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Qiu D, Wilson MS, Eisenbeis VB, Harmel RK, Riemer E, Haas TM, Wittwer C, Jork N, Gu C, Shears SB, Schaaf G, Kammerer B, Fiedler D, Saiardi A, Jessen HJ. Analysis of inositol phosphate metabolism by capillary electrophoresis electrospray ionization mass spectrometry. Nat Commun 2020; 11:6035. [PMID: 33247133 PMCID: PMC7695695 DOI: 10.1038/s41467-020-19928-x] [Citation(s) in RCA: 55] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Accepted: 11/06/2020] [Indexed: 12/22/2022] Open
Abstract
The analysis of myo-inositol phosphates (InsPs) and myo-inositol pyrophosphates (PP-InsPs) is a daunting challenge due to the large number of possible isomers, the absence of a chromophore, the high charge density, the low abundance, and the instability of the esters and anhydrides. Given their importance in biology, an analytical approach to follow and understand this complex signaling hub is desirable. Here, capillary electrophoresis (CE) coupled to electrospray ionization mass spectrometry (ESI-MS) is implemented to analyze complex mixtures of InsPs and PP-InsPs with high sensitivity. Stable isotope labeled (SIL) internal standards allow for matrix-independent quantitative assignment. The method is validated in wild-type and knockout mammalian cell lines and in model organisms. SIL-CE-ESI-MS enables the accurate monitoring of InsPs and PP-InsPs arising from compartmentalized cellular synthesis pathways, by feeding cells with either [13C6]-myo-inositol or [13C6]-D-glucose. In doing so, we provide evidence for the existence of unknown inositol synthesis pathways in mammals, highlighting the potential of this method to dissect inositol phosphate metabolism and signalling. Myo-Inositol phosphates (InsPs) and pyrophosphates (PP-InsPs) are important second messengers but their analysis remains challenging. Here, the authors develop a capillary electrophoresis-mass spectrometry method for the identification and quantitation of InsP and PP-InsP isomers in cells and tissues.
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Affiliation(s)
- Danye Qiu
- Institute of Organic Chemistry, University of Freiburg, Albertstr. 21, 79104, Freiburg, Germany.
| | - Miranda S Wilson
- Medical Research Council, Laboratory for Molecular Cell Biology, University College London, London, WC1E 6BT, UK
| | - Verena B Eisenbeis
- Institute of Organic Chemistry, University of Freiburg, Albertstr. 21, 79104, Freiburg, Germany
| | - Robert K Harmel
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie, Robert-Rössle-Str. 10, 13125, Berlin, Germany
| | - Esther Riemer
- Institute of Crop Science and Resource Conservation, Department of Plant Nutrition, Rheinische Friedrich-Wilhelms-University Bonn, 53115, Bonn, Germany
| | - Thomas M Haas
- Institute of Organic Chemistry, University of Freiburg, Albertstr. 21, 79104, Freiburg, Germany
| | - Christopher Wittwer
- Institute of Organic Chemistry, University of Freiburg, Albertstr. 21, 79104, Freiburg, Germany
| | - Nikolaus Jork
- Institute of Organic Chemistry, University of Freiburg, Albertstr. 21, 79104, Freiburg, Germany
| | - Chunfang Gu
- Signal Transduction Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC, 27709, USA
| | - Stephen B Shears
- Signal Transduction Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC, 27709, USA
| | - Gabriel Schaaf
- Institute of Crop Science and Resource Conservation, Department of Plant Nutrition, Rheinische Friedrich-Wilhelms-University Bonn, 53115, Bonn, Germany
| | - Bernd Kammerer
- Institute of Organic Chemistry, University of Freiburg, Albertstr. 21, 79104, Freiburg, Germany
| | - Dorothea Fiedler
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie, Robert-Rössle-Str. 10, 13125, Berlin, Germany
| | - Adolfo Saiardi
- Medical Research Council, Laboratory for Molecular Cell Biology, University College London, London, WC1E 6BT, UK.
| | - Henning J Jessen
- Institute of Organic Chemistry, University of Freiburg, Albertstr. 21, 79104, Freiburg, Germany. .,CIBSS - Centre for Integrative Biological Signalling Studies, University of Freiburg, 79104, Freiburg, Germany.
