51
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Fu X, Liu Y, Li W, Bai Y, Liao Y, Liu H. Determination of dissociation constants of aristolochic acid I and II by capillary electrophoresis with carboxymethyl chitosan-coated capillary. Talanta 2011; 85:813-5. [DOI: 10.1016/j.talanta.2011.03.088] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2010] [Revised: 03/27/2011] [Accepted: 03/31/2011] [Indexed: 10/18/2022]
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52
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Nehmé R, Perrin C, Cottet H, Blanchin MD, Fabre H. Stability of capillaries coated with highly charged polyelectrolyte monolayers and multilayers under various analytical conditions—Application to protein analysis. J Chromatogr A 2011; 1218:3537-44. [DOI: 10.1016/j.chroma.2011.03.040] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2011] [Revised: 03/14/2011] [Accepted: 03/15/2011] [Indexed: 11/26/2022]
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53
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Sarazin C, Delaunay N, Costanza C, Eudes V, Gareil P. Capillary electrophoresis analysis of inorganic cations in post-blast residue extracts applying a guanidinium-based electrolyte and bilayer-coated capillaries. Electrophoresis 2011; 32:1282-91. [DOI: 10.1002/elps.201000626] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2010] [Revised: 12/15/2010] [Accepted: 01/05/2011] [Indexed: 11/05/2022]
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54
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55
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Vidal DTR, Augelli MA, Hotta GM, Lopes FS, do Lago CL. Determination of fluoroacetate and fluoride in blood serum by capillary zone electrophoresis using capacitively coupled contactless conductivity detection. Electrophoresis 2011; 32:896-9. [DOI: 10.1002/elps.201000475] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2010] [Revised: 10/21/2010] [Accepted: 10/21/2010] [Indexed: 11/11/2022]
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56
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Plecis A, Pallandre A, Haghiri-Gosnet AM. Ionic and mass transport in micro-nanofluidic devices: a matter of volumic surface charge. LAB ON A CHIP 2011; 11:795-804. [PMID: 21290048 DOI: 10.1039/c0lc00079e] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The shape and the surface charge of microchannels are critical parameters for ionic and mass transport in microfluidic systems. A great number of studies and developments have been carried out in order to optimize these features separately. We propose to consider them together within a new fundamental parameter for microfluidics, that we named the Volumic Surface Charge (VSC), which is the ratio of the surface charge to the section height in planar microchannels. The non-linear effects induced by rapid VSC variations can result in selective preconcentration processes, which can be used for a simultaneous preconcentration and separation of biomolecules within simple straight channels. In this review, we first present 3 different techniques that we developed to tune the VSC either by surface chemical patterning, integration of polarisable interfaces or geometrical constrictions. The proof of concept of the selective preconcentration using VSC variations will be presented on the basis of experimental results obtained with fluorescent probes and numerical simulations.
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Affiliation(s)
- Adrien Plecis
- Laboratoire de Photonique et des Nanostructures, LPN-CNRS, route de Nozay, 91460 Marcoussis, France
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57
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Haselberg R, Brinks V, Hawe A, de Jong GJ, Somsen GW. Capillary electrophoresis-mass spectrometry using noncovalently coated capillaries for the analysis of biopharmaceuticals. Anal Bioanal Chem 2011; 400:295-303. [PMID: 21318246 PMCID: PMC3062027 DOI: 10.1007/s00216-011-4738-4] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2010] [Revised: 12/24/2010] [Accepted: 01/27/2011] [Indexed: 10/29/2022]
Abstract
In this work, the usefulness of capillary electrophoresis-electrospray ionization time-of-flight-mass spectrometry for the analysis of biopharmaceuticals was studied. Noncovalently bound capillary coatings consisting of Polybrene-poly(vinyl sulfonic acid) or Polybrene-dextran sulfate-Polybrene were used to minimize protein and peptide adsorption, and achieve good separation efficiencies. The potential of the capillary electrophoresis-mass spectrometry (CE-MS) system to characterize degradation products was investigated by analyzing samples of the drugs, recombinant human growth hormone (rhGH) and oxytocin, which had been subjected to prolonged storage, heat exposure, and/or different pH values. Modifications could be assigned based on accurate masses as obtained with time-of-flight-mass spectrometry (TOF-MS) and migration times with respect to the parent compound. For heat-exposed rhGH, oxidations, sulfonate formation, and deamidations were observed. Oxytocin showed strong deamidation (up to 40%) upon heat exposure at low pH, whereas at medium and high pH, mainly dimer (>10%) and trisulfide formation (6-7%) occurred. Recombinant human interferon-β-1a (rhIFN-β) was used to evaluate the capability of the CE-MS method to assess glycan heterogeneity of pharmaceutical proteins. Analysis of this N-glycosylated protein revealed a cluster of resolved peaks which appeared to be caused by at least ten glycoforms differing merely in sialic acid and hexose N-acetylhexosamine composition. Based on the relative peak area (assuming an equimolar response per glycoform), a quantitative profile could be derived with the disialytated biantennary glycoform as most abundant (52%). Such a profile may be useful for in-process and quality control of rhIFN-β batches. It is concluded that the separation power provided by combined capillary electrophoresis and TOF-MS allows discrimination of highly related protein species.
