The journal of microcolumn separations : JMS最新文献

{"title":"Effect of pore size on speed of chiral separations using packed capillary column SFC","authors":"Yi Shen,&nbsp;Naijun Wu,&nbsp;Qinglin Tang,&nbsp;Zhen Chen,&nbsp;Jerald S. Bradshaw,&nbsp;Milton L. Lee","doi":"10.1002/1520-667X(2000)12:9<475::AID-MCS1>3.0.CO;2-E","DOIUrl":"10.1002/1520-667X(2000)12:9<475::AID-MCS1>3.0.CO;2-E","url":null,"abstract":"<p>β-Cyclodextrin polysiloxane-encapsulated 10-μm silica particles with pore sizes of 80, 300, and 1400 Å were prepared for evaluation in packed capillary column supercritical fluid chromatography with neat carbon dioxide as the mobile phase. The effects of pore size on linear velocity, retention, selectivity, efficiency, resolution, and resolution per unit time were investigated. It was found that at constant pressure, the highest linear velocity was obtained for columns containing particles of 80 Å pores, followed by particles with 1400 Å and then 300 Å pores. The highest column efficiency was achieved using 1400 Å pore particles, indicating that convective mass transfer was generated by a very small portion of mobile phase flowing through the larger pores. The chiral selectivity generally increased as the pore size increased. There was no significant difference between 80 and 1400 Å pore particles in terms of resolution per unit time. Both can be used to achieve rapid separations of small enantiomers, such as (±)-1-phenylalcohol in 3 min. © 2000 John Wiley &amp; Sons, Inc. J Micro Sep 12: 475–481, 2000</p>","PeriodicalId":83120,"journal":{"name":"The journal of microcolumn separations : JMS","volume":"12 9","pages":"475-481"},"PeriodicalIF":0.0,"publicationDate":"2000-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/1520-667X(2000)12:9<475::AID-MCS1>3.0.CO;2-E","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50650950","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}

{"title":"Carrier gas effects on relative retention and resolution in capillary GLC†","authors":"V. G. Berezkin","doi":"10.1002/1520-667X(2000)12:9<515::AID-MCS6>3.0.CO;2-2","DOIUrl":"10.1002/1520-667X(2000)12:9<515::AID-MCS6>3.0.CO;2-2","url":null,"abstract":"<p>It was theoretically and experimentally shown that the nature of carrier gas has an influence on relative retention Rel(<i>P</i>_av) and that the relative retention is linearly dependent on average column pressure <i>P</i>_av under the conditions of conventional capillary gas chromatography (i.e., at carrier gas pressure less than 5 atm). An invariant limiting value of relative retention lim Rel(<i>P</i>_av)=Rel(0) at <i>P</i>_av=0 was suggested as a chromatographic constant of the solute. Exchanging one carrier gas for another has a significant influence on the retention up to variation in elution order. Carrier gas nature and the pressure of the carrier gas are the factors that actively influence the separation. © 2000 John Wiley &amp; Sons, Inc. J Micro Sep 12: 515–519, 2000</p>","PeriodicalId":83120,"journal":{"name":"The journal of microcolumn separations : JMS","volume":"12 9","pages":"515-519"},"PeriodicalIF":0.0,"publicationDate":"2000-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/1520-667X(2000)12:9<515::AID-MCS6>3.0.CO;2-2","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50651482","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}

