1
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Hajba L, Guttman A. Recent advances in column coatings for capillary electrophoresis of proteins. Trends Analyt Chem 2017. [DOI: 10.1016/j.trac.2017.02.013] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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2
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Smela E. Challenges in realizing a self-contained hydraulically-driven contractile fiber actuator. Faraday Discuss 2017; 199:465-485. [DOI: 10.1039/c6fd00235h] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The field of soft robots would benefit from electrically controlled contractile actuators in the form of fibers that achieve a strain of 20% in less than a second while exerting high force. This work explores possible designs for achieving this goal using self-contained electroosmotic fluid pumping within a tube-shaped structure. The most promising configuration is a combination of a bellows and a McKibben-type muscle, since pumping fluid from the former to the latter results in contraction of both portions. Realizing such a device entails challenges in fabrication and electrokinetic fluid pumping in closed systems. Further studies of electroosmotic flow in salt-free organic solvents are needed.
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Affiliation(s)
- Elisabeth Smela
- Department of Mechanical Engineering and Institute for Systems Research
- University of Maryland
- College Park
- USA
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3
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Bodnar J, Hajba L, Guttman A. A fully automated linear polyacrylamide coating and regeneration method for capillary electrophoresis of proteins. Electrophoresis 2016; 37:3154-3159. [PMID: 27731499 DOI: 10.1002/elps.201600405] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2016] [Revised: 09/09/2016] [Accepted: 09/10/2016] [Indexed: 11/07/2022]
Abstract
Surface modification of the inner capillary wall in CE of proteins is frequently required to alter EOF and to prevent protein adsorption. Manual protocols for such coating techniques are cumbersome. In this paper, an automated covalent linear polyacrylamide coating and regeneration process is described to support long-term stability of fused-silica capillaries for protein analysis. The stability of the resulting capillary coatings was evaluated by a large number of separations using a three-protein test mixture in pH 6 and 3 buffer systems. The results were compared to that obtained with the use of bare fused-silica capillaries. If necessary, the fully automated capillary coating process was easily applied to regenerate the capillary to extend its useful life-time.
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Affiliation(s)
- Judit Bodnar
- MTA-PE Translational Glycomics Research Group, University of Pannonia, Veszprem, Hungary
| | - Laszlo Hajba
- MTA-PE Translational Glycomics Research Group, University of Pannonia, Veszprem, Hungary
| | - Andras Guttman
- MTA-PE Translational Glycomics Research Group, University of Pannonia, Veszprem, Hungary.,Horváth Csaba Memorial Institute for Bioanalytical Research, University of Debrecen, Debrecen, Hungary
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4
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Poly(N,N-Dimethylacrylamide)-Based Coatings to Modulate Electroosmotic Flow and Capillary Surface Properties for Protein Analysis. Methods Mol Biol 2016. [PMID: 27473485 DOI: 10.1007/978-1-4939-4014-1_9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
Abstract
Capillary electrophoresis (CE) is one of the most powerful techniques for the separation of biomolecules. However, the separation efficiency of proteins in CE is often compromised by their tendency to interact with the silanol groups on the surface of the inner capillary and by an uncontrolled electroosmotic flow. Herein, we report on the use of novel hydrophilic polymeric coatings that can modulate the properties of the capillary walls. The novelty of these poly(N,N-dimethylacrylamide)-based copolymers relies on the simultaneous presence of chemically reactive groups (N-acryloyloxysuccinimide and glycidyl methacrylate) and silane groups in the backbone, which results in highly stable films due to the covalent reaction between the polymer and the glass silanols. A careful optimization of monomer concentration confers anti-fouling properties to the polymer coatings, and thus allows for highly efficient acidic and alkaline protein separations. Furthermore, the presence of these monomers makes it possible to modulate the electroosmotic flow from negligible to reduced values, depending on the desired application.
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5
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A Comprehensive Study of Silanization and Co-Condensation for Straightforward Single-Step Covalent Neutral Capillary Coating. Chromatographia 2015. [DOI: 10.1007/s10337-015-2895-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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6
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Mikuma T, Iwata YT, Miyaguchi H, Kuwayama K, Tsujikawa K, Kanamori T, Inoue H. The use of a sulfonated capillary on chiral capillary electrophoresis/mass spectrometry of amphetamine-type stimulants for methamphetamine impurity profiling. Forensic Sci Int 2015; 249:59-65. [DOI: 10.1016/j.forsciint.2015.01.015] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2014] [Revised: 01/20/2015] [Accepted: 01/22/2015] [Indexed: 10/24/2022]
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7
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Misra TK, Chen TS, Wong KT, Liu CY. A Convenient Modified Short Route for the Preparation of [32]ane-N8Hydrochloride. J CHIN CHEM SOC-TAIP 2013. [DOI: 10.1002/jccs.200500111] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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8
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Polymerized phospholipid bilayers as permanent coatings for small amine separations using mixed aqueous/organic capillary zone electrophoresis. J Chromatogr A 2012; 1267:80-8. [DOI: 10.1016/j.chroma.2012.07.017] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2012] [Revised: 07/05/2012] [Accepted: 07/06/2012] [Indexed: 11/24/2022]
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9
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Modulation of electroosmotic flow in capillary electrophoresis using functional polymer coatings. J Chromatogr A 2012. [DOI: 10.1016/j.chroma.2012.10.039] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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10
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Separation of selected transition metals by capillary chelation ion chromatography using acetyl-iminodiacetic acid modified capillary polymer monoliths. J Chromatogr A 2012; 1249:155-63. [DOI: 10.1016/j.chroma.2012.06.026] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2012] [Revised: 06/08/2012] [Accepted: 06/08/2012] [Indexed: 11/20/2022]
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11
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Pan Q, Hong S, Zhu X, Zhao M, Lee LP. On-line electrophoretic sample clean-up for sensitive and reproducible μCE immunoassay. LAB ON A CHIP 2012; 12:932-938. [PMID: 22278032 DOI: 10.1039/c2lc21111d] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
We report a novel on-line electrophoretic sample clean-up approach for highly sensitive and reproducible microchip electrophoretic (μCE) immunoassay of low-abundance proteins in human serum. The method takes advantage of the differential effect of field-amplified sample stacking on molecules with different electrophoretic mobility. Large interfering proteins are removed from the loading channel by simple voltage control, resulting in selective concentration and injection of smaller target analytes to the separation channel. As a proof of concept, an antibody-free injection mode was developed for direct μCE immunoassay of human insulin-like growth factor-I (IGF-I) in serum samples without any additional purification steps. Clear and sharp peaks were obtained for IGF-I with low background and excellent reproducibility. Besides, the assay sensitivity was further increased by addition of ethanol to the sample buffer at a concentration of 50% right before performing the μCE detection. The lower limit of detection of IGF-I achieved 0.68 ng mL(-1), with an overall signal enhancement factor of 2750. The established on-line electrophoretic sample clean-up approach may find wide applications in the development of other microchip-based high-throughput analytical platforms for clinical and biological use.
