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Gärtner A, de Almeida Santos G, Ruff AJ, Schwaneberg U. A Screening Method for P450 BM3 Mutant Libraries Using Multiplexed Capillary Electrophoresis for Detection of Enzymatically Converted Compounds. Methods Mol Biol 2022; 2461:195-210. [PMID: 35727452 DOI: 10.1007/978-1-0716-2152-3_13] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Capillary electrophoresis (CE) is an analytical method in which charged species are separated by attraction or repulsion performed in submillimeter diameter capillaries or micro- and nanofluidic channels through the application of a high voltage electric field. When capillary electrophoresis is assembled in a multicapillary instrument such as 96-well format (multiplexed), it becomes a powerful high-throughput system with the ability to simultaneously screen several types of samples like genetic mutations, metabolomes, kinase inhibitors, or enzymatic activities to name a few. The usage of a 96-multiplexed capillary electrophoresis system (96-MP-CE) represents a new platform for product-specific high-throughput screening of enzyme mutant libraries from directed evolution campaigns providing a comprehensive view on enzyme activity through the detection of all products formed. We describe the application of 96-MP-CE to screen mutant libraries of P450 BM3. MP-CE was used in directed evolution campaigns toward benzo-1,4-dioxane and α-isophorone.
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Affiliation(s)
- Anna Gärtner
- Institute of Biotechnology, RWTH Aachen University, Aachen, Germany
| | | | - Anna Joëlle Ruff
- Institute of Biotechnology, RWTH Aachen University, Aachen, Germany
| | - Ulrich Schwaneberg
- Institute of Biotechnology, RWTH Aachen University, Aachen, Germany.
- DWI-Leibniz Institut für Interaktive Materialien, Aachen, Germany.
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Essam HM, Saad MN, Elzanfaly ES, Amer SM. Stepwise optimization and sensitivity improvement of green micellar electrokinetic chromatography method to simultaneously determine some fluoroquinolones and glucocorticoids present in various binary ophthalmic formulations. Biomed Chromatogr 2020; 34:e4941. [PMID: 32627197 DOI: 10.1002/bmc.4941] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Revised: 06/26/2020] [Accepted: 07/01/2020] [Indexed: 01/31/2023]
Abstract
A sensitive micellar electrokinetic chromatography method is presented to simultaneously quantify ofloxacin, gatifloxacin, dexamethasone sodium phosphate and prednisolone acetate. The method has the advantages of being rapid, accurate, reproducible, ecologically acceptable and sensitive. The electrophoretic separation utilized 20 mm borate buffer as background electrolyte with pH 10.0 ± 0.1 and 50 mm sodium dodecyl sulfate as a micelle forming molecule. A capillary tube (50 μm i.d., 33 cm) of fused silica was used and on-column diode array detection at 243 nm for dexamethasone sodium phosphate and prednisolone acetate, and 290 nm for ofloxacin and gatifloxacin. Various factors were optimized such as the background electrolyte (type, concentration and pH), addition of sodium dodecyl sulfate and its concentration, detection wavelength, applied voltage and injection parameters. The studied drugs were efficiently separated in 6.2 min, at 20 kV with high resolution. The greenness of the method was estimated using an eco-scale tool and the presented method was found to have excellent green characteristics. The method was validated in conformance with International Conference on Harmonization guidelines, with acceptable accuracy, precision and selectivity. The suggested method can be employed for the economic analysis of the four drugs in dissimilar binary combinations of eye drops saving solvents and chemicals.
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Affiliation(s)
- Hebatallah M Essam
- Analytical Chemistry Department, Faculty of Pharmacy, Cairo University, Cairo, Egypt
| | - Martin N Saad
- Analytical Chemistry Department, Faculty of Pharmacy, Cairo University, Cairo, Egypt
| | - Eman S Elzanfaly
- Analytical Chemistry Department, Faculty of Pharmacy, Cairo University, Cairo, Egypt
| | - Sawsan M Amer
- Analytical Chemistry Department, Faculty of Pharmacy, Cairo University, Cairo, Egypt
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Chen M, Chang R, Xu L, Huang Y, Zhang H, Chen A. Simultaneous separation and determination of praeruptorin A, B and C by micellar electrokinetic chromatography using sodium dodecyl sulphate and sodium cholate as mixed micelles. PHYTOCHEMICAL ANALYSIS : PCA 2018; 29:425-431. [PMID: 29392793 DOI: 10.1002/pca.2746] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Revised: 12/19/2017] [Accepted: 12/31/2017] [Indexed: 06/07/2023]
Abstract
INTRODUCTION Praeruptorin A, B and C are major bioactive constituents in Peucedani Radix. They display anti-inflammatory effect, anti-hypertension effect, antiplatelet aggregation, potential anti-cancer activities and so on. They are worthy of investigation as potentially novel and versatile drugs. OBJECTIVE To develop a method using micellar electrokinetic chromatography (MEKC) for the application in simultaneously separation and determination of praeruptorin A, B and C from Peucedani Radix and its medicinal preparations. METHODS Method optimisation was carried out by investigating influences of significant factors on the separation. The method was subjected to validation. The determination of praeruptorin A, B and C in Peucedani Radix and its drug formulations was accomplished by the developed method. RESULTS The optimal separation condition was 20 mM borate buffer containing 40 mM sodium cholate (SC), 22 mM sodium dodecyl sulphate (SDS) and 25% (v/v) acetonitrile (pH 10.00); 15 kV of voltage; 25°C of temperature; detection at 224 nm. Under this condition, three analytes were baseline separated within 16 min. A good linearity was obtained with correlation coefficients from 0.9988 to 0.9995. The limits of detection (LODs) and limits of quantitation (LOQs) ranged from 0.50 to 0.80 μg/mL and from 1.50 to 2.50 μg/mL, respectively. The recoveries ranged between 95.3% and 103.4%. CONCLUSION The proposed method has been successfully applied to the simultaneous determination of praeruptorin A, B and C in Peucedani Radix and its pharmaceutical preparations. Additionally, it could be a potential alternative to the quality control of Peucedani Radix.
