1
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Sensitive monitoring of 3-hydroxybutyrate as an indicator of human fasting by capillary electrophoresis in a PAMAMPS coated capillary. Talanta 2022; 247:123582. [DOI: 10.1016/j.talanta.2022.123582] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Revised: 05/19/2022] [Accepted: 05/20/2022] [Indexed: 11/20/2022]
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2
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Capillary and microchip electrophoresis with contactless conductivity detection for analysis of foodstuffs and beverages. Food Chem 2021; 375:131858. [PMID: 34923397 DOI: 10.1016/j.foodchem.2021.131858] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Revised: 11/29/2021] [Accepted: 12/10/2021] [Indexed: 12/17/2022]
Abstract
The paper provides a comprehensive survey of the use of capillary and microchip electrophoresis in combination with contactless conductivity detection (C4D) for the analysis of drinking water, beverages and foodstuffs. The introduction sets forth the fundamentals of conductivity detection anddescribes an axialC4Dversion. There is also a detailed discussion of the determination of inorganic ions, organic acids, fatty acids, amino acids, amines, carbohydrates, foreign substances and poisons from the standpoint of separation conditions, sample treatment and detection limits. Special attention is paid to the analysis of foodstuffs at microchips with emphasis on the employed material and connection of the microchip with the C4D. The review attempts to draw attention to modern trends, such as dual-opposite injection, field-enhanced sample injection, electromembrane extraction and on-line combination of microdialysis with CE. CE/C4D is characterised by high universality, high speed of analysis, simple sample preparation, small consumption of sample and other chemicals.
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3
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Tůma P, Hložek T, Kamišová J, Gojda J. Monitoring of circulating amino acids in patients with pancreatic cancer and cancer cachexia using capillary electrophoresis and contactless conductivity detection. Electrophoresis 2021; 42:1885-1891. [PMID: 34228371 DOI: 10.1002/elps.202100174] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Revised: 07/01/2021] [Accepted: 07/02/2021] [Indexed: 11/12/2022]
Abstract
Branched chain amino acids (BCAAs), alanine and glutamine are determined in human plasma by capillary electrophoresis with contactless conductivity detection (CE/C4 D). The baseline separation of five amino acids from other plasma components is achieved on the short capillary effective length of 18 cm in 3.2 mol/L acetic acid with addition of 13% v/v methanol as background electrolyte. Migration times range from 2.01 min for valine to 2.84 min for glutamine, and LODs for untreated plasma are in the interval 0.7-0.9 μmol/L. Sample treatment is based on the addition of acetonitrile to only 15 μL of plasma and supernatant is directly subjected to CE/C4 D. Circulating amino acids are measured in patients with pancreatic cancer and cancer cachexia during oral glucose tolerance test. It is shown that patients with pancreatic cancer and cancer cachexia syndrome exhibit low basal circulating BCAAs and glutamine levels and loss of their insulin-dependent suppression.
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Affiliation(s)
- Petr Tůma
- Third Faculty of Medicine, Department of Hygiene, Charles University, Prague, Czechia
| | - Tomáš Hložek
- Third Faculty of Medicine, Department of Hygiene, Charles University, Prague, Czechia
| | - Jana Kamišová
- Third Faculty of Medicine, Department of Internal Medicine, Charles University and Královské Vinohrady University Hospital, Prague, Czechia.,Centre for the Research on Diabetes, Metabolism and Nutrition, Third Faculty of Medicine, Prague, Czechia
| | - Jan Gojda
- Third Faculty of Medicine, Department of Internal Medicine, Charles University and Královské Vinohrady University Hospital, Prague, Czechia.,Centre for the Research on Diabetes, Metabolism and Nutrition, Third Faculty of Medicine, Prague, Czechia
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4
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Tůma P, Sommerová B, Koval D, Couderc F. Electrophoretic Determination of Symmetric and Asymmetric Dimethylarginine in Human Blood Plasma with Whole Capillary Sample Injection. Int J Mol Sci 2021; 22:2970. [PMID: 33804011 PMCID: PMC7998904 DOI: 10.3390/ijms22062970] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Revised: 03/09/2021] [Accepted: 03/10/2021] [Indexed: 12/16/2022] Open
Abstract
Asymmetric and symmetric dimethylarginines are toxic non-coded amino acids. They are formed by post-translational modifications and play multifunctional roles in some human diseases. Their determination in human blood plasma is performed using capillary electrophoresis with contactless conductivity detection. The separations are performed in a capillary covered with covalently bonded PAMAPTAC polymer, which generates anionic electroosmotic flow and the separation takes place in the counter-current regime. The background electrolyte is a 750 mM aqueous solution of acetic acid with pH 2.45. The plasma samples for analysis are treated by the addition of acetonitrile and injected into the capillary in a large volume, reaching 94.5% of the total volume of the capillary, and subsequently subjected to electrophoretic stacking. The attained LODs are 16 nm for ADMA and 22 nM for SDMA. The electrophoretic resolution of both isomers has a value of 5.3. The developed method is sufficiently sensitive for the determination of plasmatic levels of ADMA and SDMA. The determination does not require derivatization and the individual steps in the electrophoretic stacking are fully automated. The determined plasmatic levels for healthy individuals vary in the range 0.36-0.62 µM for ADMA and 0.32-0.70 µM for SDMA.
