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Li L, Ren DD, Zhang PY, Song YP, Li TX, Gao MH, Xu JN, Zhou L, Zeng ZC, Pu Q. Pushing the Limits of Capacitively Coupled Contactless Conductivity Detection for Capillary Electrophoresis. Anal Chem 2024; 96:10356-10364. [PMID: 38863415 DOI: 10.1021/acs.analchem.4c01367] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2024]
Abstract
Capillary electrophoresis with capacitively coupled contactless conductivity detection (CE-C4D) has proven to be an efficient technique for the separation and detection of charged inorganic, organic, and biochemical analytes. It offers several advantages, including cost-effectiveness, nanoliter injection volume, short analysis time, good separation efficiency, suitability for miniaturization, and portability. However, the routine determination of common inorganic cations (NH4+, K+, Na+, Ca2+, Mg2+, and Li+) and inorganic anions (F-, Cl-, Br-, NO2-, NO3-, PO43-, and SO42-) in water quality monitoring typically exhibits limits of detection of about 0.3-1 μM without preconcentration. This sensitivity often proves insufficient for the applications of CE-C4D in trace analysis situations. Here, we explore methods to push the detection limits of CE-C4D through a comprehensive consideration of signal and noise sources. In particular, we (i) studied the model of C4D and its guiding roles in C4D and CE-C4D, (ii) optimized the bandwidth and noise performance of the current-to-voltage (I-V) converter, and (iii) reduced the noise level due to the strong background signal of the background electrolyte by adaptive differential detection. We characterized the system with Li+; the 3-fold signal-to-noise (S/N) detection limit for Li+ was determined at 20 nM, with a linear range spanning from 60 nM to 1.6 mM. Moreover, the optimized CE-C4D method was applied to the analysis of common mixed inorganic cations (K+, Na+, Ca2+, Mg2+, and Li+), anions (F-, Cl-, Br-, NO2-, NO3-, PO43-, and SO42-), toxic halides (BrO3-) and heavy metal ions (Pb2+, Cd2+, Cr3+, Co2+, Ni2+, Zn2+, and Cu2+) at trace concentrations of 200 nM. All electropherograms showed good S/N ratios, thus proving its applicability and accuracy. Our results have shown that the developed CE-C4D method is feasible for trace ion analysis in water quality control.
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Affiliation(s)
- Lin Li
- State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000, China
| | - Dou-Dou Ren
- State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000, China
| | - Peng-Yu Zhang
- State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000, China
| | - Yun-Peng Song
- State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000, China
| | - Tang-Xiu Li
- State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000, China
| | - Ming-Hui Gao
- State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000, China
| | - Jia-Nan Xu
- State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000, China
| | - Lei Zhou
- State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000, China
| | - Zhi-Cong Zeng
- State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000, China
| | - Qiaosheng Pu
- State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000, China
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Somnin C, Chamieh J, Saetear P, Cottet H. Taylor dispersion analysis using capacitively coupled contactless conductivity detector. Talanta 2024; 272:125815. [PMID: 38402737 DOI: 10.1016/j.talanta.2024.125815] [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: 11/12/2023] [Revised: 02/17/2024] [Accepted: 02/18/2024] [Indexed: 02/27/2024]
Abstract
Taylor dispersion analysis (TDA) is a simple and absolute method to determine the hydrodynamic radius of solutes that respond to UV or fluorescence detections. To broaden the application range of TDA, it is necessary to develop new detection modes. This study aims to study capacitively coupled contactless conductivity detector (C4D) for the analysis of charged macromolecules. The detection sensitivities and hydrodynamic radii were compared for a C4D detector and a UV detector on positively or negatively charged polymers responding both to UV and C4D (poly-L-lysine and poly(acrylamide-co-2-acrylamido-1-methyl-propanesulfonate). The influence of the composition of the background electrolyte on the detection sensitivity has been studied and optimized for C4D detection. The influence of the molar mass and of the polymer chemical charge density on the C4D and UV sensitivities of detection have been investigated based on well-characterized copolymers samples of different molar masses and charge densities. The advantages and disadvantages compared to UV detection, as well as the range of applicability of C4D detection in TDA were identified. C4D detection can be an alternative method for sizing charged polymers of reasonable molar mass (typically below 105 g mol-1) that do not absorb in UV. A decline in the sensitivity of detection in C4D was observed for higher molar masses.
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Affiliation(s)
| | - Joseph Chamieh
- IBMM, Université de Montpellier, CNRS, ENSCM, Montpellier, France
| | - Phoonthawee Saetear
- Flow Innovation-Research for Science and Technology Laboratories (Firstlabs), Ratchathewi District, Bangkok, 10110, Thailand; Department of Chemistry and Center of Excellence for Innovation in Chemistry, Faculty of Science, Mahidol University, Rama 6 Road, Ratchathewi District, Bangkok, 10400, Thailand.
| | - Hervé Cottet
- IBMM, Université de Montpellier, CNRS, ENSCM, Montpellier, France.
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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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Opekar F, Tůma P. A new coaxial flow-through probe for electromembrane extraction of methadone from clinical samples on-line coupled to capillary electrophoresis. Anal Chim Acta 2024; 1300:342461. [PMID: 38521571 DOI: 10.1016/j.aca.2024.342461] [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: 01/17/2024] [Revised: 03/05/2024] [Accepted: 03/06/2024] [Indexed: 03/25/2024]
Abstract
BACKGROUND A new design of a flow-through coaxial electromembrane extraction (EME) probe that can be on-line coupled with CE instrument is described and tested. The supporting base of the probe is a PDMS microchip with T-shaped channels into which two coaxially arranged capillaries for inlet and outlet solutions are inserted. The extraction part of the probe is a porous polypropylene hollow fiber, sealed at one end and modified with nitrophenyloctyl ether (NPOE) extraction fluid. The internal volume of the extraction probe is 1.1 μL. RESULTS The EME probe was tested on laboratory samples and methadone was extracted into 3.0 M AcOH as acceptor. The concentration dependence was linear in the range of 0.1-1.0 μg mL-1 at EME 300 s/150 V and in the range of 0.5-10.0 μg mL-1 at EME 100 s/150 V. The enrichment factor was greater than 30 and the LOD was 0.21 μg mL-1. The EME of methadone in clinical samples showed a linear concentration dependence in human urine and a nonlinear concentration dependence in serum. The distribution of methadone in each phase of the extraction system and the effect of extraction membrane thickness on the enrichment factor were studied. The EME probe can be applied repeatedly. SIGNIFICANCE The supporting base of EME probe and flow gating interface (FGI) are realized by a microfluidic PDMS microchips cast in the laboratory without the use of lithography. A supporting PDMS chip with coaxially arranged capillaries and extraction membrane forms a compact analytical instrument. The entire EME/CE analysis process is performed on a laboratory-made instrument and automated by LabView.
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Affiliation(s)
- František Opekar
- Charles University, Faculty of Science, Department of Analytical Chemistry, Albertov 2030, 2, 128 43, Prague, Czech Republic.
| | - Petr Tůma
- Charles University, Third Faculty of Medicine, Department of Hygiene, Ruská 87, 10, 100 00, Prague, Czech Republic.
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Elbashir AA, Osman A, Elawad M, Ziyada AK, Aboul-Enein HY. Application of capillary electrophoresis with capacitively contactless conductivity detection for biomedical analysis. Electrophoresis 2024; 45:400-410. [PMID: 38100198 DOI: 10.1002/elps.202300216] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Revised: 11/26/2023] [Accepted: 12/06/2023] [Indexed: 03/20/2024]
Abstract
The coupling of capillary electrophoresis (CE) with capacitively coupled contactless conductivity detection (C4 D) has become convenient analytical method for determination of small molecules that do not possess chromogenic or fluorogenic group. The implementations of CE with C4 D in the determination of inorganic and organic ions and amino acids in biomedical field are demonstrated. Attention on background electrolyte composition, sample treatment procedures, and the utilize of multi-detection systems are described. A number of tables summarizing highly developed CE-C4 D methods and the figures of merit attained are involved. Lastly, concluding remarks and perspectives are argued.
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Affiliation(s)
- Abdalla A Elbashir
- Department, of Chemistry, College of Science, King Faisal University, Al-Hofuf, Al-Ahsa, Saudi Arabia
- Department of Chemistry, Faculty of Science, University of Khartoum, Khartoum, Sudan
| | - Abdelbagi Osman
- Department of Chemical Engineering, College of Engineering, Najran University, Najran, Saudi Arabia
| | - Mohammed Elawad
- Department of Chemistry, Faculty of Science, Omdurman Islamic University, Omdurman, Sudan
| | - Abobakr K Ziyada
- Department of General Studies, Jubail Industrial College, Jubail Industrial City, Saudi Arabia
| | - Hassan Y Aboul-Enein
- Pharmaceutical and Medicinal Chemistry Department, Division of Pharmaceutical and Drug Industries Research Division, National Research Centre, Cairo, Egypt
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Rocha KN, da Silva JAF, de Jesus DP. Capillary electrophoresis with capacitively coupled contactless conductivity detection (C 4 D) for rapid and simple determination of lactate in sweat. Electrophoresis 2024; 45:392-399. [PMID: 38072648 DOI: 10.1002/elps.202300179] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2023] [Revised: 11/28/2023] [Accepted: 11/30/2023] [Indexed: 03/20/2024]
Abstract
An analytical method based on capillary electrophoresis (CE) using capacitively coupled contactless conductivity detection (C4 D) was developed and validated for fast, straightforward, and reliable determination of lactate in artificial and human sweat samples. The background electrolyte was composed of equimolar concentrations (10 mmol/L) of 2-(N-morpholino)ethanesulfonic acid and histidine, with 0.2 mmol/L of cetyltrimethylammonium bromide as electroosmotic flow inverter. The limit of detection and quantification were 3.1 and 10.3 µmol/L, respectively. Recoveries in the 97 to 118% range were obtained using sweat samples spiked with lactate at three concentration levels, indicating an acceptable accuracy. The intraday and interday precisions were 1.49 and 7.08%, respectively. The proposed CE-C4 D method can be a starting point for monitoring lactate concentrations in sweat samples for diagnostics, physiological studies, and sports performance assessment applications.
