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Li L, Song YP, Ren DD, Li TX, Gao MH, Zhou L, Zeng ZC, Pu QA. A compact and high-performance setup of capillary electrophoresis with capacitively coupled contactless conductivity detection (CE-C 4D). Analyst 2024; 149:3034-3040. [PMID: 38624147 DOI: 10.1039/d4an00354c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/17/2024]
Abstract
Capillary electrophoresis with capacitively coupled contactless conductivity detection (CE-C4D) has the advantages of high throughput (simultaneous detection of multiple ions), high separation efficiency (higher than 105 theoretical plates) and rapid analysis capability (less than 5 min for common inorganic ions). A compact CE-C4D system is ideal for water quality control and on-site analysis. It is suitable not only for common cations (e.g. Na+, K+, Li+, NH4+, Ca2+, etc.) and anions (e.g. Cl-, SO42-, BrO3-, etc.) but also for some ions (e.g. lanthanide ions, Pb2+, Cd2+, etc.) that require complex derivatization procedures to be detected by ion chromatography (IC). However, an obvious limitation of the CE-C4D method is that its sensitivity (e.g. 0.3-1 μM for common inorganic ions) is often insufficient for trace analysis (e.g. 1 ppb or 20 nM level for common inorganic ions) without preconcentration. For this technology to become a powerful and routine analytical technique, the system should be made compact while maintaining trace analysis sensitivity. In this study, we developed an all-in-one version of the CE-C4D instrument with custom-made modular components to make it a convenient, compact and high-performance system. The system was designed using direct digital synthesis (DDS) technology to generate programmable sinusoidal waveforms with any frequency for excitation, a kilovolt high-voltage power supply for capillary electrophoresis separation, and an "effective" differential C4D cell with a low-noise circuitry for high-sensitivity detection. We characterized the system with different concentrations of Cs+, and even a low concentration of 20 nM was detectable without preconcentration. Moreover, the optimized CE-C4D setup was applied to analyse mixed ions at a trace concentration of 200 nM with excellent signal-to-noise ratios. In typical applications, the limits of detection based on the 3σ criterion (without baseline filtering) were 9, 10, 24, 5, and 12 nM for K+, Cs+, Li+, Ca2+, and Mg2+, respectively, and about 7, 6, 6 and 6 nM for Br-, ClO4-, BrO3- and SO42-, respectively. Finally, the setup was also applied for the analysis of all 14 lanthanide ions and rare-earth minerals, and it showed an improvement in sensitivity by more than 25 times.
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Affiliation(s)
- Lin Li
- State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, China.
| | - Yun-Peng Song
- State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, China.
| | - Dou-Dou Ren
- State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, China.
| | - Tang-Xiu Li
- State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, China.
| | - Ming-Hui Gao
- State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, China.
| | - Lei Zhou
- State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, China.
| | - Zhi-Cong Zeng
- State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, China.
| | - Qi-Aosheng Pu
- State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, China.
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Adımcılar V, Saygılı MT, Cansever MŞ, Öztekin N. Highly sensitive rapid determination of orotic acid in urine samples using a field-amplified sample stacking approach in capillary electrophoresis coupled with contactless conductivity detection. J Pharm Biomed Anal 2024; 238:115826. [PMID: 37922673 DOI: 10.1016/j.jpba.2023.115826] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2023] [Revised: 10/25/2023] [Accepted: 10/26/2023] [Indexed: 11/07/2023]
Abstract
Orotic aciduria is a severe, hereditary, life-threatening condition, particularly in newborns. An increased orotic acid (OA) content in urine may be a strong indicator of this condition. In this study, we developed a rapid, simple, highly sensitive diagnostic method for use in monitoring the OA levels in urine samples, which were successfully determined using capillary electrophoresis combined with capacitively coupled contactless conductivity detection (CE-C4D). A straightforward analysis with an increased sensitivity towards OA and an analysis time of approximately 5 min were realized, and the limit of detection of the developed method was 0.014 mg/L in aqueous solution. The optimized composition of the separation electrolyte was 20 mM 2-(N-morpholino)ethanesulfonic acid/histidine with 0.1 mM cetyltrimethylammonium bromide at a pH of 6.5. The sensitivity of the developed method was significantly increased using a sample stacking approach with a 10% acetonitrile (v/v) plug solution. The method was validated, and satisfactory recoveries of 80.0-92.3% were obtained. The amounts of OA in five urine samples were successfully determined.
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Affiliation(s)
- Veselina Adımcılar
- Istanbul Technical University, Department of Chemistry, Maslak, 34469 Istanbul, Türkiye
| | - Merve Taşer Saygılı
- Istanbul Technical University, Department of Chemistry, Maslak, 34469 Istanbul, Türkiye
| | - Mehmet Şerif Cansever
- Department of Medical Services and Techniques, Vocational School of Health Services, Istanbul University-Cerrahpaşa, 34265 Istanbul, Türkiye
| | - Nevin Öztekin
- Istanbul Technical University, Department of Chemistry, Maslak, 34469 Istanbul, Türkiye.
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3
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Niezen LE, Bos TS, Schoenmakers PJ, Somsen GW, Pirok BWJ. Capacitively coupled contactless conductivity detection to account for system-induced gradient deformation in liquid chromatography. Anal Chim Acta 2023; 1271:341466. [PMID: 37328247 DOI: 10.1016/j.aca.2023.341466] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Revised: 05/12/2023] [Accepted: 05/31/2023] [Indexed: 06/18/2023]
Abstract
The time required for method development in gradient-elution liquid chromatography (LC) may be reduced by using an empirical modelling approach to describe and predict analyte retention and peak width. However, prediction accuracy is impaired by system-induced gradient deformation, which can be especially prominent for steep gradients. As the deformation is unique to each LC instrument, it needs to be corrected for if retention modelling for optimization and method transfer is to become generally applicable. Such a correction requires knowledge of the actual gradient profile. The latter has been measured using capacitively coupled "contactless" conductivity detection (C4D), featuring a low detection volume (approximately 0.05 μL) and compatibility with very high pressures (80 MPa or more). Several different solvent gradients, from water to acetonitrile, water to methanol, and acetonitrile to tetrahydrofuran, could be measured directly without the addition of a tracer component to the mobile phase, exemplifying the universal nature of the approach. Gradient profiles were found to be unique for each solvent combination, flowrate, and gradient duration. The profiles could be described by convoluting the programmed gradient with a weighted sum of two distribution functions. Knowledge of the exact profiles was used to improve the inter-system transferability of retention models for toluene, anthracene, phenol, emodin, sudan-I and several polystyrene standards.
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Affiliation(s)
- Leon E Niezen
- Analytical-Chemistry Group, van 't Hoff Institute for Molecular Sciences, Faculty of Science, University of Amsterdam, Science Park 904, 1098 XH, Amsterdam, the Netherlands; Centre for Analytical Sciences Amsterdam (CASA), the Netherlands
| | - Tijmen S Bos
- Centre for Analytical Sciences Amsterdam (CASA), the Netherlands; Division of Bioanalytical Chemistry, Amsterdam Institute of Molecular and Life Sciences, Vrije Universiteit Amsterdam, De Boelelaan 1085, 1081 HV, Amsterdam, the Netherlands
| | - Peter J Schoenmakers
- Analytical-Chemistry Group, van 't Hoff Institute for Molecular Sciences, Faculty of Science, University of Amsterdam, Science Park 904, 1098 XH, Amsterdam, the Netherlands; Centre for Analytical Sciences Amsterdam (CASA), the Netherlands
| | - Govert W Somsen
- Centre for Analytical Sciences Amsterdam (CASA), the Netherlands; Division of Bioanalytical Chemistry, Amsterdam Institute of Molecular and Life Sciences, Vrije Universiteit Amsterdam, De Boelelaan 1085, 1081 HV, Amsterdam, the Netherlands
| | - Bob W J Pirok
- Analytical-Chemistry Group, van 't Hoff Institute for Molecular Sciences, Faculty of Science, University of Amsterdam, Science Park 904, 1098 XH, Amsterdam, the Netherlands; Centre for Analytical Sciences Amsterdam (CASA), the Netherlands.
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4
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Development of a Contactless Conductivity Sensor in Flowing Micro Systems for Cerium Nitrate. Processes (Basel) 2022. [DOI: 10.3390/pr10102075] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Impedance spectroscopy has a high potential to detect chemical reactions in flowing systems. In this work, the approach using impedance spectroscopy as a possible analytical tool for a continuous hydrothermal syntheses (CHTS) is presented. With the CHTS-process, it is possible to produce metalloxide nanoparticles with a close particle size distribution and specific surface properties. For this, it is necessary to evaluate the electrode geometry, frequency and other factors influencing the impedance with respect to concentration measurements. In case of frequency-sweep measurements possible electrode geometries for C4D-Sensors (capacitively coupled contactless conductivity detection) are evaluated. Then distinguishability and reproducibility are tested applying titration measurements to show the ability for concentration detection in constant flow systems. The possibility to measure concentration changes in flowing systems in a reproducible and fast manner as well as with high distinguishability for the test solution cerium nitrate will be presented. Furthermore, the major influencing-factors like electrode geometry, frequency etc. could be determined. It has been shown that with increasing electrode spacing and electrode width, the distinguishability of the concentrations increases and shifts them to lower frequencies.