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Tabani H, Nojavan S, Alexovič M, Sabo J. Recent developments in green membrane-based extraction techniques for pharmaceutical and biomedical analysis. J Pharm Biomed Anal 2018; 160:244-267. [DOI: 10.1016/j.jpba.2018.08.002] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Revised: 08/01/2018] [Accepted: 08/03/2018] [Indexed: 01/11/2023]
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The potential of electrophoretic sample pretreatment techniques and new instrumentation for bioanalysis, with a focus on peptidomics and metabolomics. Bioanalysis 2013; 5:2785-801. [DOI: 10.4155/bio.13.254] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
This Review highlights the potential of new electromigration-based sample pretreatment techniques for bioanalysis. Sample pretreatment is a challenging part of the analytical workflow, especially in the fields of peptidomics and metabolomics, where the analytes are very diverse, both in physicochemical properties and in endogenous concentration. Electromigration-based techniques have several strengths, such as fast selective analyte concentration and that complementary information on the content of a sample can be obtained when compared with more conventional (chromatography-based) techniques. In the past decade, various new electromigration-based sample pretreatment techniques have been developed, and importantly, new instrumental setups. In this Review, we provide an introduction on electromigration and its strengths. Then, selected examples of electromigration-based sample pretreatment techniques and instrumentation are discussed, namely free-flow electrophoresis, isoelectric focusing, isotachophoresis, electrodialysis, electromembrane extraction and electroextraction. Finally, the promising perspectives of electromigration-based sample pretreatment techniques are outlined.
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4
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Direct coupling of supported liquid membranes to capillary electrophoresis for analysis of complex samples: A tutorial. Anal Chim Acta 2013; 787:10-23. [DOI: 10.1016/j.aca.2013.04.065] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2013] [Revised: 04/24/2013] [Accepted: 04/26/2013] [Indexed: 01/10/2023]
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Kubáň P, Boček P. Direct analysis of formate in human plasma, serum and whole blood by in-line coupling of microdialysis to capillary electrophoresis for rapid diagnosis of methanol poisoning. Anal Chim Acta 2013; 768:82-9. [DOI: 10.1016/j.aca.2013.01.021] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2012] [Revised: 01/10/2013] [Accepted: 01/11/2013] [Indexed: 10/27/2022]
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Kvasnička F, Čopíková J, Ševčík R, Václavíková E, Synytsya A, Vaculová K, Voldřich M. Determination of phytic acid and inositolphosphates in barley. Electrophoresis 2011; 32:1090-3. [DOI: 10.1002/elps.201000578] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2010] [Revised: 12/13/2010] [Accepted: 12/13/2010] [Indexed: 11/09/2022]
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7
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Doan TKO, Kubáň P, Kubáň P, Kiplagat IK, Boček P. Analysis of inorganic cations in biological samples by the combination of micro-electrodialysis and capillary electrophoresis with capacitively coupled contactless conductivity detection. Electrophoresis 2011; 32:464-71. [DOI: 10.1002/elps.201000423] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2010] [Revised: 10/27/2010] [Accepted: 11/16/2010] [Indexed: 11/12/2022]
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8
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Electric field-enhanced transport across phase boundaries and membranes and its potential use in sample pretreatment for bioanalysis. Electrophoresis 2010; 31:768-85. [DOI: 10.1002/elps.200900561] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Flow/sequential injection sample treatment coupled to capillary electrophoresis. A review. Anal Chim Acta 2009; 648:129-45. [DOI: 10.1016/j.aca.2009.06.034] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2009] [Revised: 06/10/2009] [Accepted: 06/11/2009] [Indexed: 11/20/2022]