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Affiliation(s)
- Qiong Pan
- Beijing National Laboratory for Molecular Sciences, MOE Key Laboratory of Bioorganic Chemistry and Molecular Engineering, College of Chemistry and Molecular Engineering, Peking University, Beijing, China
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12
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Lee CH, Huang BY, Chen YC, Liu CP, Liu CY. Zirconia nanoparticles-coated column for the capillary electrochromatographic separation of iron-binding- and phosphorylated-proteins. Analyst 2011; 136:1481-7. [DOI: 10.1039/c0an00900h] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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13
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He Y, Wei Y, Zheng X, Zheng J. Capillary modified with covalently attached coating for enhanced CE separation of biopolymers. Electrophoresis 2010; 31:630-3. [DOI: 10.1002/elps.200900463] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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14
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Abstract
Controlling and manipulating liquids and analytes at the sub-millimeter scale is a challenge that frequently requires new methods to be developed. Indeed, scaling-down of traditional macroscopic ideas often fails. For instance, pumping liquids using pressure differences is often impractical and counterproductive because the resulting parabolic flow profile deforms sample zones. As the size of the system shrinks, the surface-to-volume ratio increases and interfacial effects become dominant. This actually opens new possibilities since the phenomenon of electroosmotic flow (EOF), wherein a fluid is made to move relative to a stationary charged boundary, can then be exploited to design efficient microfluidic devices. In this chapter, we review the fundamental principles of EOF as well as some of the methods used to coat channel walls and reduce the impact of EOF in situations where it would be unfavorable for the device performance.
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Affiliation(s)
- Gary W Slater
- Department of Physics, University of Ottawa, Ottawa, ON, Canada
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15
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Huhn C, Ramautar R, Wuhrer M, Somsen GW. Relevance and use of capillary coatings in capillary electrophoresis–mass spectrometry. Anal Bioanal Chem 2009; 396:297-314. [DOI: 10.1007/s00216-009-3193-y] [Citation(s) in RCA: 154] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2009] [Revised: 09/22/2009] [Accepted: 09/24/2009] [Indexed: 11/24/2022]
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16
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Boonyakong C, Tucker SA. Capillary electrophoresis using core-based hyperbranched polyethyleneimine (CHPEI) static-coated capillaries. J Sep Sci 2009; 32:3489-96. [DOI: 10.1002/jssc.200900332] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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17
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Huang KP, Wang GR, Huang BY, Liu CY. Preparation and application of ionic liquid-coated fused-silica capillary fibers for solid-phase microextraction. Anal Chim Acta 2009; 645:42-7. [DOI: 10.1016/j.aca.2009.04.037] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2009] [Revised: 04/24/2009] [Accepted: 04/28/2009] [Indexed: 10/20/2022]
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18
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Jurcic K, Yeung KKC. Sphingomyelins as semi-permanent capillary coatings for protein separations in CE and off-line analysis with MALDI-MS. Electrophoresis 2009; 30:1817-27. [DOI: 10.1002/elps.200800633] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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19
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Wu CH, Chen TH, Wang GR, Huang KP, Liu CY. Retention Behavior of Highly Hydrophobic, Structurally Related Corticosteroids with SDS Based Microemulsion. J LIQ CHROMATOGR R T 2009. [DOI: 10.1080/10826070902768088] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Affiliation(s)
- Chi-Hung Wu
- a Department of Chemistry , National Taiwan University , Taipei, Taiwan
| | - Tse-Hsien Chen
- a Department of Chemistry , National Taiwan University , Taipei, Taiwan
| | - Guan-Ren Wang
- a Department of Chemistry , National Taiwan University , Taipei, Taiwan
| | - Kuan-Pin Huang
- a Department of Chemistry , National Taiwan University , Taipei, Taiwan
| | - Chuen-Ying Liu
- a Department of Chemistry , National Taiwan University , Taipei, Taiwan
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20
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Abstract
Complex biological samples hold significant information on the health status and on development of disease. Approximately 35,000 human genes give rise to more than 1,000,000 functional entities at the protein level. Thus, the proteome provides a much richer source of information than the genome for describing the state of health or disease of humans. The composition body fluids comprise a rich source of information on changes of protein and peptide expression. Here we describe the application of capillary electrophoresis (CE) coupled online to an electrospray-ionization time-of-flight mass spectrometer (ESI-TOF-MS) to analyze human urine for the identification of biomarkers specific for complications after allogeneic hematopoietic stem cell transplantation (HSCT). Sequencing of native proteins/peptides is necessary for the identification of possible new therapeutic targets.
