The journal of microcolumn separations : JMS最新文献

Development for the analysis of reactive oxygen species using capillary electrophoresis with laser-induced fluorescence detection 激光诱导荧光毛细管电泳分析活性氧的研究进展

The journal of microcolumn separations : JMS Pub Date : 2001-11-30 DOI: 10.1002/mcs.10014

Eunah Yu, Eunmi Ban, Mun Kyo In, Young Sook Yoo

{"title":"Development for the analysis of reactive oxygen species using capillary electrophoresis with laser-induced fluorescence detection","authors":"Eunah Yu, Eunmi Ban, Mun Kyo In, Young Sook Yoo","doi":"10.1002/mcs.10014","DOIUrl":"10.1002/mcs.10014","url":null,"abstract":"Reactive oxygen species (ROS) have been identified as important chemical mediators that regulate signal transduction pathways. Today, the importance of ROS in pathological events has become increasingly apparent. To monitor the ROS in biological systems, various techniques such as cytochrome c peroxidase assay and malonaldialdehyde detection were developed and used clinically. However, these methods are very laborious and time-consuming. Therefore, in this study, we developed a capillary electrophoresis (CE)-based ROS monitoring technique using dihydrorhodamine 123 (DHR-123). DHR-123 is a nonfluorescent compound, and can be oxidized irreversibly and rapidly by ROS to rhodamine 123 (Rho-123), which is a fluorescent dye. Upon detecting the amount of the fluorescence from Rho-123, we could indirectly quantify the amount of ROS generation in biological systems. Determination of Rho-123 was performed in an uncoated silica capillary (27 cm×75 μm i.d.) using a CE system with laser-induced fluorescence detection. Optimum conditions for the Rho-123 detection were 50 mM borate buffer (pH 10.0), running at 20°C, and 5 s injection. This method allowed the detection of Rho-123 with a detection limit around 50 pM. We also applied this developed method to the analysis of intracellular ROS level in methamphetamine (MA) treated PC12 cells. © 2001 John Wiley & Sons, Inc. J Micro Sep 13: 327–331, 2001","PeriodicalId":83120,"journal":{"name":"The journal of microcolumn separations : JMS","volume":"13 8","pages":"327-331"},"PeriodicalIF":0.0,"publicationDate":"2001-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/mcs.10014","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"51277275","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

Determination of isoelectric point and investigation of immunoreaction in peanut allergenic proteins–rabbit IgG antibody system by whole-column imaged capillary isoelectric focusing 花生变应原蛋白-兔IgG抗体系统的等电点测定及免疫反应研究

The journal of microcolumn separations : JMS Pub Date : 2001-11-30 DOI: 10.1002/mcs.10013

Xing-Zheng Wu, Tiemin Huang, Wayne M. Mullett, Jupiter M. Yeung, Janusz Pawliszyn

引用次数: 20

Determination of ropivacaine and its metabolites in human plasma using solid phase microextraction and GC-NPD/GC-MS 固相微萃取-气相色谱- npd /气相色谱-质谱法测定人血浆中罗哌卡因及其代谢物

The journal of microcolumn separations : JMS Pub Date : 2001-11-30 DOI: 10.1002/mcs.10012

Mohamed Abdel-Rehim, Mikael Andersson, Erik Portelius, Carina Norsten-Höög, Lars G. Blomberg

