The journal of microcolumn separations : JMS最新文献_第4页

Purity testing of air-sensitive organometallic compounds by capillary supercritical fluid chromatography 毛细管超临界流体色谱法测定空气敏感有机金属化合物的纯度

The journal of microcolumn separations : JMS Pub Date : 2001-07-02 DOI: 10.1002/mcs.1035

I. Bruheim, E. Fooladi, E. Lundanes, T. Greibrokk

{"title":"Purity testing of air-sensitive organometallic compounds by capillary supercritical fluid chromatography","authors":"I. Bruheim, E. Fooladi, E. Lundanes, T. Greibrokk","doi":"10.1002/mcs.1035","DOIUrl":"10.1002/mcs.1035","url":null,"abstract":"Capillary supercritical fluid chromatography with flame ionization detection has been used to test the purity of air-sensitive organometallic compounds such as bisethenepentamethylcyclopentadienylcobalt (Cp*Co(C2H4)2), dicarbonylcyclopentadienylcobalt (CpCo(CO)2), dicarbonylpentamethylcyclopentadienylcobalt (Cp*Co(CO)2), bisethenepentamethyl cyclopentadienylrhodium (Cp*Rh(C2H4)2), bisethenecyclopentadienylrhodium (CpRh(C2H4)2), carbonyl(1,3-dimesitylimidazol-2-ylidene)cyclopentadienylcobalt (CpCo(CO)(carbene)) and ethene(1,3-dimesitylimidazol-2-ylidene)pentamethylcyclopentadienylrhodium (Cp*Rh(C2H4)(carbene)). A sample introduction cell was constructed for loading of 10–40 mg of the air-sensitive compounds in 100% N2 atmosphere. The sample cell was subsequently filled with toluene or pentane and the analytes in solution were injected onto the 50 μm i.d. capillary column using a timed split injector with 60 nL loop. A nonpolar (5% phenylsiloxane/95% methyl siloxane) stationary phase was used and a mobile phase consisting of 100% CO2 with pressure programming. No signs of air-induced decomposition of the analytes were observed and impurities down to 1% could be determined using SFC-FID. © 2001 John Wiley & Sons, Inc. J Micro Sep 13: 156–162, 2001","PeriodicalId":83120,"journal":{"name":"The journal of microcolumn separations : JMS","volume":"13 4","pages":"156-162"},"PeriodicalIF":0.0,"publicationDate":"2001-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/mcs.1035","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"51279040","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: 1

Microcolumn abstracts 微柱凝集抽象

The journal of microcolumn separations : JMS Pub Date : 2001-07-02 DOI: 10.1002/mcs.1038

Douglas E. Raynie

引用次数: 0

Mobility and ionization constant of basic drugs in methanol. Application of nonaqueous background electrolytes for capillary zone electrophoresis based on a conventional pH scale 碱性药物在甲醇中的迁移率和电离常数。非水本底电解质在传统pH标度毛细管区带电泳中的应用

The journal of microcolumn separations : JMS Pub Date : 2001-07-02 DOI: 10.1002/mcs.1034

Simo P. Porras, Pentti Jyske, Marja-Liisa Riekkola, Ernst Kenndler

引用次数: 30

Evaporative light-scattering detection coupled to microcolumn liquid chromatography for the analysis of underivatized amino acids: Sensitivity, linearity of response and comparisons with UV absorbance detection 蒸发光散射检测耦合微柱液相色谱分析欠酸化氨基酸:灵敏度、线性响应和与紫外吸收检测的比较

The journal of microcolumn separations : JMS Pub Date : 2001-07-02 DOI: 10.1002/mcs.1037

Z. Cobb, P. N. Shaw, L. L. Lloyd, N. Wrench, D. A. Barrett

{"title":"Evaporative light-scattering detection coupled to microcolumn liquid chromatography for the analysis of underivatized amino acids: Sensitivity, linearity of response and comparisons with UV absorbance detection","authors":"Z. Cobb, P. N. Shaw, L. L. Lloyd, N. Wrench, D. A. Barrett","doi":"10.1002/mcs.1037","DOIUrl":"10.1002/mcs.1037","url":null,"abstract":"Microcolumn chromatography (1.0 mm to 0.3 mm column i.d.) of underivatized amino acids coupled to evaporative light-scattering (ELS) detection demonstrated good baseline stability using perfluorinated carboxylic acid ion-pairing agents of varying alkyl chain lengths (C2–C8) and concentrations (1–8 mM). Under the gradient elution conditions used, the baseline stability and the limits of detection for amino acids were better with ELS detection than those obtained with UV absorbance detection. Microcolumn chromatography enabled good mass sensitivity to be achieved with the ELS detector with as little as 0.5 ng of amino acid being detectable on-column with a 0.3 mm i.d. column under gradient conditions. Excellent linearity was obtained for calibration standards of four different amino acids over three orders of magnitude (0.5–500 ng on-column; R2=0.98 or better). From the data presented it can be concluded that ELS detection can be advantageously linked with microcolumn chromatography to give better sensitivity and improved linearity compared with conventional chromatography. © 2001 John Wiley & Sons, Inc. J Micro Sep 13: 169–175, 2001","PeriodicalId":83120,"journal":{"name":"The journal of microcolumn separations : JMS","volume":"13 4","pages":"169-175"},"PeriodicalIF":0.0,"publicationDate":"2001-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/mcs.1037","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"51279486","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: 35