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Affiliation(s)
- Kionnys N Rocha
- Instituto de Química, Universidade Estadual de Campinas, UNICAMP, Campinas, São Paulo, Brazil
| | - José A Fracassi da Silva
- Instituto de Química, Universidade Estadual de Campinas, UNICAMP, Campinas, São Paulo, Brazil
- Instituto Nacional de Ciência e Tecnologia de Bioanalítica, Campinas, São Paulo, Brazil
| | - Dosil P de Jesus
- Instituto de Química, Universidade Estadual de Campinas, UNICAMP, Campinas, São Paulo, Brazil
- Instituto Nacional de Ciência e Tecnologia de Bioanalítica, Campinas, São Paulo, Brazil
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Tůma P. Steady state microdialysis of microliter volumes of body fluids for monitoring of amino acids by capillary electrophoresis with contactless conductivity detection. Anal Chim Acta 2024; 1287:342113. [PMID: 38182349 DOI: 10.1016/j.aca.2023.342113] [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: 10/11/2023] [Revised: 12/03/2023] [Accepted: 12/04/2023] [Indexed: 01/07/2024]
Abstract
BACKGROUND The availability of dialysis membranes in the form of hollow fibres with diameters compatible with the fused silica capillaries used in capillary electrophoresis is very limited. However, haemodialysis bicarbonate cartridges commonly used in human medicine containing polysulfone hollow fibres are available on the market and are used for the fabrication of coaxial microdialysis probes. The miniature probe design ensures that steady-state conditions are achieved during microdialysis of minimal volumes of body fluids. RESULTS A coaxial microdialysis probe with a length of 5 cm and an inner diameter of 200 μm is used for microdialysis of 10 μL of body fluid collected into a sampling fused silica capillary with an inner diameter 430 μm. Microdialysis is performed into 0.01 M HCl as a perfusate at stopped flow and 2 μL of the resulting microdialysate are subjected to analysis by capillary electrophoresis with contactless conductivity detection. Microdialysis pre-treatment is verified by analysis of 11 common amino acids at a 100 μM concentration level, resulting in recoveries of 98.3-102.5%. The electrophoretic separation of amino acids is performed in 8.5 M acetic acid at pH 1.37 as a background electrolyte with analysis time up to 4.5 min and LOD in the range of 0.12-0.28 μM. The reproducibility of the developed technique determined for the peak area ranges from 1.2 to 4.5%. Applicability is tested in the quantification of valine and leucine in plasma during fasting and subsequent reconvalescence. SIGNIFICANCE The fabrication of a coaxial microdialysis probe for the laboratory preparation of microliter volumes of various types of clinical samples is described, which is coupled off-line with capillary electrophoretic monitoring of amino acids in 2 μL volumes of microdialysate. The developed methodology is suitable for quantification of 20 amino acids in whole human blood, plasma, tears and has potential for analysis of dry blood spots captured on hollow fibre.
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Affiliation(s)
- Petr Tůma
- Department of Hygiene, Third Faculty of Medicine, Charles University, Ruská 87, 100 00, Prague, 10, Czechia.
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Bržezická T, Mlčochová H, Glatz Z, Kohútová L. Contactless conductivity detector as a tool for improving universality and sensitivity of capillary electrophoresis-frontal analysis: Proof of concept. J Sep Sci 2024; 47:e2300667. [PMID: 38234025 DOI: 10.1002/jssc.202300667] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2023] [Revised: 11/13/2023] [Accepted: 12/05/2023] [Indexed: 01/19/2024]
Abstract
Drug binding to plasma proteins influences processes such as liberation, adsorption, disposition, metabolism, and elimination of drugs, which are thus one of the key steps of a new drug development. As a result, the characterization of drug-protein interactions is an essential part of these time- and money-consuming processes. It is important to determine not only the binding strength and the stoichiometry of interaction, but also the binding site of a drug on a protein molecule, because two drugs with the same binding site can mutually affect free drug concentration. Capillary electrophoresis-frontal analysis with mobility shift affinity capillary electrophoresis is one of the most used affinity capillary electrophoresis methods for the characterization of these interactions. In this study, a well-known sensitivity problem of most capillary electrophoresis-frontal analyses using ultraviolet detection is solved by its combination with contactless conductivity detection, which provided sixfold lower limits of quantitation and detection. Binding parameters of the human serum albumin-salicylic acid model affinity pair were evaluated by this newly developed approach and by the classical approach with ultraviolet detection primarily used for their mutual comparison. The results of both approaches agreed well and are also in agreement with literature data obtained using different techniques.
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Affiliation(s)
- Taťána Bržezická
- Department of Biochemistry, Faculty of Science, Masaryk University, Brno, Czech Republic
| | - Hana Mlčochová
- Department of Biochemistry, Faculty of Science, Masaryk University, Brno, Czech Republic
| | - Zdeněk Glatz
- Department of Biochemistry, Faculty of Science, Masaryk University, Brno, Czech Republic
| | - Lenka Kohútová
- Department of Biochemistry, Faculty of Science, Masaryk University, Brno, Czech Republic
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Yin B, Zhang Z, Wang Y, Zeng H, Xu J, Li H, Li Y, Zhang M. Compact contactless conductometric, ultraviolet photometric and dual-detection cells for capillary electrophoresis via additive manufacturing. J Chromatogr A 2023; 1712:464469. [PMID: 37924616 DOI: 10.1016/j.chroma.2023.464469] [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: 09/11/2023] [Revised: 10/16/2023] [Accepted: 10/19/2023] [Indexed: 11/06/2023]
Abstract
The growing demand for tailored detectors in capillary electrophoresis (CE), addressing tasks like field deployment or dual-detection analysis, emphasizes the necessity for compact detection cells. In this work, we propose cost-effective and user-friendly additive manufacturing (3D-printing) approaches to produce such miniaturized detection cells suitable for a range of CE applications. Firstly, capacitively-coupled contactless conductivity detection (C4D) cells of different sizes are fabricated by casting low-melting-point alloy into 3D-printed molds. Various designs of Faraday shields are integrated within the cells and compared. A mini-C4D cell (9.5×7.0×7.5 mm3) is produced, with limits of detection for alkaline cations ranging from 8-12 μM in a short-capillary based CE application. Secondly, ultraviolet photometric (UV-PD) detection cells are fabricated using 3D printing. These cells feature two narrow slits with a width of 60 μm, which are positioned along the path of incident and transmission light to facilitate collimation. A deep UV-LED (235 nm or 255 nm) is employed as the light source, and black resin is determined to be the optimal material for 3D printing the UV-PD cell, owing to its superior UV light absorption capabilities. The UV-PD cell is connected to the LED and photodetector through two optical fibers, making it easy to switch the light source and detector. The effective pathlength and stray light percentage for detecting on a 75 μm id capillary are 74 μm and 0.5 %, respectively. Thirdly, a dual-detection cell that combined C4D and UV-PD at a single detection point is proposed. The performance of direct detection by C4D and indirect detection by UV-PD is compared for detecting organic acids. The strategies for developing cost-effective compact detection cells facilitate the versatile integration of multiple detection methods in CE analysis.
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Affiliation(s)
- Bangjie Yin
- School of Life and Environmental Sciences, Guilin University of Electronic Technology, Guilin, Guangxi 541004, China
| | - Zheng Zhang
- School of Life and Environmental Sciences, Guilin University of Electronic Technology, Guilin, Guangxi 541004, China
| | - Yingchun Wang
- School of Life and Environmental Sciences, Guilin University of Electronic Technology, Guilin, Guangxi 541004, China
| | - Hui Zeng
- School of Life and Environmental Sciences, Guilin University of Electronic Technology, Guilin, Guangxi 541004, China.
| | - Jin Xu
- School of Life and Environmental Sciences, Guilin University of Electronic Technology, Guilin, Guangxi 541004, China
| | - Hongzhou Li
- School of Life and Environmental Sciences, Guilin University of Electronic Technology, Guilin, Guangxi 541004, China
| | - Yan Li
- School of Life and Environmental Sciences, Guilin University of Electronic Technology, Guilin, Guangxi 541004, China
| | - Min Zhang
- School of Life and Environmental Sciences, Guilin University of Electronic Technology, Guilin, Guangxi 541004, China.
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Liu D, Xiong Y, Zeng H, Xu J, Tang B, Li Y, Zhang M. Deep UV-LED induced nitrate-to-nitrite conversion for total dissolved nitrogen determination in water samples through persulfate digestion and capillary electrophoresis. Anal Chim Acta 2023; 1278:341743. [PMID: 37709434 DOI: 10.1016/j.aca.2023.341743] [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: 07/28/2023] [Accepted: 08/20/2023] [Indexed: 09/16/2023]
Abstract
BACKGROUND Capillary electrophoresis (CE) with capacitively coupled contactless conductivity detection (C4D) is widely used for water quality monitoring. However, there is currently no reported CE method for detecting total dissolved nitrogen (TDN), a crucial parameter for assessing water eutrophication. One challenge is the high sulfate concentration (100 mM) introduced during persulfate digestion, leading to overlap of nitrate (from TDN) and poor electrical stacking of nitrate in CE-C4D analysis. RESULTS We introduced an in-capillary UV-LED induced photoreaction to convert nitrate to nitrite, which can be baseline-separated from sulfate via the CE method, enabling accurate quantification of nitrate concentration derived from nitrite. A 2 nL post-persulfate digested sample solution within a fused silica capillary was exposed to UV-LED irradiation at the capillary tip. Subsequently, photoreduction-produced nitrite was electrophoretically separated from sulfate in an acidic buffer (pH = 3.7) within the same capillary, followed by contactless conductivity detection. The nitrate-to-nitrite conversion efficiency was influenced by irradiation wavelength, power, and duration, reaching a maximum efficiency of 77.4% when employing two 230 nm LEDs for 5 min. For more general applications, two 255 nm LEDs were used, providing a conversion efficiency of (66.4 ± 3.3)% (n = 11) for 5 min of irradiation. The proposed CE-C4D method exhibits a detection limit of 13 μM (0.18 mg N/L) and has been successfully employed for TDN determination in lake water samples. SIGNIFICANCE This innovative approach not only enhances the attractiveness of the CE-C4D method for the determination of water quality indicators but also highlights the potential for integrating deep-UV LEDs into environmental analysis.
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Affiliation(s)
- Dongmei Liu
- School of Life and Environmental Sciences, Guilin University of Electronic Technology, Guilin, Guangxi, 541004, China
| | - Yu Xiong
- School of Life and Environmental Sciences, Guilin University of Electronic Technology, Guilin, Guangxi, 541004, China
| | - Hui Zeng
- School of Life and Environmental Sciences, Guilin University of Electronic Technology, Guilin, Guangxi, 541004, China.
| | - Jin Xu
- School of Life and Environmental Sciences, Guilin University of Electronic Technology, Guilin, Guangxi, 541004, China
| | - Biyu Tang
- China Nonferrous Metals (Guilin) Geology and Mining Co., Ltd., Guilin, Guangxi, 541004, China
| | - Yan Li
- School of Life and Environmental Sciences, Guilin University of Electronic Technology, Guilin, Guangxi, 541004, China
| | - Min Zhang
- School of Life and Environmental Sciences, Guilin University of Electronic Technology, Guilin, Guangxi, 541004, China.