{"title":"Determination of ropivacaine and its metabolites in human plasma using solid phase microextraction and GC-NPD/GC-MS","authors":"Mohamed Abdel-Rehim, Mikael Andersson, Erik Portelius, Carina Norsten-Höög, Lars G. Blomberg","doi":"10.1002/mcs.10012","DOIUrl":"10.1002/mcs.10012","url":null,"abstract":"The performance of solid-phase microextraction (SPME) in combination with capillary gas chromatography (CGC) to quantify ropivacaine and its metabolites in human plasma was investigated. The analysis was performed using either a nitrogen phosphorus detector (NPD) or a mass-spectrometric detector. For extraction, Carbowax/divinylbenzene, polyacrylate and polydimethylsiloxane fibers were tested. Absorption and desorption times were studied for all analytes separately. The Carbowax/divinylbenzene fiber gave the highest recovery in plasma samples as compared to the other fibers. The effects of temperature, addition of salt, and agitation of the sample were studied. The validation of the method showed that the chromatographic selectivity was satisfactory and all metabolites were well separated. SPME gave higher deviation as compared to published data for solid-phase and liquid-liquid extraction as sample preparation methods but the acceptance criteria for the study validation were well in line with the international criteria. The major disadvantage of SPME in quantitative bioanalysis is that the fiber does not withstand a complete run (standards+blanks+QC samples+patient samples). Also, the quality of fiber and the fiber length can differ from batch to batch. © 2001 John Wiley & Sons, Inc. J Micro Sep 13: 313–321, 2001","PeriodicalId":83120,"journal":{"name":"The journal of microcolumn separations : JMS","volume":"13 8","pages":"313-321"},"PeriodicalIF":0.0,"publicationDate":"2001-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/mcs.10012","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"51277177","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

Design considerations for rapid-heating columns applied in fast capillary gas chromatography 快速毛细管气相色谱快速加热柱的设计考虑

The journal of microcolumn separations : JMS Pub Date : 2001-11-30 DOI: 10.1002/mcs.10016

Marieke Van Deursen, Hans-Gerd Janssen, Jan Beens, Gerard Rutten, Carel Cramers

{"title":"Design considerations for rapid-heating columns applied in fast capillary gas chromatography","authors":"Marieke Van Deursen, Hans-Gerd Janssen, Jan Beens, Gerard Rutten, Carel Cramers","doi":"10.1002/mcs.10016","DOIUrl":"10.1002/mcs.10016","url":null,"abstract":"Numerical calculation procedures are developed to predict the optimum experimental conditions for rapid-programming fast capillary gas chromatography (GC). Retention times and peak widths are calculated from experimentally determined thermodynamic compound properties. Errors in the predicted values are below 2 and 15% for the retention times and peak widths, respectively. It is shown that rapid temperature programming is a powerful tool for speeding up the separation of samples containing homologous series of compounds such as, e.g., triglycerides. The optimal programming rate and the minimum required column length to obtain the shortest possible analysis time with sufficient resolution (Rs=1.5) are predicted. Using a wide-bore column with a length of 10 m, a programming rate of 4°C/s and a carrier gas velocity of approximately 250 cm/s, the shortest possible analysis time for a triglycerides sample can be obtained while still maintaining sufficient resolution. With these instrumental settings the analysis time of a triglycerides separation can be reduced from 15 to approximately 5 minutes. © 2001 John Wiley & Sons, Inc. J Micro Sep 13: 337–345, 2001","PeriodicalId":83120,"journal":{"name":"The journal of microcolumn separations : JMS","volume":"13 8","pages":"337-345"},"PeriodicalIF":0.0,"publicationDate":"2001-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/mcs.10016","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"51277696","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: 13

Simple gradient system For capillary electrochromatography 用于毛细管电色谱的简单梯度系统

The journal of microcolumn separations : JMS Pub Date : 2001-11-30 DOI: 10.1002/mcs.10018