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11
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Recent applications of capillary electrophoresis–mass spectrometry (CE–MS): CE performing functions beyond separation. Anal Chim Acta 2008; 627:3-24. [DOI: 10.1016/j.aca.2008.04.023] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2008] [Revised: 04/02/2008] [Accepted: 04/08/2008] [Indexed: 11/18/2022]
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Flow Injection Analysis–Capillary Electrophoresis. ACTA ACUST UNITED AC 2008. [DOI: 10.1016/s0166-526x(08)00611-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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Campa C, Coslovi A, Flamigni A, Rossi M. Overview on advances in capillary electrophoresis-mass spectrometry of carbohydrates: A tabulated review. Electrophoresis 2006; 27:2027-50. [PMID: 16736462 DOI: 10.1002/elps.200500960] [Citation(s) in RCA: 88] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The increasing interest for carbohydrates as holder of essential bioinformations has boosted their full characterization through analytical techniques. The intent of this review is to summarize the recent trends regarding on-line and off-line CE-MS coupling for carbohydrate analysis. A statistical survey on the articles that use derivatizing agents as well as on the analyzer and type of instrument coupling (i.e. on- or off-line) is depicted. From a general overview it can be concluded that, whereas derivatization might be useful for the detection of neutral carbohydrates improving separation selectivity with volatile buffers and increasing sensitivity of the MS detection, relatively few works with derivatized carbohydrates were found; this was noticed in particular for glycosides and saccharides carrying ionizable groups, which are normally analyzed without any chemical modification. The most applied coupling is the on-line sheath-liquid interface; for on-line applications, ESI is the sole source used, whilst the most common analyzer is the IT. MS(n) is often exploited, as fragmentation increases the achieved structural information. CE-MS turned out to be mainly used for the analysis of carbohydrates in drug development (i.e. study of oligosaccharides from pathogens, carbohydrate-based drugs and drug metabolites), in nutrition and for characterization of glycans from glycoproteins. The reader will find elucidating tables regarding these recent CE-MS applications, including the main information on the analysis conditions. Comments are meant to help the immediate focus on the usefulness of the analytical technique and predict the difficulties found during analysis and, in case, their overcoming.
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Sirén H, Luomanperä K, Työppönen T, Rovio S, Vastamäki P, Savolahti P. Process control and drug analysis with an on-line capillary electrophoresis system. ACTA ACUST UNITED AC 2005; 60:295-307. [PMID: 15345297 DOI: 10.1016/j.jbbm.2004.01.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Inorganic and organic ions in pulp and paper process waters and drug mixtures were studied. Real-time measurements and on-line simulated analyses were made. A novel on-line capillary electrophoresis instrument equipped with a fixed wavelength UV detector having a 254-nm filter was used for the analyses. Three dynamic sample and electrolyte micromodules provided on-line sampling, sample introduction and solution feedings. The system was used to monitor process samples containing thiosulphate, chloride, sulphate, oxalate, acetate and carbonate. It approved good performance in separation of ethacrynic acid, furosemide, probenecid, bumetanide and hydrochlorothiazide as well as that of normethanephrine, methanephrine and dopamine standard mixtures. The LOD and LOQ values of the ions and drugs ranged from 0.1 to 1 mg/l for LOD and from 1 to 10 mg/l for LOQ. Sensitivity of the drugs was higher due to the single wavelength available in the system. It required that the drugs were to be identified by indirect UV detection. Repeatability of the analyses was good (RSD% below 5).
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Affiliation(s)
- Heli Sirén
- Technical Research Centre of Finland, VTT Processes, P.O. Box 1602, FIN-02044 VTT, Finland.