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Tůma P. Monitoring of biologically active substances in clinical samples by capillary and microchip electrophoresis with contactless conductivity detection: A review. Anal Chim Acta 2022; 1225:340161. [DOI: 10.1016/j.aca.2022.340161] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Revised: 07/08/2022] [Accepted: 07/08/2022] [Indexed: 12/11/2022]
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A Novel Planar Grounded Capacitively Coupled Contactless Conductivity Detector for Microchip Electrophoresis. MICROMACHINES 2022; 13:mi13030394. [PMID: 35334684 PMCID: PMC8953769 DOI: 10.3390/mi13030394] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/30/2022] [Revised: 02/19/2022] [Accepted: 02/25/2022] [Indexed: 11/30/2022]
Abstract
In the microchip electrophoresis with capacitively coupled contactless conductivity detection, the stray capacitance of the detector causes high background noise, which seriously affects the sensitivity and stability of the detection system. To reduce the effect, a novel design of planar grounded capacitively coupled contactless conductivity detector (PG-C4D) based on printed circuit board (PCB) is proposed. The entire circuit plane except the sensing electrodes is covered by the ground electrode, greatly reducing the stray capacitance. The efficacy of the design has been verified by the electrical field simulation and the electrophoresis detection experiments of inorganic ions. The baseline intensity of the PG-C4D was less than 1/6 of that of the traditional C4D. The PG-C4D with the new design also demonstrated a good repeatability of migration time, peak area, and peak height (n = 5, relative standard deviation, RSD ≤ 0.3%, 3%, and 4%, respectively), and good linear coefficients within the range of 0.05–0.75 mM (R2 ≥ 0.986). The detection sensitivity of K+, Na+, and Li+ reached 0.05, 0.1, and 0.1 mM respectively. Those results prove that the new design is an effective and economical approach which can improve sensitivity and repeatability of a PCB based PG-C4D, which indicate a great application potential in agricultural and environmental monitoring.
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Liénard-Mayor T, Yang B, Tran NT, Bruneel A, Guttman A, Taverna M, Mai TD. High sensitivity capillary electrophoresis with fluorescent detection for glycan mapping. J Chromatogr A 2021; 1657:462593. [PMID: 34689907 DOI: 10.1016/j.chroma.2021.462593] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Revised: 09/22/2021] [Accepted: 09/28/2021] [Indexed: 11/16/2022]
Abstract
We present in this study a novel strategy to drastically improve the detection sensitivity and peak capacity for capillary electrophoresis with laser induced fluorescent detection (CE-LIF) of glucose oligomers and released glycans. This is based on a new approach exploiting a polymer-free background electrolyte (BGE) for CE-LIF of glycans. The best performance in terms of sample stacking and suppression of electroosmotic flow (EOF) was found for a BGE composed of triethanolamine/citric acid and triethanolamine/acetic acid at elevated ionic strengths (IS up to 200 mM). Compared to the conventional protocols for CE-LIF of glucose-oligosaccharides and released glycans, our polymer-free strategy offered up to 5-fold improvement of detection sensitivity and visualization of higher degree of polymerization (DP) of glucose oligomers (18 vs 15). To further improve the detection sensitivity, a new electrokinetic preconcentration strategy via large volume sample stacking with electroosmotic modulation without having recourse to neutrally coated capillaries is proposed, offering a 200-fold signal enhancement. This approach is based on variation of the buffer's IS, rather than pH adjustment as in conventional methods, for EOF modulation or quasi-total reduction. This strategy allows selecting with high flexibility the best pH conditions to perform efficient preconcentration and separation. The new approach was demonstrated to be applicable for the analysis of N-linked oligosaccharides released from a model glycoprotein (Human Immunoglobulin G) and applied to map N-glycans from human serum for congenital disorders of glycosylation (CDG) diagnosis.
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Affiliation(s)
- Théo Liénard-Mayor
- Institut Galien Paris Sud, UMR 8612, Protein and Nanotechnology in Analytical Science (PNAS), CNRS, Univ. Paris-Sud, Univ. Paris-Saclay, 5 rue Jean Baptiste Clément, 92290 Châtenay-Malabry, France
| | - Bin Yang
- Institut Galien Paris Sud, UMR 8612, Protein and Nanotechnology in Analytical Science (PNAS), CNRS, Univ. Paris-Sud, Univ. Paris-Saclay, 5 rue Jean Baptiste Clément, 92290 Châtenay-Malabry, France
| | - Nguyet Thuy Tran
- Institut Galien Paris Sud, UMR 8612, Protein and Nanotechnology in Analytical Science (PNAS), CNRS, Univ. Paris-Sud, Univ. Paris-Saclay, 5 rue Jean Baptiste Clément, 92290 Châtenay-Malabry, France
| | - Arnaud Bruneel
- Université Paris-Saclay, INSERM UMR1193, Mécanismes cellulaires et moléculaires de l'adaptation au stress et cancérogenèse, Châtenay-Malabry, France; AP-HP, Biochimie Métabolique et Cellulaire, Hôpital Bichat-Claude Bernard, Paris, France
| | - Andras Guttman
- Translational Glycomics Research Group, Research Institute of Biomolecular and Chemical Engineering, University of Pannonia, 10 Egyetem Street, Veszprem 8200, Hungary; Horváth Csaba Laboratory of Bioseparation Sciences, Research Centre for Molecular Medicine, Faculty of Medicine, University of Debrecen, 98 Nagyerdei Krt, Debrecen, 4032, Hungary
| | - Myriam Taverna
- Institut Galien Paris Sud, UMR 8612, Protein and Nanotechnology in Analytical Science (PNAS), CNRS, Univ. Paris-Sud, Univ. Paris-Saclay, 5 rue Jean Baptiste Clément, 92290 Châtenay-Malabry, France; Institut Universitaire de France (IUF)
| | - Thanh Duc Mai
- Institut Galien Paris Sud, UMR 8612, Protein and Nanotechnology in Analytical Science (PNAS), CNRS, Univ. Paris-Sud, Univ. Paris-Saclay, 5 rue Jean Baptiste Clément, 92290 Châtenay-Malabry, France.
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8
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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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9
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Hata K, Nonaka N, Sato N, Kaneta T. Simultaneous separation of 17 anions by capillary electrophoresis with the addition of an organic solvent. Electrophoresis 2021; 42:1317-1322. [PMID: 33724495 DOI: 10.1002/elps.202100014] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Revised: 03/09/2021] [Accepted: 03/10/2021] [Indexed: 11/06/2022]
Abstract
Seventeen inorganic and organic anions, that normally are insufficiently separated via ion chromatography, were completely separated by the addition of an organic solvent to a solution of BGE combined with an adjustment of the apparent pH via CE in combination with indirect UV absorbance detection. Methanol, ethanol, and acetonitrile were examined for their utility in manipulating the selective separation of anions. Methanol and acetonitrile were better modifiers than ethanol at enhancing the resolution of anions comigrating in an aqueous solution of BGE. Methanol was selected as the modifier that provided the largest separation window that could achieve a complete separation of the target analytes. Via the use of methanol, manipulation of the selectivity between inorganic anions and that between inorganic and organic anions was enhanced, but the separation between organic anions remained difficult when only methanol was used. By varying the apparent pH of the BGE in the presence of 10% v/v methanol, however, the separation selectivity between organic anions was substantially improved. Eventually, 7 inorganic and 10 organic anions were simultaneously separated using BGE at a pH of 6.3 in the presence of 10% v/v methanol.
