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3D Printed Skin-Wash Sampler for Sweat Sampling in Cystic Fibrosis Diagnosis Using Capillary Electrophoretic Ion Ratio Analysis. SEPARATIONS 2021. [DOI: 10.3390/separations8120234] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Sweat chloride analysis is one of the important approaches in cystic fibrosis diagnosis. The commonly used Macroduct method to acquire sweat samples is semi-invasive, time consuming and expensive. Furthermore, this method often fails to collect a sufficient amount of sweat in newborns due to the insufficient sweating rate. In this work, we present a novel, simple, 3D-printed sampling device that is used to collect sweat specimens completely noninvasively in less than one minute. The device has a flow-through channel adjacent to the skin surface, through which 500 µL of deionized water is flushed and the spontaneously formed sweat on the skin in the channel area is washed into a plastic vial. The developed skin-wash procedure is a single step operation, is completely noninvasive and it always produces a sweat specimen. The ions from the skin-wash are subsequently analyzed by capillary electrophoresis with contactless conductivity detection and selected ion ratio (Cl−/K+) or ((Cl− + Na+)/K+) is used as a cut-off value to diagnose cystic fibrosis patients with sensitivity and specificity comparable to the conventional Macroduct method.
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2
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Koenka IJ, Sáiz J, Rempel P, Hauser PC. Microfluidic Breadboard Approach to Capillary Electrophoresis. Anal Chem 2016; 88:3761-7. [PMID: 26926522 DOI: 10.1021/acs.analchem.5b04666] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A breadboard approach for electrophoretic separations with contactless conductivity detection is presented. This is based on miniature off-the-shelf components such as syringe pumps, valves, and pressure controllers which could be set up in a very compact overall arrangement. It has a high flexibility for different tasks at hand, and the common operations of hydrodynamic injection and capillary flushing are automated. For demonstration of the versatility of the proposition, several very diverse configurations and modes of electrophoresis were successfully implemented, namely, standard capillary zone electrophoresis, pressure assisted zone electrophoresis, the simultaneous separation of cations and anions by dual-capillary zone electrophoresis, the separation of cationic amino acids by isotachophoresis, as well as the separation of small carboxylic acids by gradient elution moving boundary electrophoresis. The system also allows fast separations, as demonstrated by the analysis of six inorganic cations within 35 s. The approach addresses respective limitations of either conventional capillary electrophoresis instruments as well as electrophoretic lab-on-chip devices, while maintaining a performance in terms of detection limits and reproducibility comparable to standard instrumentation.
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Affiliation(s)
- Israel Joel Koenka
- Department of Chemistry, University of Basel , Spitalstrasse 51, 4056 Basel, Switzerland
| | - Jorge Sáiz
- Department of Chemistry, University of Basel , Spitalstrasse 51, 4056 Basel, Switzerland.,Department of Analytical Chemistry, Physical Chemistry and Chemical Engineering, University of Alcalá , Ctra. Madrid-Barcelona Km 33.6, Alcalá de Henares, 28871, Madrid, Spain.,University Institute of Research in Police Sciences (IUICP), University of Alcalá , Ctra. Madrid-Barcelona Km 33.6, 28871 Alcalá de Henares, Madrid, Spain
| | - Paul Rempel
- Department of Chemistry, University of Basel , Spitalstrasse 51, 4056 Basel, Switzerland
| | - Peter C Hauser
- Department of Chemistry, University of Basel , Spitalstrasse 51, 4056 Basel, Switzerland
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Tůma P, Opekar F, Samcová E. Very fast electrophoretic separation on commercial instruments using a combination of two capillaries with different internal diameters. Electrophoresis 2013; 34:552-6. [DOI: 10.1002/elps.201200524] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2012] [Revised: 10/12/2012] [Accepted: 10/12/2012] [Indexed: 12/16/2022]
Affiliation(s)
- Petr Tůma
- Institute of Biochemistry, Cell and Molecular Biology; Third Faculty of Medicine, Charles University in Prague; Prague; Czech Republic
| | - František Opekar
- Department of Analytical Chemistry; Faculty of Science, Charles University in Prague; Prague; Czech Republic
| | - Eva Samcová