Chiral capillary electrophoresis of the methaqualone rotamers: Indication of a stereoselective metabolism 甲喹酮旋体的手性毛细管电泳:立体选择性代谢的指示

The journal of microcolumn separations : JMS Pub Date : 2001-05-21 DOI: 10.1002/mcs.1027

Sandra Zaugg, Wolfgang Thormann

{"title":"Chiral capillary electrophoresis of the methaqualone rotamers: Indication of a stereoselective metabolism","authors":"Sandra Zaugg, Wolfgang Thormann","doi":"10.1002/mcs.1027","DOIUrl":"10.1002/mcs.1027","url":null,"abstract":"Methaqualone (MQ, 2-methyl-3-o-tolylquinazolin-4(3H)-one) is a hypnotic and anticonvulsive drug in which the rotation about the nitrogen-to-aryl bond between the planar 2-methyl-quinazolin-4(3H)-one structure and the o-tolyl moiety is sterically hindered. MQ is thus a chiral substance whose enantiomers are shown to be separable by acidic chiral capillary electrophoresis (CE) in presence of (2-hydroxypropyl)-β-cyclodextrin (OHP-β-CD). Using a pH 2.5 phosphate buffer containing 8 mM OHP-β-CD, chiral discrimination is possible up to an intracapillary temperature of at least 70°C. For a given capillary length, optimized separation is attained at the lowest running temperature. CE is demonstrated to be a simple and an attractive approach for analysis of MQ enantiomers in alkaline extracts of urines that were collected after single-dose administration of a tablet containing 250 mg MQ. Electropherograms obtained with urines collected at different time intervals after drug intake reveal that the size ratio of the two peaks allocated to MQ is changing with time, thus indicating the existence of a stereoselective metabolism of that drug. For unambiguous elucidation of the stereoselectivity, however, chiral analyses of urinary MQ metabolites will have to be undertaken. © 2001 John Wiley & Sons, Inc. J Micro Sep 13: 96–101, 2001","PeriodicalId":83120,"journal":{"name":"The journal of microcolumn separations : JMS","volume":"13 3","pages":"96-101"},"PeriodicalIF":0.0,"publicationDate":"2001-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/mcs.1027","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"51278772","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

Microcolumn abstracts 微柱凝集抽象

The journal of microcolumn separations : JMS Pub Date : 2001-05-21 DOI: 10.1002/mcs.1031

Douglas E. Raynie

引用次数: 0

Pyrolysis GC/MS, present and future (recent past and present needs)* 热解GC/MS，现在和未来(最近的过去和现在的需求)*

The journal of microcolumn separations : JMS Pub Date : 2001-05-21 DOI: 10.1002/mcs.1028

S. C. Moldoveanu

{"title":"Pyrolysis GC/MS, present and future (recent past and present needs)*","authors":"S. C. Moldoveanu","doi":"10.1002/mcs.1028","DOIUrl":"10.1002/mcs.1028","url":null,"abstract":"This article examines several recent advances in pyrolysis gas chromatography/mass spectrometry (Py-GC/MS). Selected aspects in the field are exemplified using original results. Only the pyrolysis component of Py-GC/MS is discussed, the GC/MS component being beyond the purposes of this article. New techniques used in Py-GC/MS are reviewed in the first part. The results obtained using an original technique, pyrolysis-SPME-GC/MS, are presented for cellulose. Also, the use of an internal standard in analytical pyrolysis is discussed. Regarding theoretical aspects of analytical pyrolysis, it is shown that the heating rate of most commercially available pyrolyzers is high enough for performing isothermal pyrolysis of polymers. One other aspect exemplified with original results is the preservation of certain stereochemical features from the parent compound to the pyrolytic fragments. Only one area regarding recent applications of Py-GC/MS is discussed in more detail, namely the analysis in pyrolysates of trace components related to health and environmental issues. The subject is exemplified with original work in analysis of polycyclic aromatic hydrocarbons and heterocyclic amines in pyrolysates. © 2001 John Wiley & Sons, Inc. J Micro Sep 13: 102–125, 2001","PeriodicalId":83120,"journal":{"name":"The journal of microcolumn separations : JMS","volume":"13 3","pages":"102-125"},"PeriodicalIF":0.0,"publicationDate":"2001-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/mcs.1028","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"51278800","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: 48