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21
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Zürbig P, Schiffer E, Mischak H. Capillary Electrophoresis Coupled to Mass Spectrometry for Proteomic Profiling of Human Urine and Biomarker Discovery. Proteomics 2009; 564:105-21. [DOI: 10.1007/978-1-60761-157-8_6] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
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22
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Li H, Liu X, Niu W, Zhu S, Fan L, Shi L, Xu G. CEC with tris(2,2′-bipyridyl) ruthenium(II) electrochemiluminescent detection. Electrophoresis 2008; 29:4475-81. [DOI: 10.1002/elps.200800088] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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23
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Herrero M, Ibañez E, Cifuentes A. Capillary electrophoresis-electrospray-mass spectrometry in peptide analysis and peptidomics. Electrophoresis 2008; 29:2148-60. [DOI: 10.1002/elps.200700404] [Citation(s) in RCA: 107] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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24
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Schiffer E, Mischak H, Vanholder RC. Biomarkers for Renal Disease and Uremic Toxins. Clin Proteomics 2008. [DOI: 10.1002/9783527622153.ch25] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
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25
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Wu Y, Xie J, Wang F, Chen Z. Electrokinetic separation of peptides and proteins using a polyvinylamine-coated capillary with UV and ESI-MS detection. J Sep Sci 2008; 31:814-23. [DOI: 10.1002/jssc.200700518] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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26
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Lin J, Wu X, Lin X, Xie Z. Preparation of polymethacrylate monolithic stationary phases having bonded octadecyl ligands and sulfonate groups: electrochromatographic characterization and application to the separation of polar solutes for pressurized capillary electrochromatography. J Chromatogr A 2007; 1169:220-7. [PMID: 17875313 DOI: 10.1016/j.chroma.2007.08.061] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2007] [Revised: 08/26/2007] [Accepted: 08/30/2007] [Indexed: 10/22/2022]
Abstract
In this report, the preparation of porous polymethacrylate-based monolithic columns by in situ copolymerization of octadecyl methacrylate (OMA), 3-sulfopropyl methacrylate (SPMA) and ethylene dimethacrylate (EDMA) in a binary porogenic solvent consisting of cyclohexanol/1,4-butanediol are proposed. These monoliths possess in their structures bonded octadecyl ligands and sulfonate groups and are evaluated in pressurized capillary electrochromatography (pCEC) system using small neutral and charged solutes. While the sulfonate groups are meant to generate the electroosmotic flow (EOF) necessary for transporting the mobile phase through the monolithic capillary; the octadecyl ligands are introduced to provide the nonpolar sites for chromatographic retention for neutral solutes. However, incorporating the sulfonate groups in the monoliths does not only support the EOF but also exhibit hydrophilic interaction as well as electrostatic interaction/repulsion with the monoliths in addition to electrophoretic migration with polar charged solutes (e.g., nucleotides). The monolithic stationary phases at different EOF velocities are easily prepared by altering the amount of SPMA in the polymerization solution as well as the composition of the porogenic solvent. Optimum EOF velocity, the highest efficiency and adequate chromatographic retention are obtained when 0.6% SPMA is added to the reaction mixture. Under these conditions, rapid separation and high plate counts reaching greater than 170,000 plates/m are readily obtained.
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Affiliation(s)
- Jian Lin
- Department of Chemistry, Fuzhou University, Fuzhou 350002, China
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27
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Mistry K, Grinberg N. Separation of Peptides and Proteins by Capillary Electrochromatography. J LIQ CHROMATOGR R T 2007. [DOI: 10.1081/jlc-120030601] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- Kavita Mistry
- a Analytical Research , Merck & Co., Inc. , RY818‐C208, P.O. Box 2000, Rahway , New Jersey , 07065 , USA
| | - Nelu Grinberg
- a Analytical Research , Merck & Co., Inc. , RY818‐C208, P.O. Box 2000, Rahway , New Jersey , 07065 , USA
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28
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Diress AG, Yassine MM, Lucy CA. Semipermanent capillary coatings in mixed organic-water solvents for CE. Electrophoresis 2007; 28:1189-96. [PMID: 17366479 DOI: 10.1002/elps.200600440] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
This report describes the creation of semipermanent capillary coatings that are compatible with organic-water solvent systems in CE. The coatings are created by simply rinsing the fused-silica capillary with long double-chain cationic surfactants, such as dimethyl-ditetradecyl ammonium bromide (2C(14)DAB), dihexadecyldimethyl ammonium bromide (2C(16)DAB), and dimethyldioctadecyl ammonium bromide (2C(18)DAB). These surfactants generate semipermanent bilayer coatings on the capillary surface, which display a high degree of stability in buffers containing up to 60% v/v of organic solvents, such as methanol and ACN. The coating stability increases with increasing hydrophobicity of the surfactant, i.e., with increasing chain length. For instance, the EOF changes by only 1.2% in a 2C(18)DAB-coated capillary after 130 capillary volumes of rinsing with 60% v/v methanol containing buffer. The bilayer coatings allow separations to be performed without the need to regenerate the coating between runs or to maintain the EOF modifier in the run buffer. Rapid separations (<2 min) of anions and basic drugs with migration time reproducibility of less than 0.5% RSD and efficiencies of 0.4-0.6 million plates/m are obtained. In addition, selectivity changes for small anions and cationic drugs are also observed when the organic solvent content is adjusted.
