The journal of microcolumn separations : JMS最新文献_第9页

Ultrahigh pressure liquid chromatography/time-of-flight mass spectrometry for fast separations 超高压液相色谱/飞行时间质谱法用于快速分离

The journal of microcolumn separations : JMS Pub Date : 2000-11-10 DOI: 10.1002/1520-667X(2000)12:8<462::AID-MCS5>3.0.CO;2-F

Naijun Wu, David C. Collins, J. Andreas Lippert, Yanqiao Xiang, Milton L. Lee

{"title":"Ultrahigh pressure liquid chromatography/time-of-flight mass spectrometry for fast separations","authors":"Naijun Wu, David C. Collins, J. Andreas Lippert, Yanqiao Xiang, Milton L. Lee","doi":"10.1002/1520-667X(2000)12:8<462::AID-MCS5>3.0.CO;2-F","DOIUrl":"10.1002/1520-667X(2000)12:8<462::AID-MCS5>3.0.CO;2-F","url":null,"abstract":"Recently, ultrahigh pressure liquid chromatography (UHPLC) has been shown to overcome the pressure limitations that small particles impose on conventional pumping systems. High speed separations in UHPLC produce peak widths that range between 100 to 1000 ms, of which many are too narrow to be monitored by scanning mass spectrometers. The only mass spectrometer that is fast enough for such separations is the time-of-flight mass spectrometer (TOFMS). State-of-the-art TOFMS instruments for liquid chromatography can record and store complete mass spectra at rates as high as 100 spectra s−1. In this study, high speed separations with high resolution were demonstrated using 13–15 cm×29–100 μm i.d. capillaries packed with 1.5 μm nonporous octadecylsilane- and isohexylsilane-modified silica particles utilizing a home-built UHPLC system. The UHPLC system was successfully coupled to TOFMS via a liquid-sheath electrospray interface. Separations of selected combinatorial chemistry samples, pharmaceutical compounds, and herbicides were completed in less than 100 s using UHPLC/TOFMS. Total column efficiencies ranged from 20,000–30,000 plates. The fundamental and practical aspects of UHPLC/TOFMS are discussed. Results are compared with those obtained from typical capillary LC. © 2000 John Wiley & Sons, Inc. J Micro Sep 12: 462–469, 2000","PeriodicalId":83120,"journal":{"name":"The journal of microcolumn separations : JMS","volume":"12 8","pages":"462-469"},"PeriodicalIF":0.0,"publicationDate":"2000-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/1520-667X(2000)12:8<462::AID-MCS5>3.0.CO;2-F","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50650932","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 54

Characterization of chemical selectivity in micellar electrokinetic chromatography: V. The effect of the surfactant hydrophobic chain 胶束电动色谱中化学选择性的表征:V.表面活性剂疏水链的作用

The journal of microcolumn separations : JMS Pub Date : 2000-11-10 DOI: 10.1002/1520-667X(2000)12:8<433::AID-MCS1>3.0.CO;2-R

Mark D. Trone, Morteza G. Khaledi

引用次数: 23

Microcolumn abstracts 微柱凝集抽象

The journal of microcolumn separations : JMS Pub Date : 2000-08-04 DOI: 10.1002/1520-667X(2000)12:7<429::AID-MCS7>3.0.CO;2-W

Douglas E. Raynie

引用次数: 0

Two-dimensional capillary electrophoresis-thin layer chromatography separations of amino acid enantiomers using electro-filament transfer 二维毛细管电泳-电丝转移薄层色谱法分离氨基酸对映体

The journal of microcolumn separations : JMS Pub Date : 2000-08-04 DOI: 10.1002/1520-667X(2000)12:7<419::AID-MCS6>3.0.CO;2-%23

