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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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2
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Król M, Nowak M, Gładysz M, Kościelniak P. The examination of red lipsticks using microemulsion electrokinetic capillary chromatography. Microchem J 2020. [DOI: 10.1016/j.microc.2020.104735] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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3
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Ye LH, Du LJ, Cao J. Fatty acids-based microemulsion liquid chromatographic determination of multiple caffeoylquinic acid isomers and caffeic acid in honeysuckle sample. J Pharm Biomed Anal 2019; 171:22-29. [PMID: 30959316 DOI: 10.1016/j.jpba.2019.03.064] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2019] [Accepted: 03/29/2019] [Indexed: 12/28/2022]
Abstract
A green and efficient microemulsion liquid chromatographic (MELC) method using fatty acid as co-surfactant and electrochemical detection was established and validated for the determination of four caffeoylquinic acid isomers and caffeic acid in honeysuckle samples. The influences of each individual component within the isocratic oil-in-water (O/W) microemulsion mobile phase were systematically investigated, such as the type and concentration of co-surfactant, concentration of sodium dodecyl sulphate (SDS), organic modifier addition, type and concentration of oil phase, pH and detection voltage. Results indicated that excellent resolution was achieved using 3.0% w/v of propionic acid, 0.5% w/v of ethyl acetate, 1.0% w/v of SDS, 5% w/v acetonitrile, 90.5% v/v of water and 25 mM sodium dihydrogen phosphate at pH = 3 as microemulsion mobile phase and 0.8 V as the optimal voltage value. Under the optimal condition, analytical performance of developed method was evaluated. The detection limits were below 17.3 ng/mL and intra-day and inter-day precisions by relative standard deviations (RSD%) were between 0.5% and 3.6%. Satisfactory recovery (in the range of 83.8-109.1%) with good repeatability lower than 4.7% (n = 3) was obtained. Therefore, the developed O/W MELC method was rapid, precise and accurate for simultaneous determination of neochlorogenic acid, chlorogenic acid, isochlorogenic acid A and isochlorogenic acid C in honeysuckle samples, with contents of 2.6, 28.7, 18.1 and 5.2 mg/g, respectively.
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Affiliation(s)
- Li-Hong Ye
- Department of Traditional Chinese Medicine, Hangzhou Red Cross Hospital, Hangzhou 310003, China
| | - Li-Jing Du
- College of Material Chemistry and Chemical Engineering, Hangzhou Normal University, Hangzhou 310036, China
| | - Jun Cao
- College of Material Chemistry and Chemical Engineering, Hangzhou Normal University, Hangzhou 310036, China.
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4
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Javed S, Ahsan W. Microemulsion based chromatographic techniques: Past lessons and future directions. J LIQ CHROMATOGR R T 2019. [DOI: 10.1080/10826076.2019.1584746] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Affiliation(s)
- Shamama Javed
- Department of Pharmaceutics, College of Pharmacy, Jazan University, Jazan, Saudi Arabia
| | - Waquar Ahsan
- Department of Pharmaceutical Chemistry, College of Pharmacy, Jazan University, Jazan, Saudi Arabia
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5
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Subirats X, Yuan HP, Chaves V, Marzal N, Rosés M. Microemulsion electrokinetic chromatography as a suitable tool for lipophilicity determination of acidic, neutral, and basic compounds. Electrophoresis 2016; 37:2010-6. [DOI: 10.1002/elps.201600080] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2016] [Revised: 04/05/2016] [Accepted: 04/21/2016] [Indexed: 11/09/2022]
Affiliation(s)
- Xavier Subirats
- Departament de Química Analítica and Institut de Biomedicina (IBUB); Universitat de Barcelona; Barcelona Spain
| | - Hui-Ping Yuan
- Departament de Química Analítica and Institut de Biomedicina (IBUB); Universitat de Barcelona; Barcelona Spain
| | - Verónica Chaves
- Departament de Química Analítica and Institut de Biomedicina (IBUB); Universitat de Barcelona; Barcelona Spain
| | - Núria Marzal
- Departament de Química Analítica and Institut de Biomedicina (IBUB); Universitat de Barcelona; Barcelona Spain
| | - Martí Rosés
- Departament de Química Analítica and Institut de Biomedicina (IBUB); Universitat de Barcelona; Barcelona Spain
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6
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Abstract
Microemulsion electrokinetic chromatography (MEEKC) is a special mode of capillary electrophoresis employing a microemulsion as carrier electrolyte. Analytes may partition between the aqueous phase of the microemulsion and its oil droplets which act as a pseudostationary phase. The technique is well suited for the separation of neutral species, in which case charged oil droplets (obtained by addition of an anionic or cationic surfactant) are present. A single set of separation parameters may be sufficient for separation of a wide range of analytes belonging to quite different chemical classes. Fine-tuning of resolution and analysis time may be achieved by addition of organic solvents, by changes in the nature of the surfactants (and cosurfactants) used to stabilize the microemulsion, or by various additives that may undergo some additional interactions with the analytes. Besides the separation of neutral analytes (which may be the most important application area of MEEKC), it can also be employed for cationic and/or anionic species. In this chapter, MEEKC conditions are summarized that have proven their reliability for routine analysis. Furthermore, the mechanisms encountered in MEEKC allow an efficient on-capillary preconcentration of analytes, so that the problem of poor concentration sensitivity of ultraviolet absorbance detection is circumvented.