- Institute of Biochemistry, Cell and Molecular Biology; Third Faculty of Medicine, Charles University in Prague; Prague; Czech Republic
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4
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Analysis of Reducing Carbohydrates and Fructosyl Saccharides in Maple Syrup and Maple Sugar by CE. Chromatographia 2012. [DOI: 10.1007/s10337-012-2199-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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5
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Chemometrics optimization of carbohydrate separations in six food matrices by micellar electrokinetic chromatography with anionic surfactant. Talanta 2011; 85:237-44. [DOI: 10.1016/j.talanta.2011.03.056] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2011] [Revised: 03/14/2011] [Accepted: 03/23/2011] [Indexed: 11/22/2022]
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6
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Determination of the spectrum of low molecular mass organic acids in urine by capillary electrophoresis with contactless conductivity and ultraviolet photometric detection—An efficient tool for monitoring of inborn metabolic disorders. Anal Chim Acta 2011; 685:84-90. [DOI: 10.1016/j.aca.2010.11.007] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2010] [Revised: 11/01/2010] [Accepted: 11/03/2010] [Indexed: 11/23/2022]
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7
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KrÌÃzÌek T, Breitbach ZS, Armstrong DW, TesarÌová E, Coufal P. Separation of inorganic and small organic anions by CE using phosphonium-based mono- and dicationic reagents. Electrophoresis 2009; 30:3955-63. [DOI: 10.1002/elps.200900416] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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8
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Opekar F, Coufal P, Štulík K. Rapid Capillary Zone Electrophoresis Along Short Separation Pathways and Its Use in Some Hyphenated Systems: A Critical Review. Chem Rev 2009; 109:4487-99. [DOI: 10.1021/cr900018r] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- František Opekar
- Charles University in Prague, Faculty of Science, Department of Analytical Chemistry, Albertov 2030, CZ-128 43 Prague 2, Czech Republic
| | - Pavel Coufal
- Charles University in Prague, Faculty of Science, Department of Analytical Chemistry, Albertov 2030, CZ-128 43 Prague 2, Czech Republic
| | - Karel Štulík
- Charles University in Prague, Faculty of Science, Department of Analytical Chemistry, Albertov 2030, CZ-128 43 Prague 2, Czech Republic
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9
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Bendazzoli C, Turroni S, Gotti R, Olmo S, Brigidi P, Cavrini V. Determination of oxalyl-coenzyme A decarboxylase activity in Oxalobacter formigenes and Lactobacillus acidophilus by capillary electrophoresis. J Chromatogr B Analyt Technol Biomed Life Sci 2007; 854:350-6. [PMID: 17499563 DOI: 10.1016/j.jchromb.2007.04.027] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2007] [Revised: 04/17/2007] [Accepted: 04/20/2007] [Indexed: 11/19/2022]
Abstract
Oxalyl-coenzyme A decarboxylase (OXC) is a key enzyme in the catabolism of the highly toxic oxalate, catalysing the decarboxylation of oxalyl-coenzyme A (Ox-CoA) to formyl-coenzyme A (For-CoA). In the present study, a capillary electrophoretic (CE) method was proposed for the assessment of the activity of recombinant OXC from two bacteria, namely Oxalobacter formigenes DSM 4420 and Lactobacillus acidophilus LA 14. In particular, the degradation of the substrate Ox-CoA occurring in the enzymatic reaction could be monitored by the off-line CE method. A capillary permanently coated with polyethylenimine (PEI) was used and in the presence of a neutral background electrolyte (50 mM phosphate buffer at pH 7.0), a reversal of the electroosmotic flow was obtained. Under these conditions, the anodic migration of Ox-CoA (substrate) and For-CoA (reaction product) occurred and their separation was accomplished in less than 12 min. The CE method was validated for selectivity, linearity (range of Ox-CoA within 0.005-0.650 mM), sensitivity (LOD of 1.5 microM at the detection wavelength of 254 nm), precision and accuracy. Steady state kinetic constants (V(max), K(m) or k') of OXC were finally estimated for both the bacteria showing that although L. acidophilus LA 14 provided a lower oxalate breakdown than O. formigenes DSM 4420, it could be a potentially useful probiotic in the prevention of diseases related to oxalate.
