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Rashidi M, Zargartalebi M, Benneker AM. Mechanistic studies of droplet electrophoresis: A review. Electrophoresis 2021; 42:869-880. [PMID: 33665851 DOI: 10.1002/elps.202000358] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Revised: 01/31/2021] [Accepted: 02/12/2021] [Indexed: 11/11/2022]
Abstract
Electrophoresis (EP) of droplets is an intriguing phenomenon that has applications in biological systems, separation strategies, and reactor engineering. Droplet EP is significantly different from the classic particle EP because of droplet characteristics such as a mobile surface charge and the nonrigidity of the interface. Also, the liquid-liquid system, where there is an interplay between the hydrodynamic and electrokinetic forces in both phases, adds to the complexity of electrophoretic motion. Due to the vast amount of potential applications of droplet EP, a mechanistic understanding of the droplet motion in the presence of an external electric field is crucial. This review provides a background on the mechanism of droplet EP and summarizes the intrinsic interplay between the different relevant forces in these systems. The review also describes the key differences between droplet EP and particle EP, and the impact of these differences on droplet mobility. Additionally, we schematically summarize the effects of key parameters on droplet EP mobility, such as electric double layer polarization, the development of internal flow inside a droplet and boundary effects.
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Affiliation(s)
- Mansoureh Rashidi
- Department of Chemical and Petroleum Engineering, Schulich School of Engineering, University of Calgary, AB, Canada
| | - Mohammad Zargartalebi
- Department of Chemical and Petroleum Engineering, Schulich School of Engineering, University of Calgary, AB, Canada.,Department of Mechanical and Industrial Engineering, University of Toronto, Toronto, ON, Canada
| | - Anne M Benneker
- Department of Chemical and Petroleum Engineering, Schulich School of Engineering, University of Calgary, AB, Canada
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2
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Lou C, Zheng M, Xu Y, Shen Y, Kang J. Detection of 2,2′-Azobis(2-amidinopropane) Dihydrochloride in Polyvinylpyrrolidone by Capillary Electrophoresis with Field-Amplified Sample Injection. Chromatographia 2019. [DOI: 10.1007/s10337-019-03765-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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3
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Foulon C, Di Giulio P, Lecoeur M. Simultaneous determination of inorganic anions and cations by supercritical fluid chromatography using evaporative light scattering detection. J Chromatogr A 2018; 1534:139-149. [DOI: 10.1016/j.chroma.2017.12.047] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2017] [Revised: 12/11/2017] [Accepted: 12/16/2017] [Indexed: 01/11/2023]
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4
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Aulakh JS, Kaur R, Malik AK. Analysis of Small Ions with Capillary Electrophoresis. Methods Mol Biol 2016; 1483:197-216. [PMID: 27645739 DOI: 10.1007/978-1-4939-6403-1_12] [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] [Indexed: 06/06/2023]
Abstract
Small inorganic ions are easily separated through capillary electrophoresis because they have a high charge-to-mass ratio and suffer little from some of the undesired phenomenon affecting higher molecular weight species like adsorption to the capillary wall, decomposition, and precipitation. This chapter is focused on the analysis of small ions other than metal ions using capillary electrophoresis. Methods are described for the determination of ions of nitrogen, phosphorus, sulfur, fluorine, chlorine, bromine, and iodine.
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Affiliation(s)
| | - Ramandeep Kaur
- Department of Chemistry, Punjabi University, Patiala, Punjab, 147 002, India
| | - Ashok Kumar Malik
- Department of Chemistry, Punjabi University, Patiala, Punjab, 147 002, India.