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Affiliation(s)
- Petr Tůma
- Department of Hygiene, Third Faculty of Medicine, Charles University, Ruská 87, 100 00 Prague 10, Czech Republic;
| | - Blanka Sommerová
- Department of Hygiene, Third Faculty of Medicine, Charles University, Ruská 87, 100 00 Prague 10, Czech Republic;
| | - Dušan Koval
- Institute of Organic Chemistry and Biochemistry, The Czech Academy of Sciences, Flemingovo n. 2, 166 10 Prague 6, Czech Republic;
| | - François Couderc
- Laboratoire des IMRCP UMR 5623, University Toulouse III-Paul Sabatier, 31062 Toulouse, France;
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5
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Large volume sample stacking of antiepileptic drugs in counter current electrophoresis performed in PAMAPTAC coated capillary. Talanta 2020; 221:121626. [PMID: 33076153 DOI: 10.1016/j.talanta.2020.121626] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Revised: 09/01/2020] [Accepted: 09/02/2020] [Indexed: 12/22/2022]
Abstract
Electrophoretic stacking is developed for sensitive determination of three zwitterionic antiepileptics, namely vigabatrin, pregabalin and gabapentin, in human serum. CE separation is performed in a 25 μm fused silica capillary covalently coated with the copolymer of acrylamide with 5% content of permanently charged 3-acrylamidopropyl trimethylammonium chloride (PAMAPTAC). In background electrolyte of 500 mM acetic acid, the 5% PAMAPTAC generates an anodic electro-osmotic flow with a magnitude of (-18.6 ± 0.5) · 10-9 m2V-1s-1, which acts against the direction of the electrophoretic migration of the analytes. A sample of the antiepileptic prepared in a 25% v/v infusion solution and 75% v/v acetonitrile is injected into the capillary in a large volume attaining a zone length of up to 270 mm. After turning on the separation voltage, the antiepileptics are isotachophoretically focussed behind the zone of Na+ ions with a sensitivity enhancement factor of 78. For the clinical determination of antiepileptics, the human serum is diluted with acetonitrile in a ratio of 1:3 v/v and a zone with a length of 90 mm is injected into the capillary. The method is linear in the 0.025-2.5 μg/mL concentration range; the attained limit of quantification is in the range 18.3-22.8 nmol/L; the within-day precision for the migration time is 0.8-1.2% and for the peak area 1.5-2.4%.
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6
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Separation of anaesthetic ketamine and its derivates in PAMAPTAC coated capillaries with tuneable counter-current electroosmotic flow. Talanta 2020; 217:121094. [PMID: 32498904 DOI: 10.1016/j.talanta.2020.121094] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2020] [Revised: 04/23/2020] [Accepted: 04/25/2020] [Indexed: 02/06/2023]
Abstract
Capillary electrophoretic separation of ketamine, norketamine, hydroxynorketamine, and dehydronorketamine was performed in the counter-current regime under the influence of oppositely-directed electroosmotic flow. For this purpose, the fused silica capillaries were covalently coated with the poly(acrylamide-co-3-acrylamidopropyl trimethylammonium chloride) copolymer (PAMAPTAC). The content of the cationic monomer APTAC in the polymerization mixture varied in the range 0-6 mol. % and the generated electroosmotic flow increased continuously in the 0-20 · 10-9 m2V-1s-1 interval. Importantly, it resulted in improved electrophoretic resolution of ketamine/norketamine, which increased from 0.8 for neutral PAM coating (i.e. 0% PAMAPTAC) to 3.0 for 6% PAMAPTAC. The determination of ketamine and its derivates in rat serum was performed in a 4% PAMAPTAC capillary with an inner diameter of 25 μm. The separation was performed in a 500 mM aqueous solution of acetic acid (pH 2.3). The clinical sample was deproteinized by the addition of acetonitrile to the serum and a large volume of the treated sample was injected directly into the capillary. The achieved limit of detection ranged from 2.2 ng/mL for dehydronorketamine to 4.1 ng/mL for hydroxynorketamine; the intra-day repeatability was 1.0-1.5% for the migration time and 2.8-3.3% for the peak area. The developed methodology was employed for time monitoring of ketamines in rat serum after intra venous administration of low doses of anaesthetic at a level of 2 μg per g of body weight.