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Affiliation(s)
- Claudia Bendazzoli
- Department of Pharmaceutical Sciences, University of Bologna, Via Belmeloro 6, Bologna 40126, Italy
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10
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Cahours X, Morin P, Dreux M. SUB-MINUTE SEPARATION OF NUCLEOSIDE 5'-TRIPHOSPHATES WITH CO-ELECTROOSMOTIC CAPILLARY ELECTROPHORESIS. J LIQ CHROMATOGR R T 2007. [DOI: 10.1081/jlc-100101809] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- X. Cahours
- a Institut de Chimie Organique et Analytique , CNRS UPRES-A 6005, B. P. 6759, Orléans Cedex 2 , 45067 , France
| | - Ph. Morin
- b Institut de Chimie Organique et Analytique , CNRS UPRES-A 6005, B. P. 6759, Orléans Cedex 2 , 45067 , France
| | - M. Dreux
- a Institut de Chimie Organique et Analytique , CNRS UPRES-A 6005, B. P. 6759, Orléans Cedex 2 , 45067 , France
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Yue ME, Jiang TF, Shi YP. Determination of gallic acid and salidroside in Rhodiola and its preparation by capillary electrophoresis. JOURNAL OF ANALYTICAL CHEMISTRY 2006. [DOI: 10.1134/s1061934806040125] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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12
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Tang ZM, Kang JW. Enzyme Inhibitor Screening by Capillary Electrophoresis with an on-Column Immobilized Enzyme Microreactor Created by an Ionic Binding Technique. Anal Chem 2006; 78:2514-20. [PMID: 16615758 DOI: 10.1021/ac052030w] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
A novel strategy for screening the enzyme inhibitors from the complex mixtures by capillary electrophoresis with an on-column immobilized enzyme microreactor created by an ionic binding technique is reported. The enzyme microreactor was prepared in two steps: First, the capillary wall was dynamically coated with a polycationic electrolyte hexadimethrine bromide (HDB) by simply flushing the column using the HDB solution. Subsequently, a plug of the enzyme solution was injected and incubated for 5 min to permit the enzyme molecules to immobilize on the positively charged coating via ionic binding. To demonstrate this strategy, angiotensin-converting enzyme (ACE) was employed as a model for the enzyme immobilization, inhibition study, and inhibitor screening. It has been proved that such a prepared immobilized ACE microreactor displays a high enough activity and stability. Furthermore, the immobilized enzyme microreactor could be easily renewed. The inhibition study or inhibitor screening was accomplished through the following procedure: (i) the substrate solution was injected and incubated within the microreactor for a short time span; (ii) subsequently, the voltage was applied to separate the product of the enzyme reaction from the unreacted substrate based on their different mobilities, the peak area of the product representing the enzyme activity; (iii) a certain amount of enzyme inhibitor or candidate compound was spiked into the substrate solution to assay the reduction of the immobilized enzyme activity. Thus, the inhibitors can be easily identified if the reduced peak area of the product is observed in electropherograms. Because the injection volume of the capillary was only 9.8 nL and the enzyme could be reusable, the assay cost could be dramatically reduced. The screening of a small compound library containing natural extracts and commercially available inhibitors was performed. The present approach has proved to be simple, rapid, and robust.