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5
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He W, Jia H, Guo S, Zheng Z. Ultrasensitive Detection of Nickel(II) Ion by Capillary Electrophoresis–Post Chemiluminescence with Field-amplified Sample Injection. CHEM LETT 2011. [DOI: 10.1246/cl.2011.676] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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6
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Rovio S, Sirén K, Sirén H. Application of capillary electrophoresis to determine metal cations, anions, organic acids, and carbohydrates in some Pinot Noir red wines. Food Chem 2011. [DOI: 10.1016/j.foodchem.2010.07.044] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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7
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Huhn C, Pyell U. Diffusion as major source of band broadening in field-amplified sample stacking under negligible electroosmotic flow velocity conditions. J Chromatogr A 2010; 1217:4476-86. [DOI: 10.1016/j.chroma.2010.04.008] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2009] [Revised: 03/31/2010] [Accepted: 04/08/2010] [Indexed: 11/30/2022]
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8
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Almeda S, Gandolfi H, Arce L, Valcárcel M. Potential of porphyrins as chromogenic reagents for determining metals in capillary electrophoresis. J Chromatogr A 2009; 1216:6256-8. [DOI: 10.1016/j.chroma.2009.06.070] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2009] [Revised: 06/05/2009] [Accepted: 06/26/2009] [Indexed: 11/26/2022]
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9
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Johns C, Breadmore MC, Macka M, Ryvolová M, Haddad PR. Recent significant developments in detection and method development for the determination of inorganic ions by CE. Electrophoresis 2009; 30 Suppl 1:S53-67. [DOI: 10.1002/elps.200900103] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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10
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Bazylak G, Monge ME, Everaert J, Nagels LJ. Hydrophobicity-aided potentiometric detection of catecholamines, beta-agonists, and beta-blockers in a mixed-solvent capillary electrophoresis system. J Sep Sci 2009; 32:135-46. [DOI: 10.1002/jssc.200800450] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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11
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High-sensitivity capillary and microchip electrophoresis using electrokinetic supercharging preconcentration. J Chromatogr A 2009; 1216:660-70. [DOI: 10.1016/j.chroma.2008.10.077] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2008] [Revised: 10/02/2008] [Accepted: 10/07/2008] [Indexed: 11/24/2022]
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12
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Xiong B, Wang W, Miao X, Zhou X, Deng Y, Zhou P, Hu J. Simultaneous LIF and retro-reflected beam interference detection for CE. Electrophoresis 2008; 29:4482-6. [DOI: 10.1002/elps.200800292] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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13
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Ali I, Gupta VK, Aboul-Enein HY. Chiral Resolution of Racemic Environmental Pollutants by Capillary Electrophoresis. Crit Rev Anal Chem 2008; 38:132-46. [DOI: 10.1080/10408340701804467] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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14
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Urbanek M, Delaunay N, Michel R, Varenne A, Gareil P. Analysis of sub-ppb levels of Fe(II), Co(II), and Ni(II) by electrokinetic supercharging preconcentration, CZE separation, and in-capillary derivatization. Electrophoresis 2007; 28:3767-76. [DOI: 10.1002/elps.200700180] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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15
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Yang X, Yuan H, Wang C, Zhao S, Xiao D, Choi MMF. In-column fiber-optic laser-induced fluorescence detection for CE. Electrophoresis 2007; 28:3105-14. [PMID: 17674418 DOI: 10.1002/elps.200600815] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
A highly sensitive in-column fiber-optic LIF detector for CE has been constructed and evaluated. In this detection system, a 457-nm diode-pumped solid-state blue laser was used as the excitation light source and an optical fiber (40 mum od) was used to transmit the excitation light. One end of the optical fiber was inserted into the separation capillary and was in situ positioned at the detection window. The other end of the fiber was protruded from the capillary to capture the excitation light beam from the blue laser. Fluorescence emission was collected by a 40 x microscope objective, focused on a spatial filter, and passed through a yellow color filter before reaching the photomultiplier tube. The present CE-fluorescence detection is a simple and compact optical system. It reduces the laser scattering effect from the capillary and fiber as compared to the conventional LIF detection for CE. Its utility was successfully demonstrated by the separation and determination of D-penicillamine labeled with naphthalene-2,3-dicarboxaldehyde. The detection limit was 0.8 nM (S/N = 3). The present detection scheme has been proven to be attractive for sensitive fluorescence detection for CE.