Juan Carlos Medina, M. Carmen Alonso, Damia Barcelo, Milton L. Lee

{"title":"Simple gradient system For capillary electrochromatography","authors":"Juan Carlos Medina, M. Carmen Alonso, Damia Barcelo, Milton L. Lee","doi":"10.1002/mcs.10018","DOIUrl":"10.1002/mcs.10018","url":null,"abstract":"A new gradient system for CEC was designed and adapted to a home-built CEC system. Chromatographic separations are initiated with a predetermined mobile phase composition and, after a desired time period, a syringe pump delivers pure organic solvent at a preset flow rate into a 2 mL vial used as the inlet buffer reservoir. Mixing is achieved by the use of a microstir bar in the buffer reservoir, which in turn is driven by an air-actuated stir plate. In this way, a convex-shaped gradient is generated, and the mobile phase is introduced into the separation column by electro-osmotic flow. Use of this system significantly reduced analysis time while still retaining acceptable reproducibility. Nonaqueous CEC was used for isocratic and gradient separation (<3.5% RSD in retention times). Demonstrated applications include the analysis of triglycerides in different vegetable oil samples. This system is expected to be well suited for generating other types of gradients, such as pH and ionic strength gradients, in electroseparation techniques. © 2001 John Wiley & Sons, Inc. J Micro Sep 13: 351–360, 2001","PeriodicalId":83120,"journal":{"name":"The journal of microcolumn separations : JMS","volume":"13 8","pages":"351-360"},"PeriodicalIF":0.0,"publicationDate":"2001-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/mcs.10018","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"51277845","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

Monitoring of extracellular signal-regulated kinase (ERK) activity with capillary electrophoresis 细胞外信号调节激酶(ERK)活性的毛细管电泳监测

The journal of microcolumn separations : JMS Pub Date : 2001-11-30 DOI: 10.1002/mcs.10015

Eunmi Ban, Hui-Sun Nam, Eunah Yu, Young Sook Yoo

{"title":"Monitoring of extracellular signal-regulated kinase (ERK) activity with capillary electrophoresis","authors":"Eunmi Ban, Hui-Sun Nam, Eunah Yu, Young Sook Yoo","doi":"10.1002/mcs.10015","DOIUrl":"10.1002/mcs.10015","url":null,"abstract":"Extracellular signal-regulated kinase (ERK), which is an isoform of mitogen-activated protein kinases (MAPKs), is an important component of various signaling pathways. ERK phosphorylates numerous substrates including myelin basic protein (MBP) and is one of the key components in linking growth factor receptor activation to serine/threonine protein phosphorylation processes. We investigated a rapid and safe method for determining ERK activity using capillary electrophoresis (CE). ERK converts MBP substrate to phosphorylated MBP product. The phosphorylation reactions of MBP by ERK were studied under varied experimental conditions. Reaction mixtures were carried out using MBP substrate and by adding ERK as well as adenosine triphosphosphate (ATP). The CE analysis method was performed in untreated fused-silica capillary columns of 37 cm×75 μm i.d. and 185 nm wavelength using the 150 mM tris-phosphate buffer (pH 2.5) as a run buffer. The method of CE provided a very rapid analysis time of less than 10 min and high reproducibility within 5% of RSD% for MBP substrate detection. In this article, ERK reactions were determined from the decrease in MBP substrates using the CE method while the formation of phosphorylated MBP product by ERK reaction was monitored using the matrix-assisted laser desorption/ionization time-of-flight mass spectrum (MALDI-TOF MS) method. These results suggest that CE can be applied to many other enzymatic assays because of its various advantages such as nonradiolabeled substrates usage, short analysis time, and inexpensive expenses. © 2001 John Wiley & Sons, Inc. J Micro Sep 13: 332–336, 2001","PeriodicalId":83120,"journal":{"name":"The journal of microcolumn separations : JMS","volume":"13 8","pages":"332-336"},"PeriodicalIF":0.0,"publicationDate":"2001-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/mcs.10015","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"51277342","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: 3

Comprehensive isotachophoresis–capillary zone electrophoresis using directly inserted columns having different diameters with a periodic counterflow and dual ultraviolet detectors 综合等速电泳-毛细管区带电泳采用不同直径的直接插入柱，周期性逆流和双紫外检测器

The journal of microcolumn separations : JMS Pub Date : 2001-11-30 DOI: 10.1002/mcs.10019