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Affiliation(s)
- Abebaw G Diress
- Department of Chemistry, Gunning/Lemieux Chemistry Centre, University of Alberta, Edmonton, Alberta, Canada
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29
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Debowski JK. SELECTED APPLICATIONS OF CAPILLARY ELECTROCHROMATOGRAPHY IN THE PHARMACEUTICAL INDUSTRY: TO BUY OR NOT TO BUY? J LIQ CHROMATOGR R T 2007. [DOI: 10.1081/jlc-120013988] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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30
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Tian Y, Zeng Z, Chen Y, Xie C, Li H, Yang X. Open‐Tubular Capillary Electrochromatography Using Capillaries Modified with p‐tert‐Butylcalix[4]arene‐1,3‐bis(allyloxyethy)ether. J LIQ CHROMATOGR R T 2007. [DOI: 10.1080/10826070500274356] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Affiliation(s)
- Yun Tian
- a Department of Chemistry , Wuhan University , Wuhan, 430072, China
| | - Zhaorui Zeng
- a Department of Chemistry , Wuhan University , Wuhan, 430072, China
| | - Yuanyin Chen
- a Department of Chemistry , Wuhan University , Wuhan, 430072, China
| | - Chuanhui Xie
- a Department of Chemistry , Wuhan University , Wuhan, 430072, China
| | - Haibing Li
- b Institute of Materia Medica, School of Life Science and Technology, Huazhong University of Science and Technology , Wuhan, 430074, China
| | - Xiangliang Yang
- b Institute of Materia Medica, School of Life Science and Technology, Huazhong University of Science and Technology , Wuhan, 430074, China
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31
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Abstract
Proteomic screening of complex biological samples becomes of increasing importance in clinical research and diagnosis. It is expected that the meager number of approx 35,000 human genes gives rise to more than 1,000,000 functional entities at the protein level. Thus, the proteome provides a much richer source of information than the genome for describing the state of health or disease of the human organism. Especially, the composition body fluids comprise a rich source of information on possible changes in the status of health or disease of particular organs and in consequence of the whole organism. Here we describe the application of capillary electrophoresis (CE) coupled on-line to an electrospray-ionization (ESI)-time-of-flight (TOF)-mass spectrometer) to the analysis of human urine for the identification of biomarkers for complications after allogeneic hematopoietic stem cell transplantation.
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Affiliation(s)
- Eva M Weissinger
- Department of Hematology, Hannover Medical School, Hannover, Germany
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32
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Gotti R, Calleri E, Massolini G, Furlanetto S, Cavrini V. Penicillin G acylase as chiral selector in CE using a pullulan-coated capillary. Electrophoresis 2006; 27:4746-54. [PMID: 17080475 DOI: 10.1002/elps.200600194] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
In the present study, penicillin G acylase (PGA), an enzyme belonging to the family of hydrolases, has been investigated as chiral selector in CE using the partial filling technique. Owing to the strong disposition of PGA to be adsorbed by the inner capillary wall, permanently coated capillaries were used to diminish both the protein-wall interactions and the EOF. In particular, the silica surface of the capillary was chemically coated by an antiadhesive and an hydrophilic layer of pullulan, a high-molecular-mass homopolysaccharide. The coating procedure consisted in the silanization with glycidoxypropyltrimethoxysilane and the subsequent coupling of the hydroxyl groups of pullulan onto the silanized capillary. Using this approach, a significant EOF suppression was obtained within a wide pH range (pH 3.0-9.0); this result was very important in order to find the suitable conditions for the application of partial filling technique. The optimization of partial filling was carried out by considering the effects of different experimental conditions (buffer pH, PGA concentration, and loading duration), on the migration time and enantioresolution of rac-ketoprofen. Under the selected conditions as: 100 mM sodium phosphate buffer (pH 5.5) containing 240 microM of PGA (partial filling of 120 s at a pressure of 50 mbar), a series of acidic compounds resulted to be enantioresolved in about 10 min. The long-term stability of the proposed coating was evaluated; more than 100 injections were performed without significant loss of reproducibility.
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Affiliation(s)
- Roberto Gotti
- Department of Pharmaceutical Sciences, University of Bologna, Bologna, Italy.
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Schiffer E, Mischak H, Novak J. High resolution proteome/peptidome analysis of body fluids by capillary electrophoresis coupled with MS. Proteomics 2006; 6:5615-27. [PMID: 16991199 DOI: 10.1002/pmic.200600230] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
All organisms contain thousands of proteins and peptides in their body fluids. A deeper insight into the functional relevance of these polypeptides under different physiological and pathophysiological conditions and the discovery of specific peptide biomarkers would greatly enhance both diagnosis and therapy of specific diseases. Proteomic methods can provide means to accomplish this grand medical vision. In this review, we will focus on the potential use of proteome analysis for clinical applications, such as disease diagnosis and assessment of response to therapy. We focus on CE coupled with MS (CE-MS) and review in detail different aspects of CE-MS coupling and the results obtained using CE-MS analysis of clinically relevant samples. We also discuss clinical applications of the technology for the diagnosis of renal diseases, urogenital cancer, and arteriosclerosis as well as monitoring the responses to therapeutic interventions.
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Affiliation(s)
- Eric Schiffer
- Mosaiques Diagnostics & Therapeutics AG, Hanover, Germany
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34
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Huang YF, Huang CC, Hu CC, Chang HT. Capillary electrophoresis-based separation techniques for the analysis of proteins. Electrophoresis 2006; 27:3503-22. [PMID: 16927348 DOI: 10.1002/elps.200600100] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
CE offers the advantages of high speed, great efficiency, as well as the requirement of minimum amounts of sample and buffer for the analysis of proteins. In this review, we summarize the CE-based techniques coupled with absorption, LIF, and MS detection systems for the analysis of proteins mostly within the past 5 years. The basic principle of each technique and its advantages and disadvantages for protein analysis are discussed in brief. Advanced CE techniques, including on-column concentration techniques and high-efficiency multidimensional separation techniques, for high-throughput protein profiling of complex biological samples and/or of single cells are emphasized. Although the developed techniques provide improved peak capacity, they have not become practical tools for proteomics, mainly because of poor reproducibility, low-sample lading capacity, and low throughput due to ineffective interfaces between two separation dimensions and that between separation and MS systems. In order to identify the complexities and dynamics of the proteomes expressed by cells, tissues, or organisms, techniques providing improved analytical sensitivity, throughput, and dynamic ranges are still demanded.