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Affiliation(s)
- Wolfgang Buchberger
- Institut für Analytische Chemie, Universität Linz, TNF-Tower, T 209, Altenbergerstraße 69, Linz, 4040, Austria.
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7
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Kaale E, Höllein L, Holzgrabe U. Development and validation of a generic stability-indicating MEEKC method for five fluoroquinolone antibiotics. Electrophoresis 2015; 36:2736-2744. [DOI: 10.1002/elps.201500025] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2015] [Revised: 04/21/2015] [Accepted: 04/21/2015] [Indexed: 11/07/2022]
Affiliation(s)
- Eliangiringa Kaale
- University of Würzburg; Institute of Pharmacy and Food Chemistry; Würzburg Germany
- School of Pharmacy; Muhimbili University of Health and Allied Sciences; Dar Es Salaam Tanzania
| | - Ludwig Höllein
- University of Würzburg; Institute of Pharmacy and Food Chemistry; Würzburg Germany
| | - Ulrike Holzgrabe
- University of Würzburg; Institute of Pharmacy and Food Chemistry; Würzburg Germany
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8
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Posch TN, Pütz M, Martin N, Huhn C. Electromigrative separation techniques in forensic science: combining selectivity, sensitivity, and robustness. Anal Bioanal Chem 2014; 407:23-58. [PMID: 25381613 DOI: 10.1007/s00216-014-8271-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2014] [Revised: 10/12/2014] [Accepted: 10/14/2014] [Indexed: 01/27/2023]
Abstract
In this review we introduce the advantages and limitations of electromigrative separation techniques in forensic toxicology. We thus present a summary of illustrative studies and our own experience in the field together with established methods from the German Federal Criminal Police Office rather than a complete survey. We focus on the analytical aspects of analytes' physicochemical characteristics (e.g. polarity, stereoisomers) and analytical challenges including matrix tolerance, separation from compounds present in large excess, sample volumes, and orthogonality. For these aspects we want to reveal the specific advantages over more traditional methods. Both detailed studies and profiling and screening studies are taken into account. Care was taken to nearly exclusively document well-validated methods outstanding for the analytical challenge discussed. Special attention was paid to aspects exclusive to electromigrative separation techniques, including the use of the mobility axis, the potential for on-site instrumentation, and the capillary format for immunoassays. The review concludes with an introductory guide to method development for different separation modes, presenting typical buffer systems as starting points for different analyte classes. The objective of this review is to provide an orientation for users in separation science considering using capillary electrophoresis in their laboratory in the future.