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7
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Tůma P, Sommerová B, Daněček V. On-line coupling of capillary electrophoresis with microdialysis for determining saccharides in dairy products and honey. Food Chem 2020; 316:126362. [PMID: 32050115 DOI: 10.1016/j.foodchem.2020.126362] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Revised: 10/24/2019] [Accepted: 02/04/2020] [Indexed: 12/19/2022]
Abstract
Free sucrose, lactose, galactose, glucose and fructose were determined in yoghurts, milk and honey using on-line coupling of capillary electrophoresis with microdialysis. The dairy products were diluted 50-fold with 10 mmol/L NaOH and sampled using laboratory-made microdialysis probes. The microdialysate was brought to the entrance of the electrophoretic capillary and the coupling consisted in a polydimethylsiloxane (PDMS) cross connector working in the flow-gating interface regime. The electrophoretic analysis was performed in 50 mmol/L NaOH (pH 12.6) background electrolyte, where baseline separation of the five saccharides was achieved in 3.5 min. The LOQs varied in the range 2.3-7.3 mg/L, the number of separation plates varied between 176,000 plates/m for glucose to 326,000 plates/m for galactose and the relative standard deviation (RSD) for ten consecutive analyses of fruit yoghurt was 0.2% for the migration time and 4.4-7.6% for the peak area.
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Affiliation(s)
- Petr Tůma
- Charles University, Third Faculty of Medicine, Department of Hygiene, Ruská 87, 100 00 Prague 10, Czech Republic.
| | - Blanka Sommerová
- Charles University, Third Faculty of Medicine, Department of Hygiene, Ruská 87, 100 00 Prague 10, Czech Republic
| | - Václav Daněček
- Charles University, Third Faculty of Medicine, Department of Biophysics, Ruská 87, 100 00 Prague 10, Czech Republic
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8
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Tůma P, Sommerová B, Vaculín Š. Rapid electrophoretic monitoring of the anaesthetic ketamine and its metabolite norketamine in rat blood using a contactless conductivity detector to study the pharmacokinetics. J Sep Sci 2019; 42:2062-2068. [PMID: 30938060 DOI: 10.1002/jssc.201900116] [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: 01/28/2019] [Revised: 03/28/2019] [Accepted: 03/28/2019] [Indexed: 01/23/2023]
Abstract
A method of capillary electrophoresis with contactless conductivity detection has been developed for non-enantioselective monitoring the anaesthetic ketamine and its main metabolite norketamine. The separation is performed in a 15 μm capillary with an overall length of 31.5 cm and length to detector of 18 cm; inner surface of the capillary is covered with a commercial coating solution to reduce the electroosmotic flow. In an optimised background electrolyte with composition 2 M acetic acid + 1% v/v coating solution under application of a high voltage of 30 kV, the migration time is 97.1 s for ketamine and 95.8 s for norketamine, with an electrophoretic resolution of 1.2. The attained detection limit was 83 ng/mL (0.3 μmol/L) for ketamine and 75 ng/mL (0.3 μmol/L) for norketamine; the number of theoretic plates for separation of an equimolar model mixture with a concentration of 2 μg/mL was 683 500 plates/m for ketamine and 695 400 plates/m for norketamine. Laboratory preparation of rat blood plasma is based on mixing 10 μL of plasma with 30 μL of acidified acetonitrile, followed by centrifugation. A pharmacokinetic study demonstrated an exponential decrease in the plasma concentration of ketamine after intravenous application and much slower kinetics for intraperitoneal application.