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Abdollahi Aghdam A, Chamanara M, Laripour R, Ebrahimi M. Micro-extraction, pre-concentration, and microfluidic-based separation of organophosphate insecticides followed by the miniaturized electrochemical detection system. BIOIMPACTS : BI 2023; 14:25288. [PMID: 38938753 PMCID: PMC11199932 DOI: 10.34172/bi.2023.25288] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Revised: 06/20/2022] [Accepted: 07/02/2022] [Indexed: 06/29/2024]
Abstract
Introduction A new analytical method based on the coupling of microextraction and microfluidics was developed and investigated for the pre-concentration, separation, and electrochemical detection of fenitrothion (FT) and parathion (PA) at the sub-ppm concentrations. Methods In the first step, the microchip capillary electrophoresis technique was used to serve as a separation and detection system. Analytes were injected in the 40 mm long microchannel with 10 mm sidearms. Then, they were separated by applying a direct electrical field (+1800 V) between the buffer and detection reservoirs. 2-(n-morpholino)ethanesulfonic acid (MES) buffer (20 mM, pH 5) was used as a running buffer. The electrochemical detection was performed using three Pt microelectrodes with the width of working, counter, and reference electrodes (50, 250, and 250 µm, respectively) in the out-channel approach. Results The system was devised to have the optimum detection potential equal to -1.2 V vs. pseudo-reference electrode. The dimensions of the SU-8 channel have 20 µm depth and 50 µm width. In the second step, an air-assisted liquid-liquid microextraction technique was used to extract and preconcentration of analytes from human blood plasma. Then, 1, 2 di-bromoethan was used as extractant solvent, the analytes were preconcentrated, and the sedimented solvent (50 µL) was evaporated in a 60 ˚C water bath followed by substitution of running buffer containing 10% ethanol. The optimal extraction cycles were found to be 8 with adding 1% NaCl to the aqueous phase. Analyzing time of the mentioned analytes was less than 100s, the precision range was 3.3 - 8.2 with a linear range of 0.8-100 ppm and 1.2-100 ppm for FT and PA, respectively. The extraction recoveries were about 91% and 87% for FT and PA, respectively. The detection limits for FT and PA were 240 and 360 ppb, respectively. Finally, the reliability of the method was investigated by GC-FID. Conclusion The proposed method and device were validated and can be used as in situ and portable detection systems for detecting fenitrothion and parathion insecticides.
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Affiliation(s)
- Abdollah Abdollahi Aghdam
- Department of Toxicology and Pharmacology, Faculty of Medicine, AJA University of Medical Sciences, Tehran, Iran
- Research Center for Pharmaceutical Nanotechnology, Biomedicine Institute, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Mohsen Chamanara
- Department of Toxicology and Pharmacology, Faculty of Medicine, AJA University of Medical Sciences, Tehran, Iran
- Toxicology Research Center, AJA University of Medical Sciences, Tehran, Iran
| | - Reza Laripour
- Department of Social and Preventive Medicine, Faculty of Medicine, AJA University of Medical Sciences, Tehran, Iran
| | - Mohsen Ebrahimi
- Department of Toxicology and Pharmacology, Faculty of Medicine, AJA University of Medical Sciences, Tehran, Iran
- Toxicology Research Center, AJA University of Medical Sciences, Tehran, Iran
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12
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Cao Y, Tao Z, Tian Y, Chen KE, Zhang L, Ren J, Xiao H, Zhang Q, Liu W, Cao C. A handheld contactless conductivity detector for monitoring the desalting of low-volume virus and cell samples. Biosens Bioelectron 2023; 237:115482. [PMID: 37406479 DOI: 10.1016/j.bios.2023.115482] [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: 03/07/2023] [Revised: 05/25/2023] [Accepted: 06/14/2023] [Indexed: 07/07/2023]
Abstract
Desalting of biosamples is crucial for analytical techniques intolerant to abundant salts. However, there is no simple tool to monitor the desalting of low-volume biosamples so far. Here we developed a handheld capacitively coupled contactless conductivity detector (hC4D) as a miniaturized device to measure the conductivity of 75 μL biosamples. Polyether-ether-ketone (PEEK) tubing was selected as the sample reservoir for sample loading via a pipette. Another pipetting of air pushed the sample solution out of the tubing to recollect the sample. Owing to the low sample consumption and easy sample recollection, hC4D is advantageous for testing expensive biosamples, such as viruses and cells. In addition, the whole process of sample injection, conductivity measurement, recollection, and calibration of conductivity can be completed within 1 min. To verify the feasibility of hC4D, we monitored the desalting progress of gel filtration (GF) of 200 μL blood samples, ultrafiltration (UF) of 300 μL virus samples, and dialysis of 7 mL cell samples. Three rounds of GF and UF completely removed the salts but led to poor sample recovery. In contrast, low concentrations of residual salts remained and better recovery was achieved after two rounds of GF and UF. We further utilized the hC4D to monitor the dialysis and tuned the salt concentration in the cell sample, such that we maintained the viability of cells in a low conductivity environment. These results indicated that hC4D is a promising tool for optimizing the desalting procedure of low-volume biosamples.
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Affiliation(s)
- Yiren Cao
- School of Sensing Science and Engineering, School of Electronic Information and Electrical Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China; School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Zhimin Tao
- School of Sensing Science and Engineering, School of Electronic Information and Electrical Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Youli Tian
- School of Life Science and Biotechnology, State Key Laboratory of Microbial Metabolism, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Ke-Er Chen
- School of Chemical and Environmental Engineering, Shanghai Institute of Technology, Shanghai, 201418, China
| | - Lu Zhang
- School of Life Science and Biotechnology, State Key Laboratory of Microbial Metabolism, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Jicun Ren
- School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Hua Xiao
- School of Life Science and Biotechnology, State Key Laboratory of Microbial Metabolism, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Qiang Zhang
- School of Sensing Science and Engineering, School of Electronic Information and Electrical Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Weiwen Liu
- School of Sensing Science and Engineering, School of Electronic Information and Electrical Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China.
| | - Chengxi Cao
- School of Sensing Science and Engineering, School of Electronic Information and Electrical Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China; School of Life Science and Biotechnology, State Key Laboratory of Microbial Metabolism, Shanghai Jiao Tong University, Shanghai, 200240, China.
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13
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Krebs F, Zagst H, Stein M, Ratih R, Minkner R, Olabi M, Hartung S, Scheller C, Lapizco-Encinas BH, Sänger-van de Griend C, García CD, Wätzig H. Strategies for capillary electrophoresis: Method development and validation for pharmaceutical and biological applications-Updated and completely revised edition. Electrophoresis 2023; 44:1279-1341. [PMID: 37537327 DOI: 10.1002/elps.202300158] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Accepted: 07/19/2023] [Indexed: 08/05/2023]
Abstract
This review is in support of the development of selective, precise, fast, and validated capillary electrophoresis (CE) methods. It follows up a similar article from 1998, Wätzig H, Degenhardt M, Kunkel A. "Strategies for capillary electrophoresis: method development and validation for pharmaceutical and biological applications," pointing out which fundamentals are still valid and at the same time showing the enormous achievements in the last 25 years. The structures of both reviews are widely similar, in order to facilitate their simultaneous use. Focusing on pharmaceutical and biological applications, the successful use of CE is now demonstrated by more than 600 carefully selected references. Many of those are recent reviews; therefore, a significant overview about the field is provided. There are extra sections about sample pretreatment related to CE and microchip CE, and a completely revised section about method development for protein analytes and biomolecules in general. The general strategies for method development are summed up with regard to selectivity, efficiency, precision, analysis time, limit of detection, sample pretreatment requirements, and validation.
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Affiliation(s)
- Finja Krebs
- Institute, of Medicinal and Pharmaceutical Chemistry, Technische Universität Braunschweig, Braunschweig, Lower Saxony, Germany
| | - Holger Zagst
- Institute, of Medicinal and Pharmaceutical Chemistry, Technische Universität Braunschweig, Braunschweig, Lower Saxony, Germany
| | - Matthias Stein
- Institute, of Medicinal and Pharmaceutical Chemistry, Technische Universität Braunschweig, Braunschweig, Lower Saxony, Germany
| | - Ratih Ratih
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, University of Surabaya, Surabaya, East Java, Indonesia
| | - Robert Minkner
- Institute, of Medicinal and Pharmaceutical Chemistry, Technische Universität Braunschweig, Braunschweig, Lower Saxony, Germany
| | - Mais Olabi
- Institute, of Medicinal and Pharmaceutical Chemistry, Technische Universität Braunschweig, Braunschweig, Lower Saxony, Germany
| | - Sophie Hartung
- Institute, of Medicinal and Pharmaceutical Chemistry, Technische Universität Braunschweig, Braunschweig, Lower Saxony, Germany
| | - Christin Scheller
- Institute, of Medicinal and Pharmaceutical Chemistry, Technische Universität Braunschweig, Braunschweig, Lower Saxony, Germany
| | - Blanca H Lapizco-Encinas
- Department of Biomedical Engineering, Kate Gleason College of Engineering, Rochester Institute of Technology, Rochester, New York, USA
| | - Cari Sänger-van de Griend
- Kantisto BV, Baarn, The Netherlands
- Department of Medicinal Chemistry, Faculty of Pharmacy, Uppsala Universitet, Uppsala, Sweden
| | - Carlos D García
- Department of Chemistry, Clemson University, Clemson, South Carolina, USA
| | - Hermann Wätzig
- Institute, of Medicinal and Pharmaceutical Chemistry, Technische Universität Braunschweig, Braunschweig, Lower Saxony, Germany
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14
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Moravčík O, Dvořák M, Kubáň P. Autonomous capillary electrophoresis processing and analysis of dried blood spots for high-throughput determination of uric acid. Anal Chim Acta 2023; 1267:341390. [PMID: 37257961 DOI: 10.1016/j.aca.2023.341390] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Revised: 04/28/2023] [Accepted: 05/16/2023] [Indexed: 06/02/2023]
Abstract
A new set-up for fully autonomous and high-throughput capillary electrophoresis (CE) analyses of dried blood spot (DBS) samples is presented. The DBS samples were prepared by collecting exactly 5 μL of capillary blood from a finger-prick onto a pre-punched DBS disc in a disposable plastic CE vial and by in-vial blood drying. The vials with the DBS samples were then loaded into a commercial CE instrument for a fully unmanned sample processing and analysis. A fused-silica capillary of the CE instrument was first used for the transfer of 100 μL of elution solvent to each vial, in-vial DBS elution, and in-vial eluate homogenization. The same capillary was also used for at-line injection, separation, and selective analysis of the resulting eluates. Novel CE sequences were tailor-programmed for consecutive processing and analyses of multiple DBSs, which facilitated a fully autonomous determination of uric acid with a throughput of 240 DBS samples per day (24 h). The presented analytical protocol (using 100 μm i. d./30 cm capillary; 30 mM 2-(N-morpholino)-ethanesulfonic acid, 30 mM l-histidine, and 30 μM cetyltrimethylammonium bromide background electrolyte solution; and UV detection at 292 nm) provided excellent precision at endogenous and spiked uric acid concentrations with RSD values of peak areas below 3.2%. Calibration curves were linear over the 33.3 - 1200 μM range (R2 better than 0.998), limits of detection and quantification in the original capillary blood were 10 and 33.3 μM, respectively, and were well below the uric acid clinical range (140-420 μM). The stability of uric acid in DBS samples stored at laboratory temperature for up to 2 months was also excellent demonstrating less than a 4.2% decrease in uric acid concentrations. The actual set-up might thus be highly attractive for clinical subjects and laboratories because it is minimally invasive and requires minimum intervention from laboratory staff.
