The journal of microcolumn separations : JMS最新文献_第5页

Packed capillary column solvating gas chromatography using neat water mobile phase and flame ionization detection 采用纯水流动相和火焰电离检测的填充毛细管柱溶剂化气相色谱法

The journal of microcolumn separations : JMS Pub Date : 2001-04-20 DOI: 10.1002/mcs.1019

Naijun Wu, Qinglin Tang, J. Andreas Lippert, Milton L. Lee

{"title":"Packed capillary column solvating gas chromatography using neat water mobile phase and flame ionization detection","authors":"Naijun Wu, Qinglin Tang, J. Andreas Lippert, Milton L. Lee","doi":"10.1002/mcs.1019","DOIUrl":"10.1002/mcs.1019","url":null,"abstract":"Neat water at temperatures above its normal boiling point was used as a mobile phase for packed capillary column chromatography. The “universal” flame ionization detector (FID) was used for detection. No restrictor or back pressure was imposed at the column outlet. The effects of temperature on column efficiency and retention were investigated using particle-bonded continuous bed columns packed and crosslinked with 3 μm polybutadiene-encapsulated zirconia particles. It was found that when the column inlet pressure was held constant and the temperature was increased to values that were higher than 100°C, the pressure drop decreased rapidly, allowing the use of long columns or small particles. Solute retention factors decreased with increasing temperature; however, column inlet pressure had little effect on retention factor. Mass transfer resistance also decreased with an increase in temperature. Mixtures of alcohols and phenols could be separated within several minutes after the interface between the column and the FID was optimized. © 2001 John Wiley & Sons, Inc. J Micro Sep 13: 41–47, 2001","PeriodicalId":83120,"journal":{"name":"The journal of microcolumn separations : JMS","volume":"13 2","pages":"41-47"},"PeriodicalIF":0.0,"publicationDate":"2001-04-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/mcs.1019","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"51278335","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

Optimization of accelerated solvent extraction for the analysis of munitions residues in sediment samples 加速溶剂萃取法分析沉积物样品中弹药残留的优化

The journal of microcolumn separations : JMS Pub Date : 2001-04-20 DOI: 10.1002/mcs.1021

Francis I. Onuska, A. H. El-Shaarawi, K. Terry, Eny M. Vieira

{"title":"Optimization of accelerated solvent extraction for the analysis of munitions residues in sediment samples","authors":"Francis I. Onuska, A. H. El-Shaarawi, K. Terry, Eny M. Vieira","doi":"10.1002/mcs.1021","DOIUrl":"10.1002/mcs.1021","url":null,"abstract":"Accelerated solvent extraction (ASE) has been compared with a Soxhlet extraction for extracting and estimating the concentration of hexahydro-1,3,5-trinitro-s-triazine (RDX) and octahydro-1,3,5,7-tetrazocine (HMX) in sediment samples. Extraction of RDX and HMX was studied in terms of process kinetics and recovery. A three factor, 16 run triplicate experimental design was used to generate data on each of two extraction solvents, acetonitrile and a mixture of acetone–methanol (1:1). Response surface methods were used to model the dependence of the concentration on the experimental conditions and to establish the optimum extraction conditions. The results were complex in that several interactions were found among analyte, method, and solvent. Acetonitrile was superior to acetone–methanol for RDX and HMX from the perspectives of kinetics and recovery, due in part to a much higher solubility. The accelerated solvent extraction generally recovered more than the Soxhlet. In terms of sample throughput, the accelerated solvent extraction offers advantages over the Soxhlet. A spike recovery study using fortified sediment yielded complete recoveries of HMX and RDX. © 2001 John Wiley & Sons, Inc. J Micro Sep 13: 54–61, 2001","PeriodicalId":83120,"journal":{"name":"The journal of microcolumn separations : JMS","volume":"13 2","pages":"54-61"},"PeriodicalIF":0.0,"publicationDate":"2001-04-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/mcs.1021","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"51278522","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: 7

Electrophoretic separations in PMMA capillaries with uniform and discontinuous buffers 均匀和不连续缓冲液在PMMA毛细管中的电泳分离

The journal of microcolumn separations : JMS Pub Date : 2001-04-20 DOI: 10.1002/mcs.1023