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Palm AK, Marko-Varga G. On-column electroextraction and separation of antisense oligonucleotides in human plasma by capillary gel electrophoresis. J Pharm Biomed Anal 2004; 35:415-23. [PMID: 15137967 DOI: 10.1016/j.jpba.2004.01.008] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2003] [Revised: 08/25/2003] [Accepted: 01/06/2004] [Indexed: 10/26/2022]
Abstract
A novel approach is presented for the direct injection, and subsequent separation, of antisense phosphorothioate oligonucleotides in human plasma by capillary gel electrophoresis. The plasma, spiked with the antisense, was simply diluted 1:1 with acidified water and inserted into the sample holder in the capillary electrophoresis instrument. The separation capillary, filled with a dextran solution (replaceable polymer) and a short zone of acidified water at the injection side, was dipped into the plasma sample vial and voltage applied for simultaneous electrokinetic extraction and injection of antisense. The sample vial was then exchanged for the buffer vial, separation voltage applied, and size-sieving separation achieved. Separation time is less than 9 min and total time per analysis cycle 20 min, including rinsing of the capillary, filling with polymer, electroextraction/injection, and separation. This automated method can handle small sample volumes (4 microl) and has a detection limit of 0.5 microgml(-1) for a 16-mer phosphorothioate employing UV-detection. The capillary is stable for about 50 analyses.
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Affiliation(s)
- Anders K Palm
- Department of Chemistry, Indiana University, Bloomington, IN 47405, USA
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Simonet BM, Ríos A, Grases F, Valcárcel M. Determination of myo-inositol phosphates in food samples by flow injection-capillary zone electrophoresis. Electrophoresis 2003; 24:2092-2098. [PMID: 12858380 DOI: 10.1002/elps.200305404] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
A capillary electrophoresis (CE) method with indirect photometric detection was developed to identify and quantify myo-inositol phosphates in food samples. A flow-injection (FI) system including a micro-column containing anionic exchange resin was used for the solid-phase extraction of the myo-inositol phosphates with a view to their preconcentration. The FI system was automatically coupled to CE equipment via a mechanical interface. The overall analysis time was shortened by incorporating an FI system for myo-inositol hexakisphosphate monitoring. The limit of detection for myo-inositol phosphates as determined by FI-CE ranged from 11 to 26 micromol/L and the coefficient of variation from 3.9 to 5.0%. On the other hand, the limit of detection and coefficient of variation for myo-inositol hexakisphosphate as monitored by the FI system were 75 micromol/L and 2.9%, respectively. The proposed method was successfully applied to a variety of food samples with recoveries ranging from 96.0 to 107.7% and the precision from 3.9 to 7.9%. Based on the results, the content of myo-inositol hexakisphosphate in nuts was two or three times higher than that in legumes.
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17
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Sirén H, Rovio S, Työppönen T, Vastamäki P. On-line measurement of pulp water anions by capillary electrophoresis with fast sequential sampling and dynamic solvent feeding. J Sep Sci 2002. [DOI: 10.1002/1615-9314(20021101)25:15/17<1136::aid-jssc1136>3.0.co;2-k] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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18
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Ali I, Aboul-Enein HY. DETERMINATION OF METAL IONS IN WATER, SOIL, AND SEDIMENT BY CAPILLARY ELECTROPHORESIS. ANAL LETT 2002. [DOI: 10.1081/al-120015519] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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19
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Abstract
One of the weak points of capillary electrophoresis is the need to implement rigorously sample pretreatment because its great impact on the quality of the qualitative and quantitative results provided. One of the approaches to solve this problem is through the symbiosis of automatic continuous flow systems (CFSs) and capillary electrophoresis (CE). In this review a systematic approach to CFS-CE coupling is presented and discussed. The design of the corresponding interface depends on three factors, namely: (a) the characteristics of the CFS involved which can be non-chromatographic and chromatographic; (b) the type of CE equipment: laboratory-made or commercially available; and (c) the type of connection which can be in-line (on-capillary), on-line or mixed off/on-line. These are the basic criteria to qualify the hyphenation of CFS (solid-phase extraction, dialysis, gas diffusion, evaporation, direct leaching) with CE described so far and applied to determine a variety of analytes in many different types of samples. A critical discussion allows one to demonstrate that this symbiosis is an important topic in research and development, besides separation and detection, to consolidate CE as a routine analytical tool.
