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Mohandas N, Kent LM, Raudsepp A, Jameson GB, Williams MAK. Progress toward Plug-and-Play Polymer Strings for Optical Tweezers Experiments: Concatenation of DNA Using Streptavidin Linkers. ACS OMEGA 2022; 7:6427-6435. [PMID: 35224404 PMCID: PMC8867789 DOI: 10.1021/acsomega.2c00198] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Accepted: 01/31/2022] [Indexed: 06/14/2023]
Abstract
Streptavidin is a tetrameric protein that is renowned for its strong binding to biotin. The robustness and strength of this noncovalent coupling has led to multitudinous applications of the pairing. Within the streptavidin tetramer, each protein monomer has the potential to specifically bind one biotin-bearing moiety. Herein, by separating various streptavidin species that have had differing numbers of their four potential binding sites blocked, several different types of "linking hub" were obtained, each with a different valency. The identification of these species and the study of the plugging process used to block sites during their preparation were carried out using capillary electrophoresis. Subsequently, a specific species, namely, a trans-divalent linker, in which the two open biotin-binding pockets are approximately opposite one another, was used to concatenate two ∼5 kb pieces of biotin-terminated double-stranded DNA. Following the incubation of this DNA with the prepared linker, a fraction of ∼10 kb strings was identified using gel electrophoresis. Finally, these concatenated DNA strings were stretched in an optical tweezer experiment, demonstrating the potential of the methodology for coupling and extending molecules for use in single-molecule biophysical experiments.
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Affiliation(s)
- Nimisha Mohandas
- School
of Fundamental Sciences, Massey University, Palmerston North 4442, New Zealand
| | - Lisa M. Kent
- School
of Fundamental Sciences, Massey University, Palmerston North 4442, New Zealand
| | - Allan Raudsepp
- School
of Fundamental Sciences, Massey University, Palmerston North 4442, New Zealand
| | - Geoffrey B. Jameson
- School
of Fundamental Sciences, Massey University, Palmerston North 4442, New Zealand
- MacDiarmid
Institute for Advanced Materials and Nanotechnology, Wellington 6012, New Zealand
- Riddet
Institute, Massey University, Palmerston North 4442, New Zealand
| | - Martin A. K. Williams
- School
of Fundamental Sciences, Massey University, Palmerston North 4442, New Zealand
- MacDiarmid
Institute for Advanced Materials and Nanotechnology, Wellington 6012, New Zealand
- Riddet
Institute, Massey University, Palmerston North 4442, New Zealand
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2
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Chetwynd AJ, Guggenheim EJ, Briffa SM, Thorn JA, Lynch I, Valsami-Jones E. Current Application of Capillary Electrophoresis in Nanomaterial Characterisation and Its Potential to Characterise the Protein and Small Molecule Corona. NANOMATERIALS (BASEL, SWITZERLAND) 2018; 8:E99. [PMID: 29439415 PMCID: PMC5853730 DOI: 10.3390/nano8020099] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/05/2018] [Revised: 01/22/2018] [Accepted: 01/30/2018] [Indexed: 12/11/2022]
Abstract
Due to the increasing use and production of nanomaterials (NMs), the ability to characterise their physical/chemical properties quickly and reliably has never been so important. Proper characterisation allows a thorough understanding of the material and its stability, and is critical to establishing dose-response curves to ascertain risks to human and environmental health. Traditionally, methods such as Transmission Electron Microscopy (TEM), Field Flow Fractionation (FFF) and Dynamic Light Scattering (DLS) have been favoured for size characterisation, due to their wide-availability and well-established protocols. Capillary Electrophoresis (CE) offers a faster and more cost-effective solution for complex dispersions including polydisperse or non-spherical NMs. CE has been used to rapidly separate NMs of varying sizes, shapes, surface modifications and compositions. This review will discuss the literature surrounding the CE separation techniques, detection and NM characteristics used for the analysis of a wide range of NMs. The potential of combining CE with mass spectrometry (CE-MS) will also be explored to further expand the characterisation of NMs, including the layer of biomolecules adsorbed to the surface of NMs in biological or environmental compartments, termed the acquired biomolecule corona. CE offers the opportunity to uncover new/poorly characterised low abundance and polar protein classes due to the high ionisation efficiency of CE-MS. Furthermore, the possibility of using CE-MS to characterise the poorly researched small molecule interactions within the NM corona is discussed.
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Affiliation(s)
- Andrew J. Chetwynd
- AB Sciex UK Ltd., Phoenix House, Lakeside Drive, Warrington, Cheshire WA1 1RX, UK;
| | - Emily J. Guggenheim
- School of Geography Earth and Environmental Sciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK; (E.J.G.); (S.M.B.); (E.V.-J.)
| | - Sophie M. Briffa
- School of Geography Earth and Environmental Sciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK; (E.J.G.); (S.M.B.); (E.V.-J.)
| | - James A. Thorn
- AB Sciex UK Ltd., Phoenix House, Lakeside Drive, Warrington, Cheshire WA1 1RX, UK;
| | - Iseult Lynch
- School of Geography Earth and Environmental Sciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK; (E.J.G.); (S.M.B.); (E.V.-J.)
| | - Eugenia Valsami-Jones
- School of Geography Earth and Environmental Sciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK; (E.J.G.); (S.M.B.); (E.V.-J.)