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Affiliation(s)
- Zhong-Mei Tang
- Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Fenglin Road 354, Shanghai, 200032, China
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Bianchi F, Careri M, Corradini C. Novel approach for the rapid determination of water-soluble organic acids in wine by co-electroosmotic flow capillary zone electrophoresis. J Sep Sci 2005; 28:898-904. [PMID: 16013815 DOI: 10.1002/jssc.200500046] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
An innovative protocol for the fast analysis of some organic acids in red wine by co-electroosmotic capillary zone electrophoresis and indirect UV detection using hexadimethrine bromide (HDB) as coating agent was proposed. The adsorption of HDB onto the capillary wall provided a stable electroosmotic flow and separation of small anions was carried out using background electrolytes containing no polymer additive. Low RSD% values (<3.6%) in terms of migration times and effective mobilities were obtained from the analysis of a mixture of nitrate and nitrite and of a mixture of organic acids. An experimental design approach was used to investigate the effects of temperature, separation voltage, and percentage of methanol added to the running buffer solution on the separation of the analytes. A faster method allowing the separation of the organic acids involved in the malolactic fermentation of wine was developed. Using a running electrolyte consisting of 35% (v/v) methanol in a solution of 22 mM benzoic acid at pH 6.10 adjusted with 1.0 M TRIS-base buffer, the separation of tartaric, malic, succinic, acetic, and lactic acids was feasible in less than 210 s. Application of the method to the quantification of the above-mentioned organic acids in Italian red wine samples is reported.
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Affiliation(s)
- Federica Bianchi
- Dipartimento di Chimica Generale ed Inorganica, Chimica Analitica, Chimica Fisica, Università degli Studi di Parma, Parco Area delle Scienze 17/A, 1-43100 Parma, Italy
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14
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Rainelli A, Hauser PC. Fast electrophoresis in conventional capillaries by employing a rapid injection device and contactless conductivity detection. Anal Bioanal Chem 2005; 382:789-94. [PMID: 15717171 DOI: 10.1007/s00216-005-3063-1] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2004] [Revised: 12/21/2004] [Accepted: 12/22/2004] [Indexed: 10/25/2022]
Abstract
A purpose-made set-up featuring an automated fast injector allowed the easy optimization of the injected amount and the adjustment of the separation length of conventional capillaries from a minimum of 5 cm upward. It was found that a compromise in capillary length for separation efficiency and analysis time also has to take into account the injected amount, which in turn affects the sensitivity and hence the detection limit. The versatility of the system was demonstrated by the analysis of the major cations and anions in natural water samples in less than 1 min, the concurrent determination of a mixture of amino acids and carbohydrates in 160 s, and of three active ingredients in a pharmaceutical preparation in 40 s. Plate numbers were typically around 50,000 and detection limits down to 1 muM could be achieved.
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Affiliation(s)
- Andrea Rainelli
- Department of Chemistry, University of Basel, Spitalstrasse 51, 4004 Basel, Switzerland
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15
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Trojanowicz M, Poboży E, Gübitz G. Speciation of oxidation states of elements by capillary electrophoresis. J Sep Sci 2003. [DOI: 10.1002/jssc.200301451] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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16
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Pirogov AV, Shpigun OA. Application of water-soluble polymers as modifiers in electrophoretic analysis of phenols. Electrophoresis 2003; 24:2099-2105. [PMID: 12858381 DOI: 10.1002/elps.200305417] [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: 11/07/2022]
Abstract
A review of application of water-soluble cationic, anionic and nonionic polymers as pseudostationary phases in capillary electrophoresis (CE) and micellar electrokinetic capillary chromatography (MEKC) is presented. The effect of the structure of the polymers on the selectivity and efficiency of separation is discussed. A novel specially designed cationic polymer, 2,10-ionene, has been used for the separation of phenols. The polymer has hydrophilic and hydrophobic parts in its backbone. The polymer shows the best selectivity as a modifier in capillary zone electrophoresis (CZE)-mode, which allows the selective determination of both hydrophilic and hydrophobic phenols.
