The entropy increase (EI) and the entropy increase per unit time (EIPUT) of the solute zone are chosen as new criteria of separation efficiency in chromatography and electrophoresis. It is verified by grand canonical ...The entropy increase (EI) and the entropy increase per unit time (EIPUT) of the solute zone are chosen as new criteria of separation efficiency in chromatography and electrophoresis. It is verified by grand canonical ensemble (GCE) that the kinetic energy distribution of the solute is a common characteristic of the entropy and the distribution of solute zones.Under the assumptions. EI of the solute system is directly proportional to the logarithm of the difference between one and one half of the substantial separation ratio. the ratio of moles of a sparated solute to its total moles. and EIPUT is direchy proportional to corrected separation rate of separation system. EI or EIPUT is a important bridge between separation efficiency of chromatography or electrophoresis and operating parameters, especially. when nonequilibriumthermodynamics(NET) would be adopted.展开更多
Development of effective chromatographic or electrophoretic separation involves judicious deciding of selection of optimal experimental conditions that can provide an adequate resolution at a reasonable run time for t...Development of effective chromatographic or electrophoretic separation involves judicious deciding of selection of optimal experimental conditions that can provide an adequate resolution at a reasonable run time for the separation of interested components. Box-Behnken factorial design was effectively applied for the separation optimization of eight structurally related sulfonamides using capillary zone electrophorosis and reverse high performance liquid chromatography. Optimum values for volume ratio of THF to H2O in eluent, column temperature and flow rate of eluent are found as 12 to 88, 35℃ and 1.0 mL/min, respectively. Box-Behnken modified optimization model is extended to separation by capillary electrophoresis (CE). While using CE, a satisfactory separation is achieved with a minimum resolution larger than 1.0 for a separation time less than 10 min.展开更多
AIM： To investigate the relationship between donor liver cold preservation, lung surfactant （LS） changes and acute lung injury （ALI） after liver transplantation. METHODS： Liver transplantation models were estab-...AIM： To investigate the relationship between donor liver cold preservation, lung surfactant （LS） changes and acute lung injury （ALI） after liver transplantation. METHODS： Liver transplantation models were estab- lished using male Wistar rats. Donor livers were pre- served in University of Wisconsin solution at 4 ℃ for different lengths of time. The effect of ammonium pyr- rolidinedithiocarbamate （PDTC） on ALI was also detect- ed. All samples were harvested after 3 h reperfusion.The severity of AU was evaluated by lung weight/body weight ratio, lung histopathological score, serum nitric oxide （NO） and endothelin （ET）-I levels, lung tumor necrosis factor （TNF）-α and interleukin （IL）-1β levels. Lung surfactants （LSs） were determined by micellar electrokinetic capillary chromatography. RESULTS： With extended donor liver cold preservation time （CPT）, lung histopathological scores, serum ET-i levels, lung weight/body weight ratio and the level of TNF-α and IL-1β in lung were increased significantly in the 180-min group compared with the sham group （3.16± 0.28 vs 1.12 ± 0.21, P 〈 0.001; 343.59±53.97 vs 141.53± 48.48, P 〈 0.001; 0.00687 ±0.00037 vs 0.00557 ±0.00056, P 〈 0.001; 17.5 ± 3.0 vs 1,3 ± 0.3, P 〈 0.001; 10.8± 2.3 vs 1.8 ± 0.4, P 〈 0.001）, but serum NO levels decreased remarkably （74.67 ± 10.01 vs 24.97 ± 3.18, P 〈 0.001）. The expression of lung phos- phatidylcholine （PC）, phosphatidylethanolamine （PE）, phosphatidylinositol （PI） and phosphatidylserine （PS） increased when CPT was 〈 120 rain, and decreased when CPT was 〉 180 min （PC： 1318.89 ± 54.79 vs 1011.18± 59.99, P 〈 0.001; PE： 1504.45± 119.96 vs 1340.80±76.39, P = 0.0019; PI： 201.23 ± 34.82 vs 185.88 ± 17.04, P = 0.2265; PS： 300.43±32.95 vs 286.55± 55.55, P = 0.5054）. All these ALI-associated indexes could be partially reversed by PDTC treatment.展开更多
Separation was reported by Dunn, Hankins and Ghowsi for the case that ions incapillary electrophoresis move opposite to electroosmosis and ions move faster than flow finally they get separated and reach the detector. ...Separation was reported by Dunn, Hankins and Ghowsi for the case that ions incapillary electrophoresis move opposite to electroosmosis and ions move faster than flow finally they get separated and reach the detector. Similar mode for electrokinetic chromatography is reported for p-xylene and toluene separation, which is called reverse direction MECC （micellar electrokinetic capillary chromatography）. The effect of injection time on separation in reverse direction micellar electrokinetic capillary chromatography is investigated. In this study, hydrostatic and diffusion injection were studied.展开更多