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Affiliation(s)
- R Haselberg
- Department of Biomedical Analysis, Utrecht University, PO Box 80082, 3508 TB Utrecht, The Netherlands.
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58
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Salim M, McArthur SL, Vaidyanathan S, Wright PC. Towards proteomics-on-chip: The role of the surface. ACTA ACUST UNITED AC 2011; 7:101-15. [DOI: 10.1039/c005236a] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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59
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Ehala S, Grishina AA, Sheshenev AE, Lyapkalo IM, Kašička V. Determination of acid–base dissociation constants of very weak zwitterionic heterocyclic bases by capillary zone electrophoresis. J Chromatogr A 2010; 1217:8048-53. [DOI: 10.1016/j.chroma.2010.08.077] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2010] [Revised: 08/25/2010] [Accepted: 08/26/2010] [Indexed: 10/19/2022]
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60
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Zheng C, Liu Y, Zhou Q, Di X. Capillary electrophoresis with noncovalently bilayer-coated capillaries for stability study of allergenic proteins in simulated gastrointestinal fluids. J Chromatogr B Analyt Technol Biomed Life Sci 2010; 878:2933-6. [DOI: 10.1016/j.jchromb.2010.08.027] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2010] [Revised: 08/17/2010] [Accepted: 08/17/2010] [Indexed: 10/19/2022]
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61
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Permanent gold nanoparticle coatings on polyelectrolyte multilayer modified capillaries for open-tubular capillary electrochromatography. J Chromatogr A 2010; 1217:6588-94. [DOI: 10.1016/j.chroma.2010.08.057] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2010] [Revised: 08/11/2010] [Accepted: 08/23/2010] [Indexed: 11/21/2022]
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62
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Non-invasive characterization of stationary phases in capillary flow systems using scanning capacitively coupled contactless conductivity detection (sC4D). Trends Analyt Chem 2010. [DOI: 10.1016/j.trac.2010.04.007] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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63
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Weinbauer M, Stutz H. Successive multiple ionic polymer layer coated capillaries in the separation of proteins - recombinant allergen variants as a case study. Electrophoresis 2010; 31:1805-12. [PMID: 20506417 DOI: 10.1002/elps.201000077] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
A successive multiple ionic polymer layer (SMIL) coating consisting of two pairs of poly(diallyldimethylammonium chloride) and dextran sulfate (DS) layers was applied for the separation of recombinant products of the major birch pollen allergen Betula verrucosa (Bet v 1a). The combination with volatile ammonium bicarbonate buffer at pH 6.70 offers the possibility for future MS hyphenation. The negative net charge of allergens required DS as terminal SMIL layer. The EOF was accelerated from 3.17x10(-8) m(2) V(-1) s(-1) in uncoated to 4.52x10(-8) m(2) V(-1) s(-1) in SMIL capillaries. Fresh prepared SMIL capillaries showed slight EOF acceleration due to gradual re-organization of SMIL structure until stabilization was achieved. Dry storage of SMIL capillaries prevented fluctuations in EOF and migration times and improved coating durability. However, the gradual reconstitution of entangled SMIL layers affected efficiency, but was cured by a 10 mmol/L NaOH rinsing step. Durability of SMIL capillaries in MS-applicable dimension was confirmed for > 70 runs and in total 42 h of voltage application with average intra-day precision of 0.22 and 0.79% and inter-day-precision of 0.91 and 1.17% for migration times of EOF and Bet v 1a, respectively. Final SMIL coating allowed for the separation of Bet v 1a, a hypoallergenic isoform and carbamylated variants with 150,000-685,000 plates.