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Affiliation(s)
- Tjorben Nils Posch
- Forschungszentrum Jülich GmbH, Central Institute for Engineering, Electronics and Analytics, Analytics ZEA-3, 52425, Jülich, Germany
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9
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Cao W, Hu SS, Li XY, Pang XQ, Cao J, Ye LH, Dai HB, Liu XJ, Da JH, Chu C. Highly sensitive analysis of flavonoids by zwitterionic microemulsion electrokinetic chromatography coupled with light-emitting diode-induced fluorescence detection. J Chromatogr A 2014; 1358:277-84. [DOI: 10.1016/j.chroma.2014.06.081] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2014] [Revised: 06/18/2014] [Accepted: 06/24/2014] [Indexed: 02/06/2023]
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10
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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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11
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Wuethrich A, Haddad PR, Quirino JP. Chiral capillary electromigration techniques-mass spectrometry-hope and promise. Electrophoresis 2013; 35:2-11. [PMID: 24265218 DOI: 10.1002/elps.201300377] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2013] [Revised: 10/06/2013] [Accepted: 10/07/2013] [Indexed: 11/09/2022]
Abstract
Analytical methods for chiral compounds require a separation step prior to mass spectrometric detection. CE can separate enantiomers by the use of a chiral selector and can be hyphenated with MS. The chiral selector can be either embedded inside the capillary (electrochromatography) or added into the background solution (EKC). This review describes the fundamentals and highlights the recent developments (September 2009-May 2013) of chiral CEC and EKC with detection using MS. There were 20 research and more than 30 review papers during this period. The research efforts were driven by fundamental studies, such as the development of novel chiral selectors in electrochromatography and of advanced partial filling techniques in EKC in order to optimise separation. Other developments were in application studies, such as in food analytics and metabolomics.
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Affiliation(s)
- Alain Wuethrich
- Australian Centre for Research on Separation Science (ACROSS), School of Chemistry, University of Tasmania, Hobart, Australia
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12
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Yang H, Ding Y, Cao J, Li P. Twenty-one years of microemulsion electrokinetic chromatography (1991-2012): A powerful analytical tool. Electrophoresis 2013; 34:1273-94. [DOI: 10.1002/elps.201200494] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2012] [Revised: 12/18/2012] [Accepted: 01/22/2013] [Indexed: 12/18/2022]
Affiliation(s)
- Hua Yang
- State Key Laboratory of Natural Medicines (China Pharmaceutical University); Nanjing; P. R. China
| | - Yao Ding
- State Key Laboratory of Natural Medicines (China Pharmaceutical University); Nanjing; P. R. China
| | - Jun Cao
- College of Material Chemistry and Chemical Engineering; Hangzhou Normal University; Hangzhou; P. R. China
| | - Ping Li
- State Key Laboratory of Natural Medicines (China Pharmaceutical University); Nanjing; P. R. China
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13
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Zhang Z, Zhang F, Liu Y. Recent Advances in Enhancing the Sensitivity and Resolution of Capillary Electrophoresis. J Chromatogr Sci 2013; 51:666-83. [DOI: 10.1093/chromsci/bmt012] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
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14
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Borst C, Holzgrabe U. Cyclodextrin-mediated enantioseparation in microemulsion electrokinetic chromatography. Methods Mol Biol 2013; 970:363-375. [PMID: 23283790 DOI: 10.1007/978-1-62703-263-6_23] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Chiral separation by means of cyclodextrins has a long-standing tradition in capillary electrophoresis techniques. Here we present a chiral method utilizing the recently introduced microemulsion electrokinetic chromatography. The microemulsion consisting of 1.0% SDS, 4.0% 1-butanol, 3.0% 2-propanol, 0.5% ethylacetate, and 91.5% 20 mM phosphate buffer pH 2.5 serves as a pseudostationary phase which is complemented by sulfated cyclodextrin as a second phase. The analytes partition between the aqueous running buffer and both pseudostationary phases, the oil droplets and the cyclodextrins. Enantiomers are separated due to the formation of transient diastereomeric complexes with the cyclodextrins. For the racemates of ephedrine derivatives studied here sulfated β-cyclodextrin was successfully applied. The method is appropriate to resolve an entire series of chiral phenethylamines and can be used for separation of the racemates and impurity profiling, e.g., the determination of the enantiomeric excess.
