The journal of microcolumn separations : JMS最新文献_第6页

On-line solvent evaporator for coupled normal phase-reversed phase high-performance liquid chromatography systems: Heavy polycyclic aromatic hydrocarbons analysis 用于正相-反相耦合高效液相色谱系统的在线溶剂蒸发器:重多环芳烃分析

The journal of microcolumn separations : JMS Pub Date : 2001-03-22 DOI: 10.1002/mcs.1013

Sabrina Moret, Vanì Cericco, Lanfranco S. Conte

引用次数: 11

Automated capillary liquid chromatography for high sensitivity amino acid monitoring 用于高灵敏度氨基酸监测的自动毛细管液相色谱法

The journal of microcolumn separations : JMS Pub Date : 2001-03-22 DOI: 10.1002/mcs.1015

Brendan W. Boyd, Robert T. Kennedy

{"title":"Automated capillary liquid chromatography for high sensitivity amino acid monitoring","authors":"Brendan W. Boyd, Robert T. Kennedy","doi":"10.1002/mcs.1015","DOIUrl":"10.1002/mcs.1015","url":null,"abstract":"An automated method for determination of trace level amino acids in 2-μL samples using on-column sample preconcentration, gradient elution on 50-μm inner diameter (i.d.) capillary columns packed with 5-μm reversed-phase particles, and electrochemical detection is described. The 50-μm i.d. capillary columns were efficiently coupled directly to an autosampler without increasing zone dispersion by preconcentrating derivatized amino acids at the head of the capillary column and minimizing gradient dwell volume. Using this system, the relative standard deviations (RSDs) of retention time for a 16 component amino acid mixture were between 0.2 and 0.8%. Using an automated microinjection method, as little as 0.3 μL of derivatized sample was consumed to perform a 0.25-μL injection with peak area RSDs of 3.0-8.4%, allowing conservation of a majority of the derivatized sample for future analysis. Precision was improved to peak area RSDs of 1.8–4.1% when consuming 1.0 μL of sample per injection. Detection limits were <0.2 nM for most amino acids. The linear solvent strength theory was used to optimize the gradient and allowed resolution of 15 amino acids in 13 min. The final gradient separation was demonstrated to be selective for the neurotransmitter amino acids in the presence of 44 primary amines commonly found in physiological samples. The system was used to characterize amino acid secretion from single pancreatic islets of Langerhans under different physiological conditions with 2 min of temporal resolution. © 2001 John Wiley & Sons, Inc. J Micro Sep 13: 24–32, 2001","PeriodicalId":83120,"journal":{"name":"The journal of microcolumn separations : JMS","volume":"13 1","pages":"24-32"},"PeriodicalIF":0.0,"publicationDate":"2001-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/mcs.1015","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"51278279","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

Microcolumn abstracts 微柱凝集抽象

The journal of microcolumn separations : JMS Pub Date : 2001-03-22 DOI: 10.1002/mcs.1016

Douglas E. Raynie

引用次数: 0

Sorption of hydrophobic organic compounds on nonpolar SPME fibers and dissolved humic organic matter—Part III: Application of the solubility parameter concept to interpret sorption on solid phase microextraction (SPME) fiber coatings 疏水有机化合物在非极性SPME纤维和溶解的腐殖质有机物上的吸附——第三部分:溶解度参数概念在解释固相微萃取(SPME)纤维涂层吸附中的应用

The journal of microcolumn separations : JMS Pub Date : 2001-02-16 DOI: 10.1002/1520-667X(2000)12:12<603::AID-MCS1006>3.0.CO;2-X