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Affiliation(s)
- Meng Chen
- College of Pharmacy, Shanxi Medical University, Taiyuan, 030001, China
| | - Ruimiao Chang
- College of Pharmacy, Shanxi Medical University, Taiyuan, 030001, China
| | - Liying Xu
- College of Pharmacy, Shanxi Medical University, Taiyuan, 030001, China
| | - Yayun Huang
- College of Pharmacy, Shanxi Medical University, Taiyuan, 030001, China
| | - Hongfen Zhang
- College of Pharmacy, Shanxi Medical University, Taiyuan, 030001, China
| | - Anjia Chen
- College of Pharmacy, Shanxi Medical University, Taiyuan, 030001, China
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Performance and selectivity of cationic nanoparticle pseudo‐stationary phases in electrokinetic chromatography. Electrophoresis 2016; 38:730-737. [DOI: 10.1002/elps.201600380] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2016] [Revised: 10/21/2016] [Accepted: 11/13/2016] [Indexed: 11/07/2022]
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Bol’shakova DS, Amelin VG. Determination of pesticides in environmental materials and food products by capillary electrophoresis. JOURNAL OF ANALYTICAL CHEMISTRY 2016. [DOI: 10.1134/s1061934816100026] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Sieradzka E, Witt K, Milnerowicz H. The application of capillary electrophoresis techniques in toxicological analysis. Biomed Chromatogr 2014; 28:1507-13. [PMID: 24828301 DOI: 10.1002/bmc.3234] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2014] [Revised: 03/25/2014] [Accepted: 04/04/2014] [Indexed: 12/17/2022]
Abstract
Capillary electrophoresis (CE) comprises a group of techniques used to separate chemical mixtures. Analytical separation is based on different electrophoretic mobilities, thereby allowing qualitative and quantitative evaluations to be made. The application of CE in medical science, especially in toxicological studies, is developing rapidly because of the short time required for analysis and its high sensitivity, selectivity and ability to determine substances of an acidic, alkaline and neutral character. This review focuses on the possibility of applying CE in toxicological analysis. Advances in different CE analyses and detection techniques connected with this method are described.
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Affiliation(s)
- Ewelina Sieradzka
- Department of Biomedical and Environmental Analysis, Faculty of Pharmacy, Wroclaw Medical University, Poland
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Hyslop JS, Hall LMG, Umansky AA, Palmer CP. RAFT polymerized nanoparticles: influences of shell and core chemistries on performance for electrokinetic chromatography. Electrophoresis 2014; 35:728-35. [PMID: 24302072 DOI: 10.1002/elps.201300403] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2013] [Revised: 11/13/2013] [Accepted: 11/17/2013] [Indexed: 11/06/2022]
Abstract
The performance and solvation characteristics of two novel latex nanoparticle (NP) pseudo-stationary phases (PSPs) for EKC are determined and compared to those of previously reported micellar, polymeric, and NP materials. The new NPs have shells composed of strongly acidic poly(AMPS) as opposed to the poly(acrylic acid) shell of the prior NP, and have varied hydrophobic core chemistry of either poly(butyl acrylate) or poly(ethyl acrylate). The NPs poly(AMPS) shell shows only minor changes in mobility and selectivity between pH 4.9 and 9.4, allowing adjustment of pH to influence and optimize separation performance. All of the NP phases have significantly different solvation characteristics and selectivity relative to SDS micelles. The selectivity and solvent character are similar for NPs with poly(butyl acrylate) cores and different shells, but vary significantly between NPs with poly(butyl acrylate) versus poly(ethyl acrylate) cores. NPs with poly(butyl acrylate) cores are among the least cohesive PSPs reported to date, while the NP with poly(ethyl acrylate) core is among the most cohesive. The results demonstrate that PSPs with unique selectivity can be generated by altering the chemistry of the hydrophobic core.
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Affiliation(s)
- Jesse S Hyslop
- Department of Chemistry and Biochemistry, University of Montana, Missoula, MT, USA
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Mora MF, Stockton AM, Willis PA. Analysis of thiols by microchip capillary electrophoresis for in situ planetary investigations. Electrophoresis 2012; 34:309-16. [PMID: 23161601 DOI: 10.1002/elps.201200379] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2012] [Revised: 08/30/2012] [Accepted: 09/01/2012] [Indexed: 11/09/2022]
Abstract
The detection of thiols on extraterrestrial bodies could provide evidence for life, as well as a host of potential prebiological or abiological processes. Here, we report a novel protocol to analyze organic thiols by microchip CE with LIF detection. Thiols were labeled with Pacific Blue C5 maleimide and analyzed by MEKC. The separation buffer consisted of 15 mM tetraborate pH 9.2 and 25 mM SDS. The optimized method provided LODs ranging from 1.4 to 15 nM. The method was validated using samples collected from geothermal pools at Hot Creek Gorge, California, which were found to contain 2-propanethiol and 1-butanethiol in the nanomolar concentration range. These samples serve as chemical analogues to material potentially present in the reducing environment of primitive Earth and also at sulfurous regions of Mars. Hence, the protocol developed here enables highly sensitive thiol analysis in samples with complexity comparable to that expected in astrobiologically relevant extraterrestrial settings. This new protocol could be readily added to the existing suite of microfluidic chemical analyses developed for in situ planetary exploration; all that is required is the incorporation of two new reagents to the payload of an existing instrument concept.