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Affiliation(s)
- Claudia Borst
- Institute of Pharmacy and Food Chemistry, University of Würzburg, Würzburg, Germany
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15
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Hu SQ, Lü WJ, Ma YH, Hu Q, Dong LJ, Chen XG. Chiral separation of β-blockers by MEEKC using neutral microemulsion: Analysis of separation mechanism and further elucidation of resolution equation. Electrophoresis 2012; 34:260-8. [DOI: 10.1002/elps.201200150] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2012] [Revised: 07/26/2012] [Accepted: 08/16/2012] [Indexed: 02/01/2023]
Affiliation(s)
| | | | | | | | | | - Xing-Guo Chen
- National Key Laboratory of Applied Organic Chemistry; Lanzhou University; Lanzhou; P. R. China
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16
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Ryan R, Altria K, McEvoy E, Donegan S, Power J. A review of developments in the methodology and application of microemulsion electrokinetic chromatography. Electrophoresis 2012; 34:159-77. [PMID: 23161220 DOI: 10.1002/elps.201200375] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2012] [Revised: 08/27/2012] [Accepted: 08/27/2012] [Indexed: 11/10/2022]
Abstract
MEEKC is a mode of CE, which utilizes microemulsion (ME) as the BGE to achieve separation of a diverse range of analytes. MEs are composed of nanometer-sized oil droplets suspended in aqueous buffer which are stabilized by the presence of a surfactant and co-surfactant. These MEs are commonly referred to as oil-in-water MEs and their application in MEEKC has been extensively examined. This review details advances in the theory, methodology, and application of MEEKC during the period 2010-2012. Areas covered include online sample concentration, advances in chiral separations, use of coated capillaries, chemometric approaches, and the use of novel additives to the ME system. This review also provides the reader with an introduction to MEEKC and a presentation of recent applications.
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Affiliation(s)
- Richie Ryan
- Waterford Institute of Technology, Waterford, Ireland.
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Abstract
AbstractEnantiomers (stereoisomers) can exhibit substantially different properties if present in chiral environments. Since chirality is a basic property of nature, the different behaviors of the individual enantiomers must be carefully studied and properly treated. Therefore, enantioselective separations are a very important part of separation science. To achieve the separation of enantiomers, an enantioselective environment must be created by the addition of a chiral selector to the separation system. Many chiral selectors have been designed and used in various fields, such as the analyses of drugs, food constituents and agrochemicals. The most popular have become the chiral selectors and/or chiral stationary phases that are of general use, i.e., are applicable in various separation systems and allow for chiral separation of structurally different compounds. This review covers the most important chiral selectors / chiral stationary phases described and applied in high performance liquid chromatography and capillary electrophoresis during the period of the last three years (2008–2011).
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18
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Yu L, Chu K, Ye H, Liu X, Yu L, Xu X, Chen G. Recent advances in microemulsion electrokinetic chromatography. Trends Analyt Chem 2012. [DOI: 10.1016/j.trac.2011.11.003] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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19
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Kašička V. Recent developments in CE and CEC of peptides (2009-2011). Electrophoresis 2011; 33:48-73. [DOI: 10.1002/elps.201100419] [Citation(s) in RCA: 95] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2011] [Revised: 09/19/2011] [Accepted: 09/20/2011] [Indexed: 12/12/2022]
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20
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Kubáň P, Timerbaev AR. CE of inorganic species - A review of methodological advancements over 2009-2010. Electrophoresis 2011; 33:196-210. [DOI: 10.1002/elps.201100357] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2011] [Revised: 07/30/2011] [Accepted: 07/30/2011] [Indexed: 01/13/2023]
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21
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Huang HY, Liu WL, Singco B, Hsieh SH, Shih YH. On-line concentration sample stacking coupled with water-in-oil microemulsion electrokinetic chromatography. J Chromatogr A 2011; 1218:7663-9. [DOI: 10.1016/j.chroma.2011.05.091] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2011] [Revised: 04/28/2011] [Accepted: 05/26/2011] [Indexed: 02/06/2023]
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22
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Svobodová E, Bosáková Z, Lokajová J, Tesařová E, Coufal P. Use of Capillary Zone Electrophoresis and Micellar Electrokinetic Chromatography for Separations of Anthraquinone Derivatives. ANAL LETT 2011. [DOI: 10.1080/00032719.2010.526269] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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23