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Affiliation(s)
- Martin Weinbauer
- Division of Chemistry and Bioanalytics, Department of Molecular Biology, University of Salzburg, Salzburg, Austria
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64
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Nagasaka M, Yoshida K, Sato K, Hoshi T, Anzai JI. Electrode potential-dependent colorimetric response of fluorescein-modified layer-by-layer films in the presence of hydrogen peroxide. J Colloid Interface Sci 2010; 348:441-5. [PMID: 20621819 DOI: 10.1016/j.jcis.2010.05.013] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2010] [Revised: 04/30/2010] [Accepted: 05/02/2010] [Indexed: 11/19/2022]
Abstract
Layer-by-layer (LbL) thin films composed of fluorescein-modified poly(allylamine) (F-PAH) and poly(styrenesulfonic acid) (PSS) were prepared on the surface of an indium-tin oxide (ITO) electrode and the electrode potential-dependent colorimetric response of the LbL films was studied in the presence of hydrogen peroxide (H(2)O(2)). The LbL films were prepared by an alternate deposition of F-PAH and PSS on the surface through an electrostatic force of attraction. The LbL films exhibited a UV-visible absorption band around 500 nm originating from fluorescein residues in the film and the intensity of the absorption band depended on the pH of the solution to which the LbL film is exposed. The absorbance of the film was higher at neutral pH than that in weakly acidic solutions. The intensity of the absorption band decreased when an electrode potential higher than 0.6 V was applied in the presence of H(2)O(2), while virtually no response was observed at lower electrode potential. The colorimetric response was suppressed in solutions with higher buffer capacity. The results were rationalized on the basis of the changes in local pH at the vicinity of the electrode surface, which in turn was induced by electrolysis of H(2)O(2) on the electrode surface. A possible application of the system for colorimetric sensing of H(2)O(2) was discussed.
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Affiliation(s)
- Munenari Nagasaka
- Graduate School of Pharmaceutical Sciences, Tohoku University, Aramaki, Aoba-ku, Sendai 980-8578, Japan
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65
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Breadmore MC. Electroosmotic flow-balanced isotachophoretic stacking with continuous electrokinetic injection for the concentration of anions in high conductivity samples. J Chromatogr A 2010; 1217:3900-6. [DOI: 10.1016/j.chroma.2010.04.011] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2010] [Revised: 03/30/2010] [Accepted: 04/08/2010] [Indexed: 12/28/2022]
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66
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Kazarian AA, Hilder EF, Breadmore MC. Capillary electrophoretic separation of mono- and di-saccharides with dynamic pH junction and implementation in microchips. Analyst 2010; 135:1970-8. [DOI: 10.1039/c0an00010h] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
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67
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Evaluation of migration behaviour of therapeutic peptide hormones in capillary electrophoresis using polybrene-coated capillaries. Anal Bioanal Chem 2009; 396:1571-9. [DOI: 10.1007/s00216-009-3344-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2009] [Revised: 11/24/2009] [Accepted: 11/24/2009] [Indexed: 10/20/2022]
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68
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Pelcová P, Kubáň V, Kiplagat IK, Kubáň P. Polyelectrolyte multilayers as stationary phases for open tubular ion chromatography. J Chromatogr A 2009; 1216:9022-6. [DOI: 10.1016/j.chroma.2009.10.067] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2009] [Revised: 10/21/2009] [Accepted: 10/23/2009] [Indexed: 10/20/2022]
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69
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Liu Q, Yao L, Shen Q, Nie Z, Guo M, Yao S. Layer-by-Layer Assembly of Polyelectrolyte and Nanoparticles, Monitored by Capillary Electrophoresis. Chemistry 2009; 15:12828-36. [DOI: 10.1002/chem.200901998] [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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70