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Gutleben W, Scherer K, Tuan ND, Stoiber H, Dierich MP, Zemann A. Simultaneous separation of 11 protease and reverse transcriptase inhibitors for human immunodeficiency virus therapy by co-electroosmotic capillary zone electrophoresis. J Chromatogr A 2002; 982:153-61. [PMID: 12489864 DOI: 10.1016/s0021-9673(02)01430-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
In the present investigation, a co-electroosmotic capillary zone electrophoretic method is shown for the simultaneous separation of protease inhibitors and reverse transcriptase inhibitors, which are used as antiretroviral therapy drags against the human immunodeficiency virus (HIV). The investigated drugs carry basic amino groups, thus the electrophoretic system takes advantage of an acidic buffer electrolyte. In order to establish a strong cathodic electroosmotic flow (EOF), a poly-anionic surfactant is added to the background electrolyte. Thus, fast migration times due to a co-directional migration of analytes and EOF (co-electroosmotic CE) are obtained. The developed separation system exhibits good selectivities for the investigated compounds and sufficient sensitivity to monitor drug levels in the low ppm range in HIV positive patients who are treated by highly active anitiretroviral therapy.
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Affiliation(s)
- Wolfgang Gutleben
- Institute of Analytical Chemistry and Radiochemistry, Leopold-Franzens-University of Innsbruck, Innrain 52a, A-6020 Innsbruck, Austria
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Pobozy E, Jarczynska M, Trojanowicz M. Speciation of sulfur-containing anions by use of capillary electrophoresis. Chromatographia 2002. [DOI: 10.1007/bf02492474] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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20
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Daunoravicius Z, Padarauskas A. Capillary electrophoretic determination of thiosulfate, sulfide and sulfite using in-capillary derivatization with iodine. Electrophoresis 2002; 23:2439-44. [PMID: 12210200 DOI: 10.1002/1522-2683(200208)23:15<2439::aid-elps2439>3.0.co;2-z] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
A new capillary electrophoresis (CE) method was developed for the rapid, simple and selective determination of thiosulfate, sulfide and sulfite species. The proposed method is based on the in-capillary derivatization of separated sulfur anions by mixing their zones with the iodine zone during the electrophoretic migration and direct UV detection of iodide formed. The optimal conditions for the separation and derivatization reaction were established by varying electrolyte pH, electrolyte counter-ion, concentration of iodine, and applied voltage. The optimized separations were carried out in 20 mmol/L Tris-chloride electrolyte (pH 8.5) using direct UV detection at 214 nm. All three sulfur species were well resolved in less than 4 min. The method gives repeatability comparable or even better than this obtained for sulfur anions using standard CE technique. The proposed CE system was applied to the monitoring of sulfur anions in spent fixing solutions during the electrolytic oxidation.
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Affiliation(s)
- Zydrunas Daunoravicius
- Department of Analytical and Environmental Chemistry, Vilnius University, Vilnius, Lithuania
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21
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Melanson JE, Baryla NE, Lucy CA. Dynamic capillary coatings for electroosmotic flow control in capillary electrophoresis. Trends Analyt Chem 2001. [DOI: 10.1016/s0165-9936(01)00067-x] [Citation(s) in RCA: 98] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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22
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Gogová K, Maichel B, Gas B, Kenndler E. Electrokinetic chromatography with micelles, polymeric and monomeric additives with similar chemical functionality as pseudo-stationary phases. J Chromatogr A 2001; 916:79-87. [PMID: 11382313 DOI: 10.1016/s0021-9673(01)00615-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
A comparison is made of the retention properties of additives applied as positively charged pseudo-stationary phases for electrokinetic chromatography of neutral analytes. All additives have a quaternary ammonium as functional group. The polymeric additive [poly(N,N,N',N'-tetramethyl-N-trimethylenehexamethylenediammonium), Polybrene] has a concentration of 2% (w/w) in the background electrolyte (acetate, pH 5.2). Monomeric octyltrimethylammonium (OTMA) was used at a concentration below or above its critical micelle concentration (CMC) (140 mmol/l). At a concentration (259 mmol/l) above the CMC the system is that normally used for micellar electrokinetic chromatography with cationic micelles. However, even below the CMC, where OTMA is present as monomer, retention of the neutral analytes is observed as well. In all systems coating of the capillary wall with Polybrene establishes an electroosmotic flow directed towards the anode, counter-migrating to the electrophoretic movement of the additive. Based on the measurement of the mobility of the analytes (15 small, monofunctional aromatic compounds with different functional groups), their capacity factors, k(i), were determined in all systems. Low correlation of the k(i) values is observed between the particular systems, indicating their different selectivity at least for individual pairs of analytes. Based on the log k(i) values, a linear free energy relationship was applied to elucidate the main types of chemical interaction responsible for retention. As a result, cavity formation and n or pi electron interactions were found being significant for the micellar OTMA system, which agrees with findings described in the literature for other (cationic and anionic) micellar systems. For the polymeric system and for the monomeric OTMA system, the significant retention parameter is indicating n and pi electron interactions.