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Affiliation(s)
- Maria F Mora
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA
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Ultra-high voltage capillary electrophoresis >300kV: Recent advances in instrumentation and analyte detection. J Chromatogr A 2012; 1261:171-8. [DOI: 10.1016/j.chroma.2012.07.082] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2012] [Revised: 07/18/2012] [Accepted: 07/25/2012] [Indexed: 11/22/2022]
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10
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Bhowmik SK, Jung BH. Analysis of plasma nucleotides in rat by micellar electrokinetic capillary chromatography/electrospray ionization mass spectrometry. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2012; 26:1426-1436. [PMID: 22592986 DOI: 10.1002/rcm.6245] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
RATIONALE The aim of this study was to establish a simultaneous quantitative analysis method of nine endogenous nucleotides in rat plasma using micellar electrokinetic capillary chromatography/electrospray ionization mass spectrometry (MEKC/ESI-MS). METHODS To select the optimum conditions for separation of the nucleotides, various pH, concentrations of running buffers and surfactants were tested. Ammonium acetate (20 mM) containing the surfactant dodecyltrimethylammonium bromide (2 mM, pH 3.5) was selected as the micellar running buffer. The plasma samples were prepared by precipitating the proteins with 2 mM EDTA in 60% ethanol. The samples were analyzed using capillary electrophoresis (CE)/MS and selected ion monitoring (SIM) mode with positive ionization. CE was performed using a silica capillary column in reversed polarity mode. RESULTS The limits of detection (LODs) and limits of quantification (LOQs) of the nucleotides ranged from 0.05-5 and 2.0-20 μM, respectively. The calibration curves were linear (R(2) >0.99) for all analytes, and the accuracy and precision were within ±15%. The developed method was applied to the analysis of nucleotides in rat plasma that was collected after oral administration of acetaminophen (1000 mg/kg/day) to evaluate the changes in plasma nucleotide levels under hepatotoxic conditions. CONCLUSIONS Decreased level of GTP and increased level of cytosine nucleotides were found to be associated with liver toxicity, which led to the conclusion that liver toxicity is closely related to changes in nucleotide levels in plasma.
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Affiliation(s)
- Salil Kumar Bhowmik
- Molecular Recognition Research Center Korea Institute of Science and Technology, P.O. Box 131, Cheongryang, Seoul 130-650, Republic of Korea
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Kühne S, Untucht C, Steinert M, Wätzig H. Fast investigations from biological matrices using CE – Test of a blood–brain barrier model. Electrophoresis 2012; 33:395-401. [DOI: 10.1002/elps.201100282] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Sascha Kühne
- Technische Universität Braunschweig, Institut für Pharmazeutische Chemie, Braunschweig, Germany
| | - Christopher Untucht
- Technische Universität Braunschweig, Institut für Mikrobiologie, Braunschweig, Germany
| | - Michael Steinert
- Technische Universität Braunschweig, Institut für Mikrobiologie, Braunschweig, Germany
| | - Hermann Wätzig
- Technische Universität Braunschweig, Institut für Pharmazeutische Chemie, Braunschweig, Germany
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12
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Chen Z, Zhong Z, Xia Z, Yang F, Mu X. Separation of Fluoroquinolones by MEKC Modified with Hydrophobic Ionic Liquid as a Modifier. Chromatographia 2011. [DOI: 10.1007/s10337-011-2150-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
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13
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Szafarska M, Wietecha-Posłuszny R, Woźniakiewicz M, Kościelniak P. Examination of colour inkjet printing inks by capillary electrophoresis. Talanta 2011; 84:1234-43. [DOI: 10.1016/j.talanta.2010.12.024] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2010] [Revised: 12/09/2010] [Accepted: 12/18/2010] [Indexed: 11/24/2022]
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Abstract
Ginseng occupies a prominent position in the list of best-selling natural products in the world. Because of its complex constituents, multidisciplinary techniques are needed to validate the analytical methods that support ginseng's use worldwide. In the past decade, rapid development of technology has advanced many aspects of ginseng research. The aim of this review is to illustrate the recent advances in the isolation and analysis of ginseng, and to highlight new applications and challenges. Emphasis is placed on recent trends and emerging techniques.
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Affiliation(s)
- Lian-Wen Qi
- Tang Center for Herbal Medicine Research and Department of Anesthesia & Critical Care, The Pritzker School of Medicine, The University of Chicago, 5841 South Maryland Avenue, Chicago, Illinois, 60637, USA
- Key Laboratory of Modern Chinese Medicines (China Pharmaceutical University), Ministry of Education, Nanjing 210009, China
| | - Chong-Zhi Wang
- Tang Center for Herbal Medicine Research and Department of Anesthesia & Critical Care, The Pritzker School of Medicine, The University of Chicago, 5841 South Maryland Avenue, Chicago, Illinois, 60637, USA
| | - Chun-Su Yuan
- Tang Center for Herbal Medicine Research and Department of Anesthesia & Critical Care, The Pritzker School of Medicine, The University of Chicago, 5841 South Maryland Avenue, Chicago, Illinois, 60637, USA
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Palmer CP, Keeffer A, Hilder EF, Haddad PR. Retention behavior and selectivity of a latex nanoparticle pseudostationary phase for electrokinetic chromatography. Electrophoresis 2011; 32:588-94. [DOI: 10.1002/elps.201000470] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2010] [Revised: 11/01/2010] [Accepted: 11/07/2010] [Indexed: 11/11/2022]
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16
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Chan KC, Veenstra TD, Issaq HJ. Quantitation of nanoparticles in serum matrix by capillary electrophoresis. Methods Mol Biol 2011; 697:145-153. [PMID: 21116963 DOI: 10.1007/978-1-60327-198-1_15] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Sensitive and fast analytical techniques are needed to determine the concentration of nanoparticles in biological samples (e.g., blood and tissues) for biodistribution and toxicity studies. This chapter describes a method for the use of capillary zone electrophoresis (CZE) and micellar electrokinetic chromatography (MEKC) for the quantitation of fullerene nanoparticles in human serum matrix. Data on the fullerene-based nanoparticle carboxyfullerene (C3 fullerene) in human serum is presented as an example.
