The journal of microcolumn separations : JMS最新文献_第7页

Nonaqueous electrochromatography on continuous bed columns of sol–gel bonded large-pore C30 material: Separation of retinyl esters† 溶胶-凝胶键合大孔C30材料连续床柱上的非水电色谱:视黄醇酯的分离

The journal of microcolumn separations : JMS Pub Date : 2001-01-03 DOI: 10.1002/1520-667X(2000)12:11<561::AID-MCS10>3.0.CO;2-0

Line Roed, Elsa Lundanes, Tyge Greibrokk

{"title":"Nonaqueous electrochromatography on continuous bed columns of sol–gel bonded large-pore C30 material: Separation of retinyl esters†","authors":"Line Roed, Elsa Lundanes, Tyge Greibrokk","doi":"10.1002/1520-667X(2000)12:11<561::AID-MCS10>3.0.CO;2-0","DOIUrl":"10.1002/1520-667X(2000)12:11<561::AID-MCS10>3.0.CO;2-0","url":null,"abstract":"A nonaqueous electrochromatographic reversed-phase separation method for retinyl esters using continuous bed columns has been developed. The packing material was C30 modified material large-pore silica (5 μm Nucleosil 4000 Å). The continuous bed columns were prepared by sol–gel bonding in 180 μm inside diameter fused silica capillaries. The mobile phase consisting of 2.5 mM lithium acetate in N,N-dimethylformamide-acetonitrile-methanol (2+7+1, v/v) gave rise to an electroosmotic flow of 1 mm/s at 350 V/cm and 40°C. Using a 36 cm effective length column separation of the commercially available and synthesized standards (all-trans-retinyl acetate, palmitate, heptadecanoate, stearate, oleoate, and linoleoate) was obtained within 12 min. Separation of isomeric retinyl palmitate (13-cis- and all-trans-retinyl palmitate) was also obtained. The selectivity was found to be temperature dependent in the temperature range investigated (30–60°C). The within-day and between-day variations (n=3) of retention times of all-trans-retinyl palmitate were 0.2% relative standard deviation (RSD) and <2.5% RSD, respectively. Further, the within-day and between-day variations (n=3) of peak areas were in both cases <4% RSD using injection. The column examined was stable for more than 1 month of extensive use. Liver extracts from arctic seal were analyzed. © 2001 John Wiley & Sons, Inc. J Micro Sep 12: 561–567, 2000","PeriodicalId":83120,"journal":{"name":"The journal of microcolumn separations : JMS","volume":"12 11","pages":"561-567"},"PeriodicalIF":0.0,"publicationDate":"2001-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/1520-667X(2000)12:11<561::AID-MCS10>3.0.CO;2-0","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50650964","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: 15

Generic approach to chiral separations: Chiral capillary electrophoresis with ternary cyclodextrin mixtures 手性分离的一般方法:三元环糊精混合物手性毛细管电泳

The journal of microcolumn separations : JMS Pub Date : 2001-01-03 DOI: 10.1002/1520-667X(2000)12:11<568::AID-MCS20>3.0.CO;2-T

Roman Szücs, Isabelle Caron, Karen A. Taylor, Steve P. Gee, Paul D. Ferguson, Martin A. Kelly, Jon V. Beaman, Andrew M. Lipczynski, Perry A. Hailey

引用次数: 11

Microcolumn abstracts 微柱凝集抽象

The journal of microcolumn separations : JMS Pub Date : 2001-01-03 DOI: 10.1002/1520-667X(2000)12:11<593::AID-MCS50>3.0.CO;2-M

Douglas E. Raynie

引用次数: 0

Determination of additives in synthetic base oils for gas turbine engines 燃气涡轮发动机合成基础油添加剂的测定

The journal of microcolumn separations : JMS Pub Date : 2001-01-03 DOI: 10.1002/1520-667X(2000)12:11<585::AID-MCS40>3.0.CO;2-O