Jitka Caslavska, Wolfgang Thormann

{"title":"Electrophoretic separations in PMMA capillaries with uniform and discontinuous buffers","authors":"Jitka Caslavska, Wolfgang Thormann","doi":"10.1002/mcs.1023","DOIUrl":"10.1002/mcs.1023","url":null,"abstract":"The basic phenomena occurring within polymethylmethacrylate (PMMA, Plexiglass) capillaries under the conditions of capillary zone electrophoresis (CZE), isotachophoresis (CITP), and isoelectric focusing (CIEF) have been explored in our laboratory and are compared to those characteristic for untreated fused-silica (FS) capillaries. The origin of charge at the inner wall of the PMMA capillary is different compared to that of FS, this having a significant impact on the magnitude of the electroosmotic flow. While both column materials are characterized with a negative surface charge, electroosmosis in PMMA is considerably smaller over the entire pH range. Furthermore, electroosmosis in PMMA and FS is shown to follow different dependencies on the ionic strength (I). Using a set of experimentally determined values, the electroosmotic mobility (μEO) of a PMMA capillary is best described using the relationship μEO=a+b/√I. For a FS capillary, μEO follows the expression μEO=a+b log(I). A dynamic capillary electrophoresis simulation model comprising the determined pH and ionic strength dependent wall titration data as input for calculation of electroosmosis is shown to provide CZE and CITP electropherograms that qualitatively agree well with those obtained experimentally. In contrast to FS and glass, electroosmosis at any pH in PMMA is too weak to perform bidirectional (i.e., simultaneous cationic and anionic) CZE and CITP analyses with a detector placed toward the cathodic capillary end. Furthermore, the same is true for the performance of CIEF with electroosmotic zone displacement. Imposed flow is demonstrated to provide the required net buffer flow. © 2001 John Wiley & Sons, Inc. J Micro Sep 13: 69–83, 2001","PeriodicalId":83120,"journal":{"name":"The journal of microcolumn separations : JMS","volume":"13 2","pages":"69-83"},"PeriodicalIF":0.0,"publicationDate":"2001-04-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/mcs.1023","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"51278214","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: 31

Chiral selective separation of tocainide by capillary electrophoresis using various cyclodextrin derivatives 不同环糊精衍生物毛细管电泳手性选择性分离托卡因胺

The journal of microcolumn separations : JMS Pub Date : 2001-04-20 DOI: 10.1002/mcs.1022

Zoltán Juvancz, Karin E. Markides, László Jicsinszky, Róbert Iványi

引用次数: 5

Optimization and validation by SPE-CGC-MSD of the analysis of tributyltin in environmental samples 环境样品中三丁基锡的SPE-CGC-MSD分析优化与验证

The journal of microcolumn separations : JMS Pub Date : 2001-04-20 DOI: 10.1002/mcs.1020

J. M. F. Nogueira, P. Teixeira, M. H. Florêncio

{"title":"Optimization and validation by SPE-CGC-MSD of the analysis of tributyltin in environmental samples","authors":"J. M. F. Nogueira, P. Teixeira, M. H. Florêncio","doi":"10.1002/mcs.1020","DOIUrl":"10.1002/mcs.1020","url":null,"abstract":"The optimization by SPE-CGC-MSD methodology of the analysis of tributyltin in environmental samples is presented. Fifteen assays with certified reference material for sediment matrices (54±15 ng/g), as well as with in-house standards for aqueous matrices (50 ng), were performed using solid phase extraction for tributyltin speciation, which was shown to be easy, solventless, and fast. The solid phase extraction tube was preconditioned with ethyl acetate to remove possible impurities, conditioned with methanol, water, and HCl 5% and after tributyltin extraction, washed again with HCl 5% and water, and finally eluted with ethyl acetate. Subsequently the samples were derivatized with methyl magnesium bromide in a diethylether solution, concentrated, injected in the splitless mode, separated by capillary gas chromatography, and detected by mass spectrometry in the selected ion-monitoring mode. The results obtained showed a value of 50±18 ng/g for tributyltin in the sediment matrices assays which, according to European Co-operation for Accreditation of Laboratories guidance for interlaboratory comparisons, led to a deviation normalized lower than 0.2, showing that the SPE-CGC-MSD methodology is validated for TBT speciation in sediment samples, due to the high accuracy reached. For the in-house standard aqueous matrices assays, a value of 44±21 ng gave recoveries higher than 85%, showing that this methodology is also validated, due to the substantial accuracy for tributyltin speciation in aqueous samples. © 2001 John Wiley & Sons, Inc. J Micro Sep 13: 48–53, 2001","PeriodicalId":83120,"journal":{"name":"The journal of microcolumn separations : JMS","volume":"13 2","pages":"48-53"},"PeriodicalIF":0.0,"publicationDate":"2001-04-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/mcs.1020","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"51278480","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: 11