Christopher R. Bowerbank, Milton L. Lee

{"title":"Comprehensive isotachophoresis–capillary zone electrophoresis using directly inserted columns having different diameters with a periodic counterflow and dual ultraviolet detectors","authors":"Christopher R. Bowerbank, Milton L. Lee","doi":"10.1002/mcs.10019","DOIUrl":"10.1002/mcs.10019","url":null,"abstract":"Isotachophoresis (ITP) coupled to capillary zone electrophoresis (CE) in a comprehensive manner was used to separate mixture components in both insufficient and sufficient quantities without heart-cutting or splitting. Examples of comprehensive ITP-CE involving multiple CE injections of preconcentrated ITP zones are demonstrated. In the comprehensive arrangement, all of the sample in the first dimension (ITP) is subjected to analysis in the second dimension (CE), without significant sample loss or decrease in sample detectability resulting from removal of a portion of the sample. This is especially important for analytes at low concentrations which may form a single mixed zone instead of individual ITP zones. Direct on-line coupling of ITP to CE in this comprehensive arrangement involved the use of columns having different diameters with one directly inserted inside of the other. A computer-controlled counterflow was applied when the isotachophoretic sample stack reached the bifurcation point. Large volume (10 μL) injections were made using an electrically insulated commercial polymeric rotary valve injector for increased reproducibility compared to previous comprehensive ITP-CE studies, with ITP and CE retention time RSD's ranging from 2 to 5%. An ultraviolet (UV) detector positioned at the bifurcation point was used to determine the beginning of CE injection. Application of a splitting voltage at the bifurcation point showed no affect on analyte transfer into the CE column. In using multiple injections of the ITP band(s), CE column overloading was not observed. © 2001 John Wiley & Sons, Inc. J Micro Sep 13: 361–370, 2001","PeriodicalId":83120,"journal":{"name":"The journal of microcolumn separations : JMS","volume":"13 8","pages":"361-370"},"PeriodicalIF":0.0,"publicationDate":"2001-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/mcs.10019","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"51277879","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

Mathematical representation of electrophoretic mobility in mixed aqueous-methanolic buffers in capillary zone electrophoresis 毛细管区带电泳中混合水-甲醇缓冲液中电泳迁移率的数学表示

The journal of microcolumn separations : JMS Pub Date : 2001-11-30 DOI: 10.1002/mcs.10017

A. Jouybana, H. K. Chan, B. J. Clark, E. Kenndler

{"title":"Mathematical representation of electrophoretic mobility in mixed aqueous-methanolic buffers in capillary zone electrophoresis","authors":"A. Jouybana, H. K. Chan, B. J. Clark, E. Kenndler","doi":"10.1002/mcs.10017","DOIUrl":"10.1002/mcs.10017","url":null,"abstract":"In a drug development program improved speed of the development phase is constantly being explored. But much effort and time is usually expended in finding suitable methods for pharmaceutical and biomedical analyses. In contrast, a mathematical model has been presented here to correlate/predict electrophoretic mobility of acidic and basic analytes in capillary electrophoresis at different concentrations of organic modifier. This model could help analysts to find the optimum concentration of organic modifier for a successful analysis. The accuracy and predictability of the proposed model have been shown using generated mobility data (five basic drugs in water-methanol mixed running buffer) and previously published data sets collected from a recent publication. Using this model the average percentage errors for correlative and predictive equations were 0.64 and 1.35%, respectively. The accuracy of the model was also examined against those of previously published models where the results are comparable. © 2001 John Wiley & Sons, Inc. J Micro Sep 13: 346–350, 2001","PeriodicalId":83120,"journal":{"name":"The journal of microcolumn separations : JMS","volume":"13 8","pages":"346-350"},"PeriodicalIF":0.0,"publicationDate":"2001-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/mcs.10017","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"51277775","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

On-line preconcentration microliquid chromatography tandem mass spectrometric method for bradykinin analysis in plasma 在线预富集微液相色谱串联质谱法分析血浆中缓激肽

The journal of microcolumn separations : JMS Pub Date : 2001-11-26 DOI: 10.1002/mcs.10006