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Affiliation(s)
- Yu-Fen Huang
- Department of Chemistry, National Taiwan University, Taipei, Taiwan
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Puerta A, Axén J, Söderberg L, Bergquist J. Novel adsorptive polyamine coating for enhanced capillary electrophoresis of basic proteins and peptides. J Chromatogr B Analyt Technol Biomed Life Sci 2006; 838:113-21. [PMID: 16714157 DOI: 10.1016/j.jchromb.2006.04.018] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2006] [Revised: 04/06/2006] [Accepted: 04/16/2006] [Indexed: 11/15/2022]
Abstract
In capillary electrophoresis (CE), the anionic and hydrophobic nature of the fused-silica capillary surface has long been known to present a problem in protein and peptide analysis. The use of capillary surface coating is one of the approaches to avoid the analyte-wall interactions. In this study, a new polymer, poly-LA 313, has been synthesized, physico-chemical characterized, and applied as polyamine coating for CE separations. The coating process is highly reproducible and provides fast separations of peptides and proteins in a few minutes and with high efficiency. The physically adsorbed polymer gives rise to a durable coating in the range of pH 2-10, in the presence of organic modifiers (acetonitrile and methanol) and with complex biological samples. The efficiency of the new cationic polymer was also tested performing protein and peptide separations with capillary electrophoresis-electrospray ionization-mass spectrometry (CE-ESI-MS).
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Affiliation(s)
- Angel Puerta
- Department of Physical and Analytical Chemistry, Analytical Chemistry, Biomedical Centre, Uppsala University, PO Box 599, SE-75124 Uppsala, Sweden
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36
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Bonoli M, Varjo SJO, Wiedmer SK, Riekkola ML. Cationic lipid vesicles as coating precursors in capillary electrochromatography: Separation of basic proteins and neutral steroids. J Chromatogr A 2006; 1119:163-9. [PMID: 16458905 DOI: 10.1016/j.chroma.2005.12.045] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2005] [Revised: 12/01/2005] [Accepted: 12/08/2005] [Indexed: 11/19/2022]
Abstract
1,2-Dioleyl-3-trymethylammoniumpropane (DOTAP) lipid vesicles were employed as coating precursors to obtain a semipermanent cationic lipid bilayer in silica capillary. The coating procedure was relatively fast and simple. Reliable results for the separation of four basic proteins (alpha-chymotrypsinogen A, ribonuclease A, cytochrome C, lysozyme) were obtained by using an acetate buffer under acidic conditions. The RSDs of the migration times were not higher than 0.5% run-to-run and about 1% day-to-day (3 days), while the RSDs of the peak areas were within 7% day-to-day (3 days). The day-to-day RSD of the EOF mobility of about 1%, confirmed that the DOTAP coating was stable for the separation of basic proteins, under acidic buffers. In addition to basic proteins the DOTAP coating was found suitable under acidic conditions for the repeatable separation of neutral steroids. The potential of DOTAP as a carrier in background electrolyte solution was studied.
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Affiliation(s)
- Matteo Bonoli
- Laboratory of Analytical Chemistry, Department of Chemistry, University of Helsinki, Finland
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37
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Hsieh MM, Chang HT. Impact of halides on the simultaneous separation of aromatic amines and their acidic metabolites by capillary electrophoresis with laser-induced native fluorescence detection under acidic conditions. J Chromatogr A 2006; 1102:302-8. [PMID: 16325830 DOI: 10.1016/j.chroma.2005.11.016] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2005] [Revised: 10/28/2005] [Accepted: 11/01/2005] [Indexed: 11/15/2022]
Abstract
This paper describes a simple, sensitive, efficient, and rapid method for simultaneous analysis of biologically active amines and acids by capillary electrophoresis in conjunction with laser-induced native fluorescence detection (CE-LINF) using a diode pumped solid state nanolaser at 266 nm. In order to optimize resolution of the amines that were prepared in 10.0 mM formate-Tris (FT) solutions, 10.0 mM FT solutions with and without containing halides were used to fill the capillary and reservoirs, respectively. The electrophoretic mobilities of tryptamine (TA) and serotonin (5-HT) at pH 4.0 decrease with the increase in halide concentration (0-10.0 mM). Taken together with a great effect of iodide than other halides, we suggest that the formation of ion pairs is a main contributor for altering the migration of the amines. In order to simultaneously analyze the amines and their metabolites (acids) at low pH, a high bulk EOF is required. The analysis of 10 anlytes including amines and acids was completed within 12 min by CE-LINF using a capillary treated with 0.5M NaOH and then filled with 10.0 mM FT solutions (pH 4.0) containing 10.0 mM KCl prior to analysis. The limits of detection for TA and 5-hydroxyindole-3-acetic acid (5-HIAA) are 0.12 and 6.0 nM, respectively. The present method has been further validated by analyzing urine samples, with an RSD less than 3.1% (migration times) and 3.9% (concentration).
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Affiliation(s)
- Ming-Mu Hsieh
- Department of Applied Chemistry, Fooyin University, 151 Chin-Hsueh Road, Ta-Liao Hsiang, 831 Kaohsiung Hsien, Taiwan.
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38
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Kodama S, Yamamoto A, Terashima H, Honda Y, Taga A, Honda S. A sulfonated capillary that gives reproducible migration times for capillary zone electrophoresis and micellar electrokinetic chromatography. Electrophoresis 2005; 26:4070-8. [PMID: 16252329 DOI: 10.1002/elps.200500445] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
To obtain reproducible migration times and rapid analyses of analytes, sulfonate groups were chemically introduced to the inner wall of untreated fused-silica capillary with 2-(4-chlorosulfonylphenyl)ethyltrichlorosilane. The sulfonated capillary showed relatively constant electroosmotic mobility which was greater than that obtained by an untreated fused-silica capillary over the pH range studied (pH 2-9). In both CZE and MEKC, the RSDs of the migration times of analytes with the sulfonated capillary were less than 0.2% which were significantly lower than those obtained with an untreated fused-silica capillary (0.5-3.5%). When BGE were set at pH 7.0 for CZE and MEKC, the analysis times with the sulfonated capillary were about half those obtained with an untreated fused-silica capillary. These results indicate that the sulfonated capillary can provide highly reproducible and rapid analyses in CE.
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Affiliation(s)
- Shuji Kodama
- Toyama Institute of Health, Kosugi-machi, Toyama, Japan.