M. Bernabei, R. Seclì, G. Bocchinfuso

{"title":"Determination of additives in synthetic base oils for gas turbine engines","authors":"M. Bernabei, R. Seclì, G. Bocchinfuso","doi":"10.1002/1520-667X(2000)12:11<585::AID-MCS40>3.0.CO;2-O","DOIUrl":"10.1002/1520-667X(2000)12:11<585::AID-MCS40>3.0.CO;2-O","url":null,"abstract":"Lubricating synthetic oils, used in gas turbine engines of aircraft, are generally made up of esters of branched-chain alcohols. Some additives are added to the base of synthetic oil improving the lubrication performance efficiency and avoiding corrosion, wear, and oxidation phenomena. Antioxidants used are generally composed of hindered phenols or aromatic amines in a concentration range of 0.25–5% (w/w). Antiwear additives are generally made up of phosphorus compounds and they should be less than 3% (w/w). In this paper, two methods are described determining additives found in lubricating oils. Both methods, based on gas chromatographic techniques, were used to measure these additives in several samples of synthetic oils, before and after accelerated oxidation. The first method is based on a gas chromatography mass spectrometer detector in selected ions monitoring, whereas the second one on a flame photometric detector with an optical filter selective for phosphorus compounds. These techniques, because of their selectivity, do not require sample pretreatments other than a dilution and addition of an internal standard and can be a useful tool evaluating ageing of lubricants in gas turbine engines. Analysis of 1–5 mL oil sample can be performed in less than 30 min. Sensitivity, reproducibility, and accuracy data of the methods are reported. ©2001 John Wiley & Sons, Inc. J Micro Sep 12: 585–592, 2000","PeriodicalId":83120,"journal":{"name":"The journal of microcolumn separations : JMS","volume":"12 11","pages":"585-592"},"PeriodicalIF":0.0,"publicationDate":"2001-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/1520-667X(2000)12:11<585::AID-MCS40>3.0.CO;2-O","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50651052","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: 22

Microcolumn abstracts 微柱凝集抽象

The journal of microcolumn separations : JMS Pub Date : 2000-12-19 DOI: 10.1002/1520-667X(2000)12:10<558::AID-MCS5>3.0.CO;2-Z

Douglas E. Raynie

引用次数: 0

Determination of absolute amount extracted by solid-phase microextraction: Different approaches under examination† 固相微萃取绝对萃取量的测定:不同方法的研究

The journal of microcolumn separations : JMS Pub Date : 2000-12-19 DOI: 10.1002/1520-667X(2000)12:10<550::AID-MCS4>3.0.CO;2-P

Ludovic Tuduri, Valérie Desauziers, Jean Louis Fanlo

{"title":"Determination of absolute amount extracted by solid-phase microextraction: Different approaches under examination†","authors":"Ludovic Tuduri, Valérie Desauziers, Jean Louis Fanlo","doi":"10.1002/1520-667X(2000)12:10<550::AID-MCS4>3.0.CO;2-P","DOIUrl":"10.1002/1520-667X(2000)12:10<550::AID-MCS4>3.0.CO;2-P","url":null,"abstract":"Component quantification in a sample by solid-phase microextraction is commonly performed by using a standard calibration with the SPME process. However, in some cases, it is necessary to determine precisely the absolute amount of analytes sorbed onto SPME fibers. Generally, it is estimated using external liquid calibration of the chromatograph. Due to the differences between SPME and liquid injections, this method can be inaccurate. In this paper, its validity was put to the test. First, the external liquid calibration was confronted with a multiple extraction approach previously described in the literature and called the “depletion experiment.” A lack of data correlation led to the development of another method to verify the external liquid calibration. It was based on an extraction of the fiber-sorbed analytes with the same solvent used for external liquid calibration. After checking that quantitative solvent-extraction was achieved, this enabled us to precisely determine the quantity of analytes present in the solvent and to quantify fiber-sorbed analytes. Statistical treatment of the data brought the conclusion that external liquid calibration, under the tested experimental conditions, was suitable to determine the absolute amount of fiber-sorbed analytes. © 2000 John Wiley & Sons, Inc. J Micro Sep 12: 550–557, 2000","PeriodicalId":83120,"journal":{"name":"The journal of microcolumn separations : JMS","volume":"12 10","pages":"550-557"},"PeriodicalIF":0.0,"publicationDate":"2000-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/1520-667X(2000)12:10<550::AID-MCS4>3.0.CO;2-P","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50650656","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: 26