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Affiliation(s)
- Kazuki Hata
- Inorganic Analysis Laboratories, Toray Research Center, Inc., Otsu, Shiga, Japan
| | - Noriko Nonaka
- Inorganic Analysis Laboratories, Toray Research Center, Inc., Otsu, Shiga, Japan
| | - Nobuyuki Sato
- Inorganic Analysis Laboratories, Toray Research Center, Inc., Otsu, Shiga, Japan
| | - Takashi Kaneta
- Department of Chemistry, Graduate School of Natural Science and Technology, Okayama University, Okayama, Okayama, Japan
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10
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Nguyen TD, Vu MT, Nguyen MH, Duong HA, Mai TD, Pham HV. A Rapid and Simple Dual-Channeled Capillary Electrophoresis with Contactless Conductivity Detection Method for the Determination of Adenosine, Cordycepin, and Inosine in Ophiocordyceps sinensis-Based Products. FOOD ANAL METHOD 2021. [DOI: 10.1007/s12161-021-02003-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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11
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Development of a Mobile Analytical Chemistry Workstation Using a Silicon Electrochromatography Microchip and Capacitively Coupled Contactless Conductivity Detector. MICROMACHINES 2021; 12:mi12030239. [PMID: 33673410 PMCID: PMC7996726 DOI: 10.3390/mi12030239] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 02/08/2021] [Accepted: 02/20/2021] [Indexed: 11/16/2022]
Abstract
Capillary electrochromatography (CEC) is a separation technique that hybridizes liquid chromatography (LC) and capillary electrophoresis (CE). The selectivity offered by LC stationary phase results in rapid separations, high efficiency, high selectivity, minimal analyte and buffer consumption. Chip-based CE and CEC separation techniques are also gaining interest, as the microchip can provide precise on-chip control over the experiment. Capacitively coupled contactless conductivity detection (C4D) offers the contactless electrode configuration, and thus is not in contact with the solutions under investigation. This prevents contamination, so it can be easy to use as well as maintain. This study investigated a chip-based CE/CEC with C4D technique, including silicon-based microfluidic device fabrication processes with packaging, design and optimization. It also examined the compatibility of the silicon-based CEC microchip interfaced with C4D. In this paper, the authors demonstrated a nanofabrication technique for a novel microchip electrochromatography (MEC) device, whose capability is to be used as a mobile analytical equipment. This research investigated using samples of potassium ions, sodium ions and aspirin (acetylsalicylic acid).
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12
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Tůma P. Determination of amino acids by capillary and microchip electrophoresis with contactless conductivity detection - Theory, instrumentation and applications. Talanta 2020; 224:121922. [PMID: 33379123 DOI: 10.1016/j.talanta.2020.121922] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Revised: 11/22/2020] [Accepted: 11/23/2020] [Indexed: 01/15/2023]
Abstract
This review article summarises aspects of the determination of amino acids using capillary and chip electrophoresis in combination with contactless conductivity detection from their historical beginnings to the present time. Discussion is included of the theory of conductivity detection in electromigration techniques, the design of contactless conductivity cells for detection in capillaries and on microchips, including the use of computer programs for simulation of the conductivity response and the process of the electrophoretic separation of amino acids. Emphasis is placed on optimisation of the background electrolyte composition, chiral separation, multidimensional separation, stacking techniques and the use of multidetection systems. There is also a description of clinical applications, the determination of amino acids in foodstuffs, waters, soils and composts with emphasis on modern techniques of sample treatment, such as microdialysis, liquid membrane extraction and many other techniques.
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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.
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13
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Hauser PC, Kubáň P. Capacitively coupled contactless conductivity detection for analytical techniques - Developments from 2018 to 2020. J Chromatogr A 2020; 1632:461616. [PMID: 33096295 DOI: 10.1016/j.chroma.2020.461616] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Revised: 10/09/2020] [Accepted: 10/10/2020] [Indexed: 12/20/2022]
Abstract
The developments of analytical contactless conductivity measurements based on capacitive coupling over the two years from mid-2018 to mid-2020 are covered. This mostly concerns applications of the technique in zone electrophoresis employing conventional capillaries and to a lesser extent lab-on-chip devices. However, its use for the detection in several other flow-based analytical methods has also been reported. Detection of bubbles and measurements of flow rates in two-phase flows are also recurring themes. A few new applications in stagnant aqueous samples, e.g. endpoint detection in titrations and measurement on paper-based devices, have been reported. Some variations of the design of the measuring cells and their read-out electronics have also been described.
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Affiliation(s)
- Peter C Hauser
- Department of Chemistry, University of Basel, Klingelbergstrasse 80, CH-4056, Basel, Switzerland.
| | - Pavel Kubáň
- Institute of Analytical Chemistry of the Czech Academy of Sciences, Veveří 97, CZ-60200, Brno, Czech Republic.
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14
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Duong HA, Vu MT, Nguyen TD, Nguyen MH, Mai TD. Determination of 10-hydroxy-2-decenoic acid and free amino acids in royal jelly supplements with purpose-made capillary electrophoresis coupled with contactless conductivity detection. J Food Compost Anal 2020. [DOI: 10.1016/j.jfca.2020.103422] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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15
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Jones J, Ha NS, Barajas AG, Chatziioannou AF, van Dam RM. Integration of High-Resolution Radiation Detector for Hybrid Microchip Electrophoresis. Anal Chem 2020; 92:3483-3491. [PMID: 31986878 PMCID: PMC7410349 DOI: 10.1021/acs.analchem.9b04827] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
For decades, there has been immense progress in miniaturizing analytical methods based on electrophoresis to improve sensitivity and to reduce sample volumes, separation times, and/or equipment cost and space requirements, in applications ranging from analysis of biological samples to environmental analysis to forensics. In the field of radiochemistry, where radiation-shielded laboratory space is limited, there has been great interest in harnessing the compactness, high efficiency, and speed of microfluidics to synthesize short-lived radiolabeled compounds. We recently proposed that analysis of these compounds could also benefit from miniaturization and have been investigating capillary electrophoresis (CE) and hybrid microchip electrophoresis (hybrid-MCE) as alternatives to the typically used high-performance liquid chromatography (HPLC). We previously showed separation of the positron-emission tomography (PET) imaging tracer 3'-deoxy-3'-fluorothymidine (FLT) from its impurities in a hybrid-MCE device with UV detection, with similar separation performance to HPLC, but with improved speed and lower sample volumes. In this paper, we have developed an integrated radiation detector to enable measurement of the emitted radiation from radiolabeled compounds. Though conventional radiation detectors have been incorporated into CE systems in the past, these approaches cannot be readily integrated into a compact hybrid-MCE device. We instead employed a solid-state avalanche photodiode (APD)-based detector for real-time, high-sensitivity β particle detection. The integrated system can reliably separate [18F]FLT from its impurities and perform chemical identification via coinjection with nonradioactive reference standard. This system can quantitate samples with radioactivity concentrations as low as 114 MBq/mL (3.1 mCi/mL), which is sufficient for analysis of radiochemical purity of radiopharmaceuticals.
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Affiliation(s)
- Jason Jones
- Crump Institute for Molecular Imaging and Department of
Molecular and Medical Pharmacology, David Geffen School of Medicine, University of
California Los Angeles, Los Angeles, CA 90095, USA
- Physics & Biology in Medicine Interdepartmental
Graduate Program, David Geffen School of Medicine, University of California Los
Angeles, Los Angeles, CA 90095, USA
| | - Noel S. Ha
- Crump Institute for Molecular Imaging and Department of
Molecular and Medical Pharmacology, David Geffen School of Medicine, University of
California Los Angeles, Los Angeles, CA 90095, USA
- Department of Bioengineering, Henry Samueli School of
Engineering and Applied Science, University of California Los Angeles, Los Angeles,
CA 90095, USA
| | - Alec G. Barajas
- Crump Institute for Molecular Imaging and Department of
Molecular and Medical Pharmacology, David Geffen School of Medicine, University of
California Los Angeles, Los Angeles, CA 90095, USA
- Department of Chemistry & Biochemistry, University of
California Los Angeles, Los Angeles, CA 90095, USA
| | - Arion F. Chatziioannou
- Crump Institute for Molecular Imaging and Department of
Molecular and Medical Pharmacology, David Geffen School of Medicine, University of
California Los Angeles, Los Angeles, CA 90095, USA
- Physics & Biology in Medicine Interdepartmental
Graduate Program, David Geffen School of Medicine, University of California Los
Angeles, Los Angeles, CA 90095, USA
- Department of Molecular & Medical Pharmacology,
University of California Los Angeles, Los Angeles, CA 90095, USA
| | - R. Michael van Dam
- Crump Institute for Molecular Imaging and Department of
Molecular and Medical Pharmacology, David Geffen School of Medicine, University of
California Los Angeles, Los Angeles, CA 90095, USA
- Physics & Biology in Medicine Interdepartmental
Graduate Program, David Geffen School of Medicine, University of California Los
Angeles, Los Angeles, CA 90095, USA
- Department of Bioengineering, Henry Samueli School of
Engineering and Applied Science, University of California Los Angeles, Los Angeles,
CA 90095, USA
- Department of Molecular & Medical Pharmacology,
University of California Los Angeles, Los Angeles, CA 90095, USA
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16
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Wu Y, Lu B, Zhang W, Jiang Y, Wang B, Huang Z. A New Logging-While-Drilling Method for Resistivity Measurement in Oil-Based Mud. SENSORS 2020; 20:s20041075. [PMID: 32079132 PMCID: PMC7070431 DOI: 10.3390/s20041075] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/21/2019] [Revised: 02/05/2020] [Accepted: 02/11/2020] [Indexed: 11/16/2022]
Abstract
Resistivity logging is an important technique for identifying and estimating reservoirs. Oil-based mud (OBM) can improve drilling efficiency and decrease operation risks, and has been widely used in the well logging field. However, the non-conductive OBM makes the traditional logging-while-drilling (LWD) method with low frequency ineffective. In this work, a new oil-based LWD method is proposed by combining the capacitively coupled contactless conductivity detection (C4D) technique and the inductive coupling principle. The C4D technique is to overcome the electrical insulation problem of the OBM and construct an effective alternating current (AC) measurement path. Based on the inductive coupling principle, an induced voltage can be formed to be the indirect excitation voltage of the AC measurement path. Based on the proposed method, a corresponding logging instrument is developed. Numerical simulation was carried out and results show that the logging instrument has good measurement accuracy, deep detection depth and high vertical resolution. Practical experiments were also carried out, including the resistance box experiment and the well logging experiment. The results of the resistance box experiment show that the logging instrument has good resistance measurement accuracy. Lastly, the results of the well logging experiment indicate that the logging instrument can accurately reflect the positions of different patterns on the wellbore of the experimental well. Both numerical simulation and practical experiments verify the feasibility and effectiveness of the new method.