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39
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Kolch W, Neusüss C, Pelzing M, Mischak H. Capillary electrophoresis-mass spectrometry as a powerful tool in clinical diagnosis and biomarker discovery. MASS SPECTROMETRY REVIEWS 2005; 24:959-977. [PMID: 15747373 DOI: 10.1002/mas.20051] [Citation(s) in RCA: 219] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Proteome analysis is now emerging as key technology for deciphering biological processes and the discovery of biomarkers for diseases from tissues and body fluids. The complexity and wide dynamic range of protein expression poses a formidable challenge to both peptide separation technologies and mass spectrometry (MS). Here we review the efforts that have been undertaken to date, focussing on capillary electrophoresis coupled to mass spectrometry (CE-MS). We discuss CE-MS from an application point of view evaluating its merits and vices in regard to biomarker discovery and clinical applications. As examples, we present the use of CE-MS for the determination of protein patterns in urine, serum, and other body fluids. Finally, the benefits and limitations of CE-MS for the analysis of proteins in clinical samples are discussed against the background of alternative technologies.
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Affiliation(s)
- Walter Kolch
- The Beatson Institute for Cancer Research, Garscube Estate, Switchback Road, Bearsden, Glasgow G61 1BD, United Kingdom
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40
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Stutz H. Advances in the analysis of proteins and peptides by capillary electrophoresis with matrix-assisted laser desorption/ionization and electrospray-mass spectrometry detection. Electrophoresis 2005; 26:1254-90. [PMID: 15776483 DOI: 10.1002/elps.200410130] [Citation(s) in RCA: 135] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
High throughput, outstanding certainty in peptide/protein identification, exceptional resolution, and quantitative information are essential pillars in proteome research. Capillary electrophoresis (CE) coupled to mass spectrometry (MS) has proven to meet these requirements. Soft ionization techniques, such as matrix-assisted laser desorption/ionization (MALDI) and electrospray ionization (ESI), have paved the way for the story of success of CE-MS in the analysis of biomolecules and both approaches are subject of discussion in this article. Meanwhile, CE-MS is far away from representing a homogeneous field. Therefore the review will cover a vast area including the coupling of different modes of CE (capillary zone electrophoresis, capillary isoelectric foscusing, capillary electrochromatography, micellar electrokinetic chromatography, nonaqueous capillary electrophoresis) to MS as well as on-line preconcentration techniques (transient capillary isotachophoresis, solid-phase extraction, membrane preconcentration) applied to compensate for restricted detection sensitivity. Special attention is given to improvements in interfacing, namely addressing nanospray and coaxial sheath liquid design. Peptide mapping, collision-induced dissociation with subsequent tandem MS, and amendments in mass accuracy of instruments improve information validity gained from MS data. With 2-D on-line coupling of liquid chromatography (LC) and CE a further topic will be discussed. A special section is dedicated to recent attempts in establishing CE-ESI-MS in proteomics, in the clinical and diagnostic field, and in the food sector.
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Affiliation(s)
- Hanno Stutz
- University of Salzburg, Department of Molecular Biology, Division of Chemistry, Salzburg, Austria.
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41
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Kamande MW, Fletcher KA, Lowry M, Warner IM. Capillary electrochromatography using polyelectrolyte multilayer coatings. J Sep Sci 2005; 28:710-8. [PMID: 15938180 DOI: 10.1002/jssc.200500006] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
This review covers recent progress in polyelectrolyte multilayer (PEM) coatings applied to analytical separations using open-tubular capillary electrochromatography (OT-CEC). The simple preparation procedure involved in the PEM approach has provided some attractive features over other modes of capillary electrophoresis-based separations including packed column capillary electrochromatography (PC-CEC) and micellar electrokinetic chromatography (MEKC). PEM coatings have been used to alleviate the adsorption of basic analytes, to improve separations, and to improve the stability of the electroosmotic flow. Fundamental aspects of PEM coatings on surfaces and analytical separation platforms are briefly outlined in this review. In addition, applications of PEM coatings to fused-silica capillaries or microchip separation devices for the separation of small achiral or chiral analytes, as well as large biomolecules, are discussed.
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Affiliation(s)
- Mary W Kamande
- Department of Chemistry, Louisiana State University, Baton Rouge, LA 70803, USA
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42
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Abstract
Homogeneous gels represent a new type of (electro)chromatographic media possessing unique separation properties unmatched with any other chromatographic beds. It is important to emphasize that they principally differ from continuous beds, polymer rods (better known as monoliths), which are particulate separation media with pores permitting hydrodynamic flow through the columns. Monoliths, thus, are more similar to beds conventionally packed with beads, although the particles building up monolithic columns are usually smaller in size (few submicometers) and covalently linked together. Consequently, homogeneous gels deserve better the term "monoliths" having a non-particulate structure formed by crosslinked free polymer chains (according to a dictionary a monolith is a non-modularized column). The goals of this minireview are to clarify the position of homogeneous gels among the separation media (including polymer solutions), to explain and to exemplify their outstanding (electro)chromatographic properties. This review gives hopefully a complete list of references to homogeneous gels developed for capillary electrochromatography.
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Affiliation(s)
- Akos Végvári
- Department of Biochemistry, Biomedical Center, Uppsala University, P O. Box 576, SE-751 23 Uppsala, Sweden.
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Luong JHT, Bouvrettea P, Liu Y, Yang DQ, Sacher E. Electrophoretic separation of aniline derivatives using fused silica capillaries coated with acid treated single-walled carbon nanotubes. J Chromatogr A 2005; 1074:187-94. [PMID: 15941054 DOI: 10.1016/j.chroma.2005.02.089] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
This paper reports on a new strategy for coating fused silica capillaries based on the ionic adsorption of acid treated single-walled carbon nanotubes (SWCNTs) on a poly(diallydimethylammonium chloride)-modified fused silica surface. The coated capillaries were used to demonstrate their performance for baseline separation of a mixture of seven nitrogen-containing aromatic compounds compared to capillary zone electrophoresis. This combined layer formed a coating material that could be useful for improvement of the selectivity of the solutes in an electrical field. We reasoned that the interaction of the solutes and the modified capillary wall occurred mainly via ionic interactions with the charged moieties of CNTs. The single-walled CNT modified capillaries were very stable and could be used for over 200 repeated analyses without compromising its analytical performance.