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Affiliation(s)
- Ondrej Moravčík
- Institute of Analytical Chemistry of the Czech Academy of Sciences, Veveří 97, CZ-60200, Brno, Czech Republic; Faculty of Science, Department of Chemistry, Masaryk University, Kamenice 5, CZ-62500, Brno, Czech Republic
| | - Miloš Dvořák
- Institute of Analytical Chemistry of the Czech Academy of Sciences, Veveří 97, CZ-60200, Brno, Czech Republic
| | - Pavel Kubáň
- Institute of Analytical Chemistry of the Czech Academy of Sciences, Veveří 97, CZ-60200, Brno, Czech Republic.
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15
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Sheng B, Huang J, Ji H, Huang Z. A New Contactless Cross-Correlation Velocity Measurement System for Gas-Liquid Two-Phase Flow. SENSORS (BASEL, SWITZERLAND) 2023; 23:4886. [PMID: 37430800 DOI: 10.3390/s23104886] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Revised: 05/09/2023] [Accepted: 05/17/2023] [Indexed: 07/12/2023]
Abstract
Based on the principle of Contactless Conductivity Detection (CCD), a new contactless cross-correlation velocity measurement system with a three-electrode construction is developed in this work and applied to the contactless velocity measurement of gas-liquid two-phase flow in small channels. To achieve a compact design and to reduce the influence of the slug/bubble deformation and the relative position change on the velocity measurement, an electrode of the upstream sensor is reused as an electrode of the downstream sensor. Meanwhile, a switching unit is introduced to ensure the independence and consistency of the upstream sensor and the downstream sensor. To further improve the synchronization of the upstream sensor and the downstream sensor, fast switching and time compensation are also introduced. Finally, with the obtained upstream and downstream conductance signals, the velocity measurement is achieved by the principle of cross-correlation velocity measurement. To test the measurement performance of the developed system, experiments are carried out on a prototype with a small channel of 2.5 mm. The experimental results show that the compact design (three-electrode construction) is successful, and its measurement performance is satisfactory. The velocity range for the bubble flow is 0.312-0.816 m/s, and the maximum relative error of the flow rate measurement is 4.54%. The velocity range for the slug flow is 0.161 m/s-1.250 m/s, and the maximum relative error of the flow rate measurement is 3.70%.
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Affiliation(s)
- Bixia Sheng
- State Key Laboratory of Industrial Control Technology, College of Control Science and Engineering, Zhejiang University, Hangzhou 310027, China
- Xiaoshan District Committee of the Communist Youth League, Hangzhou 311222, China
| | - Junchao Huang
- State Key Laboratory of Industrial Control Technology, College of Control Science and Engineering, Zhejiang University, Hangzhou 310027, China
- College of Optical, Mechanical and Electrical Engineering, Zhejiang A&F University, Hangzhou 311300, China
| | - Haifeng Ji
- State Key Laboratory of Industrial Control Technology, College of Control Science and Engineering, Zhejiang University, Hangzhou 310027, China
| | - Zhiyao Huang
- State Key Laboratory of Industrial Control Technology, College of Control Science and Engineering, Zhejiang University, Hangzhou 310027, China
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16
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Van Schepdael A. Capillary electrophoresis as a simple and low-cost analytical tool for use in money-constrained situations. Trends Analyt Chem 2023. [DOI: 10.1016/j.trac.2023.116992] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
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17
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Do YN, Kieu TLP, Dang THM, Nguyen QH, Dang TH, Tran CS, Vu AP, Do TT, Nguyen TN, Dinh SL, Nguyen TMT, Pham TNM, Hoang AQ, Pham B, Nguyen TAH. Green Analytical Method for Simultaneous Determination of Glucosamine and Calcium in Dietary Supplements by Capillary Electrophoresis with Capacitively Coupled Contactless Conductivity Detection. JOURNAL OF ANALYTICAL METHODS IN CHEMISTRY 2023; 2023:2765508. [PMID: 36760655 PMCID: PMC9904918 DOI: 10.1155/2023/2765508] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Revised: 09/25/2022] [Accepted: 11/24/2022] [Indexed: 06/18/2023]
Abstract
The need for analytical methods that are fast, affordable, and ecologically friendly is expanding. Because of its low solvent consumption, minimal waste production, and speedy analysis, capillary electrophoresis is considered a "green" choice among analytical separation methods. With these "green" features, we have utilized the capillary electrophoresis method with capacitively coupled contactless conductivity detection (CE-C4D) to simultaneously determine glucosamine and Ca2+ in dietary supplements. The CE analysis was performed in fused silica capillaries (50 μm inner diameter, 40 cm total length, 30 cm effective length), and the analytical time was around 5 min. After optimization, the CE conditions for selective determination of glucosamine and Ca2+ were obtained, including a 10 mM tris (hydroxymethyl) aminomethane/acetic acid (Tris/Ace) buffer of pH 5.0 as the background electrolyte; separation voltage of 20 kV; and hydrodynamic injection (siphoning) at 25 cm height for 30 s. The method illustrated good linearity over the concentration range of 5.00 to 200 mg/L of for glucosamine (R 2 = 0.9994) and 1.00 to 100 mg/L for Ca2+ (R 2 = 0.9994). Under the optimum conditions, the detection limit of glucosamine was 1.00 mg/L, while that of Ca2+ was 0.05 mg/L. The validated method successfully analyzed glucosamine and Ca2+ in seven dietary supplement samples. The measured concentrations were generally in line with the values of label claims and with cross-checking data from reference methods (HPLC and ICP-OES).
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Affiliation(s)
- Yen Nhi Do
- Faculty of Chemistry, University of Science, Vietnam National University, 19 Le Thanh Tong, Hanoi 10000, Vietnam
| | - Thi Lan Phuong Kieu
- Faculty of Chemistry, University of Science, Vietnam National University, 19 Le Thanh Tong, Hanoi 10000, Vietnam
- National Institute for Food Control (NIFC), 65 Pham Than Duat, Hanoi 10000, Vietnam
| | - Thi Huyen My Dang
- Faculty of Chemistry, University of Science, Vietnam National University, 19 Le Thanh Tong, Hanoi 10000, Vietnam
| | - Quang Huy Nguyen
- Faculty of Chemistry, University of Science, Vietnam National University, 19 Le Thanh Tong, Hanoi 10000, Vietnam
- Faculty of Pharmacy, University of Medicine and Pharmacy, Thai Nguyen University, 284 Luong Ngoc Quyen, Thai Nguyen 24000, Vietnam
| | - Thu Hien Dang
- National Institute for Food Control (NIFC), 65 Pham Than Duat, Hanoi 10000, Vietnam
| | - Cao Son Tran
- National Institute for Food Control (NIFC), 65 Pham Than Duat, Hanoi 10000, Vietnam
| | - Anh Phuong Vu
- Poison Control Center, Bach Mai Hospital, 78 Giai Phong, Hanoi 10000, Vietnam
| | - Thi Trang Do
- Poison Control Center, Bach Mai Hospital, 78 Giai Phong, Hanoi 10000, Vietnam
| | - Thi Ngan Nguyen
- Poison Control Center, Bach Mai Hospital, 78 Giai Phong, Hanoi 10000, Vietnam
| | - Son Luong Dinh
- Poison Control Center, Bach Mai Hospital, 78 Giai Phong, Hanoi 10000, Vietnam
| | - Thi Minh Thu Nguyen
- Faculty of Chemistry, University of Science, Vietnam National University, 19 Le Thanh Tong, Hanoi 10000, Vietnam
| | - Thi Ngoc Mai Pham
- Faculty of Chemistry, University of Science, Vietnam National University, 19 Le Thanh Tong, Hanoi 10000, Vietnam
| | - Anh Quoc Hoang
- Faculty of Chemistry, University of Science, Vietnam National University, 19 Le Thanh Tong, Hanoi 10000, Vietnam
| | - Bach Pham
- Faculty of Chemistry, University of Science, Vietnam National University, 19 Le Thanh Tong, Hanoi 10000, Vietnam
| | - Thi Anh Huong Nguyen
- Faculty of Chemistry, University of Science, Vietnam National University, 19 Le Thanh Tong, Hanoi 10000, Vietnam
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18
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Nguyen QH, Dang THM, Quynh Le TP, Luu THT, Dinh TD, Mai TK, Nguyen TMT, Nguyen TAH, Mai TD. Inexpensive and simple tool for quality control of nutraceutical and tonic products with capillary electrophoresis and contactless conductivity detection: Some developments in Vietnam. J Food Compost Anal 2023. [DOI: 10.1016/j.jfca.2022.104882] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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19
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Fejfarová V, Jarošíková R, Polák J, Sommerová B, Husáková J, Wosková V, Dubský M, Tůma P. Microdialysis as a tool for antibiotic assessment in patients with diabetic foot: a review. Front Endocrinol (Lausanne) 2023; 14:1141086. [PMID: 37139338 PMCID: PMC10150051 DOI: 10.3389/fendo.2023.1141086] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Accepted: 03/17/2023] [Indexed: 05/05/2023] Open
Abstract
Diabetic foot is a serious late complication frequently caused by infection and ischaemia. Both require prompt and aggressive treatment to avoid lower limb amputation. The effectiveness of peripheral arterial disease therapy can be easily verified using triplex ultrasound, ankle-brachial/toe-brachial index examination, or transcutaneous oxygen pressure. However, the success of infection treatment is difficult to establish in patients with diabetic foot. Intravenous systemic antibiotics are recommended for the treatment of infectious complications in patients with moderate or serious stages of infection. Antibiotic therapy should be initiated promptly and aggressively to achieve sufficient serum and peripheral antibiotic concentrations. Antibiotic serum levels are easily evaluated by pharmacokinetic assessment. However, antibiotic concentrations in peripheral tissues, especially in diabetic foot, are not routinely detectable. This review describes microdialysis techniques that have shown promise in determining antibiotic levels in the surroundings of diabetic foot lesions.