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Affiliation(s)
- K Gogová
- Institute for Analytical Chemistry, University of Vienna, Austria
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Klampfl CW, Buchberger W, Haddad PR. Fast separation of pyrimidine derivatives by capillary electrochromatography on ion-exchange/reversed-phase mixed-mode stationary phases. J Chromatogr A 2001; 911:277-83. [PMID: 11293589 DOI: 10.1016/s0021-9673(01)00515-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
This work describes the use of mixed-mode stationary phases which exhibit both strong ion-exchange (either cation-exchange, SCX, or anion-exchange, SAX) and reversed-phase chromatographic characteristics in capillary electrochromatographic separations of pyrimidine derivatives. Different packing materials, namely C6, SCX/C6 and SAX/C6, were compared and the influence of the composition of the carrier electrolyte (concentration of acetonitrile and pH) on the retention behavior of the selected solutes was investigated. A separation of all eight pyrimidine derivatives could be obtained on a 6.5 cm column packed with the SAX/C6 stationary phase in less than 3 min, with good peak shapes and efficiencies in the range 39,000 to 81,000 plates per meter.
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Affiliation(s)
- C W Klampfl
- Department of Analytical Chemistry, Johannes Kepler-University Linz, Austria.
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24
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O’Reilly JW, Dicinoski GW, Shaw MJ, Haddad PR. Chromatographic and electrophoretic separation of inorganic sulfur and sulfur–oxygen species. Anal Chim Acta 2001. [DOI: 10.1016/s0003-2670(00)01389-1] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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25
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Ebber A. Separation of oil shale phenols by capillary zone electrophoresis and micellar electrokinetic chromatography. Chromatographia 2001. [DOI: 10.1007/bf02490347] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Yang WP, O'Flaherty B, Cholli AL. Fast analysis of water samples for detection of anions by capillary zone electrophoresis. JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH. PART A, TOXIC/HAZARDOUS SUBSTANCES & ENVIRONMENTAL ENGINEERING 2001; 36:1271-1285. [PMID: 11545352 DOI: 10.1081/ese-100104877] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
A capillary zone electrophoresis (CZE) method with relatively low separation voltage and short capillary length, using indirect UV detection was developed for the fast and quantitative determination of Cl-, NO2-, SO4(2-), NO3-, F- and HCO3- in potable water samples. Baseline separation of inorganic and organic anions was achieved within 1 min. The optimal carrier electrolyte consisted of 6.0 mM sodium chromate, 2.5 mM CTAB and 3.5% acetonitrile at pH 9.0. The effects of pH and the concentrations of electrolyte and flow modifiers on the resolution were investigated. Two injection methods, gravity and electrokinetic, were compared. The application of electrokinetic injection, using pyroglutamic acid as an internal standard was found to provide a method that is fast, sensitive and quantitative, with an R.S.D. for migration times from 0.1% to 0.3% and for peak areas from 1.8% to 4.1%. The limits of detection were 0.08 mg/L Cl-, 0.3 mg/L NO2-, 0.1 mg/L SO4(2-), 0.1 mg/L NO3-, 0.07 mg/L F-, and 0.3 mg/L HCO3-. This method has been successfully applied to determine Cl-, NO2-, SO4(2-), NO3-, F-, HCO3- in municipal water, surface water and bottled water samples.