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Affiliation(s)
- M Valcárcel
- Analytical Chemistry Division, University of Córdoba, Spain.
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20
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Gaspari M, Gu?ek M, Walhagen K, Vreeken RJ, Verheij ER, Tjaden UR, Van der Greef J. Ion trap mass spectrometry as detector for capillary electrochromatography of peptides: Possibilities and limitations. ACTA ACUST UNITED AC 2001. [DOI: 10.1002/mcs.1049] [Citation(s) in RCA: 15] [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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21
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Walhagen K, Gaspari M, Tjaden UR, Rozing GP, van der Greef J. In-line coupling of low-pressure short capillary electrochromatography columns to electrospray ionisation mass spectrometry. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2001; 15:878-883. [PMID: 11382936 DOI: 10.1002/rcm.291] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
A new in-house designed and constructed injection valve for capillary electrochromatography (CEC) based on a rotating injection part with compartments for the eluent as well as for the sample has been coupled to a mass spectrometer via a sheath flow electrospray ionisation (ESI) interface, using short capillary columns of 15 cm length. The CEC columns were packed with 3 microm C(18) bonded silica particles, and a mixture of peptides was analysed using an ammonium acetate/acetonitrile eluent. A significant increase in the signal-to-noise ratio was obtained when the peptides were dissolved in water with the same content of organic modifier as in the eluent with an addition of 0.5% (v/v) acetic acid. When the CEC analysis was performed without any additional pressure, the separation current sometimes dropped tremendously due to bubble formation, caused by different permeability in the first and packed part of the column causing an extremely low electroosmotic flow. The separation current was restored to its original value by applying only 7 bar at the inlet of the CEC column, and the separation performance for the test peptides was recovered. A comparison of the CEC performance of peptides in pure CEC mode and in low-pressure CEC mode is reported.
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Affiliation(s)
- K Walhagen
- Leiden/Amsterdam Center for Drug Research, Leiden University, P.O. Box 9502, NL-2300 RA Leiden, The Netherlands.
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Cordero BM, Pérez Pavón JL, García Pinto C, Fernández Laespada ME, Carabias Martínez R, Rodriguez Gonzalo E. Analytical applications of membrane extraction in chromatography and electrophoresis. J Chromatogr A 2000; 902:195-204. [PMID: 11192155 DOI: 10.1016/s0021-9673(00)00835-9] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
An overview of the analytical applications of membrane-based systems for sample enrichment in chromatography and capillary electrophoresis is presented. A brief introduction to the different types of membranes and the main forces related to the transport through them is also given.
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Affiliation(s)
- B M Cordero
- Departamento de Química Analítica, Nutrición y Bromatología, Facultad de Química, Universidad de Salamanca, Spain.
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Pinto CG, Laespada MEF, Pavón JLP, Cordero BM. Analytical applications of separation techniques through membranes. ACTA ACUST UNITED AC 1999. [DOI: 10.1016/s1381-141x(99)00014-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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van de Merbel NC. Membrane-based sample preparation coupled on-line to chromatography or electrophoresis. J Chromatogr A 1999; 856:55-82. [PMID: 10526784 DOI: 10.1016/s0021-9673(99)00581-6] [Citation(s) in RCA: 95] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
A review on the use of membranes for on-line sample preparation prior to chromatographic and electrophoretic analysis is provided. The current state-of-the-art of four membrane-based techniques (dialysis, electrodialysis, filtration and membrane extraction) is described by reviewing their principles and applications. Possible future developments are discussed.