{"title":"Development of automated in-tube SPME/LC/MS method for drug analysis†","authors":"Hiroyuki Kataoka,&nbsp;Heather L. Lord,&nbsp;Shigeo Yamamoto,&nbsp;Shizuo Narimatsu,&nbsp;Janusz Pawliszyn","doi":"10.1002/1520-667X(2000)12:9<493::AID-MCS3>3.0.CO;2-C","DOIUrl":"10.1002/1520-667X(2000)12:9<493::AID-MCS3>3.0.CO;2-C","url":null,"abstract":"<p>The technique of automated in-tube solid-phase microextraction (SPME) coupled with liquid chromatography/electrospray ionization mass spectrometry (LC/ESI-MS) was developed for the determination of stimulants and β-blockers in biological samples. In-tube SPME is an extraction technique for organic compounds in aqueous samples, in which analytes are extracted from the sample directly into an open tubular capillary column by repeated draw/eject cycles of sample solution. LC/MS analyses of stimulants and β-blockers were initially performed by liquid injection onto a LC column. Five stimulants and nine β-blockers tested in this study gave very simple ESI mass spectra, and strong signals corresponding to [M+H]⁺ were observed for all drugs. The stimulants were separated with a Supelcosil LC-CN column using acetonitrile/50 mM ammonium acetate (15:85) as a mobile phase. The β-blockers were separated with a Hypersil BDS C₁₈ column using acetonitrile/methanol/water/acetic acid (15:15:70:1) as a mobile phase. In order to optimize the extraction of these drugs, several in-tube SPME parameters were examined. The optimum extraction conditions were 15 draw/eject cycles of 30–35 μL of sample in 50–100 mM Tris-HCl (pH 8.5) at a flow rate of 100 μL/min using Omegawax 250 capillary column (Supelco, Bellefonte, PA). The drugs extracted on the capillary column were easily desorbed by mobile phase flow, and carryover of drugs was not observed. Using in-tube SPME/LC/ESI-MS with selected ion monitoring, the calibration curves of drugs were linear in the range of 2–100 ng/mL with correlation coefficients above 0.9982 (n=18), and detection limits (S/N=3) of 0.1–1.2 ng/mL. This technique was successfully applied to the analysis of biological samples, such as urine and serum, without interference peaks. The recoveries of drugs spiked into human urine and serum samples were above 81 and 71%, respectively. © 2000 John Wiley &amp; Sons, Inc. J Micro Sep 12: 493–500, 2000</p>","PeriodicalId":83120,"journal":{"name":"The journal of microcolumn separations : JMS","volume":"12 9","pages":"493-500"},"PeriodicalIF":0.0,"publicationDate":"2000-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/1520-667X(2000)12:9<493::AID-MCS3>3.0.CO;2-C","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50651092","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}

{"title":"Simultaneous determination of polymer average molar mass and molar mass distribution, and concentration of additives by GPC–GC†","authors":"Nobuya Kobayashi,&nbsp;Hiromi Arimoto,&nbsp;Yuzuru Nishikawa","doi":"10.1002/1520-667X(2000)12:9<501::AID-MCS4>3.0.CO;2-L","DOIUrl":"10.1002/1520-667X(2000)12:9<501::AID-MCS4>3.0.CO;2-L","url":null,"abstract":"<p>In this paper, the gel permeation chromatography–gas chromatography (GPC–GC) method was proposed to carry out determination of average molar masses and molar mass distribution of polymers and concentration of additives simultaneously. In this method, after the determination of average molar masses and molar mass distribution by ordinary GPC, a part of the effluent that contains additives was transferred to GC, and the analysis was done successively. As an apparatus, Shimadzu LC-10A system and GC-17AAFver.3 were applied. Tetrahydrofuran was used as the mobile phase of GPC, and a mixed gel-type column was applied. Repeatability of the analysis was examined using polyvinyl chloride in which plasticizers of phthalic acid esters were added. The R.S.D. for each peak area of plasticizers were within 0.5–2.0%. This GPC–GC method was also available for the analysis of samples that contain additives, such as antioxidants. © 2000 John Wiley &amp; Sons, Inc. J Micro Sep 12: 501–507, 2000</p>","PeriodicalId":83120,"journal":{"name":"The journal of microcolumn separations : JMS","volume":"12 9","pages":"501-507"},"PeriodicalIF":0.0,"publicationDate":"2000-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/1520-667X(2000)12:9<501::AID-MCS4>3.0.CO;2-L","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50651403","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}