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Affiliation(s)
- Petr Tůma
- Department of Hygiene, Third Faculty of Medicine, Charles University, Prague, Czechia
| | - Blanka Sommerová
- Department of Hygiene, Third Faculty of Medicine, Charles University, Prague, Czechia
| | - Šimon Vaculín
- Department of Physiology, Third Faculty of Medicine, Charles University, Prague, Czechia
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9
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Selective capillary electrophoresis separation of mono and divalent cations within a high-surface area-to-volume ratio multi-lumen capillary. Anal Chim Acta 2019; 1051:41-48. [DOI: 10.1016/j.aca.2018.11.033] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2018] [Revised: 11/14/2018] [Accepted: 11/15/2018] [Indexed: 12/16/2022]
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10
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Tůma P, Sommerová B, Šiklová M. Monitoring of adipose tissue metabolism using microdialysis and capillary electrophoresis with contactless conductivity detection. Talanta 2019; 192:380-386. [DOI: 10.1016/j.talanta.2018.09.076] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Revised: 09/19/2018] [Accepted: 09/20/2018] [Indexed: 02/02/2023]
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11
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Furter JS, Hauser PC. Injection system for fast capillary electrophoresis based on pressure regulation with flow restrictors. Electrophoresis 2018; 40:410-413. [DOI: 10.1002/elps.201800250] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2018] [Revised: 08/21/2018] [Accepted: 08/22/2018] [Indexed: 11/05/2022]
Affiliation(s)
| | - Peter C. Hauser
- Department of Chemistry; University of Basel; Basel Switzerland
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12
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Direct sample injection from a syringe needle into a separation capillary. Anal Chim Acta 2018; 1042:133-140. [PMID: 30428980 DOI: 10.1016/j.aca.2018.07.026] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Revised: 07/05/2018] [Accepted: 07/10/2018] [Indexed: 11/22/2022]
Abstract
An automatic micro-injector was developed for electrophoretic analysis of a microlitre amount of clinical samples, enabling injection of the sample from a Hamilton syringe. The outlet of the syringe needle is located directly opposite the inlet of the separation capillary at a defined distance of the order of hundreds of μm in the injection space. During the injection, the background electrolyte is forced out by air from this space and a drop of the sample is forced out of the syringe by a micro-pump so that it is caught at the entrance to the capillary. From the drop the sample is injected into the capillary by applying a negative pressure pulse or simply by spontaneous injection. The injection space is then filled with background electrolyte, which washes away excess sample and separation is commenced. The injector was tested in electrophoretic separation of a model sample with equimolar concentrations of 100 μM NH4+, K+, Na+, Mg2+ and Li+ in a short capillary with total/effective length of 16.5/11.5 cm. The repeatability of the migration time and peak area expressed as the RSD value is 2% and 4%, respectively. The practical applicability of the injector was verified on the determination of the antiparasitic pentamidine in 10 μL of rat plasma. Electrophoretic separation of pentamidine was performed in 100 mM of acetic acid/NaOH at pH 4.55, the sample consumption per analysis is 125 nL, the separation time is 45 s and the attained LOQ using contactless conductivity detection is 8 μM.
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13
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20th anniversary of axial capacitively coupled contactless conductivity detection in capillary electrophoresis. Trends Analyt Chem 2018. [DOI: 10.1016/j.trac.2018.03.007] [Citation(s) in RCA: 78] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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14
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Pavlíček V, Tůma P. The use of capillary electrophoresis with contactless conductivity detection for sensitive determination of stevioside and rebaudioside A in foods and beverages. Food Chem 2017; 219:193-198. [DOI: 10.1016/j.foodchem.2016.09.135] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2015] [Revised: 08/02/2016] [Accepted: 09/21/2016] [Indexed: 10/21/2022]
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15
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Tůma P. Frequency-tuned contactless conductivity detector for the electrophoretic separation of clinical samples in capillaries with very small internal dimensions. J Sep Sci 2017; 40:940-947. [PMID: 27995764 DOI: 10.1002/jssc.201601213] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2016] [Revised: 11/19/2016] [Accepted: 11/28/2016] [Indexed: 12/27/2022]
Abstract
An axial design of a capacitively coupled contactless conductivity detector was tested in combination with fused-silica capillaries with internal diameters of 10, 15, and 25 μm, which are used for high-efficiency electrophoretic separation. The transmission of the signal in the detection probe dependent on the specific conductivity of the solution in the capillary in the range 0-278 mS.m-1 has a complex character and a minimum appears on the curve at very low conductivities. The position of the minimum of the calibration dependence gradually shifts with decreasing frequency of the exciting signal from 1.0 to 0.25 MHz toward lower specific conductivity values. The presence of a minimum on the calibration curves is a natural property of the axial design of contactless conductivity detector, demonstrated by solution of the equivalent electrical circuit of the detection probe, and is specifically caused by the use of shielding foil. The behavior of contactless conductivity detector in the vicinity of the minimum was documented for practical separations of amino acids in solutions of 3.2 M acetic acid with addition of 0-50% v/v methanol.