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Affiliation(s)
- Yongkang Wu
- State Key Laboratory of Industrial Control Technology, College of Control Science and Engineering, Zhejiang University, Hangzhou 310027, China; (Y.W.); (Y.J.); (Z.H.)
| | - Baoping Lu
- Sinopec Research Institute of Petroleum Engineering, Beijing 100101, China; (B.L.); (W.Z.)
| | - Wei Zhang
- Sinopec Research Institute of Petroleum Engineering, Beijing 100101, China; (B.L.); (W.Z.)
- State Key Laboratory of Shale Oil and Gas Enrichment Mechanisms and Effective Development, Beijing 100101, China
| | - Yandan Jiang
- State Key Laboratory of Industrial Control Technology, College of Control Science and Engineering, Zhejiang University, Hangzhou 310027, China; (Y.W.); (Y.J.); (Z.H.)
| | - Baoliang Wang
- State Key Laboratory of Industrial Control Technology, College of Control Science and Engineering, Zhejiang University, Hangzhou 310027, China; (Y.W.); (Y.J.); (Z.H.)
- Correspondence:
| | - Zhiyao Huang
- State Key Laboratory of Industrial Control Technology, College of Control Science and Engineering, Zhejiang University, Hangzhou 310027, China; (Y.W.); (Y.J.); (Z.H.)
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17
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Chaneam S, Kaewyai K, Mantim T, Chaisuksant R, Wilairat P, Nacapricha D. Simultaneous and direct determination of urea and creatinine in human urine using a cost-effective flow injection system equipped with in-house contactless conductivity detector and LED colorimeter. Anal Chim Acta 2019; 1073:54-61. [DOI: 10.1016/j.aca.2019.05.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Revised: 04/17/2019] [Accepted: 05/02/2019] [Indexed: 12/15/2022]
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18
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Cieslarova Z, Magaldi M, Barros LA, do Lago CL, Oliveira DR, Fonseca FAH, Izar MC, Lopes AS, Tavares MFM, Klassen A. Capillary electrophoresis with dual diode array detection and tandem mass spectrometry to access cardiovascular biomarkers candidates in human urine: Trimethylamine-N-Oxide and l-carnitine. J Chromatogr A 2019; 1583:136-142. [DOI: 10.1016/j.chroma.2018.10.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Revised: 10/02/2018] [Accepted: 10/06/2018] [Indexed: 02/06/2023]
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19
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Rapid and Sensitive Determination of Branched-Chain Amino Acids in Human Plasma by Capillary Electrophoresis with Contactless Conductivity Detection for Physiological Studies. Methods Mol Biol 2019; 1972:15-24. [PMID: 30847781 DOI: 10.1007/978-1-4939-9213-3_2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Capillary electrophoresis (CE) with contactless conductivity detection (C4D) represents a strong tool for determining amino acids in clinical samples. This chapter provides detailed instructions for CE/C4D determination of the branched-chain amino acids (BCAAs) valine, isoleucine, and leucine in human plasma, which can be readily employed in physiological studies. Baseline separation of all the BCAAs is achieved on a short separation length equal to 18 cm in optimized background electrolyte consisting of 3.2 M acetic acid dissolved in 20% v/v methanol with addition of 1.0% v/v INST-coating solution. The analysis time does not exceed 3 min and the limit of detection is 0.4 μM for all BCAAs. The pretreatment of human plasma is very simple and is based on fourfold plasma dilution by acetonitrile and subsequent filtration. Only 50 μL of plasma is used for the analysis. The high sensitivity of the CE/C4D method is achieved by injecting a large volume of sample, combined with application of negative pressure to flush the acetonitrile zone out of the capillary.
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20
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Tai CT, See HH. Rapid quantification of quinine by multi-stacking in a portable microchip electrophoresis system. Electrophoresis 2018; 40:455-461. [DOI: 10.1002/elps.201800398] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2018] [Revised: 10/23/2018] [Accepted: 10/23/2018] [Indexed: 01/16/2023]
Affiliation(s)
- Chee Tung Tai
- Centre for Sustainable Nanomaterials; Ibnu Sina Institute for Scientific and Industrial Research; Universiti Teknologi Malaysia; UTM Johor Bahru Johor Malaysia
- Department of Chemistry; Faculty of Science; Universiti Teknologi Malaysia; UTM Johor Bahru Johor Malaysia
| | - Hong Heng See
- Centre for Sustainable Nanomaterials; Ibnu Sina Institute for Scientific and Industrial Research; Universiti Teknologi Malaysia; UTM Johor Bahru Johor Malaysia
- Department of Chemistry; Faculty of Science; Universiti Teknologi Malaysia; UTM Johor Bahru Johor Malaysia
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21
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Dual-channeled capillary electrophoresis coupled with contactless conductivity detection for rapid determination of choline and taurine in energy drinks and dietary supplements. Talanta 2018; 193:168-175. [PMID: 30368287 DOI: 10.1016/j.talanta.2018.10.002] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Revised: 09/26/2018] [Accepted: 10/01/2018] [Indexed: 11/21/2022]
Abstract
In this study is reported a simple and inexpensive method for concurrent determination of taurine and choline in different supplementary nutrient samples using dual-channeled capillary electrophoresis (CE) instrument with capacitively coupled contactless conductivity detection (C4D). The objective of the work is to propose a tool for food control activities that allows screening of different target compounds (having different characteristics) in a single run for high throughput and can be realizable even with modest infrastructure. Taurine was analyzed in the first CE channel using the background electrolyte (BGE) composed of 150 mM tris(hydroxymethyl)aminomethane/lactic acid (pH 8.96) whereas choline was simultaneously separated in the second CE channel using a BGE containing 150 mM tris(hydroxymethyl)aminomethane/acetic acid (pH 9.5). The best achieved detection limit was 0.27 mg/L and 0.45 mg/L for taurine and choline, respectively, using the developed CE-C4D method. Good agreement between results obtained from CE-C4D and those with the standard confirmation methods (HPLC-DAD for taurine and LC/MS for choline) was achieved, with the result deviation for the two pairs of data being less than 12%.
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22
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Ferreira Santos MS, Cordeiro TG, Noell AC, Garcia CD, Mora MF. Analysis of inorganic cations and amino acids in high salinity samples by capillary electrophoresis and conductivity detection: Implications for in‐situ exploration of ocean worlds. Electrophoresis 2018; 39:2890-2897. [DOI: 10.1002/elps.201800266] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Revised: 07/31/2018] [Accepted: 08/02/2018] [Indexed: 12/12/2022]
Affiliation(s)
| | - Thiago Gomes Cordeiro
- Department of ChemistryClemson University Clemson SC USA
- Departamento de Química Fundamental, Instituto de QuímicaUniversidade de São Paulo Sao Paulo Brazil
| | - Aaron C. Noell
- Jet Propulsion LaboratoryCalifornia Institute of Technology Pasadena CA USA
| | | | - Maria F. Mora
- Jet Propulsion LaboratoryCalifornia Institute of Technology Pasadena CA USA
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23
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Kubáň P, Hauser PC. Contactless conductivity detection for analytical techniques: Developments from 2016 to 2018. Electrophoresis 2018; 40:124-139. [PMID: 30010203 DOI: 10.1002/elps.201800248] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2018] [Revised: 07/10/2018] [Accepted: 07/10/2018] [Indexed: 01/05/2023]
Abstract
The publications concerning capacitively coupled contactless conductivity detection for the 2-year period from mid-2016 to mid-2018 are covered in this update to the earlier reviews of the series. Relatively few reports on fundamental investigations or new designs have appeared in the literature in this time interval, but the development of new applications with the detection method has continued strongly. Most often, contactless conductivity measurements have been employed for the detection of inorganic or small organic ions in conventional capillary electrophoresis, less often in microchip electrophoresis. A number of other uses, such as detection in chromatography or the gauging of bubbles in streams have also been reported.