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Haddad PR, Doble P, Macka M. Developments in sample preparation and separation techniques for the determination of inorganic ions by ion chromatography and capillary electrophoresis. J Chromatogr A 1999; 856:145-77. [PMID: 10526787 DOI: 10.1016/s0021-9673(99)00431-8] [Citation(s) in RCA: 79] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A review is presented of sample preparation and separation techniques for the determination of inorganic ions by ion chromatography (IC) and capillary electrophoresis (CE). Emphasis has been placed on those sample treatment methods which are specific to inorganic analysis, and the developments in separation methods which are discussed are those which enhance the capabilities of IC and CE to handle complex sample matrices. Topics discussed include solid-phase extraction for sample clean-up and preconcentration, dialytic methods, combustion methods, matrix-elimination IC, electrostatic IC, electrically polarised ion-exchange resins, electromigration sample preparation in CE, chromatographic sample preparation for CE, use of high-ionic strength background electrolytes, buffering of background electrolytes in CE, use of capillary electrochromatography for inorganic determinations, and methods for the manipulation of separation selectivity in both IC and CE. Finally, some possible future trends are discussed.
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Affiliation(s)
- P R Haddad
- School of Chemistry, University of Tasmania, Hobart, Australia.
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26
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Danková M, Kaniansky D, Fanali S, Iványi F. Capillary zone electrophoresis separations of enantiomers present in complex ionic matrices with on-line isotachophoretic sample pretreatment. J Chromatogr A 1999; 838:31-43. [PMID: 10327632 DOI: 10.1016/s0021-9673(98)00974-1] [Citation(s) in RCA: 68] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Analytical capabilities of capillary zone electrophoresis (CZE) with on-line coupled capillary isotachophoresis (ITP) sample pretreatment in the column-coupling capillary electrophoresis equipment to separate and determine enantiomers present in multicomponent ionic matrices were studied. Tryptophan was used as a model analyte in the ITP-capillary zone electrophoresis experiments performed in this context while a 90-component model mixture of UV-light absorbing organic anions and urine served as multicomponent sample matrices. Various working modes in which the on-line coupled capillary isotachophoresis-capillary zone electrophoresis combination in the column-coupling separation system can operate were employed in the anionic regime of the separation with direct injections of the samples. Advantages and limitations of these working modes in the separations of enantiomers present in model and urine matrices were assessed. Experiments with model mixtures of tryptophan enantiomers revealed that the two were resolved in the capillary zone electrophoresis stage with the aid of alpha-cyclodextrin also when their concentration ratio in the sample was 1:200 while the concentration of L(-)-tryptophan was 25 nmol/l. The limits of detection for the enantiomers were at approximately 10 nmol/l (approximately 1.5 ng/ml) concentrations for a 220 nm detection wavelength of the UV detector employed in the capillary zone electrophoresis stage and for a 30 microliters sample load. A high sample load capacity of the on-line coupled capillary isotachophoresis stage was effective in separating the samples corresponding to 3-6 microliters volumes of undiluted urine. The results from the runs with urine samples showed that only the capillary isotachophoresis-capillary zone electrophoresis combination with a post-column on-line coupled capillary isotachophoresis sample clean-up (responsible for a removal of more than 99% of the sample anionic constituents migrating in the on-line coupled capillary isotachophoresis stack and detectable in the capillary zone electrophoresis stage) provided a universal alternative for the detection and quantitation of the model analyte (L(-)-tryptophan).
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Affiliation(s)
- M Danková
- Department of Analytical Chemistry, Faculty of Natural Sciences, Comenius University, Bratislava, Slovak Republic
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27
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Affiliation(s)
- D Perrett
- Department of Medicine, St Bartholomew's, London, UK
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28
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Buscher B, Tjaden U, van der Greef J. Three-compartment electrodialysis device for on-line sample clean-up and enrichment prior to capillary electrophoresis. J Chromatogr A 1997. [DOI: 10.1016/s0021-9673(97)00707-3] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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