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Nehmé R, Perrin C, Guerlavais V, Fehrentz JA, Cottet H, Martinez J, Fabre H. Use of coated capillaries for the electrophoretic separation of stereoisomers of a growth hormone secretagogue. Electrophoresis 2009; 30:3772-9. [DOI: 10.1002/elps.200900093] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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71
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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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72
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Chu BL, Feng Q, Wang Z, Lin JM. Enantiomeric Separation of Two Antiparkinsonian Drugs by Electrokinetic Chromatography Using Dextran Sulfate. Chromatographia 2009. [DOI: 10.1365/s10337-009-1232-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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73
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Alahmad Y, Thuy Tran N, Duboeuf J, Grégoire A, Rancé I, Taverna M. CZE for glycoform profiling and quality assessment of recombinant human interleukin-7. Electrophoresis 2009; 30:2347-54. [DOI: 10.1002/elps.200800789] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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74
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Nehmé R, Perrin C, Cottet H, Blanchin M, Fabre H. Influence of polyelectrolyte capillary coating conditions on protein analysis in CE. Electrophoresis 2009; 30:1888-98. [DOI: 10.1002/elps.200800688] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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75
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Stutz H. Protein attachment onto silica surfaces - a survey of molecular fundamentals, resulting effects and novel preventive strategies in CE. Electrophoresis 2009; 30:2032-61. [DOI: 10.1002/elps.200900015] [Citation(s) in RCA: 114] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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76
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Loading and release of methyl orange in layer-by-layer assembled polyelectrolyte films. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2009. [DOI: 10.1016/j.msec.2008.09.016] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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77
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Jaafar J, Konishi K, Terabe S, Ikegami T, Tanaka N. Field Enhanced Sample Injection for the CE Determination of Arsenic Compounds Using Successive Multiple Ionic Polymer Layer Coated Capillaries. Chromatographia 2009. [DOI: 10.1365/s10337-009-1063-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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78
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Isemura T, Kitagawa F, Otsuka K. Separation of complex mixtures of fluorobenzoic acids by capillary electrophoresis. J Sep Sci 2009; 32:381-7. [DOI: 10.1002/jssc.200800549] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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79
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Castillo JA, Narciso DM, Hayes MA. Bionanotubule formation from surface-attached liposomes using electric fields. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2009; 25:391-396. [PMID: 19063629 DOI: 10.1021/la8028897] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Spontaneous formation of long-range (millimeters) membrane-bound nanotubules from surface-immobilized liposomes is possible by application of modest electric fields (2 -20 V/cm), providing a novel fabrication strategy for these hollow cylindrical structures. Stable tubes generally aligned with the applied electric field were created from liposomes prepared with phosphatidylcholine (PC), phosphatidic acid (PA), phosphoethanolamine (PE), and cholesterol. The minimum voltage which causes nanotubular formation (the onset voltage) and the average number of tubules per liposome of varying composition was examined with fluorescent microscopy using labeled phospholipids. Generally, the onset voltages ranged between 4 and 15 V/cm and depended on the mother vesicle composition. The results of this study suggest that increasing the charged lipid content can decrease the onset voltage. Conversely, a cholesterol content of more than 30% (by mass) was found to hinder extension of lipid tubules. Basic calculations that assume lipid migration and domain formation on the mother liposome as a nucleating site for tubule extension are assessed and suggest this is a reasonable model to describe the mechanism of tubular growth from immobilized liposomes.