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Guzman NA, Guzman DE. An emerging micro-scale immuno-analytical diagnostic tool to see the unseen. Holding promise for precision medicine and P4 medicine. J Chromatogr B Analyt Technol Biomed Life Sci 2016; 1021:14-29. [DOI: 10.1016/j.jchromb.2015.11.026] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2015] [Revised: 11/15/2015] [Accepted: 11/17/2015] [Indexed: 01/10/2023]
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4
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Tang S, Liu S, Guo Y, Liu X, Jiang S. Recent advances of ionic liquids and polymeric ionic liquids in capillary electrophoresis and capillary electrochromatography. J Chromatogr A 2014; 1357:147-57. [PMID: 24786657 DOI: 10.1016/j.chroma.2014.04.037] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2014] [Revised: 04/09/2014] [Accepted: 04/11/2014] [Indexed: 12/16/2022]
Abstract
Ionic liquids (ILs) and polymeric ionic liquids (PILs) with unique and fascinating properties have drawn considerable interest for their use in separation science, especially in chromatographic techniques. In this article, significant contributions of ILs and PILs in the improvement of capillary electrophoresis and capillary electrochromatography are described, and a specific overview of the most relevant examples of their applications in the last five years is also given. Accordingly, some general conclusions and future perspectives in these areas are discussed.
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Affiliation(s)
- Sheng Tang
- Key Laboratory of Chemistry of Northwestern Plant Resources, CAS/Key Laboratory for Natural Medicine of Gansu Province, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, China; University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing 100049, China
| | - Shujuan Liu
- Key Laboratory of Chemistry of Northwestern Plant Resources, CAS/Key Laboratory for Natural Medicine of Gansu Province, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, China
| | - Yong Guo
- Key Laboratory of Chemistry of Northwestern Plant Resources, CAS/Key Laboratory for Natural Medicine of Gansu Province, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, China.
| | - Xia Liu
- Key Laboratory of Chemistry of Northwestern Plant Resources, CAS/Key Laboratory for Natural Medicine of Gansu Province, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, China
| | - Shengxiang Jiang
- Key Laboratory of Chemistry of Northwestern Plant Resources, CAS/Key Laboratory for Natural Medicine of Gansu Province, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, China.
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BAI X, WANG Y, ZHAO H, SUN Z, XIA L, FU Y, SUO Y, LI Y, YOU J. Separation of derivatized aliphatic aldehydes in beverage by nonaqueous capillary electrophoresis. Se Pu 2010; 28:78-83. [DOI: 10.3724/sp.j.1123.2010.00078] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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7
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Single-Molecule Spectroscopy Using Microfluidic Platforms. Methods Enzymol 2010. [DOI: 10.1016/s0076-6879(10)72013-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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8
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Ionic liquids used in and analyzed by capillary and microchip electrophoresis. J Chromatogr A 2009; 1216:4817-23. [DOI: 10.1016/j.chroma.2009.04.024] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2009] [Revised: 04/03/2009] [Accepted: 04/08/2009] [Indexed: 11/18/2022]
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9
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Liu Y, Li W, Ling X, Lai X, Li Y, Zhang Q, Zhao Y. Simultaneous Determination of the Active Ingredients in Abelmoschus manihot (L.) Medicus by CZE. Chromatographia 2008. [DOI: 10.1365/s10337-008-0564-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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10
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Esaka Y, Okumura N, Uno B. Separation Analysis of Reactive Chemical Species by Non-Aqueous Capillary Electrophoresis. BUNSEKI KAGAKU 2008. [DOI: 10.2116/bunsekikagaku.57.961] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- Yukihiro Esaka
- Gifu Pharmaceutical University
- United Graduate School of Drug Discovery and medical Information Sciences, Gifu University
| | | | - Bunji Uno
- Gifu Pharmaceutical University
- United Graduate School of Drug Discovery and medical Information Sciences, Gifu University
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Tenorio-López FA, Valle-Mondragón L, Martínez-Lazcano JC, Sánchez-Mendoza A, Ríos C, Pastelín-Hernández G, Pérez-Severiano F. CZE Determination of Quinolinic Acid in Rat Brain Tissue and Plasma. Chromatographia 2007. [DOI: 10.1365/s10337-007-0241-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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12
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Fox SB, Culha M, Sepaniak MJ. DEVELOPMENT OF A GRID SEARCH MOLECULAR MECHANICS MODELING STRATEGY TO STUDY ELUTION BEHAVIOR IN CYCLODEXTRIN MODIFIED CAPILLARY ELECTROPHORESIS. J LIQ CHROMATOGR R T 2007. [DOI: 10.1081/jlc-100103443] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- Shannon B. Fox
- a Department of Chemistry , University of Tennessee , Knoxville, TN, 37996-1600, U.S.A
| | - Mustafa Culha
- a Department of Chemistry , University of Tennessee , Knoxville, TN, 37996-1600, U.S.A
| | - Michael J. Sepaniak
- b Department of Chemistry , University of Tennessee , Knoxville, TN, 37996-1600, U.S.A
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13
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Liu C, Xu X, Wang Q, Chen J. Mathematical model for DNA separation by capillary electrophoresis in entangled polymer solutions. J Chromatogr A 2007; 1142:222-30. [PMID: 17239893 DOI: 10.1016/j.chroma.2006.12.039] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2006] [Revised: 12/12/2006] [Accepted: 12/12/2006] [Indexed: 11/16/2022]
Abstract
A mathematical model of DNA separation by capillary electrophoresis in entangled polymer solution is presented. The mechanism is modeled as a DNA molecule moving through transient pores formed in polymer solutions and colliding with blobs of polymer molecules encountered during migration. By taking account of the average retardation time (t(c)) of DNA-blob collision and calculating the total collision number (N(c)), a quantitative mathematical equation was reported, leading to predictions for the DNA mobility as a function of the experimental conditions like the size of DNA, the polymer concentration and the electric field strength. For DNA fragments in frequent size range, the initial experimental data agree well with the model. The DNA shape function (f(E)) was suggested and then discussed by the experimental data. The relationship between f(E) and electric field strength E was empirically estimated. Then, the average retardation time t(c) was obtained as about (2 approximately 3)x10(-6)s in linear polyacrylamide (LPA) and hydroxyethylcellulose (HEC) solution.