A. J. Oosterkamp, M. Carrascal, D. Closa, G. Escolar, E. Gelpi, J. Abian

{"title":"On-line preconcentration microliquid chromatography tandem mass spectrometric method for bradykinin analysis in plasma","authors":"A. J. Oosterkamp, M. Carrascal, D. Closa, G. Escolar, E. Gelpi, J. Abian","doi":"10.1002/mcs.10006","DOIUrl":"10.1002/mcs.10006","url":null,"abstract":"The practical limitations of miniaturized liquid chromatography (LC) methods for the analysis of endogenous peptides in plasma samples are studied. An automatic column switching method is used for on-line micropreconcentration and microLC-MS–MS (mass spectrometry) analysis of bradykinin and its metabolites in plasma. Both preconcentration (PC) and analytical columns were filled with C18 reversed phase due to the failure of anion exchange precolumns to retain bradykinins. The detection limit for bradykinin in water was 10 pmol/L (2 fmols on column) and a good linearity was found in the range 5–2000 fmols. In plasma, detection limit was 50 pmol/L (25 μL injected) with a linear response in the 100–2000 pmol/L range. Important rules for stable work were: (1) Cleaning the PC column after every run with pure acetonitrile (ACN) to eliminate organic matrix components; (2) to trap the more apolar organic matrix components on the analytical column to prevent their elution to the MS entrance; and (3) to set the electrospray needle to an off-axis position to prevent accumulation of contaminants in the MS entrance. By using this setup, other procedures to reduce the organic load to the MS entrance such as the heart-cutting of the peaks eluting from the LC column were not required. © 2001 John Wiley & Sons, Inc. J Micro Sep 13: 265–274, 2001","PeriodicalId":83120,"journal":{"name":"The journal of microcolumn separations : JMS","volume":"13 7","pages":"265-274"},"PeriodicalIF":0.0,"publicationDate":"2001-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/mcs.10006","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"51277094","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

Fibrous rigid-rod heterocyclic polymer as the stationary phase in packed capillary gas chromatography 纤维刚性棒杂环聚合物在填充毛细管气相色谱中的固定相研究

The journal of microcolumn separations : JMS Pub Date : 2001-11-26 DOI: 10.1002/mcs.10005

Yoshihiro Saito, Motohiro Imaizumi, Kaori Nakata, Tsutomu Takeichi, Kenzo Kotera, Hiroo Wada, Kiyokatsu Jinno

{"title":"Fibrous rigid-rod heterocyclic polymer as the stationary phase in packed capillary gas chromatography","authors":"Yoshihiro Saito, Motohiro Imaizumi, Kaori Nakata, Tsutomu Takeichi, Kenzo Kotera, Hiroo Wada, Kiyokatsu Jinno","doi":"10.1002/mcs.10005","DOIUrl":"10.1002/mcs.10005","url":null,"abstract":"A fibrous rigid-rod polymer was successfully introduced as the stationary phase in capillary gas chromatography (GC) and the basic separation performance was investigated. Zylon®, poly(p-phenylene-2,6-benzobisoxazole), fibers were adopted as the stationary phase taking into account the chemical structure, heat resistance, solvent resistance, and the physical strength for the convenience in column packing process. About 330 and 600 filaments of the polymer were packed longitudinally into fused-silica capillaries of 0.32 and 0.53 mm inner diameter, respectively, and the separation of several test mixtures, such as n-alkylbenzenes and n-alkanes was carried out with these fiber-packed capillary columns in GC. The results clearly indicated that the fiber-packed capillary columns have a great potential as the separation media for volatile compounds. The results also showed the possibility of the synthesis of novel tailored polymer fiber to separate particular class of compounds based on the specific selectivity by the chemical structure of the fiber. Coated-fiber packings were also evaluated to confirm the contribution of the fibers and the coatings to the separation characteristics. © 2001 John Wiley & Sons, Inc. J Micro Sep 13: 259–264, 2001","PeriodicalId":83120,"journal":{"name":"The journal of microcolumn separations : JMS","volume":"13 7","pages":"259-264"},"PeriodicalIF":0.0,"publicationDate":"2001-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/mcs.10005","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"51277017","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: 28