Gerald L. DeVault, Michael J. Sepaniak

{"title":"Two-dimensional capillary electrophoresis-thin layer chromatography separations of amino acid enantiomers using electro-filament transfer","authors":"Gerald L. DeVault, Michael J. Sepaniak","doi":"10.1002/1520-667X(2000)12:7<419::AID-MCS6>3.0.CO;2-%23","DOIUrl":"https://doi.org/10.1002/1520-667X(2000)12:7<419::AID-MCS6>3.0.CO;2-%23","url":null,"abstract":"Capillary electrophoresis (CE) is coupled to thin-layer chromatography (TLC) to demonstrate a convenient technique for performing two-dimensional microseparations. CE is interfaced with electrospray, which is operated in the electro-filament mode to produce a narrow (ca. 20 μm) liquid filament. The liquid filament deposits spatially focused bands (ca. 200 μm wide) onto a TLC plate. The TLC plate stores the separation from the CE capillary in the first dimension and then serves as the stationary phase for the chiral separation in the second dimension. Mixtures of dansylated (DNS) derivatives of selected amino acids are separated in the first dimension by the micellar electrokinetic chromatography variation of CE. Reversed-phase TLC separates the enantiomers in the second dimension with a mobile phase containing highly concentrated solutions of β-cyclodextrin. The TLC plates are imaged by using laser-induced fluorescence and a charge-coupled device camera. Prior to TLC development, off-column efficiencies of 130,000 to 190,000 plates per meter were obtained. The enantiomers of four DNS amino acids were baseline resolved using two-dimensional separation and a significant enhancement of the peak capacity over one-dimensional separations is demonstrated. © 2000 John Wiley & Sons, Inc. J Micro Sep 12: 419–428, 2000","PeriodicalId":83120,"journal":{"name":"The journal of microcolumn separations : JMS","volume":"12 7","pages":"419-428"},"PeriodicalIF":0.0,"publicationDate":"2000-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134879080","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Pressurized hot water extraction (PHWE) of n-alkanes and polyaromatic hydrocarbons (PAHs): Comparison for PAHs with supercritical fluid extraction† 高压热水萃取(PHWE)正构烷烃和多芳烃(PAHs):超临界流体萃取法对PAHs的比较

The journal of microcolumn separations : JMS Pub Date : 2000-08-04 DOI: 10.1002/1520-667X(2000)12:7<412::AID-MCS5>3.0.CO;2-N

Kari Hartonen, Georg Meissner, Taru Kesälä, Marja-Liisa Riekkola

{"title":"Pressurized hot water extraction (PHWE) of n-alkanes and polyaromatic hydrocarbons (PAHs): Comparison for PAHs with supercritical fluid extraction†","authors":"Kari Hartonen, Georg Meissner, Taru Kesälä, Marja-Liisa Riekkola","doi":"10.1002/1520-667X(2000)12:7<412::AID-MCS5>3.0.CO;2-N","DOIUrl":"10.1002/1520-667X(2000)12:7<412::AID-MCS5>3.0.CO;2-N","url":null,"abstract":"High-temperature liquid water and steam were used to extract n alkanes and polyaromatic hydrocarbons (PAHs) from spiked sea sand at different temperatures. Pressurized hot water extraction (PHWE) was followed by solid phase collection. Tenax as the trapping material with n-heptane as the eluent gave recoveries larger than 95% for diesel hydrocarbons extracted with steam at 250°C. Recoveries from Tenax of hydrocarbons extracted with liquid water under the same conditions were lower. Good (>90%) recoveries were also obtained for low molecular weight PAHs, extracted with steam at 250°C and with n-heptane as eluent for the Tenax trap. n-Heptane containing 10% ethyl acetate was more efficient, eluting high as well as low molecular weight PAHs with good recovery. PHWE was also tested in the extraction of a real sediment sample certified for PAHs, and the results were compared with those obtained with supercritical fluid extraction (SFE) using neat CO2 and modified CO2. Steam at 250°C and 300°C gave similar recoveries as those obtained by SFE with use of a modifier. © 2000 John Wiley & Sons, Inc. J Micro Sep 12: 412–418, 2000","PeriodicalId":83120,"journal":{"name":"The journal of microcolumn separations : JMS","volume":"12 7","pages":"412-418"},"PeriodicalIF":0.0,"publicationDate":"2000-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/1520-667X(2000)12:7<412::AID-MCS5>3.0.CO;2-N","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50651132","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 43

Two-dimensional electrophoretic/chromatographic separations combined with electrospray ionization FTICR mass spectrometry for high throughput proteome analysis 二维电泳/色谱分离结合电喷雾电离FTICR质谱进行高通量蛋白质组分析

The journal of microcolumn separations : JMS Pub Date : 2000-08-04 DOI: 10.1002/1520-667X(2000)12:7<383::AID-MCS1>3.0.CO;2-S