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Affiliation(s)
- Chunye Liu
- School of Life Science and Technology, Xi'an Jiaotong University, Xi'an 710049, China
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14
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Mohanty A, Dey J. Enantioselectivity of vesicle-forming chiral surfactants in capillary electrophoresis. J Chromatogr A 2006; 1128:259-66. [PMID: 16814304 DOI: 10.1016/j.chroma.2006.06.036] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2006] [Revised: 06/11/2006] [Accepted: 06/12/2006] [Indexed: 10/24/2022]
Abstract
Two vesicle-forming single-tailed amino acid derivatized surfactants sodium N-[4-n-dodecyloxybenzoyl]-L-leucinate (SDLL) and sodium N-[4-n-dodecyloxybenzoyl]-L-isoleucinate (SDLIL) have been synthesized and used as pseudo-stationary phase in micellar electrokinetic chromatography to evaluate the role of steric factor of amino acid headgroup and hydrophobic/hydrophilic interactions for enantiomeric separations. The aggregation behavior of the surfactants has been studied in aqueous buffered solution using surface tension and fluorescence probe techniques. Results of these studies have suggested formation of vesicles in aqueous solutions. Microenvironment of the vesicle, which determines the depth of penetration of the analytes into vesicle was determined by fluorescence probe technique using pyrene, N-phenyl-1-naphthylamine (NPN), and 1,6-diphenyl-1,3,5-hexatriene (DPH) as probe molecules. Atropisomeric compounds (+/-)-1,1'-bi-2-naphthol (BOH), (+/-)-1,1'-binaphthyl-2,2'-diamine (BDA), (+/-)-1,1'-binaphthyl-2,2'-diylhydrogen phosphate (BNP) and Tröger's base (TB) and chiral compound benzoin (BZN) has been enantioseparated. The separations were optimized with respect to surfactant concentration, pH, and borate buffer concentration. SDLL was found to provide better resolution for BOH, BNP, and BZN. On the other hand, SDLIL offers better resolution for BDA. The chromatographic results have been discussed in the light of the aggregation behavior of the surfactants and the interaction of the solutes with the vesicles.
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Affiliation(s)
- Ashok Mohanty
- Department of Chemistry, Indian Institute of Technology, Kharagpur 721302, India
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15
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Zhang H, Hu Z, Yang G, Shi Z, Sun H. Study on Migration Behavior of Organic Acids of Low Molecular Weights in Capillary Zone Electrophoresis. J LIQ CHROMATOGR R T 2006. [DOI: 10.1080/10826079808003413] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- Hongyi Zhang
- a Chemistry Department , Lanzhou University , Lanzhou, 730000, P. R. China
- b Chemistry Department , Hebei University , Baoding, 071002, P. R. China
| | - Zhide Hu
- a Chemistry Department , Lanzhou University , Lanzhou, 730000, P. R. China
| | - Gengliang Yang
- b Chemistry Department , Hebei University , Baoding, 071002, P. R. China
| | - Zhihong Shi
- c Research Center of Chemical and Chemical Analysis , Hebei University , Baoding, 071002, P. R. China
| | - Hanwen Sun
- b Chemistry Department , Hebei University , Baoding, 071002, P. R. China
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16
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Liang HR, Vuorela H, Vuorela P, Hiltunen R, Riekkola ML. The Statistical Evaluation of Migration Parameters of Flavonoids in Capillary Electrophoresis with Reference to Structural Descriptors. J LIQ CHROMATOGR R T 2006. [DOI: 10.1080/10826079808005846] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- Hai-Rui Liang
- a Pharmacognosy Division Department of Pharmacy , P.O. Box 56 FIN-00014 University of Helsinki , Finland
| | - Heikki Vuorela
- a Pharmacognosy Division Department of Pharmacy , P.O. Box 56 FIN-00014 University of Helsinki , Finland
| | - Pia Vuorela
- a Pharmacognosy Division Department of Pharmacy , P.O. Box 56 FIN-00014 University of Helsinki , Finland
| | - Raimo Hiltunen
- a Pharmacognosy Division Department of Pharmacy , P.O. Box 56 FIN-00014 University of Helsinki , Finland
| | - Marja-Liisa Riekkola
- b Laboratory of Analytical Chemistry Department of Chemistry , P.O. Box 55 FIN-00014 University of Helsinki , Finland
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17
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Li J, Waldron KC. EFFECT OF SURFACTANT CONCENTRATION ON THE DETERMINATION OFTRANS,TRANS-MUCONIC ACID IN URINE BY CATIONIC MICELLAR ELECTROKINETIC CHROMATOGRAPHY WITH THERMO-OPTICAL ABSORBANCE DETECTION. J LIQ CHROMATOGR R T 2006. [DOI: 10.1081/jlc-100101776] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- Jianjun Li
- a Institute for Biological Sciences , National Research Council, Ottawa , ON , K1A 0R6 , Canada
| | - Karen C. Waldron
- b Department of Chemistry , University of Montréal , Montréal , Quebéc , H3C 3J7 , Canada