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Affiliation(s)
- Petr Tůma
- Department of Biochemistry, Cell and Molecular Biology, Third Faculty of Medicine, Charles University, Prague, Czech Republic
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16
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Zhang M, Stamos BN, Amornthammarong N, Dasgupta PK. Capillary Scale Admittance Detection. Anal Chem 2014; 86:11538-46. [DOI: 10.1021/ac503245a] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Min Zhang
- Department of Chemistry and
Biochemistry, The University of Texas at Arlington, Arlington, Texas 76019-0065, United States
| | - Brian N. Stamos
- Department of Chemistry and
Biochemistry, The University of Texas at Arlington, Arlington, Texas 76019-0065, United States
| | - Natchanon Amornthammarong
- Department of Chemistry and
Biochemistry, The University of Texas at Arlington, Arlington, Texas 76019-0065, United States
| | - Purnendu K. Dasgupta
- Department of Chemistry and
Biochemistry, The University of Texas at Arlington, Arlington, Texas 76019-0065, United States
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17
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Determination of artificial sweeteners by capillary electrophoresis with contactless conductivity detection optimized by hydrodynamic pumping. Anal Chim Acta 2013; 787:254-9. [PMID: 23830447 DOI: 10.1016/j.aca.2013.05.039] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2013] [Revised: 05/16/2013] [Accepted: 05/23/2013] [Indexed: 11/22/2022]
Abstract
The common sweeteners aspartame, cyclamate, saccharin and acesulfame K were determined by capillary electrophoresis with contactless conductivity detection. In order to obtain the best compromise between separation efficiency and analysis time hydrodynamic pumping was imposed during the electrophoresis run employing a sequential injection manifold based on a syringe pump. Band broadening was avoided by using capillaries of a narrow 10 μm internal diameter. The analyses were carried out in an aqueous running buffer consisting of 150 mM 2-(cyclohexylamino)ethanesulfonic acid and 400 mM tris(hydroxymethyl)aminomethane at pH 9.1 in order to render all analytes in the fully deprotonated anionic form. The use of surface modification to eliminate or reverse the electroosmotic flow was not necessary due to the superimposed bulk flow. The use of hydrodynamic pumping allowed easy optimization, either for fast separations (80s) or low detection limits (6.5 μmol L(-1), 5.0 μmol L(-1), 4.0 μmol L(-1) and 3.8 μmol L(-1) for aspartame, cyclamate, saccharin and acesulfame K respectively, at a separation time of 190 s). The conditions for fast separations not only led to higher limits of detection but also to a narrower dynamic range. However, the settings can be changed readily between separations if needed. The four compounds were determined successfully in food samples.
