The separation method using chiral stationary phase （CSP） for the preparation of enantioselective compound was widely used. In this work, supercritical fluid chromatography（SFC） was proposed to resolve the chiral ...The separation method using chiral stationary phase （CSP） for the preparation of enantioselective compound was widely used. In this work, supercritical fluid chromatography（SFC） was proposed to resolve the chiral mixtures. To determine the optimum operating conditions for the chiral separation of the racemic ibuprofen, the retention factors and resolutions with the change in pressure, temperature and the content of IPA （%, by volume） in supercritical CO2 were investigated. Experiments showed that the retention factor decreased with the increase of pressure and decrease in temperature. The retention factor was also influenced by the content of IPA in mobile phase, as the content of IPA in the supercritical fluid increased, the retention factor decreased. The resolution of the enantiomers became worse with the increase of IPA in the supercritical fluid. Through optimizing the experimental conditions, a SFC procedure with 13MPa, 311.15K and 4% IPA in CO2 was obtained. The peak shape of the enantiomers was symmetric with supercritical fluid chromatography when compared to the asymmetric peak shape obtained by the conventional liquid chromatography. This work demonstrated that the developed supercritical fluid chromatography procedure was suitable for the chiral separation of ibuprofen enantiomers.展开更多
A packed column supercritical fluid chromatography (SFC) method for the separation of clopidogrel enantiomers on a chiral stationary phase and CO2 with modifier as mobile phase has been developed at an analytical scal...A packed column supercritical fluid chromatography (SFC) method for the separation of clopidogrel enantiomers on a chiral stationary phase and CO2 with modifier as mobile phase has been developed at an analytical scale. Among 11 different 2 stationary phases the Chiral cel OD-H column showed by far the best separation properties. The influence of different modifiers, injection solvents, temperature, and pressure, and density of the fluid, respectively, on the separation behaviour has been studied. It was found that the separation behaviour strongly depends on the type of modifier and the modifier content. Temperature and pressure are of less influence.展开更多
An efficient and environment-friendly method for simultaneous determination of 13 typical derivatives of polycyclic aromatic hydrocarbon(PAH)in petroleum-polluted soil with nitro-,oxy-and alkylfunctional group was dev...An efficient and environment-friendly method for simultaneous determination of 13 typical derivatives of polycyclic aromatic hydrocarbon(PAH)in petroleum-polluted soil with nitro-,oxy-and alkylfunctional group was developed using supercritical fluid extraction(SFE)followed by ultra-high performance supercritical fluid chromatography(UHPSFC).Parameters of UHPSFC,including type of stationary phase and mobile phase modifiers,gradient elution process,backpressure,column temperature,and the flow rate of mobile phase,were systematically optimized,achieving a fast separation within4.2 min.Limits of detection(LOD)were 0.005-0.1μg mL^(-1)or 0.1-2.0 ng g^(-1),respectively,with a good repeatability(RSD<5.0%).Before UHPSFC-PDA analysis,the PAH-derivatives in soil samples were effectively enriched in 15.0 min using SFE with an online carbon nanotubes(CNTs)collection trap.The soil samples were analyzed by the proposed method and the results were verified by GC-MS.Thus,SFE equipped with an online CNTs trap followed by UHPSFC-PDA analysis,which only consumed about2.0 mL organic solvent for a whole run,has been demonstrated to be an efficient way for screening and quantitative analysis of trace-level PAH-derivatives in soil samples.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
Six newly synthesized racemic 1-（substituted phenyl）-4-[3-（indole-4-yl-oxy）-2-hydroxypropyl]-piperazine 1-6 were successfully resolved by carbon dioxide supercritical fluid chromatography （SFC） on an analytical ...Six newly synthesized racemic 1-（substituted phenyl）-4-[3-（indole-4-yl-oxy）-2-hydroxypropyl]-piperazine 1-6 were successfully resolved by carbon dioxide supercritical fluid chromatography （SFC） on an analytical scale column packed with immobilized polysaccharide-based chiral stationary phases （CSPs）. We found that separation on the Chiralpak IA CSP was superior to the other two immobilized CSPs （Chiralpak IB and Chiralpak IC）, and isopropanol （IPA） was a superior modifier compared to the other five solvents including ethanol, methanol, tetrahydrofuran, acetonitrile and dichloromethane. The effects of organic modifier composition, back pressure, and column temperature for enantioseparation of all six compounds were studied. Of the physical parameters studied, modifier composition had the greatest impact on retention. Changing temperature generally had less impact on retention but produced the greatest selectivity changes. The optimum condition was found as follows： Chiralpak IA column, column temperature 35 ~C, back pressure 120 bar, 35% IPA containing 0.1% diethylamine （v/v） in mobile phase, flow rate of mobile phase 3.0 mL/min, UV detection 283 nm. Separation of all six racemic compounds was completed within 10 rain and excellent resolution was obtained. Thus, SFC was found to be the methodology of choice for resolving the enantiomers of this class of compounds.展开更多
文摘The separation method using chiral stationary phase （CSP） for the preparation of enantioselective compound was widely used. In this work, supercritical fluid chromatography（SFC） was proposed to resolve the chiral mixtures. To determine the optimum operating conditions for the chiral separation of the racemic ibuprofen, the retention factors and resolutions with the change in pressure, temperature and the content of IPA （%, by volume） in supercritical CO2 were investigated. Experiments showed that the retention factor decreased with the increase of pressure and decrease in temperature. The retention factor was also influenced by the content of IPA in mobile phase, as the content of IPA in the supercritical fluid increased, the retention factor decreased. The resolution of the enantiomers became worse with the increase of IPA in the supercritical fluid. Through optimizing the experimental conditions, a SFC procedure with 13MPa, 311.15K and 4% IPA in CO2 was obtained. The peak shape of the enantiomers was symmetric with supercritical fluid chromatography when compared to the asymmetric peak shape obtained by the conventional liquid chromatography. This work demonstrated that the developed supercritical fluid chromatography procedure was suitable for the chiral separation of ibuprofen enantiomers.