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Affiliation(s)
- King C Chan
- Laboratory of Proteomics and Analytical Technologies, Advanced Technology Program, SAIC-Frederick, Inc., National Cancer Institute at Frederick, Frederick, MD, USA
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Puangpila C, Petsom A, Nhujak T. Theoretical models of separation selectivity for charged compounds in micellar electrokinetic chromatography. Electrophoresis 2010; 32:203-9. [DOI: 10.1002/elps.201000405] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2010] [Revised: 10/18/2010] [Accepted: 10/18/2010] [Indexed: 11/05/2022]
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Palmer CP, Hilder EF, Quirino JP, Haddad PR. Electrokinetic chromatography and mass spectrometric detection using latex nanoparticles as a pseudostationary phase. Anal Chem 2010; 82:4046-54. [PMID: 20402470 DOI: 10.1021/ac902922u] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The utility of novel latex nanoparticles as pseudostationary phases for electrokinetic chromatography with UV and mass spectrometric detection is demonstrated. The nanoparticles are synthesized using ab initio RAFT (reversible addition-fragmentation chain transfer) in emulsion polymerization, which yields small (63 nm) particles with a narrow size distribution, a hydrophobic core, and an ionic shell. The nanoparticles are shown to provide efficient and selective separations, with retention and separation selectivity dominated by hydrophobic interactions. The nanoparticles are highly retentive, such that they are effective at relatively low concentrations. Addition of the nanoparticles to the background electrolyte at these concentrations has a minor effect on the noise with UV detection, no measurable effect on the separation current, and minor effects on analyte ionization efficiency during electrospray ionization. The nanoparticles do not cause fouling or degradation of the electrospray-mass spectrometer interface even after several weeks of use. The combination of online sample preconcentration via sweeping and selective mass spectrometric detection yields low detection limits (10-16 ppb), particularly for more hydrophobic compounds.
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Affiliation(s)
- Christopher P Palmer
- Department of Chemistry and Biochemistry, University of Montana, Missoula, Montana 59803, USA.
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Noh HB, Lee KS, Lim BS, Kim SJ, Shim YB. Total analysis of endocrine disruptors in a microchip with gold nanoparticles. Electrophoresis 2010; 31:3053-60. [DOI: 10.1002/elps.201000112] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Chen B, Du Y. Evaluation of the enantioseparation capability of the novel chiral selector clindamycin phosphate towards basic drugs by micellar electrokinetic chromatography. J Chromatogr A 2010; 1217:1806-12. [DOI: 10.1016/j.chroma.2010.01.043] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2009] [Revised: 01/02/2010] [Accepted: 01/14/2010] [Indexed: 11/28/2022]
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Foteeva LS, Huang Z, Timerbaev AR, Hirokawa T. Focusing of anionic micelles using sample-induced transient isotachophoresis: Computer simulation and experimental verification in MEKC. J Sep Sci 2010; 33:637-42. [DOI: 10.1002/jssc.200900707] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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Li R, Zou H, Xiao H, Wu R. Carbon nanotubes as intracellular carriers for multidrug resistant cells studied by capillary electrophoresis-laser-induced fluorescence. Methods Mol Biol 2010; 625:153-168. [PMID: 20422388 DOI: 10.1007/978-1-60761-579-8_13] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Fluorescently labeled carbon nanotube probes (CNTP) are prepared by derivatizing oxidized (o)-MWNTs with a fluorescein dye. Capillary electrophoresis coupled with laser-induced fluorescence (CE-LIF) detection is used to separate and detect CNTP in multidrug-resistant cells (K562A) and the parent cells (K562S). CE-LIF and flow cytometry investigation reveal that the CNTP can traverse the membranes in both cell lines without being pumped out by P-glycoprotein. The CE-LIF method is also useful for quantitative analysis of CNT in single cells, enabling drug delivery and multidrug resistance (MDR) studies. Moreover, toward quantifying the intracellular uptake of oxidized (o)-SWNTs with anchored Rhodamine123 (Rho123), fluorescence-quenching of Rho123 is measured by micellar electrokinetic chromatography coupled with LIF detection. Enhanced uptake of Rho123 in multidrug-resistant leukemia cells can be achieved with the aid of the o-SWNTs carriers. Besides being able to overcome MDR, o-SWNTs are shown to be excellent intracellular carriers possessing large adsorption capacity and prolonged release ability. Finally, it is demonstrated that o-SWNTs are safe for biological applications at concentrations of up to 40 microg/mL.
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Affiliation(s)
- Ruibin Li
- National Chromatographic R & A Center, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, P.R., China.