Standard on-column injection: A fast and simple method for large volume injection in medium-resolution gas chromatography† 标准柱上进样:一种在中分辨率气相色谱中快速简便的大体积进样方法

The journal of microcolumn separations : JMS Pub Date : 2000-12-19 DOI: 10.1002/1520-667X(2000)12:10<523::AID-MCS1>3.0.CO;2-S

Hans-Gerd Janssen, Herrald Steenbergen, Jeroen Oomen, Jan Beens

{"title":"Standard on-column injection: A fast and simple method for large volume injection in medium-resolution gas chromatography†","authors":"Hans-Gerd Janssen, Herrald Steenbergen, Jeroen Oomen, Jan Beens","doi":"10.1002/1520-667X(2000)12:10<523::AID-MCS1>3.0.CO;2-S","DOIUrl":"10.1002/1520-667X(2000)12:10<523::AID-MCS1>3.0.CO;2-S","url":null,"abstract":"In gas chromatography (GC) large volume injection of samples containing very high molecular weight analytes presents unique problems. Standard programmed-temperature vaporizing or on-column large volume injection systems cannot be used, mainly due to instrumental difficulties. A new, simple solution to this problem is presented. If short, wide-bore columns are used at carrier gas velocities above optimum, the cloud of vapor formed upon evaporation of the solvent can be rapidly discharged from the system by the column flow alone. Hence, in medium-resolution GC, large sample volumes (e.g., 50 μL) can be injected using a standard on-column injector. Neither a retention gap nor a solvent vapor exit is needed. The absence of column connectors makes this setup extremely rugged. The optimization of the direct on-column large volume injection is described. The applicability of the new technique for the injection of large volumes of triacylglycerides and heavy mineral oil fractions is shown. It is demonstrated that the new technique is relatively insensitive toward solvent composition. This makes the new method eminently suited for combination with gradient liquid chromatography preseparations. © 2000 John Wiley & Sons, Inc. J Micro Sep 12: 523–529, 2000","PeriodicalId":83120,"journal":{"name":"The journal of microcolumn separations : JMS","volume":"12 10","pages":"523-529"},"PeriodicalIF":0.0,"publicationDate":"2000-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/1520-667X(2000)12:10<523::AID-MCS1>3.0.CO;2-S","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50650541","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: 4

Chromatographic properties of reversed phase stationary phases under pressure and electro driven conditions. Effect of buffer composition† 压力和电驱动条件下反相固定相的色谱特性。缓冲液成分的影响

The journal of microcolumn separations : JMS Pub Date : 2000-12-19 DOI: 10.1002/1520-667X(2000)12:10<530::AID-MCS2>3.0.CO;2-X