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Affiliation(s)
- W P Yang
- Center for Advanced Materials, University of Massachusetts Lowell, 01854, USA
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Hilder EF, Klampfl CW, Haddad PR. Pressurized-flow anion-exchange capillary electrochromatography using a polymeric ion-exchange stationary phase. J Chromatogr A 2000; 890:337-45. [PMID: 11009037 DOI: 10.1016/s0021-9673(00)00612-9] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The feasibility of using capillary columns equipped with silica frits and packed with a polymer-based anion exchanger (Dionex AS9-HC) for CEC separations of inorganic anions has been investigated. Experiments using a conventional 25 cm packed bed, and mobile phase flow that is a combination of hydrodynamic and electroosmotic flow were used to demonstrate that by varying the applied voltage (electrophoresis component) or the concentration of the competing ion in the mobile phase (ion-exchange component), considerable changes in the separation selectivity could be obtained. Using an artificial neural network, this separation system was modelled and the results obtained used to determine the optimum conditions (9 mM perchlorate and--10 kV) for the separation of eight inorganic anions. When a short (8 cm) packed bed was used, with detection immediately following the packed section, the separation of eight test analytes in under 2.2 min was possible using pressure-driven flow and a simple step voltage gradient. A more rapid separation of these analytes was obtained by only applying high voltage (-30 kV), where many of the same analytes were separated in less than 20 s and with a different separation selectivity to that obtained in conventional ion-exchange or capillary electrophoresis separations.
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Affiliation(s)
- E F Hilder
- University of Tasmania, Separation Science Group, School of Chemistry, Australia
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Cahours X, Morin P, Agrofoglio L, Dreux M. Fast Separation of Nucleosides by Capillary Electrochromatography on Non-Endcapped Phenyl-Bonded Silica Phase Using Short-End Injection Method. ACTA ACUST UNITED AC 2000. [DOI: 10.1002/(sici)1521-4168(20000201)23:2<138::aid-jhrc138>3.0.co;2-e] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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30
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Determination of organic acids in air by capillary electrophoresis and ion-exclusion chromatography. Chromatographia 2000. [DOI: 10.1007/bf02492827] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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31
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Harakuwe AH, Haddad PR, Davies NW. Effect of drying on the degradation of cationic surfactants and separation performance in capillary zone electrophoresis of inorganic anions. J Chromatogr A 1999; 863:81-7. [PMID: 10591466 DOI: 10.1016/s0021-9673(99)00952-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Tetradecyltrimethylammonium bromide (TTAB) is used in capillary zone electrophoresis (CZE) to control the direction and magnitude of the electroosmotic flow and the migration time of analyte anions. Drying of the hygroscopic TTAB at 100 degrees C overnight has been found to influence the final CZE separation by providing improved resolution, precision of migration times, and enhanced detection response for hydrogenphosphate. Chemical analysis of the dried TTAB using IR and GC-MS indicated the presence of small amounts of an unexpected tertiary alkylamine, tetradecyldimethylamine. This amine appears to contribute to the improved separation, probably by making more effective the masking of silanophilic activity at the capillary surface and/or generating a more stable double-layer.
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Affiliation(s)
- A H Harakuwe
- Applied Science Department, PNG University of Technology, MP, Papua New Guinea.