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Affiliation(s)
- Josemar A Castillo
- Department of Chemistry and Biochemistry, Arizona State University, Tempe, Arizona 85287, USA
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80
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Wang Y, Sun J, Liu H, Liu J, Zhang L, Liu K, He Z. Predicting skin permeability using liposome electrokinetic chromatography. Analyst 2009; 134:267-72. [DOI: 10.1039/b807497f] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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81
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82
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Zhang Z, Yan B, Liu K, Liao Y, Liu H. CE-MS analysis of heroin and its basic impurities using a charged polymer-protected gold nanoparticle-coated capillary. Electrophoresis 2009; 30:379-87. [DOI: 10.1002/elps.200800069] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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83
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Jung B, Caslavska J, Thormann W. Determination of ethyl sulfate in human serum and urine by capillary zone electrophoresis. J Chromatogr A 2008; 1206:26-32. [DOI: 10.1016/j.chroma.2008.05.086] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2008] [Revised: 05/27/2008] [Accepted: 05/28/2008] [Indexed: 11/13/2022]
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84
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Boonsong K, Caulum MM, Dressen BM, Chailapakul O, Cropek DM, Henry CS. Influence of polymer structure on electroosmotic flow and separation efficiency in successive multiple ionic layer coatings for microchip electrophoresis. Electrophoresis 2008; 29:3128-34. [DOI: 10.1002/elps.200800186] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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85
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Liang RP, Gan GH, Qiu JD. Surface modification of poly(dimethylsiloxane) microfluidic devices and its application in simultaneous analysis of uric acid and ascorbic acid in human urine. J Sep Sci 2008; 31:2860-7. [PMID: 18655017 DOI: 10.1002/jssc.200800149] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Ru-Ping Liang
- Department of Chemistry and Institute for Advanced Study, Nanchang University, Nanchang, PR China
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86
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Huang YF, Chiang CK, Lin YW, Liu K, Hu CC, Bair MJ, Chang HT. Capillary electrophoretic separation of biologically active amines and acids using nanoparticle-coated capillaries. Electrophoresis 2008; 29:1942-51. [PMID: 18383029 DOI: 10.1002/elps.200700534] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
This manuscript describes dynamic coating of capillaries with poly(L-lysine) (PLL) and silica nanoparticles (SiO2 NPs) and use of the as-prepared capillaries for the separation of biogenic amines and acids by CE in conjunction with LIF detection. The directions of EOF are controlled by varying the outmost layer of the capillaries with PLL and SiO2 NPs, respectively. Over the pH range 3.0-5.0, the (PLL-SiO2NP)n-PLL capillaries have an EOF toward the anodic end and are more suitable for the separation of acids with respect to speed, while the (PLL-SiO2NP)n capillaries have an EOF toward the cathodic end and are more suitable for the separation of biogenic amines regarding speed and sensitivity. The separations of standard solutions containing five amines and two acids by CE with LIF detection using (PLL-SiO2NP)2-PLL and (PLL-SiO2NP)3 capillaries were accomplished within 10 and 7 min, providing plate numbers of 3.8 and 5.0x10(4) plates/m for 5-hydroxytryptamine (5-HT), respectively. The LODs for 5-HT and 5-hydroxyindole-3-acetic acid (5-HIAA) are 32 and 2 nM and 0.2 and 1.5 nM when using the (PLL-SiO2NP)2-PLL and (PLL-SiO2NP)3 capillaries, respectively. Identification and quantification of 5-HIAA, homovanillic acid, and DL-vanillomandelic acid in urine samples from a male before and after drinking green tea were tested to validate practicality of the present approach. The results show that the (PLL-SiO2NP)2-PLL capillary provides greater resolving power, while the (PLL-SiO2NP)3 capillary provides better sensitivity, higher efficiency, and longer durability for the separation of the amines and acids.
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Affiliation(s)
- Yu-Fen Huang
- Department of Chemistry, National Taiwan University, Taipei, Taiwan
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87
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Nehmé R, Perrin C, Cottet H, Blanchin MD, Fabre H. Influence of polyelectrolyte coating conditions on capillary coating stability and separation efficiency in capillary electrophoresis. Electrophoresis 2008; 29:3013-23. [DOI: 10.1002/elps.200700886] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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88
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Lucy CA, MacDonald AM, Gulcev MD. Non-covalent capillary coatings for protein separations in capillary electrophoresis. J Chromatogr A 2008; 1184:81-105. [DOI: 10.1016/j.chroma.2007.10.114] [Citation(s) in RCA: 252] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2007] [Revised: 10/25/2007] [Accepted: 10/31/2007] [Indexed: 11/27/2022]
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89
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Lokajová J, Hruška V, Tesařová E, Gaš B. System peaks in micellar electrophoresis: I. Utilization of system peaks for determination of critical micelle concentration. Electrophoresis 2008; 29:1189-95. [DOI: 10.1002/elps.200700780] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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90
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Luces CA, Fakayode SO, Lowry M, Warner IM. Protein separations using polyelectrolyte multilayer coatings with molecular micelles in open tubular capillary electrochromatography. Electrophoresis 2008; 29:889-900. [DOI: 10.1002/elps.200700634] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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91
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Taga A, Maruyama R, Yamamoto Y, Honda S. Observation of interactions of human serum components with transferrin by affinity capillary electrophoresis. J Pharm Biomed Anal 2008; 46:395-8. [DOI: 10.1016/j.jpba.2007.10.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2007] [Revised: 09/26/2007] [Accepted: 10/01/2007] [Indexed: 11/24/2022]
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92
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Webb R, Doble P, Dawson M. A rapid CZE method for the analysis of benzodiazepines in spiked beverages. Electrophoresis 2007; 28:3553-65. [PMID: 17853510 DOI: 10.1002/elps.200700110] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
A rapid CZE method was developed for the simultaneous determination of nine benzodiazepines in spiked beverages (nitrazepam oxazepam, alprazolam, flunitrazepam, temazepam, diazepam, 7-aminoflunitrazepam, 7-aminonitrazepam and 7-aminoclonazepam). The method employed a double-coated capillary coated with poly(diallyldimethylammonium chloride) and then dextran sulphate. The BGE conditions were 100 mM ammonium phosphate buffer, pH 2.5, which gave baseline resolution between consecutive peaks and a run time of less than 6.5 min. This method offers improvements in both resolution and run time, compared to those attained under analogous conditions with an uncoated capillary. The validated method was successfully applied to beverages that had been spiked with benzodiazepines at concentrations simulating prescription tablets. No sample pretreatment was required to quantify five benzodiazepines in Coca-Cola, orange juice, beer, bourbon and Bacardi. The exception was white wine, where the complex sample matrix did not enable the accurate quantification of nitrazepam.
