A new capillary gas chromatography stationary phase, monokis (2,6 di O benzyl 3 O propyl (3’)) hexakis(2,6 di O benzyl 3 O methyl) β CD bonded polysiloxane, was synthesized. It ex...A new capillary gas chromatography stationary phase, monokis (2,6 di O benzyl 3 O propyl (3’)) hexakis(2,6 di O benzyl 3 O methyl) β CD bonded polysiloxane, was synthesized. It exhibited separation abilities to disubstituted benzene isomers and some chiral solutes. It was also found that the polarity of CD derivatives can be lowered both by chemically bonding it to polysiloxane and by diluting it in polysiloxane. The separation abilities of the polysiloxane anchored CDs (SP CD) are higher than that of the unbonded CDs (S CD) and the diluted S CD at lower column temperature. Hydrosilylation reaction is one of the best methods to lower the operating temperature of CDs.展开更多
Six peralkylated β- cyclodec\xtrins used as capillary gas chromatographic stationary phases were prepared and characterized by differential by differential scannning calorimetry(DSC) and pyrolysis gas chromatograp...Six peralkylated β- cyclodec\xtrins used as capillary gas chromatographic stationary phases were prepared and characterized by differential by differential scannning calorimetry(DSC) and pyrolysis gas chromatography (PyGC). The DSC profiles illustrated that the peralkylated β-cyclodextrins synthesized possess the supercoooled state and the glass state below their melting point The PYGC results showed that the long-chain alkylated β-cyclodextrins are more thermostable than the short-chain. one All ofthese peralkylated β-cyclodextrins are suitable for use as capillary column gas chromatographic stationary phases,which can easily be coatal on the fused silica capilary columns and have nice chromatographic retention behaviour. For example, the capillary colunns coated with these materials can excellently separate three methylphenol isomers and six dimehylphenol isomers.展开更多
SAPO-34 molecular sieves were synthesized by the addition of β-cyclodextrin（β-CD） as crystal growth inhibitor using metakaolin as silicon and aluminum sources. Properties of the obtained samples were characterized...SAPO-34 molecular sieves were synthesized by the addition of β-cyclodextrin（β-CD） as crystal growth inhibitor using metakaolin as silicon and aluminum sources. Properties of the obtained samples were characterized by XRD,SEM,N2adsorption–desorption,FTIR,XRF,EDX,NH293-TPD andSi MAS NMR. When β-CD was added,crystal size of the SAPO-34 crystals decreased. Variation of Si content from the crystal center to surface decreased while total Si content hardly changed.29 Si MAS NMR results showed that β-CD contributed to better Si dispersion and decreased the size of Si（4Si） patches. Moreover,the MTO（methanol-to-olefin） process was conducted to investigate the influence of β-CD on catalytic performance. The synthesized sample with molar ratio of β-CD/Al2O3 equaling 0.055 remained active for 610 min while the sample synthesized without β-CD for only 280 min,which indicates that the lifetime of catalyst synthesized with β-CD is greatly prolonged.展开更多
Aim To study the chromatographis beheviors of three new cinnamyl cyclodextrin derivative stationary phases. Mehtods Three new cinnamyl β-cyclodextrins, heptakis-(2, 6-di-O-cinnamyl-3-O-methyl)-β-CD, heptakis-(2, 6-...Aim To study the chromatographis beheviors of three new cinnamyl cyclodextrin derivative stationary phases. Mehtods Three new cinnamyl β-cyclodextrins, heptakis-(2, 6-di-O-cinnamyl-3-O-methyl)-β-CD, heptakis-(2, 6-di-O-cinnamyl-3-O-acetyl-)-β-CD and heptakis-2, 6-di-O-cirinamyl-3-O-trifluoroacetyl)-β-CD were synthesized and coatal on fused-silica capillary columns . Results The new stationary phases have better thermal stability, good column efficiency and excellent mpaxation power for some sutstituted benzene positional isomers. It was found that the introduction of cinnamyl groups has a significant effect on these stationary phases. Conclusion There new subetituted β-CD compounds are very suitable to be ed as gas chromatographic stationary phases.展开更多