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Affiliation(s)
- Pavel Kubáň
- Institute of Analytical Chemistry of the Czech Academy of Sciences, Brno, Czech Republic
| | - Peter C Hauser
- Department of Chemistry, University of Basel, Basel, Switzerland
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24
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de Castro Costa BM, Marra MC, da Costa Oliveira T, Munoz RAA, Batista AD, do Lago CL, Richter EM. Ultrafast capillary electrophoresis method for the simultaneous determination of ammonium and diphenhydramine in pharmaceutical samples. J Sep Sci 2018; 41:2969-2975. [PMID: 29785728 DOI: 10.1002/jssc.201800273] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Revised: 04/21/2018] [Accepted: 05/04/2018] [Indexed: 01/24/2023]
Abstract
Ammonium and diphenhydramine are active ingredients commonly found in the same pharmaceutical preparations. We report, for the first time, a sub-minute method for the simultaneous determination of ammonium and diphenhydramine. The method is based on capillary electrophoresis with capacitively coupled contactless conductivity detection. Both analytes can be quantified in a single run (∼80 injections/h) using 30 mmol/L 2-(N-morpholino)ethanesulfonic acid and 15 mmol/L lithium hydroxide (pH 6.0) as background electrolyte. The separation by capillary electrophoresis was achieved on a fused-silica capillary (50 cm total length, 10 cm effective length, and 50 μm inside diameter). The limits of detection were 0.04 and 0.02 mmol/L for ammonium and diphenhydramine, respectively. The proposed method also provided adequate recovery values for spiked samples (100-106 and 97-104% for ammonium and diphenhydramine, respectively). The results obtained with the new capillary electrophoresis method were compared with those of the high-performance liquid chromatography method for diphenhydramine and the Kjeldahl method for ammonium and no statistically significant differences were found (95% confidence level).
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Affiliation(s)
| | - Mariana Cardoso Marra
- Institute of Chemistry, Federal University of Uberlandia, Av. João Naves de Ávila, Uberlândia, Brazil
| | - Thiago da Costa Oliveira
- Institute of Chemistry, Federal University of Uberlandia, Av. João Naves de Ávila, Uberlândia, Brazil
| | | | - Alex Domingues Batista
- Institute of Chemistry, Federal University of Uberlandia, Av. João Naves de Ávila, Uberlândia, Brazil
| | - Claudimir Lucio do Lago
- Department of Fundamental Chemistry, Institute of Chemistry, University of São Paulo, Av. Prof. Lineu Prestes, São Paulo, Brazil
| | - Eduardo Mathias Richter
- Institute of Chemistry, Federal University of Uberlandia, Av. João Naves de Ávila, Uberlândia, Brazil
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25
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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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26
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Drevinskas T, Telksnys L, Maruška A, Gorbatsova J, Kaljurand M. Capillary Electrophoresis Sensitivity Enhancement Based on Adaptive Moving Average Method. Anal Chem 2018; 90:6773-6780. [DOI: 10.1021/acs.analchem.8b00664] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Tomas Drevinskas
- Instrumental Analysis Open Access Centre, Faculty of Natural Sciences, Vytautas Magnus University, Vileikos 8, LT44404 Kaunas, Lithuania
- Department of Systems’ Analysis, Faculty of Informatics, Vytautas Magnus University, Vileikos 8, LT44404 Kaunas, Lithuania
| | - Laimutis Telksnys
- Department of Systems’ Analysis, Faculty of Informatics, Vytautas Magnus University, Vileikos 8, LT44404 Kaunas, Lithuania
- Recognition Processes Department, Institute of Mathematics and Informatics, Goštauto 12, LT01108 Vilnius, Lithuania
| | - Audrius Maruška
- Instrumental Analysis Open Access Centre, Faculty of Natural Sciences, Vytautas Magnus University, Vileikos 8, LT44404 Kaunas, Lithuania
| | - Jelena Gorbatsova
- Department of Chemistry, Faculty of Sciences, Tallinn University of Technology, Akadeemia tee 15, 12618 Tallinn, Estonia
| | - Mihkel Kaljurand
- Instrumental Analysis Open Access Centre, Faculty of Natural Sciences, Vytautas Magnus University, Vileikos 8, LT44404 Kaunas, Lithuania
- Department of Chemistry, Faculty of Sciences, Tallinn University of Technology, Akadeemia tee 15, 12618 Tallinn, Estonia
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27
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Huang Z, Yang M, You H, Xie Y. Concurrent determination and separation of inorganic cations and anions in microchip electrophoresis with precisely controlled high-voltage. Electrophoresis 2018; 39:1802-1807. [PMID: 29676805 DOI: 10.1002/elps.201800077] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2018] [Revised: 04/12/2018] [Accepted: 04/13/2018] [Indexed: 11/10/2022]
Abstract
An improved method for the concurrent determination and separation of cations and anions by microchip electrophoresis with capacitively coupled contactless conductivity detection (ME-C4 D) is described. Two kinds of microchip structures were designed. The first microchip has a long bent separation channel. And for the defects of the first microchip, the second microchip with a Y-type separation channel has been proposed. The background electrolyte (BGE) composed of 20 mm His/MES and 0.01 mm CTAB was optimized for inhibiting the electroosmotic flow (EOF). Due to the low electroosmotic flow, the cations and anions migrate in opposite directions and can be separated from each other. With the precisely controlled high-voltage, cations and anions can be migrated in microchannels according to our requirements and sequentially detected by a C4 D detector built in-house. Samples containing K+ , Na+ , Li+ , Cl- , F- and PO43- were analyzed simultaneously in a single run (within 140 s) by both methods. The reproducibility obtained by both methods remained below 5% for migration time and within 3.5-9.1% for peak areas. The proposed concurrent determination methods are inexpensive, simple, fast, ease of operation, high degree of integration.
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Affiliation(s)
- Zhe Huang
- Institute of Intelligent Machines, Chinese Academy of Sciences, Hefei, P. R. China
- Department of Instruments Science and Engineering, University of Science and Technology of China, Hefei, P. R. China
| | - Mingpeng Yang
- Institute of Intelligent Machines, Chinese Academy of Sciences, Hefei, P. R. China
- Department of Instruments Science and Engineering, University of Science and Technology of China, Hefei, P. R. China
| | - Hui You
- Institute of Intelligent Machines, Chinese Academy of Sciences, Hefei, P. R. China
- Department of Instruments Science and Engineering, University of Science and Technology of China, Hefei, P. R. China
| | - Yang Xie
- Institute of Intelligent Machines, Chinese Academy of Sciences, Hefei, P. R. China
- Department of Instruments Science and Engineering, University of Science and Technology of China, Hefei, P. R. China
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28
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Crosnier de Lassichère C, Mai TD, Otto M, Taverna M. Online Preconcentration in Capillaries by Multiple Large-Volume Sample Stacking: An Alternative to Immunoassays for Quantification of Amyloid Beta Peptides Biomarkers in Cerebrospinal Fluid. Anal Chem 2018; 90:2555-2563. [DOI: 10.1021/acs.analchem.7b03843] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Affiliation(s)
- Cédric Crosnier de Lassichère
- Institut Galien
Paris Sud, UMR 8612, Protein and Nanotechnology in Analytical Science (PNAS), CNRS,
Univ. Paris-Sud, Univ. Paris-Saclay, 5 rue Jean Baptiste Clément, 92290 Châtenay-Malabry, France
| | - Thanh Duc Mai
- Institut Galien
Paris Sud, UMR 8612, Protein and Nanotechnology in Analytical Science (PNAS), CNRS,
Univ. Paris-Sud, Univ. Paris-Saclay, 5 rue Jean Baptiste Clément, 92290 Châtenay-Malabry, France
| | - Markus Otto
- University of Ulm, Department of Neurology, Oberer Eselsberg 45, 89081 Ulm, Germany
| | - Myriam Taverna
- Institut Galien
Paris Sud, UMR 8612, Protein and Nanotechnology in Analytical Science (PNAS), CNRS,
Univ. Paris-Sud, Univ. Paris-Saclay, 5 rue Jean Baptiste Clément, 92290 Châtenay-Malabry, France
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29
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Ha NS, Sadeghi S, van Dam RM. Recent Progress toward Microfluidic Quality Control Testing of Radiopharmaceuticals. MICROMACHINES 2017; 8:E337. [PMID: 30400527 PMCID: PMC6190332 DOI: 10.3390/mi8110337] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/27/2017] [Revised: 11/08/2017] [Accepted: 11/18/2017] [Indexed: 01/18/2023]
Abstract
Radiopharmaceuticals labeled with short-lived positron-emitting or gamma-emitting isotopes are injected into patients just prior to performing positron emission tomography (PET) or single photon emission tomography (SPECT) scans, respectively. These imaging modalities are widely used in clinical care, as well as in the development and evaluation of new therapies in clinical research. Prior to injection, these radiopharmaceuticals (tracers) must undergo quality control (QC) testing to ensure product purity, identity, and safety for human use. Quality tests can be broadly categorized as (i) pharmaceutical tests, needed to ensure molecular identity, physiological compatibility and that no microbiological, pyrogenic, chemical, or particulate contamination is present in the final preparation; and (ii) radioactive tests, needed to ensure proper dosing and that there are no radiochemical and radionuclidic impurities that could interfere with the biodistribution or imaging. Performing the required QC tests is cumbersome and time-consuming, and requires an array of expensive analytical chemistry equipment and significant dedicated lab space. Calibrations, day of use tests, and documentation create an additional burden. Furthermore, in contrast to ordinary pharmaceuticals, each batch of short-lived radiopharmaceuticals must be manufactured and tested within a short period of time to avoid significant losses due to radioactive decay. To meet these challenges, several efforts are underway to develop integrated QC testing instruments that automatically perform and document all of the required tests. More recently, microfluidic quality control systems have been gaining increasing attention due to vastly reduced sample and reagent consumption, shorter analysis times, higher detection sensitivity, increased multiplexing, and reduced instrumentation size. In this review, we describe each of the required QC tests and conventional testing methods, followed by a discussion of efforts to directly miniaturize the test or examples in the literature that could be implemented for miniaturized QC testing.