Microcolumn abstracts 微柱凝集抽象

The journal of microcolumn separations : JMS Pub Date : 2001-04-20 DOI: 10.1002/mcs.1024

Douglas E. Raynie

引用次数: 0

New editorial board members 编委会新成员

The journal of microcolumn separations : JMS Pub Date : 2001-04-20 DOI: 10.1002/mcs.1018

引用次数: 0

Fluorimetric detection of cyclodextrins via complexation with fluorescence probe in microcolumn liquid chromatography 微柱液相色谱中荧光探针络合环糊精的荧光检测

The journal of microcolumn separations : JMS Pub Date : 2001-03-22 DOI: 10.1002/mcs.1014

Toyohide Takeuchi, Yuko Kitamaki, Tomoo Miwa

引用次数: 2

Monodisperse polymer-based stationary phase for carbohydrate analysis by reduced-diameter column anion-exchange chromatography with pulsed amperometric detector 用小直径柱阴离子交换色谱脉冲安培检测器分析碳水化合物的单分散聚合物基固定相

The journal of microcolumn separations : JMS Pub Date : 2001-03-22 DOI: 10.1002/mcs.1012

Aya Ohkubo, Osamu Shirota, Atsushi Kobayashi, Tomohiko Kimura, Yutaka Ohtsu, Ken Hosoya, Nobuo Tanaka

引用次数: 1

The use of solid-phase microextraction/gas chromatography-mass spectrometry for the determination of degradation products of volatile and semivolatile compounds 采用固相微萃取/气相色谱-质谱法测定挥发性和半挥发性化合物的降解产物

The journal of microcolumn separations : JMS Pub Date : 2001-03-22 DOI: 10.1002/mcs.1011

Kenneth G. Karaisz, Nicholas H. Snow

{"title":"The use of solid-phase microextraction/gas chromatography-mass spectrometry for the determination of degradation products of volatile and semivolatile compounds","authors":"Kenneth G. Karaisz, Nicholas H. Snow","doi":"10.1002/mcs.1011","DOIUrl":"10.1002/mcs.1011","url":null,"abstract":"One of the more important applications in the pharmaceutical and personal care industries is the determination of degradation products in volatile and semivolatile compounds. The conventional approaches to these studies often utilize time-consuming and labor-intensive techniques in conjunction with potentially hazardous solvents. A new approach developed in our laboratory using solid-phase microextraction (SPME) in conjunction with gas chromatography-mass spectrometry (GC/MS) to determine degradation products for volatile and semivolatile organic compounds is described. The approach was evaluated by the measurement of diphenhydramine hydrochloride, a known over-the-counter (active) pharmaceutical product. Aqueous solutions of diphenhydramine HCl were subjected to stress and subsequently examined using SPME-GC/MS. The hydrolysis degradation products benzhydrol, benzophenone, and dimethylaminoethanol were detected. Solid diphenhydramine was thermally stressed and subsequently examined by headspace SPME/GC-MS. The thermal degradation products detected were dimethylaminoethanol, diphenylmethane, diphenylchloromethane, benzhydrol, and benzophenone. These results were in agreement with degradation studies in the literature performed on diphenhydramine HCl using conventional approaches. SPME-GC/MS was then used to determine the acid hydrolysis degradation product for a cosmetic preservative iodopropynyl butyl carbamate (3-iodo-2-propynyl-n-butyl carbamate) also known as IPBC. SPME/GC-MS analysis of an acid-stressed IPBC solution yielded evidence of the compound 3-iodo-2-chloro-2-propenyl-n-butyl carbamate, indicative of addition of HCl across the triple bond of IPBC. © 2001 John Wiley & Sons, Inc. J Micro Sep 13: 1–7, 2001","PeriodicalId":83120,"journal":{"name":"The journal of microcolumn separations : JMS","volume":"13 1","pages":"1-7"},"PeriodicalIF":0.0,"publicationDate":"2001-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/mcs.1011","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"51277962","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: 16