{"title":"Diluted modified cyclodextrins as chiral stationary phases in capillary gas chromatography–octakis(2,3-di-O-propionyl-6-O-tert-butyldimethylsilyl)-γ-cyclodextrin","authors":"Thomas Beck,&nbsp;Jan Nandzik,&nbsp;Armin Mosandl","doi":"10.1002/1520-667X(2000)12:9<482::AID-MCS2>3.0.CO;2-J","DOIUrl":"10.1002/1520-667X(2000)12:9<482::AID-MCS2>3.0.CO;2-J","url":null,"abstract":"<p>The synthesis of octakis(2,3-di-<i>O</i>-propionyl-6-<i>O</i>-<i>tert</i>-butyldimethylsilyl)-γ-cyclodextrin and its use as chiral stationary phase in capillary gas chromatography is described. Separation factors and thermodynamic parameters of several chiral compounds on two columns with different cyclodextrin content and different polysiloxanes as diluting phase are investigated. © 2000 John Wiley &amp; Sons, Inc. J Micro Sep 12: 482–492, 2000</p>","PeriodicalId":83120,"journal":{"name":"The journal of microcolumn separations : JMS","volume":"12 9","pages":"482-492"},"PeriodicalIF":0.0,"publicationDate":"2000-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/1520-667X(2000)12:9<482::AID-MCS2>3.0.CO;2-J","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50651024","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}

{"title":"Microcolumn abstracts","authors":"Douglas E. Raynie","doi":"10.1002/1520-667X(2000)12:9<520::AID-MCS7>3.0.CO;2-D","DOIUrl":"https://doi.org/10.1002/1520-667X(2000)12:9<520::AID-MCS7>3.0.CO;2-D","url":null,"abstract":"","PeriodicalId":83120,"journal":{"name":"The journal of microcolumn separations : JMS","volume":"12 9","pages":"520-521"},"PeriodicalIF":0.0,"publicationDate":"2000-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/1520-667X(2000)12:9<520::AID-MCS7>3.0.CO;2-D","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134802652","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}

{"title":"Fast liquid chromatography/time-of-flight mass spectrometry using sol-gel bonded continuous-bed capillary columns","authors":"David C. Collins,&nbsp;Qinglin Tang,&nbsp;Naijun Wu,&nbsp;Milton L. Lee","doi":"10.1002/1520-667X(2000)12:8<442::AID-MCS2>3.0.CO;2-Q","DOIUrl":"10.1002/1520-667X(2000)12:8<442::AID-MCS2>3.0.CO;2-Q","url":null,"abstract":"<p>Continuous-bed capillary columns of 50 μm inside diameter, 360 μm outside diameter containing sol-gel bonded large pore octadecylsilica particles (3 μm, 1500 Å) were examined for potential use in fast liquid chromatographic separations. Selected triazine herbicides and benzodiazepines were separated and detected using time-of-flight mass spectrometry. Interfacing and ionization were achieved through a home-built liquid sheath electrospray ionization interface. Demonstration of optimum column performance was achieved through baseline separation of triazine herbicides using a column 25 cm in length. A short column, cut to the minimum physical distance between the column injector and the interface plate of the mass spectrometer (9.3 cm), was used to achieve separation of eight triazine herbicides and seven benzodiazepines in 40 and 35 s, respectively. A maximum syringe pump pressure (43 MPa) was applied to the shortened column, and conditions were optimized to obtain the best separation in the shortest amount of time for both triazine herbicides and benzodiazepines. The advantages of using time-of-flight mass spectrometry as a detector for fast separations are discussed. © 2000 John Wiley &amp; Sons, Inc. J Micro Sep 12: 442–449, 2000</p>","PeriodicalId":83120,"journal":{"name":"The journal of microcolumn separations : JMS","volume":"12 8","pages":"442-449"},"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<442::AID-MCS2>3.0.CO;2-Q","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50651295","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}