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Yu K, Wang YW, Cheng YY. Determination of Protocatechuic Aldehyde, Danshensu, Salvianolic Acid B and Gallic Acid in Chinese Medicine 'SHUANGDAN' Granule by MEKC. Chromatographia 2006. [DOI: 10.1365/s10337-006-0758-1] [Citation(s) in RCA: 6] [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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Yu K, Wang YW, Cheng YY. Determination of the Active Components in Chinese Herb Cortex Moutan by MEKC and LC. Chromatographia 2006. [DOI: 10.1365/s10337-006-0760-7] [Citation(s) in RCA: 14] [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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Yu K, Lin Z, Cheng Y. Optimization of the buffer system of micellar electrokinetic capillary chromatography for the separation of the active components in Chinese medicine ‘SHUANGDAN’ granule by genetic algorithm. Anal Chim Acta 2006. [DOI: 10.1016/j.aca.2006.01.048] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Zhang LH, Zhang CJ, Wu XZ. Isoelectric Focusing Sample Injection for Capillary Zone Electrophoresis in a Fused Silica Capillary. ANAL SCI 2006; 22:1039-41. [PMID: 16837761 DOI: 10.2116/analsci.22.1039] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
An improvement has been made to couple isoelectric focusing (IEF) sample injection and capillary zone electrophoresis in an untreated fused silica capillary. Electroosmotic flow is efficiently prevented by simply using a rubber block at the outlet end of the capillary during IEF sample injection. The experimental conditions that affect the concentration effect are discussed. A concentration enhancement factor of over 100-fold can be easily obtained for two model proteins: lysozyme and ribonuclease A.
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Affiliation(s)
- Luo-Hong Zhang
- Department of Materials Science and Engineering, Faculty of Engineering, University of Fukui, Bunkyo 3-9-1. Fukui 910-8507, Japan
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Jiang TF, Lv ZH, Wang YH, Yue ME. Separation of Plant Hormones from Biofertilizer by Capillary Electrophoresis Using a Capillary Coated Dynamically with Polycationic Polymers. ANAL SCI 2006; 22:811-4. [PMID: 16772676 DOI: 10.2116/analsci.22.811] [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: 11/23/2022]
Abstract
A new, simple and rapid capillary electrophoresis (CE) method, using hexadimethrine bromide (HDB) as electroosmotic flow (EOF) modifier, was developed for the identification and quantitative determination of four plant hormones, including gibberellin A3 (GA3), indole-3-acetic acid (IAA), alpha-naphthaleneacetic acid (NAA) and 4-chlorophenoxyacetic acid (4-CA). The optimum separation was achieved with 20 mM borate buffer at pH 10.00 containing 0.005% (w/v) of HDB. The applied voltage was -25 kV and the capillary temperature was kept constant at 25 degrees C. Salicylic acid was used as internal standard for quantification. The calibration dependencies exhibited good linearity within the ratios of the concentrations of standard samples and internal standard and the ratios of the peak areas of samples and internal standard. The correlation coefficients were from 0.9952 to 0.9997. The relative standard deviations of migration times and peak areas were < 1.93 and 6.84%, respectively. The effects of buffer pH, the concentration of HDB and the voltage on the resolution were studied systematically. By this method, the contents of plant hormone in biofertilizer were successfully determined within 7 min, with satisfactory repeatability and recovery.
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Affiliation(s)
- Ting-Fu Jiang
- Marine Drug and Food Institute, Ocean University of China, Qingdao, P. R. China
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Liu B, Yue ME, Yang SR, Shi YP. Determination of Phenolic Glucosides in Gentiana piasezkii by Capillary Zone Electrophoresis. Chromatographia 2005. [DOI: 10.1365/s10337-005-0684-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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26
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Yu K, Wang YW, Cheng YY. Determination of paeonol and paeoniflorin in Chinese medicine Cortex Moutan and 'Shuangdan' granule by micellar electrokinetic capillary chromatography. J Pharm Biomed Anal 2005; 40:1257-62. [PMID: 16253465 DOI: 10.1016/j.jpba.2005.09.005] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2005] [Revised: 09/06/2005] [Accepted: 09/08/2005] [Indexed: 11/29/2022]
Abstract
An easy, simple and rapid micellar electrokinetic capillary chromatography (MEKC) method was developed for the separation of two active components paeonol (PN) and paeoniflorin (PF) within 7 min. Capillary electrophoresis (CE) was performed using a 50.0 cm (42.0 cm to the detector window) x 75 microm i.d. fused-silica capillary. The optimal running buffer containing 10mM borate and 25 mM SDS at pH 9.54 was employed. The applied voltage 15 kV and the temperature 25 degrees C was used in CE separation. The linearities between peak areas and the concentrations of the analytes were investigated, and they exhibited excellent linear behavior over the investigated concentration ranges (R(2): 0.9945 for PN and 0.9992 for PF). The method was successfully applied to the determination of these two components contained in Cortex Moutan and 'Shuangdan' granule. The average recoveries ranged between 97.6 and 105.3% for PN and 95.3 and 106.1% for PF, respectively.