Aim To study the chromatographic behaviors of two dipentyl cyclodextrin derivative stationary phases. Methods Two new β-cyclodextrin derivatives, heptakis-[2, 6-di-O-pentyl-3-O-(4-nitrobenzyl)] -β-CD and heptakis-[...Aim To study the chromatographic behaviors of two dipentyl cyclodextrin derivative stationary phases. Methods Two new β-cyclodextrin derivatives, heptakis-[2, 6-di-O-pentyl-3-O-(4-nitrobenzyl)] -β-CD and heptakis-[2, 6-di-O-pentyl-3 -O-(5 -hexenyl)]-β-CD, were synthesized and coatal on fed-silica capillary columns. The chromatographic behaviors of the columns were characterized . Results It was found that the she, polarity, and aromatic property of the substituted group at the 3-position of heptakis-(2, 6 - di - O - pentyl) - β - cyclodextrins greatly influenced their chromatographic properties and separation ability. The introduction of aromatic group or a group containing a double-bond may bring π-π interactions between the host and guest molecules, and therefore increases the separation ability of the β-CDs for substituted benzene isomers. Conclusion The new substituted β-CD compounds are very suitable for being used as gas chromatogaphic stationary phases.展开更多
Six new kinds of amino acid derived β-cyclodextrins were synthesized to improve their water solubility and chiral separation properties. They are heptakis{2,6-di-O-[3-L-(1-isopropyl carboxyl methyl amino)-2-(hydroxy)...Six new kinds of amino acid derived β-cyclodextrins were synthesized to improve their water solubility and chiral separation properties. They are heptakis{2,6-di-O-[3-L-(1-isopropyl carboxyl methyl amino)-2-(hydroxy) propyl]}-β-cyclodextrin (i.e. L-Val-β-CD), heptakis{2,6-di-O-[3-L-(1-benzyl carboxyl methyl amino)-2-hydroxy propyl]}-β-cyclodextrin (i.e. L-Phe-β-CD), heptakis{2,6-di-O-[3-(D, L-1-benzyl carboxyl methyl amino)-2-hydroxy propyl]}-β-cyclodextrin (i.e. D,L-Phe-β-CD), heptakis{2,6-di-O-[3-(L-1-hydroxymethyl carboxyl methyl amino)-2-hydroxy propyl]}-β-cyclodextrin (i.e. L-Ser-β-CD), heptakis{2,6-di-O-[3-(L-1-carboxylmethyl carboxyl methyl amino)- 2-hydroxy propyl]}-β-cyclodextrin (i.e. L-Asp-β-CD), heptakis{2,6-di-O-[3-(L-2-carboxyl tetramethylene amino)-2-hydroxy propyl]}-β-cyclodextrin (i.e. L-Pro-β-CD). Their chemical structures were certified using FTIR and ()~1H NMR. Except for L-Phe-β-CD and D,L-Phe-β-CD, that are in soluble in water, the other amino acid derived β-CDs all have good water solubility. D,L-tyrosine and promethazine were baselinely separated by L-Val-β-CD in capillary electrophoresis.展开更多
The solubility of β-cyclodextrin （β-CD） in ionic liquid/N, N-dimethyl-acetamide （IL/DMAC） mixed solvent and in LiCI/DMAC mixed solvent was investigated at 323.15 K and 353.15 K. The results showed that the solub...The solubility of β-cyclodextrin （β-CD） in ionic liquid/N, N-dimethyl-acetamide （IL/DMAC） mixed solvent and in LiCI/DMAC mixed solvent was investigated at 323.15 K and 353.15 K. The results showed that the solubility of β-CD in IL/DMAC system increased with increasing temperature, but decreased in LiCI/DMAC system. β-CD had the highest solubility in IL/DMAC system with [Cl]- or [Br]- anions. The solubility of β-CD in LiCl/DMAC system was lower than that in IL/DMAC system with [Cl]- or [Br]- anions but higher than that in IL/DMAC system with weak-coordinated anions （e.g [BF4]- or [PF6]-）. The effects of substituent groups （benzyl and butyl） of cation and the structure of cations on β-cyclodextrin solubility were also investigated.展开更多
Synthesis and properties of β-cyclodextrin derivatized ovalbumin used as chiral selector were investigated, β-cyclodextrin derivatized ovalbumin was synthesized using β-cyclodextrin and ovalbumin in the presence of...Synthesis and properties of β-cyclodextrin derivatized ovalbumin used as chiral selector were investigated, β-cyclodextrin derivatized ovalbumin was synthesized using β-cyclodextrin and ovalbumin in the presence of ethylene glycol diglycidyl ether in boric acid buffer at pH value 8.7 at 37℃. Amino group was coated on the internal surface of the silica capillary by sol-gel technology with triethoxylmethylsiloxane and （3-aminopropyl）trimethoxysiloxane. Covalent binding of g-cyclodextrin derivatized ovalbumin was performed by glutaraldehyde. Enantiomers of chlorpheniramine, phenylalanine and atropine were separated by pressure capillary electrochromatography column coated with β-cyclodextrin derivatized ovalbumin.展开更多