文摘A packed column supercritical fluid chromatography (SFC) method for the separation of clopidogrel enantiomers on a chiral stationary phase and CO2 with modifier as mobile phase has been developed at an analytical scale. Among 11 different 2 stationary phases the Chiral cel OD-H column showed by far the best separation properties. The influence of different modifiers, injection solvents, temperature, and pressure, and density of the fluid, respectively, on the separation behaviour has been studied. It was found that the separation behaviour strongly depends on the type of modifier and the modifier content. Temperature and pressure are of less influence.
基金financially supported by the National Natural Science Foundation of China(No.21874153)Science Foundation of China University of Petroleum,Beijing(No.2462017BJB09)PetroChina Innovation Foundation(No.2016D-5007-0402)。
文摘An efficient and environment-friendly method for simultaneous determination of 13 typical derivatives of polycyclic aromatic hydrocarbon(PAH)in petroleum-polluted soil with nitro-,oxy-and alkylfunctional group was developed using supercritical fluid extraction(SFE)followed by ultra-high performance supercritical fluid chromatography(UHPSFC).Parameters of UHPSFC,including type of stationary phase and mobile phase modifiers,gradient elution process,backpressure,column temperature,and the flow rate of mobile phase,were systematically optimized,achieving a fast separation within4.2 min.Limits of detection(LOD)were 0.005-0.1μg mL^(-1)or 0.1-2.0 ng g^(-1),respectively,with a good repeatability(RSD<5.0%).Before UHPSFC-PDA analysis,the PAH-derivatives in soil samples were effectively enriched in 15.0 min using SFE with an online carbon nanotubes(CNTs)collection trap.The soil samples were analyzed by the proposed method and the results were verified by GC-MS.Thus,SFE equipped with an online CNTs trap followed by UHPSFC-PDA analysis,which only consumed about2.0 mL organic solvent for a whole run,has been demonstrated to be an efficient way for screening and quantitative analysis of trace-level PAH-derivatives in soil samples.
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Science and Technology Program of Guangzhou City(Grant No.2010U1-E0531-2)
文摘Six newly synthesized racemic 1-（substituted phenyl）-4-[3-（indole-4-yl-oxy）-2-hydroxypropyl]-piperazine 1-6 were successfully resolved by carbon dioxide supercritical fluid chromatography （SFC） on an analytical scale column packed with immobilized polysaccharide-based chiral stationary phases （CSPs）. We found that separation on the Chiralpak IA CSP was superior to the other two immobilized CSPs （Chiralpak IB and Chiralpak IC）, and isopropanol （IPA） was a superior modifier compared to the other five solvents including ethanol, methanol, tetrahydrofuran, acetonitrile and dichloromethane. The effects of organic modifier composition, back pressure, and column temperature for enantioseparation of all six compounds were studied. Of the physical parameters studied, modifier composition had the greatest impact on retention. Changing temperature generally had less impact on retention but produced the greatest selectivity changes. The optimum condition was found as follows： Chiralpak IA column, column temperature 35 ~C, back pressure 120 bar, 35% IPA containing 0.1% diethylamine （v/v） in mobile phase, flow rate of mobile phase 3.0 mL/min, UV detection 283 nm. Separation of all six racemic compounds was completed within 10 rain and excellent resolution was obtained. Thus, SFC was found to be the methodology of choice for resolving the enantiomers of this class of compounds.