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Angkanasiriporn S, Singsung W, Petsom A, Nhujak T. Comparison and prediction of the retention in micellar electrokinetic chromatography and microemulsion electrokinetic chromatography for disubstituted benzenes. Electrophoresis 2010; 31:695-701. [DOI: 10.1002/elps.200900486] [Citation(s) in RCA: 4] [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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Glavač NK, Injac R, Kreft S. Optimization and Validation of a Capillary MEKC Method for Determination of Proteins in Urine. Chromatographia 2009. [DOI: 10.1365/s10337-009-1317-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Tano C, Son SH, Furukawa JI, Furuike T, Sakairi N. Enantiomeric separation by MEKC using dodecyl thioglycoside surfactants: Importance of an equatorially oriented hydroxy group at C-2 position in separation of dansylated amino acids. Electrophoresis 2009; 30:2743-6. [DOI: 10.1002/elps.200800685] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Horká M, Růžička F, Holá V, Kahle V, Moravcová D, Šlais K. Capillary Electromigration Separation of Proteins and Microorganisms Dynamically Modified by Chromophoric Nonionogenic Surfactant. Anal Chem 2009; 81:6897-904. [DOI: 10.1021/ac900897c] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Marie Horká
- Institute of Analytical Chemistry Academy of Sciences of the Czech Republic, v. v. i., Veveří 97, 602 00 Brno, Czech Republic, and Department of Microbiology, Faculty of Medicine, Masaryk University Brno, Czech Republic
| | - Filip Růžička
- Institute of Analytical Chemistry Academy of Sciences of the Czech Republic, v. v. i., Veveří 97, 602 00 Brno, Czech Republic, and Department of Microbiology, Faculty of Medicine, Masaryk University Brno, Czech Republic
| | - Veronika Holá
- Institute of Analytical Chemistry Academy of Sciences of the Czech Republic, v. v. i., Veveří 97, 602 00 Brno, Czech Republic, and Department of Microbiology, Faculty of Medicine, Masaryk University Brno, Czech Republic
| | - Vladislav Kahle
- Institute of Analytical Chemistry Academy of Sciences of the Czech Republic, v. v. i., Veveří 97, 602 00 Brno, Czech Republic, and Department of Microbiology, Faculty of Medicine, Masaryk University Brno, Czech Republic
| | - Dana Moravcová
- Institute of Analytical Chemistry Academy of Sciences of the Czech Republic, v. v. i., Veveří 97, 602 00 Brno, Czech Republic, and Department of Microbiology, Faculty of Medicine, Masaryk University Brno, Czech Republic
| | - Karel Šlais
- Institute of Analytical Chemistry Academy of Sciences of the Czech Republic, v. v. i., Veveří 97, 602 00 Brno, Czech Republic, and Department of Microbiology, Faculty of Medicine, Masaryk University Brno, Czech Republic
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Su HL, Lan MT, Hsieh YZ. Using the cationic surfactants N-cetyl-N-methylpyrrolidinium bromide and 1-cetyl-3-methylimidazolium bromide for sweeping–micellar electrokinetic chromatography. J Chromatogr A 2009; 1216:5313-9. [DOI: 10.1016/j.chroma.2009.05.001] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2008] [Revised: 04/27/2009] [Accepted: 05/05/2009] [Indexed: 11/17/2022]
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28
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Ahmed FE. The role of capillary electrophoresis–mass spectrometry to proteome analysis and biomarker discovery. J Chromatogr B Analyt Technol Biomed Life Sci 2009; 877:1963-81. [DOI: 10.1016/j.jchromb.2009.05.023] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2008] [Revised: 04/24/2009] [Accepted: 05/10/2009] [Indexed: 01/25/2023]
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29
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Li R, Wu R, Wu M, Zou H, Ma H, Yang L, Chris Le X. MEKC‐LIF analysis of rhodamine123 delivered by carbon nanotubes in K562 cells. Electrophoresis 2009; 30:1906-12. [DOI: 10.1002/elps.200800737] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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30
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Maier V, Znaleziona J, Jirovský D, Skopalová J, Petr J, Ševčík J. Determination of antihyperglycemic drugs in nanomolar concentration levels by micellar electrokinetic chromatography with non-ionic surfactant. J Chromatogr A 2009; 1216:4492-8. [DOI: 10.1016/j.chroma.2009.03.052] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2008] [Revised: 02/28/2009] [Accepted: 03/05/2009] [Indexed: 10/21/2022]
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31
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Injac R, Karljikovic-Rajic K, Strukelj B. SPE and large-volume sample stacking in MEKC for determination of doxycycline in biological fluids: comparison of direct injection to SPE-MEKC. Electrophoresis 2009; 29:4431-8. [PMID: 18956436 DOI: 10.1002/elps.200800339] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
A novel and simple method has been developed for the determination of doxycycline (DOX) in biological fluids. The method is based on SPE, large-volume sample stacking (LVSS) and MEKC with UV-DAD detection. Six SPE cartridges have been used in investigation for sample clean up and pre-concentration (Supelco LC-8, LC-18, LC-SCX, and LC-WCX, as well as Strata-X and X-C). DOX was determined on a 56 cm (effective length 50 cm) x 50 microm id fused-silica capillary. The BGE was 20 mM borate buffer, pH 9.3, containing 80 mM SDS and 7.5% v/v of methanol (30 sx50 mbar), and the temperature and voltage were 25 degrees C and 30 kV, respectively. The analytical wavelength was set at 210 nm. Under optimized conditions it is possible to determine DOX in human serum, urine, semen, tears and saliva with recovery of 97.5% (RSD 2.5%). The method was shown to be sensitive (LOD is 1 microg/L) and precise (intra-day RSD 0.2 and 2.4%; inter-days 0.4 and 3.5% for migration time and peak area, respectively). Results for developed SPE-LVSS-MEKC were compared with LVSS-MEKC method with direct sample injection. The new LVSS-MEKC method is presented as a useful technique for rapid determination without extraction procedure of DOX in human urine and serum, using 80 mM of SDS, 10% v/v of methanol and 40 mM borate buffer (pH 9.3; 30 s x 50 mbar; 25 degrees C; 30 kV; 350 nm), but not for the other biological fluids, according to lower sensitivity of the method and because of the sample composition.
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Affiliation(s)
- Rade Injac
- Faculty of Pharmacy, The Chair of Pharmaceutical Biology, University of Ljubljana, Ljubljana, Slovenia.