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Affiliation(s)
- Noel S Ha
- Department of Bioengineering, Henry Samueli School of Engineering and Applied Science, University of California Los Angeles, Los Angeles, CA 90095, USA.
- Crump Institute for Molecular Imaging and Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA 90095, USA.
| | - Saman Sadeghi
- Crump Institute for Molecular Imaging and Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA 90095, USA.
| | - R Michael van Dam
- Department of Bioengineering, Henry Samueli School of Engineering and Applied Science, University of California Los Angeles, Los Angeles, CA 90095, USA.
- Crump Institute for Molecular Imaging and Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA 90095, USA.
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30
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Paul P, Duchateau T, Sänger-van de Griend C, Adams E, Van Schepdael A. Capillary electrophoresis with capacitively coupled contactless conductivity detection method development and validation for the determination of azithromycin, clarithromycin, and clindamycin. J Sep Sci 2017; 40:3535-3544. [DOI: 10.1002/jssc.201700560] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2017] [Revised: 06/28/2017] [Accepted: 06/29/2017] [Indexed: 11/09/2022]
Affiliation(s)
- Prasanta Paul
- KU Leuven - University of Leuven; Department of Pharmaceutical and Pharmacological Sciences; Leuven Belgium
| | - Tom Duchateau
- KU Leuven - University of Leuven; Department of Pharmaceutical and Pharmacological Sciences; Leuven Belgium
| | - Cari Sänger-van de Griend
- Analytical Pharmaceutical Chemistry; Uppsala University; Uppsala Sweden
- Kantisto BV; Baarn The Netherlands
| | - Erwin Adams
- KU Leuven - University of Leuven; Department of Pharmaceutical and Pharmacological Sciences; Leuven Belgium
| | - Ann Van Schepdael
- KU Leuven - University of Leuven; Department of Pharmaceutical and Pharmacological Sciences; Leuven Belgium
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31
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Le THH, Nguyen TQH, Tran CS, Vu TT, Nguyen TL, Cao VH, Ta TT, Pham TNM, Nguyen TAH, Mai TD. Screening determination of food additives using capillary electrophoresis coupled with contactless conductivity detection: A case study in Vietnam. Food Control 2017. [DOI: 10.1016/j.foodcont.2017.02.020] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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32
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Vu AP, Nguyen TN, Do TT, Doan TH, Ha TH, Ta TT, Nguyen HL, Hauser PC, Nguyen TAH, Mai TD. Clinical screening of paraquat in plasma samples using capillary electrophoresis with contactless conductivity detection: Towards rapid diagnosis and therapeutic treatment of acute paraquat poisoning in Vietnam. J Chromatogr B Analyt Technol Biomed Life Sci 2017; 1060:111-117. [PMID: 28609698 DOI: 10.1016/j.jchromb.2017.06.010] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2017] [Revised: 05/26/2017] [Accepted: 06/05/2017] [Indexed: 10/19/2022]
Abstract
The employment of a purpose-made capillary electrophoresis (CE) instrument with capacitively coupled contactless conductivity detection (C4D) as a simple and cost-effective solution for clinical screening of paraquat in plasma samples for early-stage diagnosis of acute herbicide poisoning is reported. Paraquat was determined using an electrolyte composed of 10mM histidine adjusted to pH 4 with acetic acid. A detection limit of 0.5mg/L was achieved. Good agreement between results from CE-C4D and the confirmation method (HPLC-UV) was obtained, with relative errors for the two pairs of data better than 20% for 31 samples taken from paraquat-intoxicated patients. The results were used by medical doctors for identification and prognosis of acute paraquat poisoning cases. The objective of the work is the deployment of the developed approach in rural areas in Vietnam as a low-cost solution to reduce the mortality rate due to accidental or suicidal ingestion of paraquat.
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Affiliation(s)
- Anh Phuong Vu
- Poison Control Center, Bach Mai Hospital, 78 Giai Phong road, Dong Da, Hanoi, Viet Nam; Department of Analytical Chemistry, Faculty of Chemistry, VNU University of Science, Vietnam National University, Hanoi - 19 Le Thanh Tong, Hanoi, Viet Nam(1)
| | - Thi Ngan Nguyen
- Poison Control Center, Bach Mai Hospital, 78 Giai Phong road, Dong Da, Hanoi, Viet Nam; Department of Analytical Chemistry, Faculty of Chemistry, VNU University of Science, Vietnam National University, Hanoi - 19 Le Thanh Tong, Hanoi, Viet Nam(1)
| | - Thi Trang Do
- Poison Control Center, Bach Mai Hospital, 78 Giai Phong road, Dong Da, Hanoi, Viet Nam; Department of Analytical Chemistry, Faculty of Chemistry, VNU University of Science, Vietnam National University, Hanoi - 19 Le Thanh Tong, Hanoi, Viet Nam(1)
| | - Thu Ha Doan
- Poison Control Center, Bach Mai Hospital, 78 Giai Phong road, Dong Da, Hanoi, Viet Nam
| | - Tran Hung Ha
- Poison Control Center, Bach Mai Hospital, 78 Giai Phong road, Dong Da, Hanoi, Viet Nam
| | - Thi Thao Ta
- Department of Analytical Chemistry, Faculty of Chemistry, VNU University of Science, Vietnam National University, Hanoi - 19 Le Thanh Tong, Hanoi, Viet Nam(1)
| | - Hung Long Nguyen
- Vietnam Food Administration, Ministry of Health, 138A Giang Vo, Ba Đinh, Hanoi, Viet Nam
| | - Peter C Hauser
- University of Basel, Department of Chemistry, Spitalstrasse 51, 4056 Basel, Switzerland
| | - Thi Anh Huong Nguyen
- Department of Analytical Chemistry, Faculty of Chemistry, VNU University of Science, Vietnam National University, Hanoi - 19 Le Thanh Tong, Hanoi, Viet Nam(1).
| | - Thanh Duc Mai
- PNAS, Institut Galien de Paris-Sud, Faculté de Pharmacie, Université Paris-Sud, CNRS, 5 rue JB Clément, 92296 Châtenay-Malabry, France.
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33
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Cunha RR, Ribeiro MMAC, Muñoz RAA, Richter EM. Fast determination of codeine, orphenadrine, promethazine, scopolamine, tramadol, and paracetamol in pharmaceutical formulations by capillary electrophoresis. J Sep Sci 2017; 40:1815-1823. [PMID: 28217928 DOI: 10.1002/jssc.201601275] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2016] [Revised: 01/31/2017] [Accepted: 02/02/2017] [Indexed: 12/16/2022]
Abstract
Paracetamol is an active ingredient commonly found in pharmaceutical formulations in combination with one of the following compounds: codeine, orphenadrine, promethazine, scopolamine, and tramadol. In this work, we propose a unique analytical method for determination of these active ingredients in pharmaceutical samples. The method is based on capillary electrophoresis with capacitively coupled contactless conductivity detection. The separation was achieved on a fused silica capillary (50 cm total length, 40 cm effective length, and 50 μm id) using an optimized background electrolyte composed of 20 mmol/L β-alanine/4 mmol/L sodium chloride/4 μmol/L sodium hydroxide (pH 9.6). Each sample can be analyzed in a single run (≤2 min) and the limits of detection were 2.5, 0.62, 0.63, 2.5, 15, and 1.6 μmol/L for scopolamine, tramadol, orphenadrine, promethazine, codeine, and paracetamol, respectively. Recovery values for spiked samples were between 94 and 104%.