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Affiliation(s)
- Rebecca Webb
- Centre for Forensic Science, Department of Chemistry, Materials and Forensic Science, University of Technology, Sydney, NSW, Australia
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93
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Evenhuis CJ, Yang WC, Johns C, Macka M, Haddad PR. Fluorinated ethylenepropylene copolymer as a potential capillary material in CE. Electrophoresis 2007; 28:3477-84. [PMID: 17847133 DOI: 10.1002/elps.200700171] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
In this work, a new generation UV-transparent polymer, fluorinated ethylenepropylene copolymer (FEP) exhibiting a low degree of crystallinity, extruded in dimensions similar to the most commonly used CE capillaries of approximately 80 mum id and about 360 mum od was investigated for its use as a CE capillary. FEP is transparent down to the low-UV region, and as fluorinated polymers in general are good electrical insulators and exhibit reasonable heat conductivity, it has considerable potential as a material for electrodriven analysis in capillary or microchip formats. The FEP capillary has been characterised with regard to some important aspects for its use as a CE capillary, including its profile of EOF versus pH, as well as procedures for manipulating EOF by coating the inner capillary wall with various semipermanent and dynamic layers. The FEP capillaries were tested and compared with fused-silica capillary for the separation of inorganic and small organic ions using conditions involving direct and indirect detection in the low-UV region. Finally, advantages of the use of the FEP capillary for simultaneous detection of a mixture containing nine inorganic cations and anions using indirect photometric detection with a movable light-emitting diode (LED) detector and a novel electrolyte are demonstrated.
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94
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Thormann W, Caslavska J, Mosher RA. Modeling of electroosmotic and electrophoretic mobilization in capillary and microchip isoelectric focusing. J Chromatogr A 2007; 1155:154-63. [PMID: 17307189 DOI: 10.1016/j.chroma.2007.01.121] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2006] [Revised: 01/20/2007] [Accepted: 01/25/2007] [Indexed: 11/26/2022]
Abstract
Our dynamic capillary electrophoresis model which uses material specific input data for estimation of electroosmosis was applied to investigate fundamental aspects of isoelectric focusing (IEF) in capillaries or microchannels made from bare fused-silica (FS), FS coated with a sulfonated polymer, polymethylmethacrylate (PMMA) and poly(dimethylsiloxane) (PDMS). Input data were generated via determination of the electroosmotic flow (EOF) using buffers with varying pH and ionic strength. Two models are distinguished, one that neglects changes of ionic strength and one that includes the dependence between electroosmotic mobility and ionic strength. For each configuration, the models provide insight into the magnitude and dynamics of electroosmosis. The contribution of each electrophoretic zone to the net EOF is thereby visualized and the amount of EOF required for the detection of the zone structures at a particular location along the capillary, including at its end for MS detection, is predicted. For bare FS, PDMS and PMMA, simulations reveal that EOF is decreasing with time and that the entire IEF process is characterized by the asymptotic formation of a stationary steady-state zone configuration in which electrophoretic transport and electroosmotic zone displacement are opposite and of equal magnitude. The location of immobilization of the boundary between anolyte and most acidic carrier ampholyte is dependent on EOF, i.e. capillary material and anolyte. Overall time intervals for reaching this state in microchannels produced by PDMS and PMMA are predicted to be similar and about twice as long compared to uncoated FS. Additional mobilization for the detection of the entire pH gradient at the capillary end is required. Using concomitant electrophoretic mobilization with an acid as coanion in the catholyte is shown to provide sufficient additional cathodic transport for that purpose. FS capillaries dynamically double coated with polybrene and poly(vinylsulfonate) are predicted to provide sufficient electroosmotic pumping for detection of the entire IEF gradient at the cathodic column end.