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32
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Terabe S. Capillary separation: micellar electrokinetic chromatography. ANNUAL REVIEW OF ANALYTICAL CHEMISTRY (PALO ALTO, CALIF.) 2009; 2:99-120. [PMID: 20636055 DOI: 10.1146/annurev.anchem.1.031207.113005] [Citation(s) in RCA: 79] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Micellar electrokinetic chromatography (MEKC), a separation mode of capillary electrophoresis (CE), has enabled the separation of electrically neutral analytes. MEKC can be performed by adding an ionic micelle to the running solution of CE without modifying the instrument. Its separation principle is based on the differential migration of the ionic micelles and the bulk running buffer under electrophoresis conditions and on the interaction between the analyte and the micelle. Hence, MEKC's separation principle is similar to that of chromatography. MEKC is a useful technique particularly for the separation of small molecules, both neutral and charged, and yields high-efficiency separation in a short time with minimum amounts of sample and reagents. To improve the concentration sensitivity of detection, several on-line sample preconcentration techniques such as sweeping have been developed.
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Affiliation(s)
- Shigeru Terabe
- Graduate School of Material Science, University of Hyogo, Kamigori, Hyogo 678-1297, Japan.
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33
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Hoeman KW, Culbertson CT. A novel, environmentally friendly sodium lauryl ether sulfate-, cocamidopropyl betaine-, cocamide monoethanolamine-containing buffer for MEKC on microfluidic devices. Electrophoresis 2008; 29:4900-5. [DOI: 10.1002/elps.200800463] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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34
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Foteeva LS, Stolyarova NV, Timerbaev AR, Keppler BK. Capillary electrophoretic assay for the stability of tris(8-quinolinolato)gallium(III) in tablet formulations. J Pharm Biomed Anal 2008; 48:218-22. [DOI: 10.1016/j.jpba.2008.05.017] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2008] [Revised: 05/09/2008] [Accepted: 05/12/2008] [Indexed: 11/26/2022]
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35
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Hommerson P, Khan AM, de Jong GJ, Somsen GW. Comparison of electrospray ionization and atmospheric pressure photoionization for coupling of micellar electrokinetic chromatography with ion trap mass spectrometry. J Chromatogr A 2008; 1204:197-203. [DOI: 10.1016/j.chroma.2008.04.017] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2008] [Revised: 03/29/2008] [Accepted: 04/09/2008] [Indexed: 11/27/2022]
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36
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Abstract
Recent research and development efforts concerning polymeric pseudostationary phases (PSPs) for electrokinetic chromatography are reviewed. The introduction of new materials, characterization of structural effects on performance and selectivity, applications, and the use of polymeric PSPs with mass spectrometric detection are considered. Very interesting results concerning the effects of polymer structure have been reported. Significant developments have also been reported in the development of novel applications of polymeric PSPs, particularly for sample preconcentration using micellar affinity gradient focusing. The use of mass spectrometric detection with electrokinetic chromatography has seen significant development, and recent reports indicate that this is a robust and sensitive approach.
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Affiliation(s)
- Christopher P Palmer
- Australian Centre for Research, on Separation Science (ACROSS), School of Chemistry, University of Tasmania, Hobart, Tasmania, Australia.
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37
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Foley JP, Hong M, Polinko MA, Pascoe RJ, Ahuja ES. Compositional effects on electrophoretic and chromatographic figures of merit in electrokinetic chromatography with cetyltrimethylammonium bromide/sodium octyl sulfate vesicles as the pseudostationary phase. Part 1: Effect of the phase ratio. Electrophoresis 2008; 29:1180-8. [DOI: 10.1002/elps.200700809] [Citation(s) in RCA: 8] [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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38
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Van Biesen G, Bottaro CS. Linear solvation energy relationships of anionic dimeric surfactants in micellar electrokinetic chromatography. J Chromatogr A 2008; 1180:171-8. [DOI: 10.1016/j.chroma.2007.11.059] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2007] [Revised: 11/04/2007] [Accepted: 11/21/2007] [Indexed: 10/22/2022]
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39
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Abstract
The article brings a comprehensive survey of recent developments and applications of high-performance capillary electromigration methods, zone electrophoresis, ITP, IEF, affinity electrophoresis, EKC, and electrochromatography, to analysis, preparation, and physicochemical characterization of peptides. New approaches to the theoretical description and experimental verification of electromigration behavior of peptides and to methodology of their separations, such as sample preparation, adsorption suppression, and detection, are presented. Novel developments in individual CE and CEC modes are shown and several types of their applications to peptide analysis are presented: conventional qualitative and quantitative analysis, purity control, determination in biomatrices, monitoring of chemical and enzymatical reactions and physical changes, amino acid and sequence analysis, and peptide mapping of proteins. Some examples of micropreparative peptide separations are given and capabilities of CE and CEC techniques to provide important physicochemical characteristics of peptides are demonstrated.
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Affiliation(s)
- Václav Kasicka
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Prague, Czech Republic.
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40
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Schappler J, Guillarme D, Rudaz S, Veuthey JL. Microemulsion electrokinetic chromatography hyphenated to atmospheric pressure photoionization mass spectrometry. Electrophoresis 2008; 29:11-9. [DOI: 10.1002/elps.200700647] [Citation(s) in RCA: 40] [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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41
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Application of micellar electrokinetic capillary chromatography for routine analysis of different materials. HEMIJSKA INDUSTRIJA 2008. [DOI: 10.2298/hemind0803181i] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Micellar electrokinetic capillary chromatography (MEKC) has become a popular mode among the several capillary electro-migration techniques. Most drug analysis can be performed by using MEKC because of its wide applicability. Separation of very complex mixtures, determination of drugs in the biological materials, etc., can be successfully achieved by MEKC. This review surveys typical applications of MEKC analysis. Recent advances in MEKC, especially with solid-phase extraction and large-volume sample stacking, are described. Modes of electrokinetic chromatography including MEKC, a separation theory of MEKC, environmental friendly analysis, and selectivity manipulation in MEKC are also briefly mentioned.