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Affiliation(s)
- Xiupei Yang
- College of Chemistry, Sichuan University, Chengdu, PR China
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16
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Zacharis CK, Tempels FWA, Theodoridis GA, Voulgaropoulos AN, Underberg WJM, Somsen GW, de Jong GJ. Coupling of sequential injection analysis and capillary electrophoresis - Laser-induced fluorescence via a valve interface for on-line derivatization and analysis of amino acids and peptides. J Chromatogr A 2006; 1132:297-303. [PMID: 16919652 DOI: 10.1016/j.chroma.2006.07.076] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2006] [Revised: 07/20/2006] [Accepted: 07/28/2006] [Indexed: 10/24/2022]
Abstract
The on-line coupling of sequential injection analysis (SIA) and capillary electrophoresis (CE) via an in-line injection valve is presented. The SIA system is used for automated derivatization of amino acids and peptides. Dichlorotriazinylaminofluorescein serves as the derivatization agent, thus enabling sensitive laser-induced fluorescence detection of the derivatized analytes. The SIA procedure includes the following steps: (a) introduction of reagent and sample zones in a holding coil, (b) sample and reagent mixing in a reaction coil, (c) stop-flow step for increase of the reaction time, and (d) delivery of derivatized sample into the loop of the micro-valve interface. A small portion of the analyte zone is introduced electrokinetically in the separation capillary via the valve interface and CE analysis is performed. Factors affecting the CE separation, such as pH, the borate and sodium dodecyl sulphate concentration of the background electrolyte have been optimized. The derivatization conditions have been studied to obtain a high reaction yield in a relative short time. The transfer of a part of the reaction plug into the loop of the valve interface has been optimized. Using des-Tyr(1)-[Met]-enkephalinamide as test compound, it is demonstrated that after automated derivatization, on-line electrophoretic analysis could be achieved. Glycine has been selected as the internal standard in order to correct for variations in reaction time and filling of the injection loop. For the enkephalin, good reproducibility (RSD<4.5% calculated by the ratio of the peak areas) and linearity (0.5-5 microg mL(-1), R(2)>or=0.994) are obtained with a detection limit of 30 ng mL(-1) (S/N=3).
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Affiliation(s)
- Constantinos K Zacharis
- Laboratory of Analytical Chemistry, Department of Chemistry, Aristotle University Thessaloniki, 541 24 Thessaloniki, Greece
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17
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18
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Zhao S, Yuan H, Xiao D. Optical fiber light-emitting diode-induced fluorescence detection for capillary electrophoresis. Electrophoresis 2006; 27:461-7. [PMID: 16358357 DOI: 10.1002/elps.200500300] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
A highly sensitive optical fiber light-emitting diode (LED)-induced fluorescence detector for CE has been constructed and evaluated. In this detector, a violet or blue LED was used as the excitation source and an optical fiber with 40 microm OD was used to transmit the excitation light. The upper end of the fiber was inserted into the separation capillary and was situated right at the detection window. Fluorescence emission was collected by a 40 x microscope objective, focused on a spatial filter, and passed through a cutoff filter before reaching the photomultiplier tube. Output signals were recorded and processed with a computer using in-house written software. The present CE/fluorescence detector deploys a simple and inexpensive optical system that requires only an LED as the light source. Its utility was successfully demonstrated by the separation and determination of amino acids (AAs) labeled with naphthalene-2,3-dicarboxaldehyde (NDA) and FITC. Low detection limits were obtained ranging from 17 to 23 nM for NDA-tagged AAs and 8 to 12 nM for FITC-labeled AAs (S/N=3). By virtue of such valuable features as low cost, convenience, and miniaturization, the presented detection scheme was proven to be attractive for sensitive fluorescence detection in CE.
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Affiliation(s)
- Shulin Zhao
- College of Chemical Engineering, Sichuan University, Chengdu, China
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19
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Pyrzyńska K, Kilian K. Application of cyclodextrins as modifiers in electrophoretic separation of metalloporphyrins. J Sep Sci 2006; 29:282-7. [PMID: 16524104 DOI: 10.1002/jssc.200500330] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Several metallocomplexes of tetrakis-carboxyphenylporphyrin (TCPP) were separated on fused-silica capillary using CZE with UV-VIS detection. Metalloporphyrins of Co(II), Cu(II), Mn(II), Ni(II), and Zn(II) were formed directly in TCPP solution with addition of Cd(II) to increase the formation reaction rate. The composition of BGE, its concentration, and pH were optimized to ensure the stability of complexes and proper resolution. In particular, the problem of signals' shape was investigated and discussed. The presence of beta-CD in borate buffer significantly improved separation efficiency and signal shapes due to formation of inclusion complexes. Under the best separation conditions (50 mM borate running buffer at pH 9 with addition of 2 mM beta-CD, 30 kV applied voltage) a separation of metal complexes with TCPP was accomplished in 16 min.