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18
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Mai TD, Hauser PC. Study on the interrelated effects of capillary diameter, background electrolyte concentration, and flow rate in pressure assisted capillary electrophoresis with contactless conductivity detection. Electrophoresis 2013; 34:1796-803. [DOI: 10.1002/elps.201200586] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2012] [Revised: 11/27/2012] [Accepted: 11/27/2012] [Indexed: 11/11/2022]
Affiliation(s)
| | - Peter C. Hauser
- Department of Chemistry; University of Basel; Spitalstrasse; Basel; Switzerland
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19
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Tůma P, Opekar F, Samcová E, Štulík K. The use of a multichannel capillary for electrophoretic separations of mixtures of clinically important substances with contactless conductivity and UV photometric detection. Electrophoresis 2013; 34:2058-64. [DOI: 10.1002/elps.201200498] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2012] [Revised: 10/16/2012] [Accepted: 10/17/2012] [Indexed: 11/10/2022]
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
| | - Karel Štulík
- Department of Analytical Chemistry, Faculty of Science; Charles University in Prague; Prague; Czech Republic
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20
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Kubáň P, Hauser PC. Contactless conductivity detection for analytical techniques: Developments from 2010 to 2012. Electrophoresis 2012; 34:55-69. [DOI: 10.1002/elps.201200358] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2012] [Revised: 08/08/2012] [Accepted: 08/09/2012] [Indexed: 11/08/2022]
Affiliation(s)
- Pavel Kubáň
- Institute of Analytical Chemistry of the Academy of Sciences of the Czech Republic; Brno; Czech Republic
| | - Peter C. Hauser
- Department of Chemistry; University of Basel; Basel; Switzerland
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21
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Qiao L, Sartor R, Gasilova N, Lu Y, Tobolkina E, Liu B, Girault HH. Electrostatic-Spray Ionization Mass Spectrometry. Anal Chem 2012; 84:7422-30. [DOI: 10.1021/ac301332k] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Liang Qiao
- Laboratoire d’Electrochimie Physique
et Analytique, Ecole Polytechnique Fédérale de Lausanne, Station 6, CH-1015 Lausanne, Switzerland
| | - Romain Sartor
- Laboratoire d’Electrochimie Physique
et Analytique, Ecole Polytechnique Fédérale de Lausanne, Station 6, CH-1015 Lausanne, Switzerland
| | - Natalia Gasilova
- Laboratoire d’Electrochimie Physique
et Analytique, Ecole Polytechnique Fédérale de Lausanne, Station 6, CH-1015 Lausanne, Switzerland
| | - Yu Lu
- Laboratoire d’Electrochimie Physique
et Analytique, Ecole Polytechnique Fédérale de Lausanne, Station 6, CH-1015 Lausanne, Switzerland
| | - Elena Tobolkina
- Laboratoire d’Electrochimie Physique
et Analytique, Ecole Polytechnique Fédérale de Lausanne, Station 6, CH-1015 Lausanne, Switzerland
| | - Baohong Liu
- Department of Chemistry, Institute
of Biomedical Sciences, Fudan University, Shanghai, 200433, P.R. China
| | - Hubert H. Girault
- Laboratoire d’Electrochimie Physique
et Analytique, Ecole Polytechnique Fédérale de Lausanne, Station 6, CH-1015 Lausanne, Switzerland
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22
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Mark JJP, Scholz R, Matysik FM. Electrochemical methods in conjunction with capillary and microchip electrophoresis. J Chromatogr A 2012; 1267:45-64. [PMID: 22824222 DOI: 10.1016/j.chroma.2012.07.009] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2012] [Revised: 07/01/2012] [Accepted: 07/06/2012] [Indexed: 02/06/2023]
Abstract
Electromigrative techniques such as capillary and microchip electrophoresis (CE and MCE) are inherently associated with various electrochemical phenomena. The electrolytic processes occurring in the buffer reservoirs have to be considered for a proper design of miniaturized electrophoretic systems and a suitable selection of buffer composition. In addition, the control of the electroosmotic flow plays a crucial role for the optimization of CE/MCE separations. Electroanalytical methods have significant importance in the field of detection in conjunction with CE/MCE. At present, amperometric detection and contactless conductivity detection are the predominating electrochemical detection methods for CE/MCE. This paper reviews the most recent trends in the field of electrochemical detection coupled to CE/MCE. The emphasis is on methodical developments and new applications that have been published over the past five years. A rather new way for the implementation of electrochemical methods into CE systems is the concept of electrochemically assisted injection which involves the electrochemical conversions of analytes during the injection step. This approach is particularly attractive in hyphenation to mass spectrometry (MS) as it widens the range of CE-MS applications. An overview of recent developments of electrochemically assisted injection coupled to CE is presented.
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Affiliation(s)
- Jonas J P Mark
- Institute of Analytical Chemistry, Chemo- and Biosensors, University of Regensburg, Regensburg, Germany
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Elbashir AA, Aboul-Enein HY. Recent advances in applications of capillary electrophoresis with capacitively coupled contactless conductivity detection (CE-C⁴D): an update. Biomed Chromatogr 2012; 26:990-1000. [PMID: 22430262 DOI: 10.1002/bmc.2729] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2012] [Accepted: 02/12/2012] [Indexed: 11/06/2022]
Abstract
Capillary electrophoresis with a capacitively contactless conductivity detector (CE-C⁴D) is becoming a significant useful technique for the analysis of analytes in various fields such as pharmaceutical, biomedical, food and environmental. This review is an update describing the recent developments in the application of CE with a C⁴D detector.
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