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42
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Hasemann P, ter Balk M, Wätzig H. Analysis of substances to be used as internal standards in MEKC. Electrophoresis 2007; 28:1798-804. [PMID: 17480043 DOI: 10.1002/elps.200600796] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The use of internal standards (ISs) improves the quantitative performance of CE. However, ISs chosen for use in CZE often cannot be used for micellar EKC (MEKC). Therefore 22 substances were investigated as potential ISs in MEKC. These substances were selected based upon a literature search. The substances were investigated using a method similar to the standard operating conditions for MEKC as recommended by S. Terabe. Furthermore, the migration time and the corrected migration time (k(S)) were determined for each substance to establish the migration position relative to other peaks in the electropherograms. A combination of eight substances, selected according to the obtained results (t(m) = 4 up to 12 min), was tested for practical benefit and applicability. The peak area precision was in the range of 0.8 and 1.2% (n = 60), and the peaks were well shaped for all the investigated substances. The selected substances covered a wide migration time window and therefore they can be regarded as suitable for future analysis at any required migration position.
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Affiliation(s)
- Phillip Hasemann
- Institute of Pharmaceutical Chemistry, TU Braunschweig, Braunschweig, Germany
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43
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Hasemann P, ter Balk M, Preu L, Wätzig H. Separation of cold medicine ingredients using a precise MEKC method at elevated pH. Electrophoresis 2007; 28:1779-87. [PMID: 17450538 DOI: 10.1002/elps.200600676] [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: 11/12/2022]
Abstract
An MEKC method was developed in order to separate a cold medicine formulation containing acetaminophen, ephedrine sulfate, doxylamine succinate, and dextromethorphan hydrobromide as active pharmaceutical ingredients. Because of their similar physical and chemical properties, it was a challenge to separate the basic compounds without sample pretreatment. In addition, the high content of alcohol and sucrose together with the variety of further excipients had to be considered. Thus, the complex matrix required several optimization steps. These included the search for the optimum pH and for a suitable sodium dodecyl sulfate concentration to avoid matrix-capillary wall interaction and to ensure precision. As a second developing step, an internal standard (benzocaine) was chosen to guarantee a high level of quantitative performance. An RSD% value of the peak areas between 1.0 and 2.0 was reached. The employed method development strategy can be generalized to similar separation approaches in the future.
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Affiliation(s)
- Phillip Hasemann
- Institute of Pharmaceutical Chemistry, TU Braunschweig, Braunschweig, Germany
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44
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Spégel P, Viberg P, Carlstedt J, Petersson P, Jörntén-Karlsson M. Continuous full filling capillary electrochromatography: Nanoparticle synthesis and evaluation. J Chromatogr A 2007; 1154:379-85. [PMID: 17449050 DOI: 10.1016/j.chroma.2007.02.092] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2006] [Revised: 02/13/2007] [Accepted: 02/20/2007] [Indexed: 10/23/2022]
Abstract
Reversed phase continuous full filling capillary electrochromatography with electrospray ionisation mass spectrometric detection was performed with highly sulphated poly[styrene-co-(lauryl methacrylate)-co-(divinylbenzene)] nanoparticles. The nanoparticles that contained a hydrophobic core and a hydrophilic surface were prepared in a one step synthesis using soap free emulsion polymerisation. By changing the concentration of monomers, the polymerisation temperature, and the polarity of the dispersive phase, the size of the nanoparticles could be controlled. With the optimised conditions, nanoparticles with an average size of 157 nm were obtained. These nanoparticles were dispersed in the background electrolyte and used for reversed phase continuous full filling. An orthogonal electrospray ionisation interface was used to separate the eluting nanoparticles from the eluting analytes prior to mass spectrometry detection. Compared to previous studies on reversed phase continuous full filling, the retention, the separation efficiency, and the resolution of a homologous series of dialkyl phthalates were greatly improved.
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Affiliation(s)
- Peter Spégel
- Analytical Chemistry, Centre for Chemistry and Chemical Engineering, Lund University, P.O. Box 124, SE-221 00 Lund, Sweden
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45
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Sniehotta M, Schiffer E, Zürbig P, Novak J, Mischak H. CE – a multifunctional application for clinical diagnosis. Electrophoresis 2007; 28:1407-17. [PMID: 17427258 DOI: 10.1002/elps.200600581] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
CE has been used widely as an analytical tool with high separation power taking advantage of size, charge-to-size ratio, or isoelectric point of various analytes. In combination with detection methods, such as UV absorption, electrochemical detection, fluorescence, or mass spectrometry (MS), it allows the separation and detection of inorganic and organic ions, as well as complex compounds, such as polypeptides, nucleic acids, including PCR amplicons from viruses or bacteria. Recent interest in identification of biomarkers of diseases using body fluids leads to development of CE-MS techniques. These applications allowed identification of new potential biomarkers for clinical diagnosis and monitoring of therapeutic interventions. In this report, we present a technical overview of various CE techniques and discuss their applications in clinical medicine.
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Affiliation(s)
- Maike Sniehotta
- Mosaiques Diagnostics and Therapeutics AG, Hannover, Germany
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46
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Chan KC, Patri AK, Veenstra TD, McNeil SE, Issaq HJ. Analysis of fullerene-based nanomaterial in serum matrix by CE. Electrophoresis 2007; 28:1518-24. [PMID: 17447247 DOI: 10.1002/elps.200600724] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
With the increasing interest in using nanoparticles as vehicles for drug delivery and image contrast agents, there is a need to develop assays for their detection and quantitation in complex matrices to facilitate monitoring their biodistribution. In this study, we developed a CE approach for the analysis of two nanoparticles: carboxyfullerene (C3) and dendrofullerene (DF1) in both standard solutions and a serum matrix. These highly soluble, charged C(60) derivatives were characterized by CZE using either a bare or dynamically coated fused-silica capillaries. The resolution of both nanoparticles was slightly lower with the coated capillary; however, their migration times were faster. While separation of the DF1 nanoparticles using MEKC resulted in a greater number of observable peaks, the peak profile of C3 was basically unchanged regardless of whether SDS micelles were added to the running buffers or not. The MEKC and/or CZE assays were then used to quantitate the C3 and DF1 nanoparticles in spiked human serum samples. The quantitation of the nanoparticles was linear from 0-500 microg/mL with detection limits ranging from 0.5 to 6 microg/mL.