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A quantitative structure–activity approach for lipophilicity estimation of antitumor complexes of different metals using microemulsion electrokinetic chromatography. J Pharm Biomed Anal 2011; 55:409-13. [DOI: 10.1016/j.jpba.2011.02.011] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2010] [Revised: 02/09/2011] [Accepted: 02/10/2011] [Indexed: 11/22/2022]
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24
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Lynen F, Saveedra L, Nickerson B, Sandra P. Evaluation of a multiarray system for pharmaceutical analysis by microemulsion electrokinetic chromatography. Talanta 2011; 84:724-9. [DOI: 10.1016/j.talanta.2011.01.070] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2010] [Revised: 01/13/2011] [Accepted: 01/30/2011] [Indexed: 10/18/2022]
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25
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Ryan R, McEvoy E, Sheila Donegan, Power J, Altria K. Recent developments in the methodology and application of MEEKC. Electrophoresis 2010; 32:184-201. [DOI: 10.1002/elps.201000372] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2010] [Revised: 08/28/2010] [Accepted: 09/21/2010] [Indexed: 02/05/2023]
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26
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Orlandini S, Giannini I, Navarro MV, Pinzauti S, Furlanetto S. Dual CD system-modified MEEKC method for the determination of clemastine and its impurities. Electrophoresis 2010; 31:3296-304. [DOI: 10.1002/elps.201000066] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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27
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Aurora-Prado MS, Silva CA, Tavares MFM, Altria KD. Rapid Determination of Water-Soluble and Fat-Soluble Vitamins in Commercial Formulations by MEEKC. Chromatographia 2010. [DOI: 10.1365/s10337-010-1704-9] [Citation(s) in RCA: 14] [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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28
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Wongwan S, Scriba GKE. Impurity profiling of dexamphetamine sulfate by cyclodextrin-modified microemulsion electrokinetic chromatography. Electrophoresis 2010; 31:3006-11. [DOI: 10.1002/elps.201000277] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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29
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Hu SQ, Chen YL, Zhu HD, Shi HJ, Yan N, Chen XG. Effect of molecular structure of tartrates on chiral recognition of tartrate–boric acid complex chiral selectors in chiral microemulsion electrokinetic chromatography. J Chromatogr A 2010; 1217:5529-35. [DOI: 10.1016/j.chroma.2010.06.063] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2010] [Revised: 06/18/2010] [Accepted: 06/24/2010] [Indexed: 11/26/2022]
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30
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Ultra-fast two-dimensional microchip electrophoresis using SDS μ-CGE and microemulsion electrokinetic chromatography for protein separations. Anal Bioanal Chem 2010; 398:489-98. [DOI: 10.1007/s00216-010-3914-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2010] [Revised: 06/07/2010] [Accepted: 06/08/2010] [Indexed: 10/19/2022]
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31
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Recent advances of capillary electrophoresis in pharmaceutical analysis. Anal Bioanal Chem 2010; 398:29-52. [DOI: 10.1007/s00216-010-3741-5] [Citation(s) in RCA: 105] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2010] [Revised: 04/08/2010] [Accepted: 04/09/2010] [Indexed: 01/16/2023]
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Cao J, Qu H, Cheng Y. Separation of flavonoids and phenolic acids in complex natural products by microemulsion electrokinetic chromatography using surfactant-coated and carboxylic single-wall carbon nanotubes as additives. Electrophoresis 2010; 31:1689-96. [DOI: 10.1002/elps.200900696] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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33
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Haunschmidt M, Ortner K, Hainz K, Bradt E, Sternbauer L, Buchberger W, Klampfl CW. Investigations on the migration behavior of insulin and related synthetic analogues in CZE, MEKC and MEEKC employing different surfactants. Electrophoresis 2010; 31:1560-4. [PMID: 20358538 DOI: 10.1002/elps.200900547] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The retention/migration behavior of insulin and five synthetic insulin analogues in CZE, MEKC and MEEKC employing seven different detergents within the latter two techniques has been investigated. Substantial changes in separation selectivity in MEKC could be observed for several insulins when moving from SDS to cholate-based micellar systems. Customized separations could be achieved by using mixtures of SDS and deoxycholate. A similar effect could be observed in MEEKC although the overall quality of MEEKC separations was inferior to those obtained with MEKC.