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Affiliation(s)
- John H T Luong
- Biotechnology Research Institute, National Research Council Canada, Nanobiotechnology Group, 6100 Royalmount Avenue, Montreal, Que., Canada H4P 2R2.
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44
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Simpson DC, Smith RD. Combining capillary electrophoresis with mass spectrometry for applications in proteomics. Electrophoresis 2005; 26:1291-305. [PMID: 15765477 DOI: 10.1002/elps.200410132] [Citation(s) in RCA: 159] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Mass spectrometry (MS)-based proteomics is currently dominated by the analysis of peptides originating either from digestion of proteins separated by two-dimensional gel electrophoresis (2-DE) or from global digestion; the simple peptide mixtures obtained from digestion of gel-separated proteins do not usually require further separation, while the complex peptide mixtures obtained by global digestion are most frequently separated by chromatographic techniques. Capillary electrophoresis (CE) provides alternatives to 2-DE for protein separation and alternatives to chromatography for peptide separation. This review attempts to elucidate how the most promising CE modes, capillary zone electrophoresis (CZE) and capillary isoelectric focusing (CIEF), might best be applied to MS-based proteomics. CE-MS interfacing, mass analyzer performance, column coating to minimize analyte adsorption, and sample stacking for CZE are considered prior to examining numerous applications. Finally, multidimensional systems that incorporate CE techniques are examined; CZE often finds use as a fast, final dimension before ionization for MS, while CIEF, being an equilibrium technique, is well-suited to being the first dimension in automated fractionation systems.
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45
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Li H, Chen Y, Zeng Z, Xie C, Yang X. p-tert-Butylcalix[4]arene-1,3-bis(allyloxyethoxy)ether Coated Capillaries for Open-Tubular Electrochromatography. ANAL SCI 2005; 21:717-20. [PMID: 15984214 DOI: 10.2116/analsci.21.717] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The preparation and characterization of p-tert-butylcalix[4]arene-1,3-bis(allyloxyethoxy)ether (CA[4]-BAE) chemically coated capillaries via a free-radical reaction with vinyltriethoxysilane (VTES) that was attached onto the inner wall previously were carried out. IR spectra and decreased electroosmotic flow (EOF) suggested that the capillary was successfully coated with CA[4]-BAE. A slight slope of EOF versus pH at 5 < pH < 9 would help to make the separation reproducible. The CA[4]-BAE-coated capillary showed improved separations of toluidine isomers, naphthol isomers and polycyclic aromatic hydrocarbons (PAHs) compared with an uncoated capillary. The special selectivity indicates that there is a certain extent of host-guest interactions between the solutes and the CA[4]-BAE coating.
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Affiliation(s)
- Haibing Li
- Institute of Materia Medica, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China.
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46
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Progent F, Taverna M. Retention behaviour of peptides in capillary electrochromatography using an embedded ammonium in dodecacyl stationary phase. J Chromatogr A 2004; 1052:181-9. [PMID: 15527136 DOI: 10.1016/j.chroma.2004.08.107] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The potential of a silica stationary phase bearing an embedded cationic quaternary amine in dodecacyl chain, to separate peptides by capillary electrochromatography (CEC) has been evaluated. The ability of this stationary phase, to generate a consistent anodic electroosmotic flow was first evaluated. This flow was found to be independent of pH over a wide range (2-12), of the acetonitrile percentage in the electrolyte. The stability of the stationary phase evaluated through the electroosmotic flow variations was demonstrated at extreme pH values (2.5 and 9.1). A careful examination of the influence of mobile phase conditions (acetonitrile percentage, salt concentration and nature of buffer) on the electrochromatographic retention and electrophoretic migration behaviour of different standard peptides was carried out. In acidic conditions, the electrokinetic contribution appears to be predominant compared to the chromatographic one. Several types of chromatographic interactions, reversed-phase partitioning and anion exchange, were involved in the CEC of peptides, whereas repulsive electrostatic interaction could be considered as negligible. This stationary phase affords different selectivity compared to that observed on a C18 stationary phase. Finally, the method was applied to the peptide mapping of beta-lactoglobulin and human growth hormone under unpressurized and isocratic elution.
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Affiliation(s)
- Frédéric Progent
- Groupe de Chimie Analytique de Paris-Sud, Faculté de Pharmacie, Châtenay-Malabry, France
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47
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Ullsten S, Zuberovic A, Wetterhall M, Hardenborg E, Markides KE, Bergquist J. A polyamine coating for enhanced capillary electrophoresis-electrospray ionization-mass spectrometry of proteins and peptides. Electrophoresis 2004; 25:2090-2099. [PMID: 15237410 DOI: 10.1002/elps.200305787] [Citation(s) in RCA: 90] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
A procedure for enhanced capillary electrophoresis-electrospray ionization-mass spectrometry (CE-ESI-MS) of proteins is presented. The use of a newly presented capillary coating, PolyE-323, provided fast separations of typically a few minutes with high efficiency, good deactivation, and no bleeding into the mass spectrometer. Capillaries coated with PolyE-323 showed high stability over a range of pH 2-10, and tolerance towards methanol and acetonitrile, two modifiers commonly used in CE-ESI-MS. Due to the speed and simplicity of the coating procedure, the polymeric surface could, if necessary, easily be regenerated. This capability is especially valuable when working with samples of complex matrix, where a capillary surface cleaning step might be desired in order to eliminate possible memory effects. The potential of PolyE-323-coated capillaries in bioanalysis using CE-ESI-MS was demonstrated by analyzing peptides and proteins up to 66 kDa using time of flight (TOF)-MS. Due to the stable, anodal electroosmotic flow generated by the coating, the use of a sheathless ESI interface was enabled, demonstrated in peptide analysis with attomole sensitivity. The fast on-line CE-ESI-TOF system using PolyE-323-coated capillaries provided efficient separation and detection of a large number of peaks in a short time, exemplified by the analysis of a tryptic digest of bovine serum albumin (BSA). The capability of the developed capillary surface coating was demonstrated by the separation of human plasma and cerebrospinal fluid (CSF).