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Affiliation(s)
- W Thormann
- Department of Clinical Pharmacology, University of Bern, Bern, Switzerland.
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95
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Sanz-Nebot V, Balaguer E, Benavente F, Neusüss C, Barbosa J. Characterization of transferrin glycoforms in human serum by CE-UV and CE-ESI-MS. Electrophoresis 2007; 28:1949-57. [PMID: 17523137 DOI: 10.1002/elps.200600648] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Human transferrin (Tf) is a model glycoprotein for congenital disorders of glycosylation (CDG) diagnosis. In the last few years, new CE-UV methods for intact Tf glycoforms analysis have been developed using nonvolatile BGEs and organic modifiers. However, the use of these BGEs does not allow the coupling of these procedures with electrospray MS (ESI-MS). In this study, a new CE-UV separation method of Tf glycoforms is developed, using a double-layer stable coating and a volatile BGE based on ammonium acetate. The separation method is optimized using standard Tf and their potential is demonstrated applying the method to the analysis of sera Tf from healthy individuals and CDG patients. The CE-UV separation method has been coupled to ESI-MS detection. Main parameters such as sheath liquid composition are optimized in order to obtain a good sensitivity. The CE-ESI-MS method has also been used in serum samples obtaining the separation of the different proteins present in serum and partial separation of Tf glycoforms. Different mass spectra and deconvoluted molecular masses were obtained for each sialoform, allowing unequivocal glycoform identification.
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96
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Fu X, Huang L, Gao F, Li W, Pang N, Zhai M, Liu H, Wu M. Carboxymethyl chitosan-coated capillary and its application in CE of proteins. Electrophoresis 2007; 28:1958-63. [PMID: 17487918 DOI: 10.1002/elps.200600558] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
A hydrophilic basic polysaccharide, carboxymethyl chitosan (CMC) as a capillary coating is presented with a simple preparation procedure. The CMC-coated capillary showed a long lifetime of more than 100 runs, and had good tolerance to some organic solvents, 0.1 M HCl, 0.1 M NaOH, and 5 M urea. The run-to-run, day-to-day, and capillary-to-capillary RSDs for the CMC-coated capillary were all below 2.0% for the determination of EOF. Moreover, the coatings with different concentrations and molecular weights of CMC were also investigated. The CMC-coated capillary was successfully applied to separate basic proteins and recombinant human erythropoietin (rhEPO). Furthermore, several experimental parameters, such as the concentration and pH of the running buffer, temperature, and applied voltage, were optimized for the separation of rhEPO glycoforms. Comparison of an uncoated capillary with chitosan- and CMC-coated capillaries for the separation of rhEPO glycoforms was also discussed. The results demonstrated that rhEPO glycoforms can be well separated by a CMC-coated capillary within 8 min with good reproducibility and resolution. Finally, the volatile BGE HAc-NH4Ac was utilized to separate rhEPO for its further application with CE-MS, achieving a satisfactory result.