Identification of thiosteranes in contaminated marine sediments from the Mediterranean Sea by capillary GC-MS and capillary GC-AED* 毛细管气相色谱-质谱法和毛细管气相色谱- aed法测定地中海污染海洋沉积物中的硫代甾烷*

The journal of microcolumn separations : JMS Pub Date : 2001-05-21 DOI: 10.1002/mcs.1026

A. Louati, B. Elleuch, P. Sandra, F. David, A. Saliot, J. Dagaut, J. Oudot

引用次数: 7

Separation of catecholamines by capillary electrophoresis using in-run modified surfaces and covalently bonded surface coatings in capillaries 毛细管电泳分离儿茶酚胺的动态改性表面和共价键合表面涂层

The journal of microcolumn separations : JMS Pub Date : 2001-05-21 DOI: 10.1002/mcs.1029

Heli Sirén, Katariina Vuorensola

{"title":"Separation of catecholamines by capillary electrophoresis using in-run modified surfaces and covalently bonded surface coatings in capillaries","authors":"Heli Sirén, Katariina Vuorensola","doi":"10.1002/mcs.1029","DOIUrl":"10.1002/mcs.1029","url":null,"abstract":"The study was undertaken to improve the separation and the concentration sensitivity of catecholamines by capillary electrophoresis (CE) using laboratory-coated capillaries. The coatings were made by adsorption using in-run modification and by covalent bonding. The coating solutions used in-run contained triethylamine (TEA), glycine or morpholine in acetate (pH 4.0) or phosphate buffers (pH 3.0). In the covalent bonding technique the coating was made with MAPT ((γ-metacryloxypropyl)-trimethoxysilane) using 1, 10, 20, 30, 40, and 50% solutions. The results obtained with the capillaries indicated that coating improved the efficiency of the CE systems in separation of the cationic catecholamines in ammonium acetate and sodium phosphate solutions. Furthermore, the analyses were more reproducible than if they were performed in bare silica capillaries. The highest plate numbers were obtained with the 1% and 50%-MAPT coated capillaries or with 50 mM ammonium acetate–40 mM TEA electrolyte solution, although 20% and 30% MAPT-coated capillaries gave the best resolution for the analytes. © 2001 John Wiley & Sons, Inc. J Micro Sep 13: 126–133, 2001","PeriodicalId":83120,"journal":{"name":"The journal of microcolumn separations : JMS","volume":"13 3","pages":"126-133"},"PeriodicalIF":0.0,"publicationDate":"2001-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/mcs.1029","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"51278883","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: 8

Moving cryogenic modulator for the comprehensive two-dimensional gas chromatography (GC×GC) of surface water contaminants 移动低温调制器的综合二维气相色谱(GC×GC)的地表水污染物

The journal of microcolumn separations : JMS Pub Date : 2001-05-21 DOI: 10.1002/mcs.1030

Jan Beens, Jens Dallüge, Mohamed Adahchour, René J. J. Vreuls, Udo A. Th. Brinkman

{"title":"Moving cryogenic modulator for the comprehensive two-dimensional gas chromatography (GC×GC) of surface water contaminants","authors":"Jan Beens, Jens Dallüge, Mohamed Adahchour, René J. J. Vreuls, Udo A. Th. Brinkman","doi":"10.1002/mcs.1030","DOIUrl":"10.1002/mcs.1030","url":null,"abstract":"The modulation system in a comprehensive two-dimensional gas chromatograph (GC×GC) can be regarded to be the heart of the analyzer. Different ways of modulating the effluent of the first column into very narrow pulses and injecting these onto the fast second column have been demonstrated. Modulation can be established by applying heat, as in the first existing types of modulators, the two-stage heated modulator and the Sweeper system. It can also be performed by applying cooling, as was demonstrated in the “longitudinally modulated cryogenic system.” Cryogenic systems have mechanical and applicational advantages over heated systems, as they are easier to install and maintain and do not need positive temperature differences to remobilize the analytes. A homemade moving cryogenic modulator was evaluated for use in a GC×GC system for the separation of (very) polar and nonpolar surface water contaminants. The results demonstrate that the performance of this less complex modulator is very comparable to the earlier reported types of modulators. It is further demonstrated that GC×GC is a very suitable technique to fully separate complex mixtures, such as surface water contaminants. The obtained separation appeared to be complete and peak identification was facilitated. © 2001 John Wiley & Sons, Inc. J Micro Sep 13: 134–140, 2001","PeriodicalId":83120,"journal":{"name":"The journal of microcolumn separations : JMS","volume":"13 3","pages":"134-140"},"PeriodicalIF":0.0,"publicationDate":"2001-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/mcs.1030","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"51278950","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: 30