Avidin-liposome complex is a specific chiral selector used to separate the enantiomers of D,L-tryptophan,D,L-phenylthiohydantoin -serine（D,L-PTH-Ser）,D,L-phenylthiohydantoin-threonine（D,L-PTH-Thr） and R,S-pioglita...Avidin-liposome complex is a specific chiral selector used to separate the enantiomers of D,L-tryptophan,D,L-phenylthiohydantoin -serine（D,L-PTH-Ser）,D,L-phenylthiohydantoin-threonine（D,L-PTH-Thr） and R,S-pioglitazone hydrochloride in capillary electrochromatography（CEC）.The avidin is immobilized on the phospholipids coated in the capillary.The liposome used for the phospholipid coating contains l,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine-N-（Cap biotinyl）（sodium salt） （Biotinyl-cap-DPPE）（16：0） and different proportions of L-α-phosphatidylserine（PS） in Tris（hydroxymethyl） aminomethane （Tris） buffer at pH 7.4.A good resolution and reproducibility was obtained by coating the capillary with Biotinyl-cap-DPPE/PS （80：20,mol%） followed by immobilization of 1 mg/mL of avidin solution in N-（2-hydroxyethyl） piperazine-N＇-（2-ethanesulfonic acid） （HEPES） buffer at pH 7.4.A comparative study of chiral separation efficiency with different capillary coating methods and preconditioning conditions was conducted.Finally,the electrochromatographic method was successfully used to separate enantiomers of pioglitazone hydrochloride.Therefore,coated CEC will be a promising tool for pharmaceutical enantiomers separation in new drug development.展开更多
In order to determine the optimal mode of capillary electrophoresis for the impurity control of β-lactam antibiotics, different modes and various electrophoresis conditions for the separation of impurities were compa...In order to determine the optimal mode of capillary electrophoresis for the impurity control of β-lactam antibiotics, different modes and various electrophoresis conditions for the separation of impurities were compared.The results showed that micellar electrokinetic capillary chromatography（MEKC） was the optimal separation mode for the impurity profiling of β-lactam antibiotics.In MEKC,not only the common R and S isomers,Δ-2 andΔ-3 isomers,and Z and E isomers,but also the impurities of β-lactam antibiotics could be well separated compared with the capillary zone electrophoresis.Therefore,MECK is the first choice for the separation of impurities of β-lactam antibiotics with capillary electrophoresis（CE）.The optimal separation could be achieved in MEKC by optimizing the pH and the concentrations of buffered saline,micelles and organic solvent（methanol） in running buffer.展开更多
文摘The entropy increase (EI) and the entropy increase per unit time (EIPUT) of the solute zone are chosen as new criteria of separation efficiency in chromatography and electrophoresis. It is verified by grand canonical ensemble (GCE) that the kinetic energy distribution of the solute is a common characteristic of the entropy and the distribution of solute zones.Under the assumptions. EI of the solute system is directly proportional to the logarithm of the difference between one and one half of the substantial separation ratio. the ratio of moles of a sparated solute to its total moles. and EIPUT is direchy proportional to corrected separation rate of separation system. EI or EIPUT is a important bridge between separation efficiency of chromatography or electrophoresis and operating parameters, especially. when nonequilibriumthermodynamics(NET) would be adopted.
基金Project(20235010) support by the NSFC-KOSEF Scientific Cooperation ProgramProject supported by the Program for New Century Talents of University in Henan ProvinceProgram for Backbone Teacher in Henan Province, China
文摘Development of effective chromatographic or electrophoretic separation involves judicious deciding of selection of optimal experimental conditions that can provide an adequate resolution at a reasonable run time for the separation of interested components. Box-Behnken factorial design was effectively applied for the separation optimization of eight structurally related sulfonamides using capillary zone electrophorosis and reverse high performance liquid chromatography. Optimum values for volume ratio of THF to H2O in eluent, column temperature and flow rate of eluent are found as 12 to 88, 35℃ and 1.0 mL/min, respectively. Box-Behnken modified optimization model is extended to separation by capillary electrophoresis (CE). While using CE, a satisfactory separation is achieved with a minimum resolution larger than 1.0 for a separation time less than 10 min.