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Affiliation(s)
- Rafael R Cunha
- Instituto de Química, Universidade Federal de Uberlândia, Uberlândia, MG, Brazil
| | | | - Rodrigo A A Muñoz
- Instituto de Química, Universidade Federal de Uberlândia, Uberlândia, MG, Brazil
| | - Eduardo M Richter
- Instituto de Química, Universidade Federal de Uberlândia, Uberlândia, MG, Brazil
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34
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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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35
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Elbashir AA, Schmitz OJ, Aboul-Enein HY. Application of capillary electrophoresis with capacitively coupled contactless conductivity detection (CE-C4
D): An update. Biomed Chromatogr 2017; 31. [DOI: 10.1002/bmc.3945] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2016] [Revised: 01/20/2017] [Accepted: 02/03/2017] [Indexed: 12/29/2022]
Affiliation(s)
- Abdalla A. Elbashir
- Faculty of Science, Chemistry Department; University of Khartoum; Khartoum Sudan
- Applied Analytical Chemistry, Faculty of Chemistry; University of Duisburg-Essen; Essen Germany
| | - Oliver J. Schmitz
- Applied Analytical Chemistry, Faculty of Chemistry; University of Duisburg-Essen; Essen Germany
| | - Hassan Y. Aboul-Enein
- Pharmaceutical and Medicinal Chemistry Department, Pharmaceutical and Drug Industries Research Division; National Research Centre; Giza Egypt
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36
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Sustained drug release and electrochemical performance of ethyl cellulose-magnesium hydrogen phosphate composite. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2017; 71:735-743. [DOI: 10.1016/j.msec.2016.10.062] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2016] [Revised: 09/28/2016] [Accepted: 10/24/2016] [Indexed: 12/20/2022]
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37
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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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38
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Kubáň P, Hauser PC. Contactless conductivity detection for analytical techniques- Developments from 2014 to 2016. Electrophoresis 2016; 38:95-114. [DOI: 10.1002/elps.201600280] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Revised: 08/05/2016] [Accepted: 08/06/2016] [Indexed: 11/09/2022]
Affiliation(s)
- Pavel Kubáň
- Institute of Analytical Chemistry of the Czech Academy of Sciences; Brno Czech Republic
| | - Peter C. Hauser
- Department of Chemistry; University of Basel; Basel Switzerland
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39
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Koczka PI, Bodor R, Masár M, Gáspár A. Application of isotachophoresis in commercial capillary electrophoresis instrument using C4D and UV detection. Electrophoresis 2016; 37:2384-92. [DOI: 10.1002/elps.201600194] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2016] [Revised: 05/18/2016] [Accepted: 06/07/2016] [Indexed: 01/27/2023]
Affiliation(s)
- Péter I. Koczka
- Department of Inorganic and Analytical Chemistry; University of Debrecen; Debrecen Hungary
| | - Róbert Bodor
- Department of Analytical Chemistry, Faculty of Natural Sciences; Comenius University in Bratislava; Bratislava Slovakia
| | - Marián Masár
- Department of Analytical Chemistry, Faculty of Natural Sciences; Comenius University in Bratislava; Bratislava Slovakia
| | - Attila Gáspár
- Department of Inorganic and Analytical Chemistry; University of Debrecen; Debrecen Hungary
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40
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Oedit A, Ramautar R, Hankemeier T, Lindenburg PW. Electroextraction and electromembrane extraction: Advances in hyphenation to analytical techniques. Electrophoresis 2016; 37:1170-86. [PMID: 26864699 PMCID: PMC5071742 DOI: 10.1002/elps.201500530] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2015] [Revised: 01/06/2016] [Accepted: 01/31/2016] [Indexed: 12/16/2022]
Abstract
Electroextraction (EE) and electromembrane extraction (EME) are sample preparation techniques that both require an electric field that is applied over a liquid-liquid system, which enables the migration of charged analytes. Furthermore, both techniques are often used to pre-concentrate analytes prior to analysis. In this review an overview is provided of the body of literature spanning April 2012-November 2015 concerning EE and EME, focused on hyphenation to analytical techniques. First, the theoretical aspects of concentration enhancement in EE and EME are discussed to explain extraction recovery and enrichment factor. Next, overviews are provided of the techniques based on their hyphenation to LC, GC, CE, and direct detection. These overviews cover the compounds and matrices, experimental aspects (i.e. donor volume, acceptor volume, extraction time, extraction voltage, and separation time) and the analytical aspects (i.e. limit of detection, enrichment factor, and extraction recovery). Techniques that were either hyphenated online to analytical techniques or show high potential with respect to online hyphenation are highlighted. Finally, the potential future directions of EE and EME are discussed.
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Affiliation(s)
- Amar Oedit
- Division of Analytical Biosciences, Leiden Academic Center for Drug Research, Leiden University, Leiden, the Netherlands
| | - Rawi Ramautar
- Division of Analytical Biosciences, Leiden Academic Center for Drug Research, Leiden University, Leiden, the Netherlands
| | - Thomas Hankemeier
- Division of Analytical Biosciences, Leiden Academic Center for Drug Research, Leiden University, Leiden, the Netherlands
| | - Petrus W Lindenburg
- Division of Analytical Biosciences, Leiden Academic Center for Drug Research, Leiden University, Leiden, the Netherlands
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41
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Caslavska J, Koenka IJ, Hauser PC, Thormann W. Validation of CE modeling with a contactless conductivity array detector. Electrophoresis 2016; 37:699-710. [PMID: 26799858 DOI: 10.1002/elps.201500424] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2015] [Revised: 01/13/2016] [Accepted: 01/14/2016] [Indexed: 11/11/2022]
Abstract
Dynamic computer simulation data are compared for the first time with CE data obtained with a laboratory made system comprising an array of 8 contactless conductivity detectors (C(4) Ds). The experimental setup featured a 50 μm id linear polyacrylamide (LPA) coated fused-silica capillary of 70 cm length and a purpose built sequential injection analysis manifold for fluid handling of continuous or discontinuous buffer configurations and sample injection. The LPA coated capillary exhibits a low EOF and the manifold allows the placement of the first detector at about 2.7 cm from the sample inlet. Agreement of simulated electropherograms with experimental data was obtained for the migration and separation of cationic and anionic analyte and system zones in CZE configurations in which EOF and other column properties are constant. For configurations with discontinuous buffer systems, including ITP, experimental data obtained with the array detector revealed that the EOF is not constant. Comparison of simulation and experimental data of ITP systems provided the insight that the EOF can be estimated with an ionic strength dependent model similar to that previously used to describe EOF in fused-silica capillaries dynamically double coated with Polybrene and poly(vinylsulfonate). For the LPA coated capillaries, the electroosmotic mobility was determined to be 17-fold smaller compared to the case with the charged double coating. Simulation and array detection provide means for quickly investigating electrophoretic transport and separation properties. Without realistic input parameters, modeling alone is not providing data that match CE results.
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Affiliation(s)
- Jitka Caslavska
- Clinical Pharmacology Laboratory, Institute for Infectious Diseases, University of Bern, Bern, Switzerland
| | | | - Peter C Hauser
- Department of Chemistry, University of Basel, Basel, Switzerland
| | - Wolfgang Thormann
- Clinical Pharmacology Laboratory, Institute for Infectious Diseases, University of Bern, Bern, Switzerland
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42
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New C4D Sensor with a Simulated Inductor. SENSORS 2016; 16:165. [PMID: 26828493 PMCID: PMC4801543 DOI: 10.3390/s16020165] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/09/2015] [Revised: 01/09/2016] [Accepted: 01/22/2016] [Indexed: 11/16/2022]
Abstract
A new capacitively coupled contactless conductivity detection (C4D) sensor with an improved simulated inductor is developed in this work. The improved simulated inductor is designed on the basis of the Riordan-type floating simulated inductor. With the improved simulated inductor, the negative influence of the coupling capacitances is overcome and the conductivity measurement is implemented by the series resonance principle. The conductivity measurement experiments are carried out in three pipes with different inner diameters of 3.0 mm, 4.6 mm and 6.4 mm, respectively. The experimental results show that the designs of the new C4D sensor and the improved simulated inductor are successful. The maximum relative error of the conductivity measurement is less than 5%. Compared with the C4D sensors using practical inductors, the measurement accuracy of the new C4D sensor is comparable. The research results also indicate that the adjustability of a simulated inductor can reduce the requirement for the AC source and guarantee the interchangeableness. Meanwhile, it is recommended that making the potential of one terminal of a simulated inductor stable is beneficial to the running stability. Furthermore, this work indirectly verifies the possibility and feasibility of the miniaturization of the C4D sensor by using the simulated inductor technique and lays a good foundation for future research work.