Capillary electrophoresis (CE) has become a powerful tool for enantiomer separations during the last decade. Since 1993, the author has investigated enantiomer separations by affinity capillary electrophoresis (affini...Capillary electrophoresis (CE) has become a powerful tool for enantiomer separations during the last decade. Since 1993, the author has investigated enantiomer separations by affinity capillary electrophoresis (affinity CE) with some proteins and by cyclodextrin electrokinetic chromatography (CDEKC) with some charged cyclodextrins (CDs). Many successful enantiomer separations are demonstrated from our study in this review article. In the enantiomer separations by affinity CE, the deterioration of detection sensitivity was observed under high concentration of the protein in running solutions. The partial filling technique was practically useful to solve the serious problem. It allowed operation at high protein concentrations, such as 500 μmol/L, without the detection problem. Charged CDs had several advantages for the enantiomer separations over neutral ones. Strong electrostatic interactions between a charged CD and oppositely charged analytes should be effective for the formation of the complex. A large difference in electrophoretic mobility between the free analyte and the inclusion complex should also enhance the enantiomeric resolution. In CE mass spectrometry (CE MS), the partial filling technique was applied to avoid the introduction of nonvolatile chiral selectors into the CE MS interface. By replacing the nonvolatile electrolytes in the running buffer by volatile ones, the separation conditions employed in CE with the UV detection method could be transferred to CE MS.展开更多
New cyclodextrin derivatives （CDs）, heptakis（2, 6-di- O-methyl-3- O-methoxymethyl）-β-CD （ Ⅰ ） and heptakis（2, 3, 6-tri-O-methoxymethyl）-β-CD （ Ⅱ ）, were investigated for their chromatographic performance...New cyclodextrin derivatives （CDs）, heptakis（2, 6-di- O-methyl-3- O-methoxymethyl）-β-CD （ Ⅰ ） and heptakis（2, 3, 6-tri-O-methoxymethyl）-β-CD （ Ⅱ ）, were investigated for their chromatographic performance as stationary phases for capillary gas chromatography （CGC）. Both of the CDs exhibited good selectivity and satisfactory separation for test mixtures and aromatic positional isomers, and volatile compounds from Ligusticurn chuanxiong Hort. Additionally, the selectivity and elution orders of major compounds were compared with a well-recognized commercial column on the basis of the results by gas chromatography-mass spectrometry （GC-MS）. The present work demonstrates the good selectivity of the two new CDs and can be used as GC stationary phases for the separation of positional isomers and analytes in complex samples.展开更多
文摘A new capillary gas chromatography stationary phase, monokis (2,6 di O benzyl 3 O propyl (3’)) hexakis(2,6 di O benzyl 3 O methyl) β CD bonded polysiloxane, was synthesized. It exhibited separation abilities to disubstituted benzene isomers and some chiral solutes. It was also found that the polarity of CD derivatives can be lowered both by chemically bonding it to polysiloxane and by diluting it in polysiloxane. The separation abilities of the polysiloxane anchored CDs (SP CD) are higher than that of the unbonded CDs (S CD) and the diluted S CD at lower column temperature. Hydrosilylation reaction is one of the best methods to lower the operating temperature of CDs.
文摘Six peralkylated β- cyclodec\xtrins used as capillary gas chromatographic stationary phases were prepared and characterized by differential by differential scannning calorimetry(DSC) and pyrolysis gas chromatography (PyGC). The DSC profiles illustrated that the peralkylated β-cyclodextrins synthesized possess the supercoooled state and the glass state below their melting point The PYGC results showed that the long-chain alkylated β-cyclodextrins are more thermostable than the short-chain. one All ofthese peralkylated β-cyclodextrins are suitable for use as capillary column gas chromatographic stationary phases,which can easily be coatal on the fused silica capilary columns and have nice chromatographic retention behaviour. For example, the capillary colunns coated with these materials can excellently separate three methylphenol isomers and six dimehylphenol isomers.