基金Supported by Grants from the National Natural Science Foundation of China,No.30200269Science and technology projects in Shannxi Province,No.2006k12-G3(6)Science and technology projects in Xi’an city,No.SF1025(3)
文摘AIM： To investigate the relationship between donor liver cold preservation, lung surfactant （LS） changes and acute lung injury （ALI） after liver transplantation. METHODS： Liver transplantation models were estab- lished using male Wistar rats. Donor livers were pre- served in University of Wisconsin solution at 4 ℃ for different lengths of time. The effect of ammonium pyr- rolidinedithiocarbamate （PDTC） on ALI was also detect- ed. All samples were harvested after 3 h reperfusion.The severity of AU was evaluated by lung weight/body weight ratio, lung histopathological score, serum nitric oxide （NO） and endothelin （ET）-I levels, lung tumor necrosis factor （TNF）-α and interleukin （IL）-1β levels. Lung surfactants （LSs） were determined by micellar electrokinetic capillary chromatography. RESULTS： With extended donor liver cold preservation time （CPT）, lung histopathological scores, serum ET-i levels, lung weight/body weight ratio and the level of TNF-α and IL-1β in lung were increased significantly in the 180-min group compared with the sham group （3.16± 0.28 vs 1.12 ± 0.21, P 〈 0.001; 343.59±53.97 vs 141.53± 48.48, P 〈 0.001; 0.00687 ±0.00037 vs 0.00557 ±0.00056, P 〈 0.001; 17.5 ± 3.0 vs 1,3 ± 0.3, P 〈 0.001; 10.8± 2.3 vs 1.8 ± 0.4, P 〈 0.001）, but serum NO levels decreased remarkably （74.67 ± 10.01 vs 24.97 ± 3.18, P 〈 0.001）. The expression of lung phos- phatidylcholine （PC）, phosphatidylethanolamine （PE）, phosphatidylinositol （PI） and phosphatidylserine （PS） increased when CPT was 〈 120 rain, and decreased when CPT was 〉 180 min （PC： 1318.89 ± 54.79 vs 1011.18± 59.99, P 〈 0.001; PE： 1504.45± 119.96 vs 1340.80±76.39, P = 0.0019; PI： 201.23 ± 34.82 vs 185.88 ± 17.04, P = 0.2265; PS： 300.43±32.95 vs 286.55± 55.55, P = 0.5054）. All these ALI-associated indexes could be partially reversed by PDTC treatment.
文摘Separation was reported by Dunn, Hankins and Ghowsi for the case that ions incapillary electrophoresis move opposite to electroosmosis and ions move faster than flow finally they get separated and reach the detector. Similar mode for electrokinetic chromatography is reported for p-xylene and toluene separation, which is called reverse direction MECC （micellar electrokinetic capillary chromatography）. The effect of injection time on separation in reverse direction micellar electrokinetic capillary chromatography is investigated. In this study, hydrostatic and diffusion injection were studied.
文摘Avidin-liposome complex is a specific chiral selector used to separate the enantiomers of D,L-tryptophan,D,L-phenylthiohydantoin -serine（D,L-PTH-Ser）,D,L-phenylthiohydantoin-threonine（D,L-PTH-Thr） and R,S-pioglitazone hydrochloride in capillary electrochromatography（CEC）.The avidin is immobilized on the phospholipids coated in the capillary.The liposome used for the phospholipid coating contains l,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine-N-（Cap biotinyl）（sodium salt） （Biotinyl-cap-DPPE）（16：0） and different proportions of L-α-phosphatidylserine（PS） in Tris（hydroxymethyl） aminomethane （Tris） buffer at pH 7.4.A good resolution and reproducibility was obtained by coating the capillary with Biotinyl-cap-DPPE/PS （80：20,mol%） followed by immobilization of 1 mg/mL of avidin solution in N-（2-hydroxyethyl） piperazine-N＇-（2-ethanesulfonic acid） （HEPES） buffer at pH 7.4.A comparative study of chiral separation efficiency with different capillary coating methods and preconditioning conditions was conducted.Finally,the electrochromatographic method was successfully used to separate enantiomers of pioglitazone hydrochloride.Therefore,coated CEC will be a promising tool for pharmaceutical enantiomers separation in new drug development.
基金National Key New Drug R&D Program Foundation of China(Grant No.2009ZX09313-027)
文摘In order to determine the optimal mode of capillary electrophoresis for the impurity control of β-lactam antibiotics, different modes and various electrophoresis conditions for the separation of impurities were compared.The results showed that micellar electrokinetic capillary chromatography（MEKC） was the optimal separation mode for the impurity profiling of β-lactam antibiotics.In MEKC,not only the common R and S isomers,Δ-2 andΔ-3 isomers,and Z and E isomers,but also the impurities of β-lactam antibiotics could be well separated compared with the capillary zone electrophoresis.Therefore,MECK is the first choice for the separation of impurities of β-lactam antibiotics with capillary electrophoresis（CE）.The optimal separation could be achieved in MEKC by optimizing the pH and the concentrations of buffered saline,micelles and organic solvent（methanol） in running buffer.