Jan Jiskra, Tao Jiang, Henk A. Claessens, Carel A. Cramers

{"title":"Chromatographic properties of reversed phase stationary phases under pressure and electro driven conditions. Effect of buffer composition†","authors":"Jan Jiskra, Tao Jiang, Henk A. Claessens, Carel A. Cramers","doi":"10.1002/1520-667X(2000)12:10<530::AID-MCS2>3.0.CO;2-X","DOIUrl":"10.1002/1520-667X(2000)12:10<530::AID-MCS2>3.0.CO;2-X","url":null,"abstract":"Four different reversed-phase (RP) stationary phases (CEC Hypersil C18, Zorbax Rx SIL C18, Zorbax 300 Rx SIL C18 and Zorbax PSM1000/C18) were examined under high-performance liquid chromatographic (pressure-driven, HPLC), and capillary electrochromatographic (electro-driven, CEC) conditions using an acetonitrile mobile phase combined with twenty different buffer systems (different cations, anions, pH and/or ionic strengths). Chromatographic performance tests under HPLC and CEC conditions were carried out using acidic, basic and neutral polar/non-polar compounds. Parameters such as plate number, retention factor and asymmetry were used to describe the behavior of the RP-columns under both HPLC and CEC conditions. The buffer systems differently influence chromatographic characteristics of porous RP-phases under CEC and HPLC conditions. Thus the choice of an appropriate buffer can be critical for an application applied on an entire system. © 2000 John Wiley & Sons, Inc. J Micro Sep 12: 530–540, 2000","PeriodicalId":83120,"journal":{"name":"The journal of microcolumn separations : JMS","volume":"12 10","pages":"530-540"},"PeriodicalIF":0.0,"publicationDate":"2000-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/1520-667X(2000)12:10<530::AID-MCS2>3.0.CO;2-X","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87646208","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: 14

Application of well-defined β-cyclodextrins for the enantioseparation of compounds of technical toxaphene and further organochlorines† 定义良好的β-环糊精在工业毒杀芬和其他有机氯化合物对映体分离中的应用

The journal of microcolumn separations : JMS Pub Date : 2000-12-19 DOI: 10.1002/1520-667X(2000)12:10<541::AID-MCS3>3.0.CO;2-Q

Steffen Ruppe, Walter Vetter, Bernd Luckas, Georg Hottinger

{"title":"Application of well-defined β-cyclodextrins for the enantioseparation of compounds of technical toxaphene and further organochlorines†","authors":"Steffen Ruppe, Walter Vetter, Bernd Luckas, Georg Hottinger","doi":"10.1002/1520-667X(2000)12:10<541::AID-MCS3>3.0.CO;2-Q","DOIUrl":"10.1002/1520-667X(2000)12:10<541::AID-MCS3>3.0.CO;2-Q","url":null,"abstract":"Enantioselective gas chromatography with 11 columns that contained different modified cyclodextrins was applied to chiral organochlorines. We initially investigated columns that contained pure heptakis(6-O-tert-butyldimethylsilyl-2,3-di-O-methyl)-β-cyclodextrin (β-TBDM) and six fractions resulting from liquid chromatographic separation of randomly silylated β-TBDM. Four β-TBDM fractions investigated with liquid chromatography–mass spectroscopy had an excess of 1–4 methyl groups instead of tert-butyldimethylsilyl groups. In contrast to randomly silylated β-TBDM (enantioseparation of all compounds except one), relatively few compounds (2–7 of 21 organochlorines) were enantioresolved on the fractionated chiral stationary phases. No fraction with high enantioselectivity for compounds of technical toxaphene (CTTs) was obtained. A second series of experiments evaluated columns coated with chemically bonded (CB) or polysiloxane-diluted (PD) permethyl-β-cyclodextrin (β-PMCD). Of the two, only CB-β-PMCD separated the enantiomers of CTTs and atropisomeric PCBs and not PD-β-PMCD. Additionally, a column coated with PD-γ-PMCD was tested. © 2000 John Wiley & Sons, Inc. J Micro Sep 12: 541–549, 2000","PeriodicalId":83120,"journal":{"name":"The journal of microcolumn separations : JMS","volume":"12 10","pages":"541-549"},"PeriodicalIF":0.0,"publicationDate":"2000-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/1520-667X(2000)12:10<541::AID-MCS3>3.0.CO;2-Q","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50650592","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

Optimal heating rate in gas chromatography† 气相色谱的最佳加热速率

The journal of microcolumn separations : JMS Pub Date : 2000-12-05 DOI: 10.1002/1520-667X(2000)12:9<508::AID-MCS5>3.0.CO;2-Y

L. M. Blumberg, M. S. Klee

引用次数: 81