Hongying Gao, Yufeng Shen, Timothy D. Veenstra, Richard Harkewicz, Gordon A. Anderson, James E. Bruce, Ljiljana Pasa-Tolic, Richard D. Smith

{"title":"Two-dimensional electrophoretic/chromatographic separations combined with electrospray ionization FTICR mass spectrometry for high throughput proteome analysis","authors":"Hongying Gao, Yufeng Shen, Timothy D. Veenstra, Richard Harkewicz, Gordon A. Anderson, James E. Bruce, Ljiljana Pasa-Tolic, Richard D. Smith","doi":"10.1002/1520-667X(2000)12:7<383::AID-MCS1>3.0.CO;2-S","DOIUrl":"10.1002/1520-667X(2000)12:7<383::AID-MCS1>3.0.CO;2-S","url":null,"abstract":"A two-dimensional separation strategy combined with electrospray ionization-Fourier transform ion cyclotron resonance mass spectrometry (ESI-FTICR) is being developed for high throughput proteomic analyses. Capillary isoelectric focusing (CIEF) coupled online with a robotic fraction collector is used to separate and collect microliter fractions of soluble Saccharomyces cerevisiae (yeast) proteins eluting from the capillary into a microtiter plate. Following tryptic digestion of each fraction, the resultant peptides are separated using capillary high performance liquid chromatography (HPLC) and analyzed by online ESI-FTICR. Protein identification is based upon the use of the experimentally measured peptide masses as accurate mass tags, augmented by conventional MS/MS methods as necessary, to identify proteins predicted from the yeast genome sequence. This new separation strategy is being evaluated using proteins extracted from yeast grown in natural isotopic abundance and 15N-enriched media. Two isotopically distinct versions of each peptide are thus observed in the ESI-FTICR spectra. The mass differences between the two versions are used to determine the number of nitrogen atoms in the peptide, and provide an additional constraint that aids protein identification. More importantly, the use of this stable-isotope labeling strategy enables the generation of “comparative displays” of the precise relative protein abundances. This two-dimensional separation strategy combined with ESI-FTICR analysis is expected to be highly amenable to automation. © 2000 John Wiley & Sons, Inc. J Micro Sep 12: 383–390, 2000","PeriodicalId":83120,"journal":{"name":"The journal of microcolumn separations : JMS","volume":"12 7","pages":"383-390"},"PeriodicalIF":0.0,"publicationDate":"2000-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/1520-667X(2000)12:7<383::AID-MCS1>3.0.CO;2-S","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50650872","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 24

Enantioseparations in nonaqueous and aqueous capillary electrochromatography using helically chiral poly(diphenyl-2-pyridylmethylmethacrylate) as chiral stationary phase 用螺旋手性聚(二苯基-2-吡啶基甲基丙烯酸甲酯)作为手性固定相进行非水和水毛细管电色谱的对映体分离

The journal of microcolumn separations : JMS Pub Date : 2000-08-04 DOI: 10.1002/1520-667X(2000)12:7<398::AID-MCS3>3.0.CO;2-6

Kerstin Krause, Bezhan Chankvetadze, Yoshio Okamoto, Gottfried Blaschke

{"title":"Enantioseparations in nonaqueous and aqueous capillary electrochromatography using helically chiral poly(diphenyl-2-pyridylmethylmethacrylate) as chiral stationary phase","authors":"Kerstin Krause, Bezhan Chankvetadze, Yoshio Okamoto, Gottfried Blaschke","doi":"10.1002/1520-667X(2000)12:7<398::AID-MCS3>3.0.CO;2-6","DOIUrl":"10.1002/1520-667X(2000)12:7<398::AID-MCS3>3.0.CO;2-6","url":null,"abstract":"Capillary electrochromatographic (CEC) enantioseparations were performed in nonaqueous and aqueous-organic background electrolytes (BGE) using fused-silica capillaries packed with native and aminopropyl silica coated with helically chiral poly(diphenyl-2-pyridylmethyl methacrylate) (PDPM) as chiral stationary phase (CSP). The contribution of the aminopropyl groups of the silica gel and the pyridyl groups of the chiral selector to the anodic electroosmotic flow (EOF) generated in these capillaries was evaluated. Furthermore, different nonaqueous BGEs (methanol, acetonitrile) were tested; the influence of the ammonium acetate concentration, the apparent pH (pH*) of the BGE, and the composition of the aqueous-organic BGE were investigated with regard to the EOF and basic chromatographic parameters. The effect of the contributions of a pressure-driven and electrokinetically driven flows and mass transfer characteristics of the stationary phase on the plate heights and enantioseparations was evaluated. © 2000 John Wiley & Sons, Inc. J Micro Sep 12: 398–406, 2000","PeriodicalId":83120,"journal":{"name":"The journal of microcolumn separations : JMS","volume":"12 7","pages":"398-406"},"PeriodicalIF":0.0,"publicationDate":"2000-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/1520-667X(2000)12:7<398::AID-MCS3>3.0.CO;2-6","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50651005","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 24