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43
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Mai TD, Le MD, Sáiz J, Duong HA, Koenka IJ, Pham HV, Hauser PC. Triple-channel portable capillary electrophoresis instrument with individual background electrolytes for the concurrent separations of anionic and cationic species. Anal Chim Acta 2016; 911:121-128. [PMID: 26893094 DOI: 10.1016/j.aca.2016.01.029] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2015] [Revised: 01/12/2016] [Accepted: 01/16/2016] [Indexed: 01/15/2023]
Abstract
The portable capillary electrophoresis instrument is automated and features three independent channels with different background electrolytes to allow the concurrent optimized determination of three different categories of charged analytes. The fluidic system is based on a miniature manifold which is based on mechanically milled channels for injection of samples and buffers. The planar manifold pattern was designed to minimize the number of electronic valves required for each channel. The system utilizes pneumatic pressurization to transport solutions at the grounded as well as the high voltage side of the separation capillaries. The instrument has a compact design, with all components arranged in a briefcase with dimensions of 45 (w) × 35 (d) × 15 cm (h) and a weight of about 15 kg. It can operate continuously for 8 h in the battery-powered mode if only one electrophoresis channel is in use, or for about 2.5 h in the case of simultaneous employment of all three channels. The different operations, i.e. capillary flushing, rinsing of the interfaces at both capillary ends, sample injection and electrophoretic separation, are activated automatically with a control program featuring a graphical user interface. For demonstration, the system was employed successfully for the concurrent separation of different inorganic cations and anions, organic preservatives, additives and artificial sweeteners in various beverage and food matrices.
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Affiliation(s)
- Thanh Duc Mai
- Centre for Environmental Technology and Sustainable Development (CETASD), Hanoi University of Science, Nguyen Trai Street 334, Hanoi, Viet Nam
| | - Minh Duc Le
- Centre for Environmental Technology and Sustainable Development (CETASD), Hanoi University of Science, Nguyen Trai Street 334, Hanoi, Viet Nam
| | - Jorge Sáiz
- Department of Analytical Chemistry, Physical Chemistry and Chemical Engineering, University of Alcalá, Ctra. Madrid-Barcelona Km 33.6, Alcalá de Henares, Madrid, Spain
| | - Hong Anh Duong
- Centre for Environmental Technology and Sustainable Development (CETASD), Hanoi University of Science, Nguyen Trai Street 334, Hanoi, Viet Nam
| | - Israel Joel Koenka
- University of Basel, Department of Chemistry, Spitalstrasse 51, 4056 Basel, Switzerland
| | - Hung Viet Pham
- Centre for Environmental Technology and Sustainable Development (CETASD), Hanoi University of Science, Nguyen Trai Street 334, Hanoi, Viet Nam.
| | - Peter C Hauser
- University of Basel, Department of Chemistry, Spitalstrasse 51, 4056 Basel, Switzerland.
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44
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Cabot JM, Duffy E, Currivan S, Ruland A, Jalili R, Mozer AJ, Innis PC, Wallace GG, Breadmore M, Paull B. Characterisation of graphene fibres and graphene coated fibres using capacitively coupled contactless conductivity detector. Analyst 2016; 141:2774-82. [DOI: 10.1039/c5an02534f] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The use of capacitively coupled contactless conductivity detection (C4D) for the characterisation of thin conductive graphene fibres, graphene composite fibres, and graphene coated fibrous materials is demonstrated for the first time.
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45
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Koczka PI, Bodoki E, Gáspár A. Application of capacitively coupled contactless conductivity as an external detector for zone electrophoresis in poly(dimethylsiloxane) chips. Electrophoresis 2015; 37:398-405. [DOI: 10.1002/elps.201500335] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2015] [Revised: 10/16/2015] [Accepted: 10/20/2015] [Indexed: 01/06/2023]
Affiliation(s)
- Péter I. Koczka
- Department of Inorganic and Analytical Chemistry; University of Debrecen; Debrecen Hungary
| | - Ede Bodoki
- Department of Analytical Chemistry; “Iuliu Hatieganu” University of Medicine and Pharmacy; Cluj Napoca Romania
| | - Attila Gáspár
- Department of Inorganic and Analytical Chemistry; University of Debrecen; Debrecen Hungary
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46
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A simple analytical method for determining inorganic anions and formate in virgin olive oils by capillary electrophoresis with capacitively coupled contactless conductivity detection. Food Control 2015. [DOI: 10.1016/j.foodcont.2015.04.026] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
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47
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Duong HA, Le MD, Nguyen KDM, Hauser PC, Pham HV, Mai TD. In-house-made capillary electrophoresis instruments coupled with contactless conductivity detection as a simple and inexpensive solution for water analysis: a case study in Vietnam. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2015; 17:1941-1951. [PMID: 26452107 DOI: 10.1039/c5em00362h] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
A simple and inexpensive method for the determination of various ionic species in different water matrices is discussed in this study. The approach is based on the employment of in-house-made capillary electrophoresis (CE) instruments with capacitively coupled contactless conductivity detection (C(4)D), which can be realized even when only a modest financial budget and limited expertise are available. Advantageous features and considerations of these instruments are detailed following their pilot deployment in Vietnam. Different categories of ionic species, namely major inorganic cations (K(+), Na(+), Ca(2+), Mg(2+), and NH4(+)) and major inorganic anions (Cl(-), NO3(-), NO2(-), SO4(2-), and phosphate), in different water matrices in Vietnam were determined using these in-house fabricated instruments. Inorganic trivalent arsenic (As(iii)), which is the most abundant form of arsenic in reducing groundwater, was determined by CE-C(4)D. The effect of some interfering ions in groundwater on the analytical performance was investigated and is highlighted. The results from in-house-made CE-C(4)D-instruments were cross-checked with those obtained using the standard methods (AAS, AES, UV and IC), with correlation coefficients r(2) ≥ 0.9 and deviations from the referenced results less than 15%.
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Affiliation(s)
- Hong Anh Duong
- Centre for Environmental Technology and Sustainable Development (CETASD), Hanoi University of Science, Nguyen Trai Street 334, Hanoi, Vietnam.
| | - Minh Duc Le
- Centre for Environmental Technology and Sustainable Development (CETASD), Hanoi University of Science, Nguyen Trai Street 334, Hanoi, Vietnam.
| | - Kim Diem Mai Nguyen
- Centre for Environmental Technology and Sustainable Development (CETASD), Hanoi University of Science, Nguyen Trai Street 334, Hanoi, Vietnam.
| | - Peter C Hauser
- University of Basel, Department of Chemistry, Spitalstrasse 51, 4056 Basel, Switzerland
| | - Hung Viet Pham
- Centre for Environmental Technology and Sustainable Development (CETASD), Hanoi University of Science, Nguyen Trai Street 334, Hanoi, Vietnam.
| | - Thanh Duc Mai
- Centre for Environmental Technology and Sustainable Development (CETASD), Hanoi University of Science, Nguyen Trai Street 334, Hanoi, Vietnam.
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48
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Tůma P, Opekar F. Contactless conductometric determination of methanol and ethanol in samples containing water after their electrophoretic desalination. Electrophoresis 2015; 36:1976-81. [DOI: 10.1002/elps.201500174] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2015] [Revised: 04/30/2015] [Accepted: 05/10/2015] [Indexed: 11/06/2022]
Affiliation(s)
- Petr Tůma
- Charles University in Prague; Third Faculty of Medicine; Institute of Biochemistry; Cell and Molecular Biology; Prague Czech Republic
| | - František Opekar
- Charles University in Prague; Faculty of Science; Department of Analytical Chemistry; Prague Czech Republic
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49
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Zhang X, Guo L, Zhang D, Ge X, Ye J, Chu Q. Sensitive Determination of Bromate in Water Samples by Capillary Electrophoresis Coupled with Electromembrane Extraction. FOOD ANAL METHOD 2015. [DOI: 10.1007/s12161-015-0208-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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50
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Marques TT, Shiroma LS, de Jesus DP. Determination of tetrakis(hydroxymethyl)phosphonium sulfate in commercial formulations and cooling water by capillary electrophoresis with contactless conductivity detection. J Sep Sci 2015; 38:852-7. [DOI: 10.1002/jssc.201401288] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2014] [Revised: 12/15/2014] [Accepted: 12/17/2014] [Indexed: 11/11/2022]
Affiliation(s)
| | | | - Dosil Pereira de Jesus
- Institute of Chemistry; University of Campinas, UNICAMP; Campinas SP Brazil
- Instituto Nacional de Ciência e Tecnologia de Bioanalítica; Campinas SP Brazil
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