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Affiliation(s)
- Vladimíra Fejfarová
- Diabetes Centre, Institute for Clinical and Experimental Medicine, Prague, Czechia
- Second Faculty of Medicine, Charles University, Prague, Czechia
- *Correspondence: Vladimíra Fejfarová,
| | - Radka Jarošíková
- Diabetes Centre, Institute for Clinical and Experimental Medicine, Prague, Czechia
- Second Faculty of Medicine, Charles University, Prague, Czechia
| | - Jan Polák
- Department of Pathophysiology, Third Faculty of Medicine, Charles University, Prague, Czechia
| | - Blanka Sommerová
- Department of Hygiene, Third Faculty of Medicine, Charles University, Prague, Czechia
| | - Jitka Husáková
- Diabetes Centre, Institute for Clinical and Experimental Medicine, Prague, Czechia
| | - Veronika Wosková
- Diabetes Centre, Institute for Clinical and Experimental Medicine, Prague, Czechia
| | - Michal Dubský
- Diabetes Centre, Institute for Clinical and Experimental Medicine, Prague, Czechia
| | - Petr Tůma
- Department of Hygiene, Third Faculty of Medicine, Charles University, Prague, Czechia
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20
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Novel developments in capillary electrophoresis miniaturization, sampling, detection and portability: An overview of the last decade. Trends Analyt Chem 2023. [DOI: 10.1016/j.trac.2023.116941] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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21
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Wang C, Huang J, Ji H, Huang Z. Response Characteristics of Contactless Impedance Detection (CID) Sensor on Slug Flow in Small Channels: The Investigation on Slug Separation Distance. SENSORS (BASEL, SWITZERLAND) 2022; 22:8987. [PMID: 36433583 PMCID: PMC9692662 DOI: 10.3390/s22228987] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Revised: 11/04/2022] [Accepted: 11/18/2022] [Indexed: 06/16/2023]
Abstract
In recent years, CID sensors have displayed great development potential in parameter measurement of gas-liquid two-phase flow in small channels. However, the fundamental/mechanism research on the response characteristics of CID sensors is relatively insufficient. This work focuses on the investigation of the influence of separation distance between slugs on the impedance (real part, imaginary part and amplitude) response characteristics of slug flow in small channels. Experiments were carried out with the CID sensors in four small channels with inner pipe diameters of 1.96 mm, 2.48 mm, 3.02 mm and 3.54 mm, respectively. The experimental results show that for a CID sensor, the slug separation distance has significant influence on the impedance response characteristics. There is a critical value of slug separation distance. When the slug separation distance is larger than the critical value, the impedance response characteristics of each slug can be considered independent of each other, i.e., there is no interaction between the slugs. When the slug separation distance is less than the critical value, the impedance response characteristics show obvious interaction between the slugs. It is indicated that the ratios of the critical values to the pipe inner diameters are approximate 100.
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22
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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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23
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Huyen My Dang T, Quoc Hoang A, Huy Nguyen Q, Chi Le D, Duc Mai T, Nhi Do Y, Anh Kieu V, Khanh Cao C, Minh Hien Lu T, Minh Thu Nguyen T, Pham B, Anh Huong Nguyen T. Simultaneous determination of vitamin B 6 and magnesium using capillary electrophoresis coupled with contactless conductivity detection: Method development, validation, and application to pharmaceutical and nutraceutical samples. J Chromatogr B Analyt Technol Biomed Life Sci 2022; 1210:123471. [PMID: 36174264 DOI: 10.1016/j.jchromb.2022.123471] [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: 08/07/2022] [Revised: 09/09/2022] [Accepted: 09/13/2022] [Indexed: 11/29/2022]
Abstract
Vitamins and minerals are usually incorporated in pharmaceutical and nutraceutical products, but a simple, rapid, and inexpensive analytical method for their simultaneous determination is still lacking. In this study, we developed a quantification method for pyridoxine (vitamin B6) and magnesium (Mg) by using purpose-made capillary electrophoresis with capacitively coupled contactless conductivity detection (CE-C4D) instrument. Main analytical conditions include: fused silica capillary (total length 55 cm, effective length 40 cm, inner diameter 50 μm); background electrolyte consisted of 10 mM L-arginine/acetic acid (pH 5) with 20% acetonitrile; separation voltage + 20 kV; hydrodynamic injection (siphoning at 20 cm in 25 s). Detection limits of vitamin B6 and Mg were 1 and 0.1 mg/L, respectively. Good linearity (R2 > 0.999) was observed for vitamin B6 and Mg calibration curves over concentration ranges of 3-100 and 0.3-200 mg/L, respectively. The method was applied to analyze vitamin B6 and Mg in several pharmaceutical and nutraceutical samples. The analytical results obtained by our method were in good agreement with reference methods (i.e., HPLC for vitamin B6 and ICP-OES for Mg). High-efficient and low-cost CE-C4D method can accordingly serve as a promising tool for concurrent analysis of inorganic and organic species in pharmaceutical and nutraceutical analysis.
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Affiliation(s)
- Thi Huyen My Dang
- Faculty of Chemistry, University of Science, Vietnam National University, Hanoi, 19, Le Thanh Tong, Hanoi 10000, Vietnam
| | - Anh Quoc Hoang
- Faculty of Chemistry, University of Science, Vietnam National University, Hanoi, 19, Le Thanh Tong, Hanoi 10000, Vietnam.
| | - Quang Huy Nguyen
- Faculty of Chemistry, University of Science, Vietnam National University, Hanoi, 19, Le Thanh Tong, Hanoi 10000, Vietnam; Faculty of Pharmacy, University of Medicine and Pharmacy, Thai Nguyen University, 284, Luong Ngoc Quyen, Thai Nguyen 24000, Vietnam
| | - Dinh Chi Le
- Department of Analytical Chemistry and Toxicology, Hanoi University of Pharmacy, 13-15 Le Thanh Tong, Hanoi 10000, Vietnam
| | - Thanh Duc Mai
- Université Paris-Saclay, CNRS, Institut Galien Paris-Saclay, 92296, Châtenay-Malabry, France
| | - Yen Nhi Do
- Faculty of Chemistry, University of Science, Vietnam National University, Hanoi, 19, Le Thanh Tong, Hanoi 10000, Vietnam
| | - Van Anh Kieu
- Faculty of Chemistry, University of Science, Vietnam National University, Hanoi, 19, Le Thanh Tong, Hanoi 10000, Vietnam
| | - Cong Khanh Cao
- National Institute for Food Control (NIFC), 65, Pham Than Duat, Hanoi 10000, Vietnam
| | - Thi Minh Hien Lu
- National Institute for Food Control (NIFC), 65, Pham Than Duat, Hanoi 10000, Vietnam
| | - Thi Minh Thu Nguyen
- Faculty of Chemistry, University of Science, Vietnam National University, Hanoi, 19, Le Thanh Tong, Hanoi 10000, Vietnam
| | - Bach Pham
- Faculty of Chemistry, University of Science, Vietnam National University, Hanoi, 19, Le Thanh Tong, Hanoi 10000, Vietnam
| | - Thi Anh Huong Nguyen
- Faculty of Chemistry, University of Science, Vietnam National University, Hanoi, 19, Le Thanh Tong, Hanoi 10000, Vietnam.
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24
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Kanyanee T, Tianrungarun K, Somboot W, Puangpila C, Jakmunee J. Open tubular capillary ion chromatography with online dilution for small ions determination in drinks. Food Chem 2022; 382:132055. [PMID: 35255354 DOI: 10.1016/j.foodchem.2022.132055] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Revised: 12/05/2021] [Accepted: 01/02/2022] [Indexed: 11/04/2022]
Abstract
This work aims to develop a more robust, easy-to-use, low-pressure, and cost-effective nonsuppressed open tubular capillary ion chromatography (NS-OTIC) approach with online dialysis for small ions determination in drinks. The fabricated device was applied for two selected columns, including poly(butadiene-maleic acid) on a 50-μm bore and AS18 Latex on 25-µm bore fused silica capillaries, for the separation of mixed cations (Na+, K+, Ca2+, Mg2+) and mixed anions (Cl-, Br-, NO2-, NO3-), respectively. High concentrations of ions (up to 100 mM) level can be directly introduced into the NS-OTIC system without an off-line (manual) dilution step. The linear relationship of the peak area and concentration of model ions can be obtained with a resolution > 1.1. The repeatability of the peak area for both OTIC columns was < 6% RSD. Juice and tea samples were successfully analyzed with % recoveries of 77-112 and 90-119 for cation and anion determinations, respectively.
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Affiliation(s)
- Tinakorn Kanyanee
- Department of Chemistry, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand; Center of Excellence in Materials Science and Technology, Chiang Mai University, Chiang Mai 50200, Thailand; Center of Excellence for Innovation in Chemistry, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand.
| | - Kanlayarat Tianrungarun
- Department of Chemistry, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand; The Graduate School, Chiang Mai University, Chiang Mai 50200, Thailand
| | - Wasin Somboot
- Department of Chemistry, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand; The Graduate School, Chiang Mai University, Chiang Mai 50200, Thailand
| | - Chanida Puangpila
- Department of Chemistry, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand
| | - Jaroon Jakmunee
- Department of Chemistry, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand; Center of Excellence in Materials Science and Technology, Chiang Mai University, Chiang Mai 50200, Thailand; Center of Excellence for Innovation in Chemistry, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand
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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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26
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Li Y, Wang L, Qian M, Qi S, Zhou L, Pu Q. Concise analysis of γ-hydroxybutyric acid in beverages and urine by capillary electrophoresis with capacitively coupled contactless conductivity detection using 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid as background electrolyte. J Chromatogr A 2022; 1675:463191. [DOI: 10.1016/j.chroma.2022.463191] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2022] [Revised: 05/25/2022] [Accepted: 05/31/2022] [Indexed: 02/07/2023]
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Abstract
Isotachophoresis (ITP) is a versatile electrophoretic technique that can be used for sample preconcentration, separation, purification, and mixing, and to control and accelerate chemical reactions. Although the basic technique is nearly a century old and widely used, there is a persistent need for an easily approachable, succinct, and rigorous review of ITP theory and analysis. This is important because the interest and adoption of the technique has grown over the last two decades, especially with its implementation in microfluidics and integration with on-chip chemical and biochemical assays. We here provide a review of ITP theory starting from physicochemical first-principles, including conservation of species, conservation of current, approximation of charge neutrality, pH equilibrium of weak electrolytes, and so-called regulating functions that govern transport dynamics, with a strong emphasis on steady and unsteady transport. We combine these generally applicable (to all types of ITP) theoretical discussions with applications of ITP in the field of microfluidic systems, particularly on-chip biochemical analyses. Our discussion includes principles that govern the ITP focusing of weak and strong electrolytes; ITP dynamics in peak and plateau modes; a review of simulation tools, experimental tools, and detection methods; applications of ITP for on-chip separations and trace analyte manipulation; and design considerations and challenges for microfluidic ITP systems. We conclude with remarks on possible future research directions. The intent of this review is to help make ITP analysis and design principles more accessible to the scientific and engineering communities and to provide a rigorous basis for the increased adoption of ITP in microfluidics.
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Affiliation(s)
- Ashwin Ramachandran
- Department of Aeronautics and Astronautics, Stanford University, Stanford, California 94305, United States
| | - Juan G Santiago
- Department of Mechanical Engineering, Stanford University, Stanford, California 94305, United States
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Nie H, Li Z, Wang X, Gu R, Yuan H, Guo Y, Xiao D. An improved dual-channel capacitively coupled contactless conductivity detector with high detection performance. Analyst 2022; 147:2106-2114. [PMID: 35470820 DOI: 10.1039/d2an00330a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Conductivity detectors are widely used electrochemical sensors. It has long been a goal of researchers to improve detection performance. In this contribution, we propose a multi-input capacitively coupled contactless conductivity detector (MIC4D) with high sensitivity, and we carry out a detailed theoretical investigation of the detector. In order to overcome the problem of a rising baseline level as a result of sensitivity improvements when using the multi-input detection method, we innovatively combine MIC4D with differential detection to propose a further-improved detector (DFMIC4D). The detector is composed of two channels, one for the reference and the other for the analyte. The signal output from differential amplification can effectively reduce the high baseline level and detection interference. In KCl solution with a concentration range of 10-4 to 10-5 M, the response to the solution is a linear function of the logarithm of the concentration, and this detector has a high slope. The slope of DFMIC4D is 1.393, higher than a traditional single-input capacitively coupled contactless conductivity detector (C4D: 0.905) and a double-input capacitively coupled contactless conductivity detector (DIC4D: 1.314). For 10-3 M KCl solution, the response-to-baseline ratio is 1.776 for C4D, 1.779 for DIC4D, and 12.06 for DFMIC4D, with a ratio increase of nearly 6-fold shown by our new detector. At a S/N (signal-to-noise) ratio of 3, the limit of detection (LOD) of DFMIC4D is low, reaching 0.7 nM. In addition, DFMIC4D can be applied to the detection of low-conductivity solutions and total dissolved solids (TDS) analysis. Compared with a standard conductivity meter, our detector shows better detection performance.