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Affiliation(s)
- Ke Yu
- Department of Chinese Medicine Science and Engineering, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310027, China
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Jiang TF, Lv ZH, Wang YH. Separation and determination of anthraquinones inCassia obtusifolia (Leguminosae) by micellar electrokinetic capillary electrophoresis. J Sep Sci 2005; 28:2225-9. [PMID: 16318221 DOI: 10.1002/jssc.200500144] [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: 11/07/2022]
Abstract
An MEKC method was developed for the determination of the five pharmaceutically important anthraquinones: chrysophanol (1), physcion (2), emodin (3), aloe-emodinin (4), and rhein (5) in Cassia obtusifolia (Leguminosae). A buffer solution (pH 9.00) composed of 20 mM sodium borate, 20 mM sodium deoxycholate (DOC), and 15% ACN was found to be the most suitable electrolyte for this separation. Regression equations revealed linear relationships (correlation coefficients: 0.9993, 0.9992, 0.9996, 0.9989, and 0.9991) between the peak area of each compound (1, 2, 3, 4, and 5) and its concentration. The RSDs of migration times and peak areas were <1.23 and 2.72% within 1 day, respectively. The effects of pH value, surfactant (DOC) concentration, and organic modifier on the migration were also studied. By this way, the contents of five anthraquinones in the extracts of the seed of C. obtusifolia (Leguminosae) from different sources were successfully determined within 14 min.
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Affiliation(s)
- Ting-Fu Jiang
- Key Laboratory of Marine Drugs (Ocean University of China), Ministry of Education, China.
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Herrero M, Arráez-Román D, Segura A, Kenndler E, Gius B, Raggid MA, Ibáñez E, Cifuentes A. Pressurized liquid extraction-capillary electrophoresis-mass spectrometry for the analysis of polar antioxidants in rosemary extracts. J Chromatogr A 2005; 1084:54-62. [PMID: 16114236 DOI: 10.1016/j.chroma.2004.10.003] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
A method based on capillary electrophoresis-electrospray-mass spectrometry (CE-ESI-MS) was developed to qualitatively characterize natural antioxidants from rosemary (Rosmarinus officinalis L.) in different fractions obtained by pressurized liquid extraction (PLE) using subcritical water. The parameters of CE-ESI-MS were adjusted allowing the separation and characterization of different compounds from rosemary in the PLE fractions. These parameters for CE are kind, pH and concentration of the separation buffer, parameters for ESI-MS are dry gas temperature and flow, nebulizing gas pressure, and make-up flow. The following analytical conditions were found most favorable: aqueous CE buffer (40 mM ammonium acetate/ammonium hydroxide, pH 9); sheath liquid containing 2-propanol-water (60:40, v/v) and 0.1% (v/v) triethylamine at a flow rate of 0.24 mL/h; drying gas flow rate equal to 7 L/min at 350 degrees C, nebulizing gas pressure of 13.8 kPa (2 psi), using a compound stability of 50%. Different antioxidant compounds (e.g., rosmarinic acid and carnosic acid) could be detected in the rosemary extracts by CE-ESI-MS without any additional treatment, enabling the determination of variations in the extract composition caused by the different PLE conditions (i.e., 60 and 100 degrees C). The results provide complementary information to HPLC analysis.
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Affiliation(s)
- Miguel Herrero
- Department of Food Analysis, Institute of Industrial Fermentations (CSIC), Juan de la Cierva 3, 28006 Madrid, Spain
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29
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Fatemi MH, Goudarzi N. Quantitative structure property relationship study of the electrophoretic mobilities of some benzoic acids derivatives in different carrier electrolyte compositions. Electrophoresis 2005; 26:2968-73. [PMID: 16007694 DOI: 10.1002/elps.200410343] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Quantitative structure-properties relationship (QSPR) has been applied to modeling and predicting the electrophoretic mobilities of a series of benzoic acid derivatives in different carrier electrolyte composition. Descriptors that were selected by stepwise multiple linear regression (MLR) technique are radial distribution function-lag8 (RDF-8), unweighted R-maximal autocorrelation geometry, topology and atomic weight assembly-lag4 (R-GETAWAY-4), geometrical descriptor lag-26 (GEO-26), and the overall dielectric constant of the carrier electrolyte. These descriptors were used as inputs for generated 4-7-1 artificial neural network (ANN). The results obtained using ANN and MLR were compared as well as with the experimental values and showed the superiority of ANN over MLR model. Also the appearance of these descriptors in QSPR models reveals the role of electronic and steric interactions in solutes mobility in capillary electrophoresis due to the dielectric and hydrodynamic friction forces.
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30
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Castañeda G, Rodríguez-Flores J, Ríos A. Analytical approaches to expanding the use of capillary electrophoresis in routine food analysis. J Sep Sci 2005; 28:915-24. [PMID: 16013817 DOI: 10.1002/jssc.200500036] [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: 11/06/2022]
Abstract
Capillary Electrophoresis (CE) is becoming an ever more powerful analytical technique for the separation, identification, and quantification of a wide variety of compounds of interest in many application fields. Particularly in food analysis this technique can offer interesting advantages over chromatographic techniques because of its greater simplicity and efficiency. Nevertheless, CE needs to advance with regard to compatibility with sample matrices, sensitivity, and robustness of the methodologies in order to gain even wider acceptance in food analysis laboratories, specially for routine work. This article presents various approaches to expanding the analytical usefulness of CE in food analysis, discussing their advantages over conventional CE. These approaches focus on sample screening, automated sample preparation with on-line CE arrangements, and the automatic integration of calibration in routine analytical work with CE.