MEKC with bile salt micelles for the enantiomeric separation of bis(8-((pyridine-2-methylene)amino)quinoline)iron(II) hexafluorophosphate: Kinetics and mechanism of the racemization 胆盐胶束MEKC对映体分离双(8-((吡啶-2-亚甲基)氨基喹啉)铁(II)六氟磷酸:外消旋化动力学及机理

The journal of microcolumn separations : JMS Pub Date : 2000-08-04 DOI: 10.1002/1520-667X(2000)12:7<391::AID-MCS2>3.0.CO;2-U

Eric S. Okerberg, Said Elshihabi, Peter T. Carmichael, Kathryn A. Woody, Timothy A. Barckholtz, John A. Burke Jr., Michelle M. Bushey

{"title":"MEKC with bile salt micelles for the enantiomeric separation of bis(8-((pyridine-2-methylene)amino)quinoline)iron(II) hexafluorophosphate: Kinetics and mechanism of the racemization","authors":"Eric S. Okerberg, Said Elshihabi, Peter T. Carmichael, Kathryn A. Woody, Timothy A. Barckholtz, John A. Burke Jr., Michelle M. Bushey","doi":"10.1002/1520-667X(2000)12:7<391::AID-MCS2>3.0.CO;2-U","DOIUrl":"10.1002/1520-667X(2000)12:7<391::AID-MCS2>3.0.CO;2-U","url":null,"abstract":"Unsymmetrical tridentate ligands can form meridional optical isomers in octahedral complexes. Micellar electrokinetic chromatography with sodium taurochenodeoxycholate or glycochenodeoxycholate micelles is used to separate the enantiomers of bis(8-((pyridine-2-methylene)amino)quinoline)iron(II) hexafluorophosphate, Fe(PMAQ)2(PF6)2, and it is used to follow the temperature dependence of the racemization of the isolated enantiomers. The racemization is studied over a 20° temperature range (60–80°C), and at four different pH values (3.0, 4.45, 7.0, 9.0). Energies and entropies of activation are reported. There is no significant change in the energy of activation as a function of pH. Simple capillary electrophoretic instrumentation with manual, electrokinetic injection, and ambient run temperature conditions provides reliable kinetic data. Half-lives range from 28 to 640 min. A mechanism involving a trigonal prism transition state is proposed for this racemization process. © 2000 John Wiley & Sons, Inc. J Micro Sep 12: 391–397, 2000","PeriodicalId":83120,"journal":{"name":"The journal of microcolumn separations : JMS","volume":"12 7","pages":"391-397"},"PeriodicalIF":0.0,"publicationDate":"2000-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/1520-667X(2000)12:7<391::AID-MCS2>3.0.CO;2-U","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50650926","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 6

Electrophoretic separation of proteins on microchips 微芯片上蛋白质的电泳分离

The journal of microcolumn separations : JMS Pub Date : 2000-08-04 DOI: 10.1002/1520-667X(2000)12:7<407::AID-MCS4>3.0.CO;2-C

Yingjie Liu, Robert S. Foote, Christopher T. Culbertson, Stephen C. Jacobson, Roswitha S. Ramsey, J. Michael Ramsey

引用次数: 24

Characterization of a comprehensive two-dimensional anion exchange-perfusive reversed phase liquid chromatography system for improved separations of peptides 用于改进多肽分离的综合二维阴离子交换-灌注反相液相色谱系统的表征

The journal of microcolumn separations : JMS Pub Date : 2000-06-16 DOI: 10.1002/1520-667X(2000)12:6<371::AID-MCS6>3.0.CO;2-N

L. A. Holland, J. W. Jorgenson

引用次数: 41