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Affiliation(s)
- Hongyu Nie
- College of Chemistry, Sichuan University, Chengdu 610064, China.
| | - Zhihui Li
- College of Chemistry, Sichuan University, Chengdu 610064, China.
| | - Xiaokun Wang
- College of Chemical Engineering, Sichuan University, Chengdu 610064, China.
| | - Rongmeng Gu
- College of Chemical Engineering, Sichuan University, Chengdu 610064, China.
| | - Hongyan Yuan
- College of Chemical Engineering, Sichuan University, Chengdu 610064, China.
| | - Yong Guo
- College of Chemistry, Sichuan University, Chengdu 610064, China.
| | - Dan Xiao
- College of Chemistry, Sichuan University, Chengdu 610064, China. .,College of Chemical Engineering, Sichuan University, Chengdu 610064, China.
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Multi-channel contactless conductivity detection device for online detection of free-flow electrophoresis separation. Se Pu 2022; 40:384-390. [PMID: 35362686 PMCID: PMC9404027 DOI: 10.3724/sp.j.1123.2021.11011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
现有自由流电泳(FFE)装置因不具备在线检测功能,其实用性仍然存在明显不足。针对这一问题,该工作发展了一种多通道电容耦合式非接触电导检测(MC-C4D)装置并开发了自动测量软件。MC-C4D装置采用了并行分时的非接触电导检测技术,即由多个同样的非接触电导检测模块并行排列,而单个电导检测模块又由多个非接触电导检测池组成,采用模拟开关切换这些检测池,能够分时检测流经相应检测池溶液的电导率。多个电导检测模块的检测池总数等于FFE的组分数,它们分别串行接入到FFE各流路中,这样MC-C4D装置就可在线并行分时在线测量各组分溶液的电导率。为验证所设计MC-C4D装置的检测性能,采用配制的氯化钾标准溶液作为检测对象对MC-C4D装置进行了标定和测试。实验数据表明,MC-C4D装置电导率检测范围为0.015~2.5 mS/cm,检出限(LOD)为0.002 mS/cm,日内相对标准偏差(RSD, n=3)为2.31%,测量相对误差(RE)为3.03%和通道间测量相对偏差为1.60%,这些参数表明该装置检测范围较大,LOD低,重复性好,准确性高,通道间测量相对偏差小。另外,将MC-C 4D装置应用于往复式自由流等电聚焦电泳(RFFIEF)在蛋白质聚焦过程中对各组分溶液电导率进行实时在线检测,结果表明,所开发的MC-C4D装置不仅可实现对FFE各组分溶液电导率的实时在线检测,而且还可在RFFIEF实验中辅助掌握分离的实验进度,提高FFE装置的实用性。
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Liu W, Liang Z, Wang Y, Cao J, Zhang Q, Liu X, Wang Y, Cao C. A facile online multi-gear capacitively coupled contactless conductivity detector for an automatic and wide range monitoring of high salt in HPLC. Analyst 2022; 147:496-504. [DOI: 10.1039/d1an02249k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Sensing the electrolyte solution or aqueous–organic mixture has attracted much interest in chemical separation, pharmaceutical engineering, bioprocess, and biochemical experiments.
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Affiliation(s)
- Weiwen Liu
- Department of Instrument Science and Engineering, School of Electronic Information and Electrical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Ziqi Liang
- Department of Instrument Science and Engineering, School of Electronic Information and Electrical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Yuanyu Wang
- Department of Instrument Science and Engineering, School of Electronic Information and Electrical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Jun Cao
- Department of Instrument Science and Engineering, School of Electronic Information and Electrical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Qiang Zhang
- Department of Instrument Science and Engineering, School of Electronic Information and Electrical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Xiaoping Liu
- Department of Instrument Science and Engineering, School of Electronic Information and Electrical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Yuxing Wang
- School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Chengxi Cao
- Department of Instrument Science and Engineering, School of Electronic Information and Electrical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
- School of Life Sciences and Biotechnology, State Key Laboratory of Microbial Metabolism, Shanghai Jiao Tong University, Shanghai 200240, China
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31
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Simultaneous determination of scopolamine and butylscopolamine in pharmaceutical and beverage samples by capillary zone electrophoresis. Microchem J 2022. [DOI: 10.1016/j.microc.2021.106985] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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32
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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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33
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Poboży E, Trojanowicz M. Application of Capillary Electrophoresis for Determination of Inorganic Analytes in Waters. Molecules 2021; 26:6972. [PMID: 34834063 PMCID: PMC8625978 DOI: 10.3390/molecules26226972] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Revised: 11/12/2021] [Accepted: 11/15/2021] [Indexed: 11/16/2022] Open
Abstract
Aside from HPLC and GC, capillary electrophoresis (CE) is one of the most important techniques for high-performance separations in modern analytical chemistry. Its main advantages are the possibility of using different detection techniques, the possibility of in-capillary sample processing for preconcentration or derivatization, and ease of instrumental miniaturization down to the microfluidic scale. Those features are utilized in the separation of macromolecules in biochemistry and in genetic investigations, but they can be also used in determinations of inorganic ions in water analysis. This review, based on about 100 original research works, presents applications of CE methods in water analysis reported in recent decade, mostly regarding conductivity detection or indirect UV detection. The developed applications include analysis of high salinity sea waters, as well as analysis of other surface waters and drinking waters.
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Affiliation(s)
- Ewa Poboży
- Faculty of Chemistry, University of Warsaw, Pasteura 1, 02-093 Warsaw, Poland;
| | - Marek Trojanowicz
- Faculty of Chemistry, University of Warsaw, Pasteura 1, 02-093 Warsaw, Poland;
- Laboratory of Nuclear Analytical Techniques, Institute of Nuclear Chemistry and Technology, Dorodna 16, 03-195 Warsaw, Poland
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34
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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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Huang J, Guo Z, Tang XY, Ji H, Wang B, Huang Z. A method for void fraction measurement of bubble/slug flow in small channels based on contactless impedance detection. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2021; 92:105006. [PMID: 34717397 DOI: 10.1063/5.0029772] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Accepted: 09/18/2021] [Indexed: 06/13/2023]
Abstract
The flow parameter measurement of the gas-liquid two-phase flow in small channels is very crucial and challenging in both academia and industry. Conventional techniques based on radiations, optics, acoustics, or electrics most lose their superiorities in the scenario with small channels due to the spatial limitation and the online and contactless measurement requirements. In addition, the conductive characteristic of the two-phase flow is equivalent to an impedance rather than a resistance due to the existence of multi-phases. The equivalent impedance information of the two-phase flow, especially the imaginary part, is promising to provide more flowing details but has seldom been detected or analyzed. In this paper, a method for the void fraction measurement of bubble/slug flow in small channels is proposed. The method implements void fraction measurement in a contactless way, based on the acquisition of the total impedance information of the gas-liquid two-phase flow. First, a new contactless impedance detection sensor is designed, based on the simulated inductor technique and the analog phase sensitive demodulation technique, to obtain the complete equivalent impedance information of the two-phase fluid. Then, based on the flow pattern identification result, the void fraction measurement model is developed, which is a fusion of the relationships between the void fraction and the real part/the imaginary part of the equivalent impedance information, respectively. Experimental results on prototypes with different inner diameters (2.48, 3.64, and 4.52 mm, respectively) validate the effectiveness of the proposed void fraction method. The maximum void fraction measurement biases are within 5.0%.
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Affiliation(s)
- Junchao Huang
- State Key Laboratory of Industrial Control Technology, College of Control Science and Engineering, Zhejiang University, Hangzhou 310027, People's Republic of China
| | - Ziwei Guo
- State Key Laboratory of Industrial Control Technology, College of Control Science and Engineering, Zhejiang University, Hangzhou 310027, People's Republic of China
| | - Xiao-Yu Tang
- State Key Laboratory of Industrial Control Technology, College of Control Science and Engineering, Zhejiang University, Hangzhou 310027, People's Republic of China
| | - Haifeng Ji
- State Key Laboratory of Industrial Control Technology, College of Control Science and Engineering, Zhejiang University, Hangzhou 310027, People's Republic of China
| | - Baoliang Wang
- State Key Laboratory of Industrial Control Technology, College of Control Science and Engineering, Zhejiang University, Hangzhou 310027, People's Republic of China
| | - Zhiyao Huang
- State Key Laboratory of Industrial Control Technology, College of Control Science and Engineering, Zhejiang University, Hangzhou 310027, People's Republic of China
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He Y, Huang Q, He Y, Ji H, Zhang T, Wang B, Huang Z. A Low Excitation Working Frequency Capacitively Coupled Contactless Conductivity Detection (C 4D) Sensor for Microfluidic Devices. SENSORS 2021; 21:s21196381. [PMID: 34640701 PMCID: PMC8512373 DOI: 10.3390/s21196381] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Revised: 09/14/2021] [Accepted: 09/20/2021] [Indexed: 11/16/2022]
Abstract
In this work, a new capacitively coupled contactless conductivity detection (C4D) sensor for microfluidic devices is developed. By introducing an LC circuit, the working frequency of the new C4D sensor can be lowered by the adjustments of the inductor and the capacitance of the LC circuit. The limits of detection (LODs) of the new C4D sensor for conductivity/ion concentration measurement can be improved. Conductivity measurement experiments with KCl solutions were carried out in microfluidic devices (500 µm × 50 µm). The experimental results indicate that the developed C4D sensor can realize the conductivity measurement with low working frequency (less than 50 kHz). The LOD of the C4D sensor for conductivity measurement is estimated to be 2.2 µS/cm. Furthermore, to show the effectiveness of the new C4D sensor for the concentration measurement of other ions (solutions), SO42− and Li+ ion concentration measurement experiments were also carried out at a working frequency of 29.70 kHz. The experimental results show that at low concentrations, the input-output characteristics of the C4D sensor for SO42− and Li+ ion concentration measurement show good linearity with the LODs estimated to be 8.2 µM and 19.0 µM, respectively.