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Affiliation(s)
- Gregorio Castañeda
- Department of Analytical Chemistry and Food Technology, Faculty of Chemistry, University of Castilla--La Mancha, Avda. Camilo José Cela, 10, E-13004 Ciudad Real, Spain
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31
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Du G, Zhang S, Xie J, Zhong B, Liu K. Chiral separation of anticholinergic drug enantiomers in nonaqueous capillary electrophoresis. J Chromatogr A 2005; 1074:195-200. [PMID: 15941055 DOI: 10.1016/j.chroma.2005.03.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Nonaqueous capillary electrophoretic (NACE) method for the separation of nine structurally similar chiral anticholinergic drugs was developed. The eight drug enantiomers were separated on baseline within 18 min using 20mM phosphoric acid and 10 mM NaOH, containing 10 mM heptakis(2,3-dimethyl-6-sulfato)-4beta-cyclodextrin (HDMS-beta-CD) in methanol. The results were compared with those obtained in the high performance liquid chromatography system.
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Affiliation(s)
- Guohua Du
- Beijing Institute of Pharmacology and Toxicology, Beijing 100850, China
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32
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UV–Vis absorbance detection in capillary electrophoresis. ACTA ACUST UNITED AC 2005. [DOI: 10.1016/s0166-526x(05)45005-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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33
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Crego AL, Ib��ez E, Garc�a E, de Pablos RR, Se�or�ns FJ, Reglero G, Cifuentes A. Capillary electrophoresis separation of rosemary antioxidants from subcritical water extracts. Eur Food Res Technol 2004. [DOI: 10.1007/s00217-004-0980-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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34
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Sullivan J, Douek M. Analysis of hydroxide, inorganic sulphur species and organic anions in kraft pulping liquors by capillary electrophoresis. J Chromatogr A 2004; 1039:215-25. [PMID: 15250426 DOI: 10.1016/j.chroma.2004.03.078] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
A new method has been developed for the determination of hydroxide, sulphide, thiosulphate, sulphate, sulphite, chloride, oxalate and formate in kraft green, white and black liquors by capillary electrophoresis. The method provides baseline resolution of all analytes of interest using an electrolyte composed of 10 mM sodium chromate and 2 mM tetradecyltrimethylammonium hydroxide. Separations are conducted under constant current conditions at 25 degrees C and analytes are quantified by indirect UV-detection at 275 nm. A brief, post run wash of the capillary with 0.5 M NaOH and water gave improved inter- and intra-run repeatability of both migration times and peak areas. Sulphide and other oxysulphur species were relatively stable in white and green liquors diluted in helium-sparged water. However, sulphide present in black liquor samples diluted in the same solvent underwent rapid oxidation to form sulphite and thiosulphate. thereby precluding the measurement of all three anions. We discovered that quinone-type compounds present in black liquor catalyze the oxidation of sulphide and that the addition of reduced glutathione at a concentration of I mg/mL during black liquor dilution completely stabilized sulphide, sulphite and thiosulphate for at least one hour, thus allowing for quantitative analysis of the analytes. A mechanism is proposed to explain the action of both quinones and that of glutathione. Results obtained by the new method compared well with those obtained by ion chromatography, titrimetry, and from spike-recovery experiments.
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Affiliation(s)
- Joseph Sullivan
- Pulp and Paper Research Institute of Canada, 570 St. John's Boulevard, Pointe-Claire, Que., H9R 3J9 Canada.
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35
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Herbert BJ, Carpenter HE, Kane-Maguire NA, Wheeler JF. Use of chiral capillary electrophoresis and circular dichroism for the determination of absolute values of Δε for diimine transition metal complexes. Anal Chim Acta 2004. [DOI: 10.1016/j.aca.2004.03.027] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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36
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Fatemi MH. Prediction of the electrophoretic mobilities of some carboxylic acids from theoretically derived descriptors. J Chromatogr A 2004; 1038:231-7. [PMID: 15233538 DOI: 10.1016/j.chroma.2004.03.046] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
A 4-4-1 artificial neural network was constructed and trained for the prediction of the electrophoretic mobilities of some aliphatic and aromatic carboxylic acids based on quantitative structure-property relationships. The inputs of this network are theoretically derived descriptors that were chosen by the stepwise variables selection techniques. These descriptors are: shape factor, molecular surface area, the maximum value of electron density on atom in molecule, and the sum of atomic polarizability. In order to assess the accuracy and predictability of the proposed model, the cross-validation test was employed. The results obtained showed the ability of developed artificial neural network to prediction of electrophoretic mobilities of aliphatic and carboxylic acids. Also result reveals the superiority of the artificial neural network over the multiple linear regression models.
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Affiliation(s)
- M H Fatemi
- Department of Chemistry, Faculty of Basic Science, Mazandaran University, P.O. Box 453, Babolsar, Iran.