{"title":"Fluorimetric detection of magnesium and aluminum via complexation with oxine in microcolumn liquid chromatography†","authors":"Toyohide Takeuchi,&nbsp;Shiro Inoue,&nbsp;Tomoo Miwa","doi":"10.1002/1520-667X(2000)12:8<450::AID-MCS3>3.0.CO;2-S","DOIUrl":"10.1002/1520-667X(2000)12:8<450::AID-MCS3>3.0.CO;2-S","url":null,"abstract":"<p>Aluminum and magnesium were determined by fluorimetric detection via pre-column and/or in-column derivatization with 8-hydroxyquinoline (oxine) in microcolumn liquid chromatography. Since most oxine complexes are not very stable, the aluminum complex was selectively detected when the eluent contained no oxine, whereas the aluminum and magnesium complexes could be detected when the eluent contained oxine. The sensitivity was improved by on-column detection, viz., the detection in the presence of the stationary phase. The eluent conditions were optimized in terms of the sensitivity. © 2000 John Wiley &amp; Sons, Inc. J Micro Sep 12: 450–453, 2000</p>","PeriodicalId":83120,"journal":{"name":"The journal of microcolumn separations : JMS","volume":"12 8","pages":"450-453"},"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<450::AID-MCS3>3.0.CO;2-S","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50650844","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}

{"title":"Microcolumn abstracts","authors":"Douglas E. Raynie","doi":"10.1002/1520-667X(2000)12:8<470::AID-MCS6>3.0.CO;2-H","DOIUrl":"https://doi.org/10.1002/1520-667X(2000)12:8<470::AID-MCS6>3.0.CO;2-H","url":null,"abstract":"","PeriodicalId":83120,"journal":{"name":"The journal of microcolumn separations : JMS","volume":"12 8","pages":"470-471"},"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<470::AID-MCS6>3.0.CO;2-H","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134804763","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}

{"title":"Fast chiral separations using packed capillary columns and near-critical fluid carbon dioxide mobile phase","authors":"Naijun Wu,&nbsp;Zhen Chen,&nbsp;Juan Carlos Medina,&nbsp;Jerald S. Bradshaw,&nbsp;Milton L. Lee","doi":"10.1002/1520-667X(2000)12:8<454::AID-MCS4>3.0.CO;2-D","DOIUrl":"10.1002/1520-667X(2000)12:8<454::AID-MCS4>3.0.CO;2-D","url":null,"abstract":"<p>In this study, fast chiral separations were demonstrated using near-critical carbon dioxide as mobile phase. Most separations were carried out in less than 1 min at 30°C using 12–15 cm capillary columns packed with 5 μm porous (300 Å) silica particles deactivated with 3-cyanopropyldimethylchlorosilane and encapsulated with cyclodextrin-substituted polymethylsiloxane. The fastest separation was accomplished in 36 s. Effects of surface deactivation, temperature, pressure, and restrictor internal diameter on performance were investigated. Results show that 3-cyanopropyldimethylchlorosilane was a better deactivation reagent than polymethylhydrosiloxane. Near-critical fluid chromatography, which is classified along with supercritical fluid chromatography (SFC) in this paper, is more suitable for fast separation of enantiomers than open tubular column gas chromatography (GC). SFC can be performed under low temperatures and high pressures, which allow high selectivity and high speed. Temperature had a significant effect on retention factor, selectivity, resolution, and resolution per unit time. Pressure had little effect on selectivity but had a considerable effect on retention factor and resolution. Finally, dimensions of the linear restrictor (in other words, the pressure at the end of the column) had a significant influence on speed and resolution. © 2000 John Wiley &amp; Sons, Inc. J Micro Sep 12: 454–461, 2000</p>","PeriodicalId":83120,"journal":{"name":"The journal of microcolumn separations : JMS","volume":"12 8","pages":"454-461"},"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<454::AID-MCS4>3.0.CO;2-D","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50650893","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}