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Affiliation(s)
| | | | | | - Haifeng Ji
- Correspondence: ; Tel.: +86-571-8795-2145
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37
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Twenty years of amino acid determination using capillary electrophoresis: A review. Anal Chim Acta 2021; 1174:338233. [DOI: 10.1016/j.aca.2021.338233] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Revised: 01/14/2021] [Accepted: 01/16/2021] [Indexed: 12/28/2022]
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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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Investigation of the Effects of Electrode Geometry on the Performance of C 4D Sensor with Radial Configuration. SENSORS 2021; 21:s21134454. [PMID: 34209920 PMCID: PMC8272098 DOI: 10.3390/s21134454] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/21/2021] [Revised: 06/25/2021] [Accepted: 06/26/2021] [Indexed: 11/21/2022]
Abstract
Electrodes are basic components of C4D (capacitively coupled contactless conductivity detection) sensors, and different electrode structures (the configuration pattern or the electrode geometry) can lead to different measurement results. In this work, the effects of electrode geometry of radial configuration on the measurement performance of C4D sensors are investigated. Two geometrical parameters, the electrode length and the electrode angle, are considered. A FEM (finite element method) model based on the C4D method is developed. With the FEM model, corresponding simulation results of conductivity measurement with different electrode geometry are obtained. Meanwhile, practical experiments of conductivity measurement are also conducted. According to the simulation results and experimental results, the optimal electrode geometry of the C4D sensor with radial configuration is discussed and proposed. The recommended electrode length is 5–10 times of the pipe inner diameter and the recommended electrode angle is 120–160°.
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Yang L, Pan G, Zhang P, Liu Q, Liu X, Li Y, Liang Y, Zhang M. 3D printed two-in-one on-capillary detector: Combining contactless conductometric and photometric detection for capillary electrophoresis. Anal Chim Acta 2021; 1159:338427. [PMID: 33867034 DOI: 10.1016/j.aca.2021.338427] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Revised: 02/23/2021] [Accepted: 03/15/2021] [Indexed: 10/21/2022]
Abstract
In this work, for the first time, a 3D printed two-in-one on-capillary detector, combining contactless conductometric detection (C4D) and photometric detection (PD), is fabricated for capillary electrophoresis (CE). The C4D Faraday shield (FS) is printed using electrically conductive composite polylactic acid (PLA) to minimize the stray capacitance. Non-conductive PLA is also used to print the insulator of FS to prevent the electrical conduction with two stainless steel electrodes. A novel collimator, consisting of two partially aligned pinholes, is printed by conductive material to collimate the light-emitting diode beam. The C4D detection has a signal-to-noise ratio of 1092 ± 2 for 200 μM potassium on a 25 μm id capillary. The PD detection shows excellent linearity with stray light down to 8% and an effective path length at 73% of a 75 μm id capillary. The analytical performance is demonstrated by CE separation and detection of cations. PD shows limits of detection (LODs) of 1.3, 0.9, and 1.7 μM for cobalt, copper and zinc, which are complexed with 4-(2-Pyridylazo) resorcinol, while C4D shows LODs of 1.2, 1.4, 21 and 2.6 μM for potassium, sodium, cobalt and zinc, respectively.
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Affiliation(s)
- Liye Yang
- School of Life and Environmental Sciences, Guangxi Key Laboratory of Automatic Detecting Technology and Instruments, Guilin University of Electronic Technology, Guilin, Guangxi, 541004, China
| | - Guangchao Pan
- School of Life and Environmental Sciences, Guangxi Key Laboratory of Automatic Detecting Technology and Instruments, Guilin University of Electronic Technology, Guilin, Guangxi, 541004, China
| | - Piwang Zhang
- School of Life and Environmental Sciences, Guangxi Key Laboratory of Automatic Detecting Technology and Instruments, Guilin University of Electronic Technology, Guilin, Guangxi, 541004, China
| | - Qiang Liu
- School of Life and Environmental Sciences, Guangxi Key Laboratory of Automatic Detecting Technology and Instruments, Guilin University of Electronic Technology, Guilin, Guangxi, 541004, China
| | - Xing Liu
- School of Life and Environmental Sciences, Guangxi Key Laboratory of Automatic Detecting Technology and Instruments, Guilin University of Electronic Technology, Guilin, Guangxi, 541004, China
| | - Yan Li
- School of Life and Environmental Sciences, Guangxi Key Laboratory of Automatic Detecting Technology and Instruments, Guilin University of Electronic Technology, Guilin, Guangxi, 541004, China
| | - Ying Liang
- School of Life and Environmental Sciences, Guangxi Key Laboratory of Automatic Detecting Technology and Instruments, Guilin University of Electronic Technology, Guilin, Guangxi, 541004, China.
| | - Min Zhang
- School of Life and Environmental Sciences, Guangxi Key Laboratory of Automatic Detecting Technology and Instruments, Guilin University of Electronic Technology, Guilin, Guangxi, 541004, China.
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Wang M, Chen Z, Jing X, Zhou H, Wang Y, Ye J, Chu Q. Tween 20-capped gold nanoparticles for selective extraction of free low-molecular-weight thiols in saliva followed by capillary electrophoresis with contactless conductivity detection. J Chromatogr B Analyt Technol Biomed Life Sci 2021; 1176:122756. [PMID: 34022759 DOI: 10.1016/j.jchromb.2021.122756] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Revised: 04/22/2021] [Accepted: 05/02/2021] [Indexed: 11/29/2022]
Abstract
Low-molecular-weight thiols are widely present in human fluids, and are regarded as a kind of potential broad-spectrum evaluation indicators for some clinical diseases. In this work, gold nanoparticles capped with Tween 20 were used for purification and microextraction of the main free thiols (cysteine, homocysteine, glutathione and methionine) in saliva based on Au-S bond formation. Ultrasound further sped up the releasing of the target analytes, and the releasing time needed was only 10 min, and the required sample volume was only 40 µL. The desorption solution could be directly injected for electrophoretic analysis without derivatization, and field-amplified sample stacking of electrophoretic online enrichment technology further improved the detection sensitivity. The synergistic enrichment effect made the enrichment factors of four analytes reach 1119-2067 times. This developed method was applied for the analyses of saliva samples of healthy volunteers. Acceptable sensitivity (LODs: 0.15-1.5 ng mL-1) and recoveries (97.6-116%) were obtained in the saliva sample matrix. This proposed method provides an alternative for the sensitive detection of low-molecular-weight thiols in noninvasive body fluids, which has potential application prospect in the preliminary noninvasive diagnosis of diabetes, cardiovascular diseases, etc.
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Affiliation(s)
- Manman Wang
- School of Chemistry and Molecular Engineering, East China Normal University, Shanghai 200241, China
| | - Zheyan Chen
- School of Chemistry and Molecular Engineering, East China Normal University, Shanghai 200241, China
| | - Xiaofeng Jing
- School of Chemistry and Molecular Engineering, East China Normal University, Shanghai 200241, China
| | - Huan Zhou
- School of Chemistry and Molecular Engineering, East China Normal University, Shanghai 200241, China
| | - Ying Wang
- School of Chemistry and Molecular Engineering, East China Normal University, Shanghai 200241, China
| | - Jiannong Ye
- School of Chemistry and Molecular Engineering, East China Normal University, Shanghai 200241, China
| | - Qingcui Chu
- School of Chemistry and Molecular Engineering, East China Normal University, Shanghai 200241, China.
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Diffraction-based label-free photothermal detector for separation analyses in a nanocapillary. J Chromatogr A 2021; 1648:462214. [PMID: 34004365 DOI: 10.1016/j.chroma.2021.462214] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Revised: 04/19/2021] [Accepted: 04/25/2021] [Indexed: 11/23/2022]
Abstract
Miniaturization of column diameter in liquid chromatography is one of the major trends in separation sciences toward single-cell proteomics and metabolomics. Micro/nanoscale open tubular (OT) capillaries are promising tools for efficient separation analyses of the ultra-small volume of samples. However, highly sensitive and label-free on-column detection is still challenging for such ultra-small capillaries. In this study, we developed a photothermal detector using optical diffraction phenomena by a single nanocapillary. Our detection method realized concentration determination of unlabeled sample solutions in a nanocapillary with 460 nm inner diameter. The calculated limit of detection was 0.12 µM, which corresponds to 16 molecules in a detection volume of 0.23 fL. Furthermore, normal-phase chromatography was performed on a 12 cm long nanocapillary, and femtoliter sample injection, efficient separation, and label-free detection of dye molecules were demonstrated. Our photothermal detector will be widely used as a universal tool for chemical/biological analyses using capillaries with micro/nanoscale diameters.
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do Prado AA, Ribeiro MMAC, Richter EM. Ultra-rapid capillary zone electrophoresis method for simultaneous determination of arginine and ibuprofen. J Sep Sci 2021; 44:2596-2601. [PMID: 33884758 DOI: 10.1002/jssc.202100169] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Revised: 04/15/2021] [Accepted: 04/17/2021] [Indexed: 12/12/2022]
Abstract
The combination of arginine and ibuprofen is widely used for pain relief with a faster onset of action than conventional ibuprofen. Therefore, the determination of both compounds in a single run is highly desirable for rapid quality control applications. This paper reports an ultra-fast method (100 injections/h) for simultaneous determination of arginine and ibuprofen using capillary electrophoresis with capacitively coupled contactless conductivity detection. The separation of arginine as cation and ibuprofen as anion was achieved using a background electrolyte composed by an equimolar mixture of 10 mmol/L of 2-(cyclohexylamino) ethanesulfonic acid and boric acid with pH adjusted to 8.4 using potassium hydroxide. The limits of detections were 5.3 and 10.0 μmol/L for arginine and ibuprofen, respectively. The proposed method is simple, fast (one analysis every 35 s), environmentally friendly (minimal waste generation) and accurate (recovery values between 95 and 98%).
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Affiliation(s)
- Aliceana Almeida do Prado
- Instituto de Quimica, Universidade Federal de Uberlandia, Av. João Naves de Avila, 2121, Uberlandia, MG, 13400-970, Brazil
| | | | - Eduardo Mathias Richter
- Instituto de Quimica, Universidade Federal de Uberlandia, Av. João Naves de Avila, 2121, Uberlandia, MG, 13400-970, Brazil
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Graf HG, Rudisch BM, Manegold J, Huhn C. Advancements in capacitance-to-digital converter-based C 4 D technology for detection in capillary electrophoresis using amplified excitation voltages and comparison to classical and open-source C 4 Ds. Electrophoresis 2021; 42:1306-1316. [PMID: 33710630 DOI: 10.1002/elps.202000394] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Revised: 02/28/2021] [Accepted: 03/08/2021] [Indexed: 11/05/2022]
Abstract
This work introduces new hardware configurations for a capacitively coupled contactless conductivity detector (C4 D) based on capacitance-to-digital conversion (CDC) technology for CE. The aim was to improve sensitivity, handling, price, and portability of CDC-based C4 D detectors (CDCD) to reach LODs similar to classic C4 Ds with more sophisticated electric circuits. To achieve this, a systematic study on the CDCDs was carried out including a direct comparison to already established C4 D setups. Instrumental setups differing in electrode lengths, measurement modes, and amplification of excitation voltages were investigated to achieve LODs for alkali metal ions of 4 to 12 μM, similar to LODs obtained by classic C4 D setups. Lowest LODs were achieved for a setup with two 10 mm electrodes at a distance of 0.2 mm and an excitation voltage of 24 V. The detection head was exceptionally lightweight with only 2.6 g and covered only 20 mm of the capillary on total. This allowed the use of multiple detectors along the separation path to enable spatial tracking of analytes during separation. The entirely battery-powered detector assembly weighs less than 200 g, and the data are transmitted wirelessly for possible portable applications. The freely accessible hardware and software were optimized for fully automated measurements with real time data plotting and allowed handling multidetector setups. The new developments were applied to quantify the potassium salt of glyphosate in its herbicide formulation.