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37
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38
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Simal-Gándara J. The Place of Capillary Electrochromatography Among Separation Techniques—A Review. Crit Rev Anal Chem 2004. [DOI: 10.1080/10408340490475867] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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39
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Zunić G. [Capillary electrophoresis--a new method for analysis of molecules and a challenge for biochemists]. VOJNOSANIT PREGL 2004; 60:733-9. [PMID: 14737894 DOI: 10.2298/vsp0306733z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Affiliation(s)
- Gordana Zunić
- Vojnomedicinska akademija, Institut za medicinska istrazlvanja, Beograd
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40
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Fu R, Wang F, Tang L, Lei Y, Lui N, Liang M. Studies on the fabrication of strong-acid/weak-base amphoteric ion exchange fibers and their adsorption property for amino acids. J Appl Polym Sci 2004. [DOI: 10.1002/app.13651] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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41
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Yokoyama T, Tsuji H, Akamatsu T, Zenki M. Relation between Electrophoretic Behavior and Molecular Shapes of Aromatic Anions. ANAL SCI 2004; 20:657-62. [PMID: 15116964 DOI: 10.2116/analsci.20.657] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The capillary electrophoretic behavior of 44 aromatic organic ions was investigated. The observed ionic radii (r(obs0)) for the aromatic organic ions were obtained from the electrophoretic mobilities of sodium tetraborate (pH 9.2), potassium tetraborate (pH 9.2), ammonium borate (pH 9.2), and trisodium phosphate (pH 11.7) buffers with zero ionic strength. The linear relationships between the r(obs0)) values and the ionic radii (r(calc)), calculated by either the AM1 or PM3 method, were determined for benzyltrialkylammonium and aromatic sulfonate ions. However, the r(obs0)) values were constant for the aromatic carboxylate ions in buffers, in spite of the different r(calc) values. This indicates that aromatic carboxylate ions, such as benzenecarboxylate, pyridinecarboxylate, naphthalenecarboxylate, and anthracenecarboxylate ions, migrate as planar ions in buffers, whereas aromatic sulfonate ions could migrate as approximately spherical ions.
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Affiliation(s)
- Takashi Yokoyama
- Department of Chemistry, Faculty of Science, Okayama University of Science, 1-1 Ridai-cho, Okayama 700-0005, Japan.
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42
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Dash AK, Elmquist WF. Separation methods that are capable of revealing blood–brain barrier permeability. J Chromatogr B Analyt Technol Biomed Life Sci 2003; 797:241-54. [PMID: 14630153 DOI: 10.1016/s1570-0232(03)00605-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The objective of this review is to emphasize the application of separation science in evaluating the blood-brain barrier (BBB) permeability to drugs and bioactive agents. Several techniques have been utilized to quantitate the BBB permeability. These methods can be classified into two major categories: in vitro or in vivo. The in vivo methods used include brain homogenization, cerebrospinal fluid (CSF) sampling, voltametry, autoradiography, nuclear magnetic resonance (NMR) spectroscopy, positron emission tomography (PET), intracerebral microdialysis, and brain uptake index (BUI) determination. The in vitro methods include tissue culture and immobilized artificial membrane (IAM) technology. Separation methods have always played an important role as adjunct methods to the methods outlined above for the quantitation of BBB permeability and have been utilized the most with brain homogenization, in situ brain perfusion, CSF sampling, intracerebral microdialysis, in vitro tissue culture and IAM chromatography. However, the literature published to date indicates that the separation method has been used the most in conjunction with intracerebral microdialysis and CSF sampling methods. The major advantages of microdialysis sampling in BBB permeability studies is the possibility of online separation and quantitation as well as the need for only a small sample volume for such an analysis. Separation methods are preferred over non-separation methods in BBB permeability evaluation for two main reasons. First, when the selectivity of a determination method is insufficient, interfering substances must be separated from the analyte of interest prior to determination. Secondly, when large number of analytes is to be detected and quantitated by a single analytical procedure, the mixture must be separated to each individual component prior to determination. Chiral separation in particular can be essential to evaluate the stereo-selective permeation and distribution of agents into the brain. In conclusion, the usefulness of separation methods during BBB permeability evaluation is immense and more application of these methods is foreseen in the future.
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Affiliation(s)
- Alekha K Dash
- Department of Pharmacy Sciences, School of Pharmacy and Health Professions, Creighton University Medical Center, 2500 California Plaza, Omaha, NE 68178, USA.
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43
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Schimpf ME, Semenov SN. Cross-Correlation Continuous Capillary Electrophoresis: Resolution, Processing Time, and Concentration Effects. Anal Chem 2003. [DOI: 10.1021/ac0300183] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Martin E. Schimpf
- Boise State University, MS-1500, Boise, Idaho 83725, and Institute of Biochemical Physics, RAS, Kosygin Street 4, Moscow, Russia
| | - Semen N. Semenov
- Boise State University, MS-1500, Boise, Idaho 83725, and Institute of Biochemical Physics, RAS, Kosygin Street 4, Moscow, Russia
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44
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Chen YR, Her GR. A simple method for fabrication of silver-coated sheathless electrospray emitters. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2003; 17:437-441. [PMID: 12590392 DOI: 10.1002/rcm.940] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
A simple and time-saving procedure is proposed for preparing a silver-coated fused-silica capillary tip. The tapered capillary tip was coated with silver using an acrylic-based silver conductive pen. The fabrication of a silver-coated fused-silica capillary tip takes less than 5 minutes. The silver-coated fused-silica capillary tip is rugged and durable for sheathless capillary electrophoresis/electrospray mass spectrometry and also for microspray applications.