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20
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Timerbaev AR, Hirokawa T. Recent advances of transient isotachophoresis-capillary electrophoresis in the analysis of small ions from high-conductivity matrices. Electrophoresis 2006; 27:323-40. [PMID: 16421955 DOI: 10.1002/elps.200500320] [Citation(s) in RCA: 117] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Since its invasion into the field of small ion analysis, quantitation of trace ionic analytes has always been a challenging task for CE, especially when dealing with highly saline samples. This review summarizes the method's progress and significant developments in the area due to its combination with on-line preconcentration by transient ITP (tITP). Principles of tITP stacking in high-conductivity solutions and operational preconcentration modes are considered. The most important application areas covered in this review include the analysis of seawater and biological fluids (urine, serum, etc.). Examples cited in this review demonstrate that tITP-CE is now on a certain way of becoming a recognized technique when the determination of trace ionic species in loaded matrices is the aim.
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Affiliation(s)
- Andrei R Timerbaev
- Vernadsky Institute of Geochemistry and Analytical Chemistry, Russian Academy of Sciences, Moscow, Russia
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21
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Caruso JA, Wuilloud RG, Altamirano JC, Harris WR. Modeling and separation-detection methods to evaluate the speciation of metals for toxicity assessment. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART B, CRITICAL REVIEWS 2006; 9:41-61. [PMID: 16393869 DOI: 10.1080/15287390500196172] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
There is an increasing appreciation for the importance of speciation in the assessment of metal toxicity. In this review, two approaches to speciation are discussed, with an emphasis on their application to biological samples. One approach is the direct separation and detection of metal species of toxicological interest. Various "hyphenated" techniques, consisting of a chromatographic system coupled to inductively coupled plasma-mass spectrometry (ICP-MS), are discussed. The chromatographic strategies employed for separation emphasize liquid chromatography (LC), but the increasing use of gas chromatography (GC) and capillary electrophoresis (CE) in speciation analysis is discussed. The second approach to speciation is the use of computer models to calculate the speciation of a metal ion within a complex mixture of ligands. This approach is applicable to systems in which the metal cation exchanges ligands rapidly, so that the sample represents an equilibrium mixture of metal complexes. These computational models are based on the equilibrium constants for the metal complexes and a series of mass balance equations and give the distribution of metal complexes in the original sample. This approach is illustrated using the speciation of Al(III) in serum as an example.
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Ali I, Gupta VK, Aboul-Enein HY. Metal ion speciation and capillary electrophoresis: Application in the new millennium. Electrophoresis 2005; 26:3988-4002. [PMID: 16252323 DOI: 10.1002/elps.200500216] [Citation(s) in RCA: 112] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Metal ions are essential for human beings at low concentrations but they are toxic or even carcinogenic at high concentrations. Many metallic ions are found in the environment in different species which are differentiated not only by their physicochemical forms but also by their diverse toxicities with respect to living organisms (speciation). CE has been used for metal ion speciation. The present review article describes the recent trends in metal ion speciation by CE. This article deals with the speciation of metal ions, optimization of the speciation (by independent and dependent variables), hyphenation of CE, validation of the methods, mechanisms of speciation, CE versus chromatography and conclusions.
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Affiliation(s)
- Imran Ali
- National Institute of Hydrology, Roorkee, India.
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23
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Han S, Liu E, Li H. On-line chemiluminescence determination protocatechuic aldehyde and protocatechuic acid in pharmaceutical preparations by capillary electrophoresis. J Pharm Biomed Anal 2005; 37:733-8. [PMID: 15797795 DOI: 10.1016/j.jpba.2004.11.045] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2004] [Revised: 11/19/2004] [Accepted: 11/22/2004] [Indexed: 11/19/2022]
Abstract
Capillary electrophoresis (CE) with on-line direct chemiluminescence (CL) detection was first used in detecting protocatechuic aldehyde (PAH) and protocatechuic acid (PA) in their pharmaceutical preparations. It was found that the weak CL produced from the reaction of luminol with ferricyanide in an alkaline solution was strongly increased by PAH and PA which was separated by CE. Parameters affecting separation process and CL detection have been examined in detail. Under the optimum conditions, the baseline separation of PAH and PA was obtained within 6 min. The relative standard deviation (R.S.D.) for the analysis of PAH and PA was less than 1.1% for the migration time and 1.6% for the peak height. The detection limits (S/N=3) of PAH and PA were 7.0 x 10(-8)M and 5.0 x10(-8)M, respectively. The proposed method has been satisfactorily applied to the determination of PAH and PA in Salivia miltorrhrza pharmaceutical preparations.