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Affiliation(s)
- Hannes Georg Graf
- Institute of Physical and Theoretical Chemistry, Eberhard Karls Universität Tübingen, Tübingen, Germany
| | | | - Johanna Manegold
- Institute of Physical and Theoretical Chemistry, Eberhard Karls Universität Tübingen, Tübingen, Germany
| | - Carolin Huhn
- Institute of Physical and Theoretical Chemistry, Eberhard Karls Universität Tübingen, Tübingen, Germany
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Lancioni C, Aspromonte J, Tascon M, Gagliardi LG. Development of a background electrolyte for the determination of inorganic cations in high ionic strength samples by capillary electrophoresis with indirect UV-absorption detection. J Chromatogr A 2021; 1645:462091. [PMID: 33845250 DOI: 10.1016/j.chroma.2021.462091] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Revised: 03/17/2021] [Accepted: 03/19/2021] [Indexed: 11/30/2022]
Abstract
In this study, a background electrolyte capable to separate and quantify inorganic cations in high ionic strength samples by UV-absorption indirect detection was designed. In this regard, the four most abundant monovalent and divalent cations in earth crust (K+, Na+, Ca+2, Mg+2) were selected as model compounds. A group of small carboxylic acids and, several toluidines and pyridines were evaluated as mild strength complexing agents and chromophoric probes, respectively. The optimized background electrolyte was composed of 200 mM 2,4,6-trimethylpyridine as the chromophoric probe, 250 mM lactic acid as the weak complexing agent and pH buffering reagent (adjusted to pH 4.5), and 5% v/v methanol as organic solvent modifier. Based on a minimum number of components, it provided outstanding separation performance in less than 4 min in a wide linear dynamic range (10 - 2500 µg·mL-1). Performances were contrasted against a reference method based on conductometric detection. Furthermore, studies of separation efficiency and peak shape were carried out at different analyte concentrations in high electric conductivity solutions. The herein developed method demonstrated exceptional features in terms of limits of detection (~10 µg·mL-1), resolution, speed of analysis, sensitivity and peak capacity in high electric conductivity samples. Moreover, the method was successfully applied to high ionic strength samples such as rock digest, sea water, soy sauce and isotonic drinks.
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Affiliation(s)
- Carlina Lancioni
- Laboratorio de Investigación y Desarrollo de Métodos Analíticos, LIDMA, Facultad de Ciencias Exactas (Universidad Nacional de La Plata, CIC-PBA, CONICET), Calle 47 esq. 115, La Plata, 1900, Argentina
| | - Juan Aspromonte
- Laboratorio de Investigación y Desarrollo de Métodos Analíticos, LIDMA, Facultad de Ciencias Exactas (Universidad Nacional de La Plata, CIC-PBA, CONICET), Calle 47 esq. 115, La Plata, 1900, Argentina; Department of Pharmaceutical and Pharmacological Sciences, Pharmaceutical Analysis, KU Leuven - University of Leuven, Herestraat 49 - PB923, 3000, Leuven, Belgium
| | - Marcos Tascon
- Instituto de Investigación e Ingeniería Ambiental (IIIA-CONICET-UNSAM), Universidad Nacional de San Martín, 25 de Mayo y Francia, B1650, San Martín, Argentina.
| | - Leonardo G Gagliardi
- Laboratorio de Investigación y Desarrollo de Métodos Analíticos, LIDMA, Facultad de Ciencias Exactas (Universidad Nacional de La Plata, CIC-PBA, CONICET), Calle 47 esq. 115, La Plata, 1900, Argentina.
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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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Davis JJ, Foster SW, Grinias JP. Low-cost and open-source strategies for chemical separations. J Chromatogr A 2021; 1638:461820. [PMID: 33453654 PMCID: PMC7870555 DOI: 10.1016/j.chroma.2020.461820] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Revised: 12/12/2020] [Accepted: 12/14/2020] [Indexed: 12/18/2022]
Abstract
In recent years, a trend toward utilizing open access resources for laboratory research has begun. Open-source design strategies for scientific hardware rely upon the use of widely available parts, especially those that can be directly printed using additive manufacturing techniques and electronic components that can be connected to low-cost microcontrollers. Open-source software eliminates the need for expensive commercial licenses and provides the opportunity to design programs for specific needs. In this review, the impact of the "open-source movement" within the field of chemical separations is described, primarily through a comprehensive look at research in this area over the past five years. Topics that are covered include general laboratory equipment, sample preparation techniques, separations-based analysis, detection strategies, electronic system control, and software for data processing. Remaining hurdles and possible opportunities for further adoption of open-source approaches in the context of these separations-related topics are also discussed.
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Affiliation(s)
- Joshua J Davis
- Department of Chemistry & Biochemistry, Rowan University, Glassboro, NJ 08028, United States
| | - Samuel W Foster
- Department of Chemistry & Biochemistry, Rowan University, Glassboro, NJ 08028, United States
| | - James P Grinias
- Department of Chemistry & Biochemistry, Rowan University, Glassboro, NJ 08028, United States.
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Huang W. Open tubular ion chromatography: A state-of-the-Art review. Anal Chim Acta 2021; 1143:210-224. [PMID: 33384120 DOI: 10.1016/j.aca.2020.08.012] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Revised: 08/04/2020] [Accepted: 08/06/2020] [Indexed: 11/19/2022]
Abstract
This review summarizes the progress in open tubular ion chromatography (OTIC) over the period from 1981 to 2020. Although OTIC columns provide superior column efficiency, require very little sample volumes, and consume a minimum level of eluents compared to regular packed columns, not many reports can be found from the literature mainly due to the difficulties in the preparation of OTIC columns and the harsh system requirements, such as pL-nL injections and extremely small detection volumes. However, technical advances, e.g., capacitively coupled contactless conductivity detectors (C4Ds), hydroxide eluent compatible polymer-based OTIC columns, electrodialytic capillary suppressors, and nanovolume gas-free hydroxide eluent generators (EGs), have removed the obstacles to OTIC. As such, in this review, the author focused on the development of the key components in an OTIC system from the perspective of instrument development. A brief revisit of open tubular (OT) column theory is first presented, followed by a discussion of the system configuration and component development. Attention is given to the advances in the development of the suppressed open tubular ion chromatography (SOTIC) system.
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Affiliation(s)
- Weixiong Huang
- School of Environmental Studies, China University of Geosciences, Wuhan, 430078, Hubei, China.
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Maruška A, Drevinskas T, Stankevičius M, Bimbiraitė-Survilienė K, Kaškonienė V, Jonušauskas L, Gadonas R, Nilsson S, Kornyšova O. Single-chip based contactless conductivity detection system for multi-channel separations. ANALYTICAL METHODS : ADVANCING METHODS AND APPLICATIONS 2021; 13:141-146. [PMID: 33320117 DOI: 10.1039/d0ay01882a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
In this work, the design and characterization of a multi-cell capacitively coupled contactless conductivity detection system are described. The operation and simultaneous acquisition from 3 detector cells are demonstrated, however, the system is capable of supplying 8 detection cells and can be easily upgraded to maintain 64 capacitively coupled contactless conductivity detection cells. On performing flow-injection analysis, the system recorded as low as 0.01 mM of acetic acid, phosphoric acid, NaH2PO4, and Na2B4O7 solutions in water. The instrument was also capable of recording and distinguishing different mixtures of organic solvents: (a) methanol-acetonitrile, (b) hexane-acetone. The designed detection system is expected to be used coupled with multi-channel separation devices for monitoring simultaneous processes.
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Affiliation(s)
- Audrius Maruška
- Instrumental Analysis Open Access Centre, Faculty of Natural Sciences, Vytautas Magnus University, Vileikos 8, LT44404 Kaunas, Lithuania.
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Liu S, Pan Z, Liang Y, Li F, Breadmore MC, Zhang M. An electrophoretic ion analyzer for on-site autonomous water monitoring. J Chromatogr A 2020; 1637:461791. [PMID: 33359795 DOI: 10.1016/j.chroma.2020.461791] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Revised: 11/11/2020] [Accepted: 12/04/2020] [Indexed: 01/05/2023]
Abstract
An on-site ion analyzer based on capillary electrophoresis with pressure-driven flow through injection and capacitively coupled contactless conductivity detection has been developed for field monitoring of cations and anions in environmental waters. Automated time-pressure based hydrodynamic injection provides stable pL-nL scale injection (RSD = 1.96%, n = 30). A mixture of 400 mM Bis-Tris, 400 mM MOPS and 2 mM 18-crown-6 is used as the background electrolyte to provide repeatable separations. A proprietary hydrophilic coated 25 μm id capillary is used to suppress the electroosmotic flow. Separations of anions (Cl-, NO3-, NO2-, SO42-, F- and PO43-) and cations (NH4+, K+, Na+, Ca2+ and Mg2+) are achieved by switching the polarity of the high voltage power supply in two individual runs. Signal fluctuations caused by the temperature or viscosity changes in on-site monitoring are corrected by on-line introduction of internal standards. RSDs of the migration time and the corrected peak height over ~35 h and 350 analysis cycles are <4.06%. The LODs of inorganic ions are in the range of 2.1 μM (K+) to 6.8 μM (PO43-). The feasibility for on-site water monitoring with this system has been validated by a standard Ion chromatography method with comparable results obtained.
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Affiliation(s)
- Shuai Liu
- School of Life and Environmental Sciences, Guangxi Key Laboratory of Automatic Detecting Technology and Instruments, Guilin University of Electronic Technology, Guilin, Guangxi, 541004, China
| | - Zhen Pan
- School of Life and Environmental Sciences, Guangxi Key Laboratory of Automatic Detecting Technology and Instruments, Guilin University of Electronic Technology, Guilin, Guangxi, 541004, China
| | - Ying Liang
- School of Life and Environmental Sciences, Guangxi Key Laboratory of Automatic Detecting Technology and Instruments, Guilin University of Electronic Technology, Guilin, Guangxi, 541004, China.
| | - Feng Li
- Australian Centre for Research on Separation Science, School of Natural Sciences-Chemistry, University of Tasmania, Hobart, Tasmania, 7001, Australia
| | - Michael C Breadmore
- Australian Centre for Research on Separation Science, School of Natural Sciences-Chemistry, University of Tasmania, Hobart, Tasmania, 7001, Australia
| | - Min Zhang
- School of Life and Environmental Sciences, Guangxi Key Laboratory of Automatic Detecting Technology and Instruments, Guilin University of Electronic Technology, Guilin, Guangxi, 541004, China.
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