基金supported by the National Natural Science Foundation of China(21406247)
文摘SAPO-34 molecular sieves were synthesized by the addition of β-cyclodextrin（β-CD） as crystal growth inhibitor using metakaolin as silicon and aluminum sources. Properties of the obtained samples were characterized by XRD,SEM,N2adsorption–desorption,FTIR,XRF,EDX,NH293-TPD andSi MAS NMR. When β-CD was added,crystal size of the SAPO-34 crystals decreased. Variation of Si content from the crystal center to surface decreased while total Si content hardly changed.29 Si MAS NMR results showed that β-CD contributed to better Si dispersion and decreased the size of Si（4Si） patches. Moreover,the MTO（methanol-to-olefin） process was conducted to investigate the influence of β-CD on catalytic performance. The synthesized sample with molar ratio of β-CD/Al2O3 equaling 0.055 remained active for 610 min while the sample synthesized without β-CD for only 280 min,which indicates that the lifetime of catalyst synthesized with β-CD is greatly prolonged.
文摘Aim To study the chromatographis beheviors of three new cinnamyl cyclodextrin derivative stationary phases. Mehtods Three new cinnamyl β-cyclodextrins, heptakis-(2, 6-di-O-cinnamyl-3-O-methyl)-β-CD, heptakis-(2, 6-di-O-cinnamyl-3-O-acetyl-)-β-CD and heptakis-2, 6-di-O-cirinamyl-3-O-trifluoroacetyl)-β-CD were synthesized and coatal on fused-silica capillary columns . Results The new stationary phases have better thermal stability, good column efficiency and excellent mpaxation power for some sutstituted benzene positional isomers. It was found that the introduction of cinnamyl groups has a significant effect on these stationary phases. Conclusion There new subetituted β-CD compounds are very suitable to be ed as gas chromatographic stationary phases.
文摘Aim To study the chromatographic behaviors of two dipentyl cyclodextrin derivative stationary phases. Methods Two new β-cyclodextrin derivatives, heptakis-[2, 6-di-O-pentyl-3-O-(4-nitrobenzyl)] -β-CD and heptakis-[2, 6-di-O-pentyl-3 -O-(5 -hexenyl)]-β-CD, were synthesized and coatal on fed-silica capillary columns. The chromatographic behaviors of the columns were characterized . Results It was found that the she, polarity, and aromatic property of the substituted group at the 3-position of heptakis-(2, 6 - di - O - pentyl) - β - cyclodextrins greatly influenced their chromatographic properties and separation ability. The introduction of aromatic group or a group containing a double-bond may bring π-π interactions between the host and guest molecules, and therefore increases the separation ability of the β-CDs for substituted benzene isomers. Conclusion The new substituted β-CD compounds are very suitable for being used as gas chromatogaphic stationary phases.
文摘Six new kinds of amino acid derived β-cyclodextrins were synthesized to improve their water solubility and chiral separation properties. They are heptakis{2,6-di-O-[3-L-(1-isopropyl carboxyl methyl amino)-2-(hydroxy) propyl]}-β-cyclodextrin (i.e. L-Val-β-CD), heptakis{2,6-di-O-[3-L-(1-benzyl carboxyl methyl amino)-2-hydroxy propyl]}-β-cyclodextrin (i.e. L-Phe-β-CD), heptakis{2,6-di-O-[3-(D, L-1-benzyl carboxyl methyl amino)-2-hydroxy propyl]}-β-cyclodextrin (i.e. D,L-Phe-β-CD), heptakis{2,6-di-O-[3-(L-1-hydroxymethyl carboxyl methyl amino)-2-hydroxy propyl]}-β-cyclodextrin (i.e. L-Ser-β-CD), heptakis{2,6-di-O-[3-(L-1-carboxylmethyl carboxyl methyl amino)- 2-hydroxy propyl]}-β-cyclodextrin (i.e. L-Asp-β-CD), heptakis{2,6-di-O-[3-(L-2-carboxyl tetramethylene amino)-2-hydroxy propyl]}-β-cyclodextrin (i.e. L-Pro-β-CD). Their chemical structures were certified using FTIR and ()~1H NMR. Except for L-Phe-β-CD and D,L-Phe-β-CD, that are in soluble in water, the other amino acid derived β-CDs all have good water solubility. D,L-tyrosine and promethazine were baselinely separated by L-Val-β-CD in capillary electrophoresis.