Juergen Poerschmann

{"title":"Sorption of hydrophobic organic compounds on nonpolar SPME fibers and dissolved humic organic matter—Part III: Application of the solubility parameter concept to interpret sorption on solid phase microextraction (SPME) fiber coatings","authors":"Juergen Poerschmann","doi":"10.1002/1520-667X(2000)12:12<603::AID-MCS1006>3.0.CO;2-X","DOIUrl":"10.1002/1520-667X(2000)12:12<603::AID-MCS1006>3.0.CO;2-X","url":null,"abstract":"Hydrophobic organic compounds (HOCs) sorption on nonpolar poly(dimethylsiloxane) (PDMS) and polar polyacrylate (PA) fiber coatings is based on partitioning. By applying solubility parameter concept, explaining HOCs' sorption on amorphous polymers including “liquid” SPME coatings, Hildebrand solubility parameters (δ) of these fiber coatings can be calculated using fiber distribution coefficients (Kf). Hildebrand solubility parameters turned out to be decisive parameters for describing sorption on both coatings under study. Calculated solubility parameters of PDMS and PA coatings are within a very narrow range δPDMS=15.0±1.0 (J0.5 cm−1.5) and δPA=22.2±1.0 (J0.5 cm−1.5) when PAH and PCB fiber distribution coefficients are used to calculate data. Solubility parameter of the 7 μm PDMS coating is slightly, but significantly higher than the 100 μm coating. Once calculated, coating solubility parameter may serve to calculate Kf values of hydrophobic analytes based on available physicochemical data including octanol–water coefficients (KOW) and molar volumes (Vm). Sorption coefficients on nonpolar PDMS and polar PA fiber coatings, available in the literature, fit well in this universal one-parameter solubility concept. Fiber distribution coefficients and corresponding octanol–water coefficients follow a strong correlation for analytes of the same “family.” For analytes possessing δi≅21.5 J0.5 cm−1.5, relation Log Kf, PA=Log KOW is valid. © 2001 John Wiley & Sons, Inc. J Micro Sep 12: 603–612, 2000","PeriodicalId":83120,"journal":{"name":"The journal of microcolumn separations : JMS","volume":"12 12","pages":"603-612"},"PeriodicalIF":0.0,"publicationDate":"2001-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/1520-667X(2000)12:12<603::AID-MCS1006>3.0.CO;2-X","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50651124","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: 21

Quantification of testosterone and epitestosterone in human urine by capillary liquid chromatography 毛细管液相色谱法定量测定人尿中睾酮和表睾酮

The journal of microcolumn separations : JMS Pub Date : 2001-02-16 DOI: 10.1002/1520-667X(2000)12:12<623::AID-MCS1008>3.0.CO;2-L

J. Marcos, J. A. Pascual, J. Barbosa, J. Segura

{"title":"Quantification of testosterone and epitestosterone in human urine by capillary liquid chromatography","authors":"J. Marcos, J. A. Pascual, J. Barbosa, J. Segura","doi":"10.1002/1520-667X(2000)12:12<623::AID-MCS1008>3.0.CO;2-L","DOIUrl":"10.1002/1520-667X(2000)12:12<623::AID-MCS1008>3.0.CO;2-L","url":null,"abstract":"A capillary-liquid chromatography (LC) method was developed for the quantification of the endogenous steroids testosterone and epitestosterone in human urine. One milliliter of urine was used for the overall method. Free testosterone was first separated by liquid–liquid extraction with n-pentane at pH 7. Glucuronides of testosterone and epitestosterone were enzymatically hydrolyzed and the free compounds were extracted with n-pentane at pH 11. A capillary column switching system with a low back pressure precolumn (PC) was used for fast loading of large sample volumes (20 μL). Chromatographic separation was carried out on a 15 cm×300 μm inner diameter (i.d.) column, packed with 3 μm Hypersil BDS-C18 at a flow rate of 4 μL/min with isocratic elution and UV absorbance detection (240 nm). Limit of detection for free testosterone was established at 0.5 ng/mL. Limits of detection were established at 1.5 and 3.2 ng/mL for testosterone and epitestosterone, respectively, after being hydrolysed from their glucuronides. Good reproducibility and robustness were observed through the entire calibration range (up to 250 ng/mL). © 2001 John Wiley & Sons, Inc. J Micro Sep 12: 623–629, 2000","PeriodicalId":83120,"journal":{"name":"The journal of microcolumn separations : JMS","volume":"12 12","pages":"623-629"},"PeriodicalIF":0.0,"publicationDate":"2001-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/1520-667X(2000)12:12<623::AID-MCS1008>3.0.CO;2-L","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50651171","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: 9

Microcolumn abstracts 微柱凝集抽象

The journal of microcolumn separations : JMS Pub Date : 2001-02-16 DOI: 10.1002/1520-667X(2000)12:12<637::AID-MCS1010>3.0.CO;2-0

Douglas E. Raynie

引用次数: 0

Monolithic stationary phases for enantioselective capillary electrochromatography† 对映选择性毛细管电色谱的整体固定相

The journal of microcolumn separations : JMS Pub Date : 2001-02-16 DOI: 10.1002/1520-667X(2000)12:12<597::AID-MCS1005>3.0.CO;2-6

Michael Lämmerhofer, Frantisek Svec, Jean M. J. Fréchet, Wolfgang Lindner

引用次数: 42

The use of computerized peak deconvolution for determination of energy barrier to enantiomerization in dynamic gas chromatography† 用计算机峰反褶积法测定动态气相色谱中对映异构化的能垒