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Affiliation(s)
- Sara Ullsten
- Department of Analytical Chemistry, Biomedical Centre, Uppsala University, Uppsala, Sweden
| | - Aida Zuberovic
- Department of Analytical Chemistry, Biomedical Centre, Uppsala University, Uppsala, Sweden
| | - Magnus Wetterhall
- Department of Analytical Chemistry, Biomedical Centre, Uppsala University, Uppsala, Sweden
| | - Emilia Hardenborg
- Department of Analytical Chemistry, Biomedical Centre, Uppsala University, Uppsala, Sweden
| | - Karin E Markides
- Department of Analytical Chemistry, Biomedical Centre, Uppsala University, Uppsala, Sweden
| | - Jonas Bergquist
- Department of Analytical Chemistry, Biomedical Centre, Uppsala University, Uppsala, Sweden
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48
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Xu L, Feng YQ, Shi ZG, Da SL, Wei F. Preparation of a sulfonated fused-silica capillary and its application in capillary electrophoresis and electrochromatography. J Chromatogr A 2004; 1033:161-6. [PMID: 15072301 DOI: 10.1016/j.chroma.2004.01.020] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
In the present paper, two new methods, sol-gel and chemical bonding methods, were proposed for preparation of sulfonated fused-silica capillaries. In the sol-gel method, a fused-silica capillary was coated with the sol solution obtained by hydrolysis of 3-mercaptopropyltrimethoxysilane (MPTS) and tetramethoxysilane, and followed by age; while in the chemical bonding method, a capillary was chemically bonded directly with MPTS. Then, both the resulting capillaries were oxidized with an aqueous solution of hydrogen peroxide solution (H2O2) (30%, m/m) to obtain the sulfonated capillaries. The electroosmotic flow (EOF) for the sulfonated capillaries was found to remain almost constant within the studied pH range, and greater than that of the uncoated capillary. However, the coating efficiency of the capillary prepared by chemical bonding method was higher than that by sol-gel method, by comparing their magnitude of the EOF, the degree of disguise of the silanol and reproducibility of preparation procedure. The effects of the electrolyte's concentration and the content of methanol (MeOH) on the EOF were also studied. Especially, the study of the apparent pH (pH*) on the EOF in a water-MeOH system was reported. Finally, capillary electrophoretic separation of seven organic acids was achieved within 6.5 min under optimal condition using the chemically bonded sulfonated capillary. Moreover, separation of four alkaloids on the sulfonated capillary was compared with that on uncoated capillary in different conditions. Ion-exchange mechanism was found to play a key role for separation of these four basic analytes on the sulfonated capillary.
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Affiliation(s)
- Li Xu
- Department of Chemistry, Wuhan University, Wuhan 430072, China
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49
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Ullsten S, Söderberg L, Folestad S, Markides KE. Quaternary ammonium substituted agarose as surface coating for capillary electrophoresis. Analyst 2004; 129:410-5. [PMID: 15116232 DOI: 10.1039/b316492f] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A novel positively charged polymer of quaternary ammonium substituted agarose (Q-agarose) has been synthesized and explored for use as a coating in capillary electrophoresis. The fast and simple coating procedure is based on a multi-site electrostatic interaction between the polycationic agarose polymer and the negatively charged fused-silica surface. By simply flushing fused-silica capillaries with hot polymer solution a positively charged, hydrophilic deactivation layer is achieved. The polymer surface provides an intermediate electroosmotic flow of reversed direction, over a range of pH 2-11, compared to unmodified fused-silica. The coating procedure was highly reproducible with an RSD of 4%, evaluated as the electroosmotic flow mobility for 30 capillaries prepared at 10 different occasions. The application of Q-agarose coated capillaries in separation science was investigated using a set of basic drugs and model proteins and peptides. Due to the intermediate electroosmotic flow generated, the resolution of basic drugs could be increased, compared to using bare fused-silica capillaries. Moreover, the coating enabled separation of proteins and peptides with efficiencies up to 300.000 plates m(-1).
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Affiliation(s)
- Sara Ullsten
- Department of Analytical Chemistry, Uppsala University, P.O. Box 599, SE-751 24 Uppsala, Sweden
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50
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Bossi A, Castelletti L, Piletsky SA, Turner APF, Righetti PG. Properties of poly-aminophenylboronate coatings in capillary electrophoresis for the selective separation of diastereoisomers and glycoproteins. J Chromatogr A 2004; 1023:297-303. [PMID: 14753696 DOI: 10.1016/j.chroma.2003.10.023] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The polymerisation of 3-aminophenylboronic acid (APBA) in aqueous environment has been used for the open tubular modification of capillary electrophoresis (CE) capillaries. Being poly-APBA endowed with boronic acid, aromatic rings and secondary amines groups, it posses a variety of functional groups affecting selectivity. Diastereoisomers (e.g. ascorbic and isoascorbic acid) and proteins (e.g. haemoglobins) were successfully separated onto poly-APBA column, by means of a combination of electrophoresis and open tubular electrochromatography. The mechanism of selection was investigated: results indicate an interplay between enhancing or silencing the contribution of the protonable functionalities (amino groups, boronic acid). The properties of APBA polymer coating make it attractive for CE separation and for further application in affinity separations and chip technologies.
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Affiliation(s)
- Alessandra Bossi
- Department of Science and Technology, University of Verona, Strada le Grazie 15, 37134 Verona, Italy.
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