基金the Foundation of Innovation for Middle-aged and Youth,CNPC (04E7031)Program for New Century Talents in Universities,Ministry of Education,China (NCET-06-0088)the National Natural Science Foundation of China (40673043 and 20576073) for the financial support.
文摘The solubility of β-cyclodextrin （β-CD） in ionic liquid/N, N-dimethyl-acetamide （IL/DMAC） mixed solvent and in LiCI/DMAC mixed solvent was investigated at 323.15 K and 353.15 K. The results showed that the solubility of β-CD in IL/DMAC system increased with increasing temperature, but decreased in LiCI/DMAC system. β-CD had the highest solubility in IL/DMAC system with [Cl]- or [Br]- anions. The solubility of β-CD in LiCl/DMAC system was lower than that in IL/DMAC system with [Cl]- or [Br]- anions but higher than that in IL/DMAC system with weak-coordinated anions （e.g [BF4]- or [PF6]-）. The effects of substituent groups （benzyl and butyl） of cation and the structure of cations on β-cyclodextrin solubility were also investigated.
基金the National Natural Science Foundation of China(20275004)
文摘Synthesis and properties of β-cyclodextrin derivatized ovalbumin used as chiral selector were investigated, β-cyclodextrin derivatized ovalbumin was synthesized using β-cyclodextrin and ovalbumin in the presence of ethylene glycol diglycidyl ether in boric acid buffer at pH value 8.7 at 37℃. Amino group was coated on the internal surface of the silica capillary by sol-gel technology with triethoxylmethylsiloxane and （3-aminopropyl）trimethoxysiloxane. Covalent binding of g-cyclodextrin derivatized ovalbumin was performed by glutaraldehyde. Enantiomers of chlorpheniramine, phenylalanine and atropine were separated by pressure capillary electrochromatography column coated with β-cyclodextrin derivatized ovalbumin.
文摘Capillary electrophoresis (CE) has become a powerful tool for enantiomer separations during the last decade. Since 1993, the author has investigated enantiomer separations by affinity capillary electrophoresis (affinity CE) with some proteins and by cyclodextrin electrokinetic chromatography (CDEKC) with some charged cyclodextrins (CDs). Many successful enantiomer separations are demonstrated from our study in this review article. In the enantiomer separations by affinity CE, the deterioration of detection sensitivity was observed under high concentration of the protein in running solutions. The partial filling technique was practically useful to solve the serious problem. It allowed operation at high protein concentrations, such as 500 μmol/L, without the detection problem. Charged CDs had several advantages for the enantiomer separations over neutral ones. Strong electrostatic interactions between a charged CD and oppositely charged analytes should be effective for the formation of the complex. A large difference in electrophoretic mobility between the free analyte and the inclusion complex should also enhance the enantiomeric resolution. In CE mass spectrometry (CE MS), the partial filling technique was applied to avoid the introduction of nonvolatile chiral selectors into the CE MS interface. By replacing the nonvolatile electrolytes in the running buffer by volatile ones, the separation conditions employed in CE with the UV detection method could be transferred to CE MS.
文摘New cyclodextrin derivatives （CDs）, heptakis（2, 6-di- O-methyl-3- O-methoxymethyl）-β-CD （ Ⅰ ） and heptakis（2, 3, 6-tri-O-methoxymethyl）-β-CD （ Ⅱ ）, were investigated for their chromatographic performance as stationary phases for capillary gas chromatography （CGC）. Both of the CDs exhibited good selectivity and satisfactory separation for test mixtures and aromatic positional isomers, and volatile compounds from Ligusticurn chuanxiong Hort. Additionally, the selectivity and elution orders of major compounds were compared with a well-recognized commercial column on the basis of the results by gas chromatography-mass spectrometry （GC-MS）. The present work demonstrates the good selectivity of the two new CDs and can be used as GC stationary phases for the separation of positional isomers and analytes in complex samples.