The journal of microcolumn separations : JMS Pub Date : 2001-02-16 DOI: 10.1002/1520-667X(2000)12:12<630::AID-MCS1009>3.0.CO;2-I

J. Krupcík, P. Oswald, I. Spánik, P. Májek, M. Bajdichová, P. Sandra, D. W. Armstrong

{"title":"The use of computerized peak deconvolution for determination of energy barrier to enantiomerization in dynamic gas chromatography†","authors":"J. Krupcík, P. Oswald, I. Spánik, P. Májek, M. Bajdichová, P. Sandra, D. W. Armstrong","doi":"10.1002/1520-667X(2000)12:12<630::AID-MCS1009>3.0.CO;2-I","DOIUrl":"10.1002/1520-667X(2000)12:12<630::AID-MCS1009>3.0.CO;2-I","url":null,"abstract":"Computer-assisted peak deconvolution on chromatograms obtained by GC separation of enantiomers of 1-chloro-2,2-dimethylaziridine on modified α-, β-, and γ-cyclodextrin was used to determine the peak areas of enantiomers, prior to (AA, 0, BB, 0) and after the separation (AA, AB). Both Gaussian as well as exponentially modified Gaussian functions were used to approximate the peak shapes in the deconvolution procedures. Determined peak areas were used in the calculation of the rate constants and energy barriers to enantiomerization. A comparison of energy barriers determined using the deconvolution of chromatograms with data published in the literature by classical kinetics shows differences within ±5%. © 2001 John Wiley & Sons, Inc. J Micro Sep 12: 630–636, 2000","PeriodicalId":83120,"journal":{"name":"The journal of microcolumn separations : JMS","volume":"12 12","pages":"630-636"},"PeriodicalIF":0.0,"publicationDate":"2001-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/1520-667X(2000)12:12<630::AID-MCS1009>3.0.CO;2-I","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50651213","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: 9

Fast gas chromatography using vacuum outlet conditions† 快速气相色谱法使用真空出口条件†

The journal of microcolumn separations : JMS Pub Date : 2001-02-16 DOI: 10.1002/1520-667X(2000)12:12<613::AID-MCS1007>3.0.CO;2-R

Marieke Van Deursen, Hans-Gerd Janssen, Jan Beens, Peter Lipman, Roy Reinierkens, Gerard Rutten, Carel Cramers

{"title":"Fast gas chromatography using vacuum outlet conditions†","authors":"Marieke Van Deursen, Hans-Gerd Janssen, Jan Beens, Peter Lipman, Roy Reinierkens, Gerard Rutten, Carel Cramers","doi":"10.1002/1520-667X(2000)12:12<613::AID-MCS1007>3.0.CO;2-R","DOIUrl":"10.1002/1520-667X(2000)12:12<613::AID-MCS1007>3.0.CO;2-R","url":null,"abstract":"In this study the possibility of operating a wide-bore column with an inner diameter of 530 μm at vacuum conditions was investigated as a route towards fast gas chromatography. High analysis speeds can be obtained as a result of the sub-ambient pressure conditions present in the column, and the consequently high diffusion coefficient of the solute in the mobile phase. The advantage of using a wide-bore column is the high sample capacity. To enable vacuum operation through coupling a wide-bore column to a mass spectrometer, three types of restricting the column flow were investigated. The first method uses a narrow bore pre-column (60 cm length×100 μm i.d.), the second method relies on the use of a tapered on column supercritical fluid chromatography restrictor (SFC-restriction), whereas the third method makes use of a micro-injection valve. It was concluded that the best performance was obtained using the narrow-bore column restriction and the SFC-type restriction. Analysis examples in the seconds- and minutes-range are shown, with peak-widths ranging from 0.1 to 2 seconds at half height. It was concluded that with a film-thickness above 1.5 μm, the advantage of the increase in analysis-speed due to low pressures is nullified due to retention time increase on a thick film column. © 2001 John Wiley & Sons, Inc. J Micro Sep 12: 613–622, 2000","PeriodicalId":83120,"journal":{"name":"The journal of microcolumn separations : JMS","volume":"12 12","pages":"613-622"},"PeriodicalIF":0.0,"publicationDate":"2001-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/1520-667X(2000)12:12<613::AID-MCS1007>3.0.CO;2-R","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50651161","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: 39

High capacity headspace sorptive extraction† 高容量顶空吸附萃取†

The journal of microcolumn separations : JMS Pub Date : 2001-01-03 DOI: 10.1002/1520-667X(2000)12:11<577::AID-MCS30>3.0.CO;2-Q

B. Tienpont, F. David, C. Bicchi, P. Sandra

引用次数: 139