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Affiliation(s)
- Suqin Han
- Institute of Analytical Science, Northwest University, Xi'an 710069, China
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24
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YOKOYAMA T, ZENKI M, MACKA M, HADDAD PR. Enhancement of Separation Capability of Inorganic Ions by Capillary Electrochromatography. BUNSEKI KAGAKU 2005. [DOI: 10.2116/bunsekikagaku.54.107] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- Takashi YOKOYAMA
- Department of Chemistry, Faculty of Science, Okayama University of Science
| | - Michio ZENKI
- Department of Chemistry, Faculty of Science, Okayama University of Science
| | - Miroslav MACKA
- Australian Centre for Research on Separation Science, School of Chemistry, University of Tasmania
| | - Paul R. HADDAD
- Australian Centre for Research on Separation Science, School of Chemistry, University of Tasmania
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Abstract
Despite the availability of commercial capillary electrophoresis systems for over ten years, where quantitative analysis is required, capillary zone electrophoresis (CZE) has often failed to replace ion chromatography as the method of choice for a large number of analytes, not least inorganic anions. To investigate the reasons for this apparent failing, a review is presented of work that has been carried out to-date involving the quantitative application of CZE to the determination of inorganic anions in industrial and environmental samples. This review summarizes work both investigating and improving the quantitative aspects of the CZE of inorganic anions. A complete survey of how CZE has been applied to the determination of inorganic anions in real samples is given, including what, if any, analytical performance parameters were investigated and quoted, and if quality assurance data and validation methods were briefly considered, thoroughly investigated or simply ignored.
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Affiliation(s)
- Brett Paull
- National Centre for Sensor Research, School of Chemical Sciences, Dublin City University, Dublin, Ireland.
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27
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Aupiais J, Delorme A, Baglan N. Determination of the absolute mobility and the equivalent ionic conductivity of NpO2+ at 25 degrees C and at infinite dilution by capillary electrophoresis-inductively coupled plasma-mass spectrometry. J Chromatogr A 2003; 994:199-206. [PMID: 12779230 DOI: 10.1016/s0021-9673(03)00453-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The absolute mobility of NpO2+ and its equivalent ionic conductivity were extrapolated at 25 degrees C and at infinite dilution using a set of experimental data obtained at various ionic strengths. The separation was carried out by capillary electrophoresis (CE) at various concentrations of creatinine at a pH of 5. The detection of NpO2+ was performed by inductively coupled plasma mass spectrometry coupled on-line with CE. The following values have been found: mu0NpO2+ (25 degrees C) = (2.94 +/- 0.07) x 10(-4) cm2 V(-1) s(-1) and lambda0NpO2+ (x 10(4), 25 degrees C) = 28.3 +/- 0.7 m2 S mol(-1).
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Affiliation(s)
- J Aupiais
- CEA, DASE/RCE, BP 12, 91680 Bruyères-le-Châtel, France.
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28
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HIROKAWA T, OKAMOTO H, XU Z, IKUTA N. High-sensitive analysis by capillary electrophoresis and microchip electrophoresis using on-line preconcentration methods. BUNSEKI KAGAKU 2003. [DOI: 10.2116/bunsekikagaku.52.1069] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- Takeshi HIROKAWA
- Department of Applied Chemistry, Graduate School of Engineering, Hiroshima University
| | - Hikaru OKAMOTO
- Department of Applied Chemistry, Graduate School of Engineering, Hiroshima University
| | - Zhongqi XU
- Department of Applied Chemistry, Graduate School of Engineering, Hiroshima University
| | - Natsuki IKUTA
- Department of Applied Chemistry, Graduate School of Engineering, Hiroshima University
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29
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Liu S, Tian X, Chen X, Hu Z. Separation of diastereoisomers of podophyllum lignans by micellar electrokinetic chromatography. J Chromatogr A 2002; 959:263-8. [PMID: 12141552 DOI: 10.1016/s0021-9673(02)00455-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Seven pairs of diastereoisomers of podophyllum lignans at 2-position, including two pairs of spin-labeled compounds, were separated by micellar electrokinetic chromatography with 5 mM sodium tetraborate-20 mM NaH2PO4-120 mM sodium dodecylsulfate-30% (v/v) 2-propanol (pH 6.5-7) within 35 min. The migration behaviors of the compounds with different types and concentrations of organic modifiers were studied. The method can be used to identify the purification of the lignans, monitor the 2-H configuration transformation, and determine the 2-H configuration of the spin-labeled derivatives.