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Affiliation(s)
- Manuela Haunschmidt
- Institute of Analytical Chemistry, Johannes-Kepler-University, Linz, Austria
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Bytzek AK, Reithofer MR, Galanski M, Groessl M, Keppler BK, Hartinger CG. The first example of MEEKC-ICP-MS coupling and its application for the analysis of anticancer platinum complexes. Electrophoresis 2010; 31:1144-1150. [PMID: 20349510 PMCID: PMC3512080 DOI: 10.1002/elps.200900522] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
MEEKC is a powerful electrodriven separation technique with many applications in different disciplines, including medicinal chemistry; however, up to now the coupling to highly sensitive and selective MS detectors was limited due to the ion suppressive effect of the commonly used surfactant SDS. Herein, the first example of the coupling of MEEKC to ICP-MS is presented and an MEEKC method for the separation of Pt(II) and Pt(IV) anticancer drugs and drug candidates was developed. Different compositions of microemulsions were evaluated and the data were compared with those collected with standard ultraviolet/visible (UV/vis) spectroscopy detection. The MEEKC-ICP-MS system was found to be more sensitive than MEEKC-UV/vis and the analysis of UV/vis silent compounds is now achievable. The migration behavior of the Pt(II) and Pt(IV) compounds under investigation is correlated to their different chemical structures.
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Affiliation(s)
- Anna K. Bytzek
- Institute of Inorganic Chemistry, University of Vienna, Waehringer Str. 42, A-1090 Vienna, Austria
| | - Michael R. Reithofer
- Institute of Inorganic Chemistry, University of Vienna, Waehringer Str. 42, A-1090 Vienna, Austria
| | - Markus Galanski
- Institute of Inorganic Chemistry, University of Vienna, Waehringer Str. 42, A-1090 Vienna, Austria
| | - Michael Groessl
- Institute of Inorganic Chemistry, University of Vienna, Waehringer Str. 42, A-1090 Vienna, Austria
| | - Bernhard K. Keppler
- Institute of Inorganic Chemistry, University of Vienna, Waehringer Str. 42, A-1090 Vienna, Austria
| | - Christian G. Hartinger
- Institute of Inorganic Chemistry, University of Vienna, Waehringer Str. 42, A-1090 Vienna, Austria
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Ryan R, Donegan S, Power J, Altria K. Advances in the theory and application of MEEKC. Electrophoresis 2010; 31:755-67. [DOI: 10.1002/elps.200900568] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Mikus P, Maráková K. Advanced CE for chiral analysis of drugs, metabolites, and biomarkers in biological samples. Electrophoresis 2010; 30:2773-802. [PMID: 19653234 DOI: 10.1002/elps.200900173] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
An analysis of recent trends indicates that CE can show real advantages over chromatographic methods in ultratrace enantioselective determination of biologically active compounds in complex biological matrices. It is due to high separation efficiency and many applicable in-capillary electromigration effects in CE (countercurrent migration, stacking effects) enhancing significantly (enantio)separability and enabling effective sample preparation (preconcentration, purification, analyte derivatization). Other possible on-line combinations of CE, such as column coupled CE-CE techniques and implementation of nonelectrophoretic techniques (extraction, membrane filtration, flow injection) into CE, offer additional approaches for highly effective sample preparation and separation. CE matured to a highly flexible and compatible technique enabling its hyphenation with powerful detection systems allowing extremely sensitive detection (e.g. LIF) and/or structural characterization of analytes (e.g. MS). Within the last decade, more as well as less conventional analytical on-line approaches have been effectively utilized in this field and their practical potentialities are demonstrated on many new application examples in this article. Here, three basic areas of (enantioselective) drug bioanalysis are highlighted and supported by a brief theoretical description of each individual approach in a compact review structure (to create integrated view on the topic), including (i) progressive enantioseparation approaches and new enantioselective agents, (ii) in-capillary sample preparation (preconcentration, purification, derivatization), and (iii) detection possibilities related to enhanced sensitivity and structural characterization.
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Affiliation(s)
- Peter Mikus
- Department of Pharmaceutical Analysis and Nuclear Pharmacy, Faculty of Pharmacy, Comenius University, Bratislava, Slovak Republic.
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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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