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Affiliation(s)
- Yet-Ran Chen
- Department of Chemistry, National Taiwan University, Taipei, Taiwan, ROC
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45
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Simó C, Ibañez E, Señoráns FJ, Barbas C, Reglero G, Cifuentes A. Analysis of antioxidants from orange juice obtained by countercurrent supercritical fluid extraction, using micellar electrokinetic chromatography and reverse-phase liquid chromatography. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2002; 50:6648-6652. [PMID: 12405755 DOI: 10.1021/jf025590u] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Antioxidants from orange juice were determined by the combined use of countercurrent supercritical fluid extraction (CC-SFE) prior to reverse-phase liquic chromatography (RP-LC) or micellar electrokinetic chromatography (MEKC). The separation of antioxidants found in the SFE fractions was achieved by using a new MEKC method and a published LC procedure, both using diode array detection. The characterization of the different antioxidants was further done by LC-mass spectrometry. Advantages and drawbacks of LC and MEKC for analyzing the antioxidants found in the different orange extracts are discussed. Although LC yields higher peak area and slightly better reproducibility than MEKC, the latter technique provides information about the CC-SFE extracts in analysis times 7 times faster than by LC. This analysis advantage can be used for the quick adjustment of CC-SFE conditions, thus providing a fast way to obtain orange fractions of specific composition.
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Affiliation(s)
- Carolina Simó
- Departamento de Caracterización de Alimentos, Instituto de Fermentaciones Industriales (CSIC), Juan de la Cierva 3, 28006 Madrid, Spain
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46
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Capillary electrophoresis with electrochemiluminescence detection of procyclidine in human urine pretreated by ion-exchange cartridge. Anal Chim Acta 2002. [DOI: 10.1016/s0003-2670(02)00780-8] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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47
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Thibodeaux SJ, Billiot E, Warner IM. Enantiomeric separations using poly(L-valine) and poly(L-leucine) surfactants. Investigation of steric factors near the chiral center. J Chromatogr A 2002; 966:179-86. [PMID: 12214692 DOI: 10.1016/s0021-9673(02)00747-1] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
This study examined the effect of steric factors near the stereogenic center on polymerized surfactants, sodium N-undecyl-L-leucine, sodium N-undecyl-L-norleucine, sodium N-undecyl-L-tert.-butyl leucine, sodium N-undecyl-L-isoleucine. sodium N-undecyl-L-valine, sodium N-undecyl-L-norvaline. and sodium N-undecyl-L-proline. The effect of steric factors near the chiral center of the polymeric surfactants were examined using binaphthyl derivatives, aminoglutethimide, and 2,2,2-trifluoro-1-(9-anthryl)ethanol. In addition, fluorescence spectroscopy was used to determine the hydrophobicities of these surfactants using the environmentally-sensitive probe pyrene.
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Affiliation(s)
- Stefan J Thibodeaux
- Department of Chemistry, Louisiana State University, Baton Rouge 70803-1804, USA
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48
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Dong Q, Dong R, Jin M, Jin W. Direct amperometric determination of lactate at a carbon fiber bundle microdisk electrode by capillary zone electrophoresis. J Chromatogr B Analyt Technol Biomed Life Sci 2002; 774:121-6. [PMID: 12052730 DOI: 10.1016/s1570-0232(02)00186-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Capillary zone electrophoresis was employed for the determination of lactate using end-column amperometric detection at a carbon fiber bundle microdisk electrode. The optimum conditions of separation and detection are 3.6 x 10(-3) mol/l Na(2)HPO(4)-1.4 x 10(-3) mol/l NaH(2)PO (pH 7.2) for the buffer solution, 18 kV for the separation voltage and 1.60 V versus the saturated calomel electrode for the detection potential. The limit of detection is 7.6 x 10(-7) mol/l or 1.7 fmol (S/N=3) and the linear range is 1.7 x 10(-6)-8.2 x 10(-4) mol/l for the injection voltage of 6 kV and injection time of 5 s. The RSD is 1.8% for the migration time and 3.3% for the electrophoretic peak current. The method was applied to the determination of lactate in human saliva. The recovery of the method is between 95 and 109%.
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Affiliation(s)
- Qian Dong
- School of Chemistry and Chemical Engineering, and State Key Laboratory of Microbial Technology, Shandong University, Jinan 250100, PR China
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49
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Peterson DS, Palmer CP. Novel alkyl-modified anionic siloxanes as pseudostationary phases for electrokinetic chromatography. III. Performance in organic-modified buffers. J Chromatogr A 2002; 959:255-61. [PMID: 12141551 DOI: 10.1016/s0021-9673(02)00442-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Anionic water-soluble siloxanes modified with different amounts of alkyl chains have been used as pseudostationary phases in electrokinetic chromatography. Ionic siloxane polymers with attached alkyl chains of C8 and C12 and having different alkyl chain densities have been employed previously to achieve selective and efficient separations with a range of electrophoretic mobilities and methylene selectivities. In this study, the performance of three alkyl-modified siloxanes is examined in different organic-modified buffers and at differing amounts of organic modifier. The organic modifiers used are acetonitrile and methanol. The siloxanes are stable in these organic solvents and show good mobility and good methylene selectivities even at high concentration of organic solvent. Siloxanes have also been used to separate a mixture of 14 polynuclear aromatic hydrocarbons in an acetonitrile-modified buffer.
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50
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Study of uptake kinetics of vincristine for human erythrocytes by capillary zone electrophoresis with electrochemical detection. Anal Chim Acta 2002. [DOI: 10.1016/s0003-2670(02)00226-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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