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Affiliation(s)
- Xiaofang Fu
- Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, Institute of Analytical Chemistry, College of Chemistry and Molecular Engineering, Peking University, Beijing, PR China
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97
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Mwongela SM, Lee K, Sims CE, Allbritton NL. Separation of fluorescent phosphatidyl inositol phosphates by CE. Electrophoresis 2007; 28:1235-42. [PMID: 17366487 DOI: 10.1002/elps.200600594] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Phosphatidyl inositol 4,5-bisphosphate (PIP2) and phosphatidyl inositol 3,4,5-trisphosphate (PIP3) labeled with 4,4-difluoro-5,7-dimethyl-4-bora-3a,4a-diaza-s-indacene-3-propionic acid (BODIPY FL) on the acyl chain or a phosphatidyl ethanolamine head group were separated by CE with LIF detection. Several methods and capillary-coating procedures were tested for the separation of these phosphatidyl inositol phosphates (PIPs) at 20 degrees C. Separation of the PIPs in less than 20 min with excellent resolution was achieved using a buffer containing sodium deoxycholate (SDC), 1-propanol, MgCl2 and the polymer coating reagent, EOTrol LR. The efficiency of the optimized method was as high as 1.3x10(5) plates. The dependence of the separation on the concentration of 1-propanol, SDC, and MgCl2 was determined. The separation of PIP2 and PIP3 was primarily due to differential binding of the lipids to Mg2+ rather than to different solubilities in the micellar phase. The role of the SDC was to prevent adsorption of the hydrophobic lipids to the capillary wall and thus enhance the efficiency. The fluorescent PIPs are of value for both in vitro and in vivo assays of phospholipid metabolism. In particular, the use of these lipids with the optimized capillary-based separation will be of utility for drug screening as well as cell-based assays.
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Affiliation(s)
- Simon M Mwongela
- Department of Physiology and Biophysics, University of California, Irvine, CA, USA
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98
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Robb CS. Applications of Physically Adsorbed Polymer Coatings in Capillary Electrophoresis. J LIQ CHROMATOGR R T 2007. [DOI: 10.1080/10826070701191029] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- Christina S. Robb
- a Department of Analytical Chemistry , Connecticut Agricultural Experiment Station , New Haven , Connecticut , USA
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99
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Danger G, Ramonda M, Cottet H. Control of the EOF in CE using polyelectrolytes of different charge densities. Electrophoresis 2007; 28:925-31. [PMID: 17309049 DOI: 10.1002/elps.200600360] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The control of the EOF direction and magnitude remains one of the more challenging issues for the optimization of separations in CE. In this work, we investigated the possibility to use variously charged polyanions for a fine-tuning of the EOF using polyelectrolyte multilayers. For that purpose, polyanions of poly(acrylamide-co-2-acrylamido-2-methyl-1-propanesulfonate) (PAMAMPS) with different chemical charge rates varying between 3 and 100% were used. These copolymers are statistic hydrophilic copolymers of acrylamide (AM) and 2-acrylamido-2-methyl-1-propanesulfonate (AMPS). The study of the influence of the chemical charge rate (AMPS molar proportion in the copolymer) on the electroosmotic mobility (mu(eo)) of a capillary modified by a polyelectrolyte bilayer (polycation/PAMAMPS) revealed that the fine-tuning of the EOF was possible, at least for cathodic or slightly anodic EOF (micro(eo) from -5 x 10(-5) to +35 x 10(-5) cm(2)V(-1)s(-1)). Electroosmotic mobility values were compared with the free-draining electrophoretic mobilities of the PAMAMPS constituting the last layer of the capillary coating. The stability of the EOF is discussed in detail on the basis of successive determinations of electroosmotic mobility and migration times. The application to the separation of a model peptide mixture demonstrated the interest (and the simplicity) of this approach for optimizing resolution and analysis time. Experimental resolutions were compared to the theoretical ones that we would obtain on a fused-silica capillary having the same EOF as the coated capillary.
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Affiliation(s)
- Grégoire Danger
- Institut Max Mousseron, Université Montpellier 1,Université Montpellier 2, CNRS, France
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100
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Blanco D, Herrero I, Laviana L, Gutie`rrez MD. CAPILLARY ZONE ELECTROPHORETIC SEPARATION OF PROTEINS USING COATED CAPILLARIES. J LIQ CHROMATOGR R T 2007. [DOI: 10.1081/jlc-120004016] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- D. Blanco
- a Department of Physical and Analytical Chemistry , Faculty of Chemistry , University of Oviedo , Oviedo , Spain
| | - I. Herrero
- a Department of Physical and Analytical Chemistry , Faculty of Chemistry , University of Oviedo , Oviedo , Spain
| | - L. Laviana
- a Department of Physical and Analytical Chemistry , Faculty of Chemistry , University of Oviedo , Oviedo , Spain
| | - M. D. Gutie`rrez
- b Department of Physical and Analytical Chemistry , Faculty of Chemistry , University of Oviedo , Oviedo , Spain
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