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Mayrhofer K, Zemann AJ, Schnell E, Bonn GK. Capillary Electrophoresis and Contactless Conductivity Detection of Ions in Narrow Inner Diameter Capillaries. Anal Chem 1999; 71:3828-33. [DOI: 10.1021/ac990019o] [Citation(s) in RCA: 86] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Karl Mayrhofer
- Institute of Analytical Chemistry and Radiochemistry, Leopold-Franzens-University of Innsbruck, Innrain 52a, A-6020 Innsbruck, Austria
| | - Andreas J. Zemann
- Institute of Analytical Chemistry and Radiochemistry, Leopold-Franzens-University of Innsbruck, Innrain 52a, A-6020 Innsbruck, Austria
| | - Erhard Schnell
- Institute of Analytical Chemistry and Radiochemistry, Leopold-Franzens-University of Innsbruck, Innrain 52a, A-6020 Innsbruck, Austria
| | - Günther K. Bonn
- Institute of Analytical Chemistry and Radiochemistry, Leopold-Franzens-University of Innsbruck, Innrain 52a, A-6020 Innsbruck, Austria
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Abstract
This review deals with the separation mechanisms applied to the separation of inorganic anions by capillary electrophoresis (CE) techniques. It covers various CE techniques that are suitable for the separation and/or determination of inorganic anions in various matrices, including capillary zone electrophoresis, micellar electrokinetic chromatography, electrochromatography and capillary isotachophoresis. Detection and sample preparation techniques used in CE separations are also reviewed. An extensive part of this review deals with applications of CE techniques in various fields (environmental, food and plant materials, biological and biomedical, technical materials and industrial processes). Attention is paid to speciations of anions of arsenic, selenium, chromium, phosphorus, sulfur and halogen elements by CE.
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Affiliation(s)
- D Kaniansky
- Department of Analytical Chemistry, Faculty of Natural Sciences, Comenius University, Bratislava, Slovak Republic
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Sádecká J, Polonský J. Determination of inorganic ions in food and beverages by capillary electrophoresis. J Chromatogr A 1999; 834:401-17. [PMID: 10189696 DOI: 10.1016/s0021-9673(98)00959-5] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
A review of the applications of electrophoresis to the determination of inorganic anions (sulphate, sulphite, phosphate, nitrate, nitrite and halides) and inorganic cations (ammonium, alkali and alkaline metals and trace elements) in food and beverages is presented.
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Affiliation(s)
- J Sádecká
- Department of Analytical Chemistry, Slovak Technical University of Technology, Bratislava, Slovak Republic
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Wätzig H, Degenhardt M, Kunkel A. Strategies for capillary electrophoresis: method development and validation for pharmaceutical and biological applications. Electrophoresis 1998; 19:2695-752. [PMID: 9870372 DOI: 10.1002/elps.1150191603] [Citation(s) in RCA: 157] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
This review is in support of the development of selective, reproducible and validated capillary electrophoretis (CE) methods. Focusing on pharmaceutical and biological applications, the successful use of CE is demonstrated by more than 800 references, mainly from 1994 until 1998. Approximately 80 recent reviews have been catalogued. These articles sum up the existing strategies for method development in CE, especially in the search for generally accepted concepts, but also looking for new, promising reagents and ideas. General strategies for method development were derived not only with regard to selectivity and efficiency, but also with regard to precision, short analysis time, limit of detection, sample pretreatment requirements and validation. Standard buffer recipes, surfactants used in micellar electrokinetic capillary chromatography (MEKC), chiral selectors, useful buffer additives, polymeric separation media, electroosmotic flow (EOF) modifiers, dynamic and permanent coatings, actions to deal with complex matrices and aspects of validation are collected in 20 tables. Detailed schemes for the development of MEKC methods and chiral separations, for optimizing separation efficiency, means of troubleshooting, and other important information for key decisions during method development are given in 19 diagrams. Method development for peptide and protein separations, possibilities to influence the EOF and how to stabilize it, as well as indirect detection are considered in special sections.
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Affiliation(s)
- H Wätzig
- Institut für Pharmazie und Lebensmittelchemie, Würzburg, Germany.
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