantiomers with the same column due to the lower column tempera- ture used in SFC.
基金financially supported by the National Natural Science Foundation of China(21822407,22074154)Xinjiang“Tianshan Youth Plan”Project(No.2017Q027)+1 种基金the“Light of West China”Program from Chinese Academy of Sciencethe Gansu Province Basic Research Innovation Group Program(20JR5RA573)
文摘Chromatographic substrate material,as a carrier of chromatographic stationary phases,plays a vital role in defining its chromatographic characteristics,including column efficiency,stability,peak capacity and so on.In recent years,superficially porous silica(SPS)was widely valued for its excellent performance in improving the column efficiency due to its special structural properties,which was considered as a real substitute for fully porous SiO_(2)(FPS)and had been used to develop a new generation of highly efficient stationary phase.To help researchers better understand the SPS and further promote its application and development in the field of chromatography,the rapid separation mechanism,preparation method and its applications in the rapid separation and analysis of enantiomers were systematically introduced,and the development prospects of SPS were also prospected in this paper.
文摘Cellulose tris(4-methylphenylcarbamate), amylosetris(3,5-di-methylphenylcarbamate) and amylose tris (phenylcarbamate) were prepared by the methodreported by Okamoto and were coated onto an aminopropylated mesoporous spherical silica gel. Thesefinal products were used as chiral stationary phases of high performance liquid chromatography forthe eighteen structurally related biphenyl compounds. The resolution was made using normal-phasemethodology with a mobile phase consisting of n-hexane-alcohol (ethanol, 1-propanol, 2-pro-panol or1-butanol). The effects of various aliphatic alcohols in the mobile phase were studied. Thestructural features of the solutes that influence then- k′ were discussed. A dominant effect oftrifluoroacetic acid on chiral separation of acidic solutes was noted.
基金Project supported by the National Natural Science Foundation of China (No. 29675033) the Natural Science Foundation of Guangdong Province(No. 001237) and Pandeng Foundation of Beijing Jiaotong University (No. PD245).
文摘Enantiomeric separations of epinephrine and salbutamol, by means of micellar electrokinetic chromatography (MEKC) employing β-cyclodextrin as chiral additive in ammonium chloride-ammonia solution were investigated. In this system, the analytes migrated with the micellar phase towards the anode and were detected by electrochem- istry using gold microelectrode at +0.65 V vs. SCE. The success of the chiral separations is strongly dependent on the concentration of β-CD and SDS, and the optimal concentration is 8 mmol?L-1 and 15 mmol?L-1 respectively. The effects of detection potential, pH value of electrolyte and applied voltage were discussed also. Using the pro- posed method, baseline separation of the enantiomers could be accomplished in 6 min. Further, an attempt was made to elucidate the plausible mechanism of the chiral recognition.
文摘The enantiomers of thirty-nine O-ethyl O-phenyl N-isopropyl phosphoroamidothioates have been separated by high performance liquid chromatography on a Pirkle model chiral stationary phase using ten mobile phase. Chromatographic data are presented for the separation of these organic phosphorus enantiomers on the chiral phase. The influences of molecular structures and compositions of mobile phases have been described.