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Affiliation(s)
- King C Chan
- Laboratory of Proteomics and Analytical Technologies, SAIC-Frederick Inc, NCI-Frederick, Frederick, MD 21702, USA.
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47
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Tzeng HF, Chen JY, Huang SW, Wang YJ, Yang CS. Simultaneous determination ofmyo-inositol andscyllo-inositol by MEKC as a rapid monitoring tool for inositol levels. Electrophoresis 2007; 28:1221-8. [PMID: 17351885 DOI: 10.1002/elps.200600683] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
A simple and rapid MEKC method was developed for the simultaneous determination of myo-inositol, scyllo-inositol, and glucose. Prior to electrophoretic separation, the nonfluorescent inositols and glucose were derivatized by N-methylisatoic anhydride at 25 degrees C for 10 min so that they could be detected by a fluorescence detector during separation. The good separation with high efficiency by MEKC was achieved in 13 min with a glycine buffer containing SDS and PEG 4000. Several parameters affecting the separation were studied, including the pH of BGE, the concentrations of glycine, SDS, and PEG 4000, and the applied voltage. Using glycerol as an internal standard, the linear ranges of the method for myo-inositol, scyllo-inositol, and glucose were 0.03-10, 0.01-5, and 0.05-20 mM; the concentration LODs of myo-inositol, scyllo-inositol, and glucose were 0.020, 0.0078, and 0.026 mM, respectively. The method was applied to analyze extracellular myo-inositol and glucose in the microdialysates from rat brain cortex of ischemia animal model and intracellular myo-inositol and scyllo-inositol in the rat brain extract.
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Affiliation(s)
- Huey-Fen Tzeng
- Department of Applied Chemistry, National Chi Nan University, Puli, Nantou, Taiwan.
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48
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Simionato AVC, Mauro Lanças F, Antônio Ruggiero M. Separation of Water‐Soluble Vitamins by Micellar Electrokinetic Capillary Chromatography in Pharmaceutical Samples. J LIQ CHROMATOGR R T 2007. [DOI: 10.1080/10826070500451889] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
| | - Fernando Mauro Lanças
- a Laboratory of Chromatography , Institute of Chemistry at São Carlos, University of São Paulo , São Carlos, SP, Brazil
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49
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Huang J, Kang J. A simple peptide mapping method by partial filling micellar electrokinetic capillary chromatography with a zwitterionic–nonionic mixed micelle. J Chromatogr B Analyt Technol Biomed Life Sci 2007; 846:364-7. [PMID: 16963322 DOI: 10.1016/j.jchromb.2006.08.035] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2005] [Revised: 08/13/2006] [Accepted: 08/20/2006] [Indexed: 10/24/2022]
Abstract
A partial filling micellar electrokinetic capillary chromatography (PF-MEKC) method with a mixed micelle system composed of a zwitterionic surfactant named 3-(N,N-dimethylhexadecylammonium)propanesulfonate (PAPS) and a nonionic surfactant polyethylene glycol dodecyl ether (Brij 35) for peptide mapping is described. The method was demonstrated by the separation of tryptic digestion of bovine serum albumin (BSA). The optimal mixed micelle solution was 50 mM NH(4)OH-HCOOH buffer (pH 2.0) containing 32 mM PAPS and 0.6% (m/v) Brij 35. It was found that the mixed micelle system permitted a highly selective separation of the tryptic digestion. The high separation selectivity was probably due to the ion-pairing interaction between the zwitterionic surfactant molecules and the peptides.
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Affiliation(s)
- Jing Huang
- Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 200032, China
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50
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Himmelsbach M, Haunschmidt M, Buchberger W, Klampfl CW. Microemulsion Electrokinetic Chromatography with On-Line Atmospheric Pressure Photoionization Mass Spectrometric Detection. Anal Chem 2007; 79:1564-8. [PMID: 17297956 DOI: 10.1021/ac061584b] [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: 11/29/2022]
Abstract
In the present paper we report, for the first time, the successful on-line coupling of microemulsion electrokinetic chromatography (MEEKC) with mass spectrometric (MS) detection using an atmospheric pressure photoionization interface. Microemulsions (MEs) including mostly volatile ingredients and classical MEs based on nonvolatile buffer components and sodium dodecyl sulfate (SDS) as surfactant were compared with respect to their compatibility with MS detection. The investigations performed revealed that MEs with up to 3% SDS and buffers containing sodium borate can be employed without significant suppression of the MS signals. A test mixture of nine substances could be separated by MEEKC using a ME consisting of 0.8% octane, 2% SDS, 6.6% butanol, and 90.6% of 20-mmol ammonium hydrogencarbonate buffer (pH 9.5). Operating the MS instrument in the MS(2) mode provided improved signal/noise ratios for analytes leading to characteristic MS-MS transitions. Thereby, limits of detection ranging between 0.5 (carbamazepine) and 5 microg mL(-1) (phenacetin) could be obtained.
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Affiliation(s)
- Markus Himmelsbach
- Institute of Analytical Chemistry, Johannes Kepler University, Altenbergerstrasse 69, A-4040 Linz, Austria
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