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Affiliation(s)
- Shuhui Liu
- Department of Chemistry, Lanzhou University, Gansu Province, China
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30
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Abstract
Capillary electrophoresis techniques offer high plate numbers and are highly suited for the efficient separations of a wide variety of chemical components in diverse matrices. Because of the small capillary and detection cell dimensions, together with the minute volumes of samples to be injected, sensitive detection schemes based on different physicochemical principles are being developed. One logical approach to increased sensitivity in capillary electrophoresis detection has been the development of chemiluminescence-based detectors. The development of on-line ultrasensitive chemiluminescence detection (referred to the concentration detection limit of nM order of magnitude or mass detection limit of amol order of magnitude) in capillary electrophoresis system is reviewed. The applications and limitations of the current detection methodology are briefly considered and future prospects for the development are discussed.
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Affiliation(s)
- Yan-Ming Liu
- Department of Chemistry, Wuhan University, China
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31
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Breadmore MC, Palmer AS, Curran M, Macka M, Avdalovic N, Haddad PR. On-column ion-exchange preconcentration of inorganic anions in open tubular capillary electrochromatography with elution using transient-isotachophoretic gradients. 3. Implementation and method development. Anal Chem 2002; 74:2112-8. [PMID: 12033314 DOI: 10.1021/ac011217u] [Citation(s) in RCA: 93] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A solid-phase extraction method based on an ion-exchange retention mechanism has been used for in-line preconcentration of inorganic anions prior to their separation by capillary electrophoresis (CE). A single capillary containing a preconcentration and a separation zone has been used in a commercial CE instrument without instrumental modification. Analyte anions were retained on a preconcentration zone comprising an adsorbed layer of cationic latex particles, while separation was achieved in a separation zone comprising fused silica modified by adsorption of a cationic polymer. Elution of the adsorbed analytes was achieved using an eluotropic gradient formed by a transient isotachophoretic boundary between a fluoride electrolyte and a naphthalenedisulfonate electrolyte. Optimization of the electrolyte concentrations, sample injection times, and back-flushing times allowed the successful separation of sub-ppb levels of inorganic anions using a 100-min injection at 2 bar pressure, introducing over 40 capillary volumes of sample. A method based on a 10-min injection allowed a 100-fold increase in sensitivity over conventional hydrodynamic injection for Br-, I-, NO3-, CrO4(2-), and MoO4(2-) with a total analysis time of 25 min. Detection limits were dependent on the injection time but were in the range 2.2-11.6 ppb for a 10-min injection time. This approach was used to determine NO3- in Antarctic ice cores where the analysis could be performed using a sample volume 100 times less than that used for ion chromatography.
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Affiliation(s)
- Michael C Breadmore
- Australian Centre for Research on Separation Science, School of Chemistry, University of Tasmania, Hobart
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Liu YM, Cheng JK. Highly sensitive chemiluminescence detection of copper(II) in capillary electrophoresis with field-amplified sample injection. Electrophoresis 2002; 23:556-8. [PMID: 11870764 DOI: 10.1002/1522-2683(200202)23:4<556::aid-elps556>3.0.co;2-s] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Field-amplified sample injection of copper(II) was investigated using capillary electrophoresis with chemiluminescence detection. The sensitivity of copper(II) has been improved markedly by the field-amplified sample injection technique and the detection limit reaches 2 x 10(-11) M. By injection of a short plug of water before sample introduction, the sensitivity can be further improved 5-fold and the detection limit reaches 4 x 10(-12) M. The relative standard deviations (n = 6) of the migration time and the peak height are 0.61% and 4.7% at 1.0 x 10(-9) M Cu(II), respectively. Parameters affecting the field-amplified sample injection, such as separation voltage and concentration of electrophoretic buffer, have been investigated.
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Affiliation(s)
- Yan-Ming Liu
- Department of Chemistry, Wuhan University, Wuhan, China
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Timerbaev AR, Semenova OP, Petrukhin OM. Migration behavior of metal complexes in capillary zone electrophoresis. Interpretation in terms of quantitative structure-mobility relationships. J Chromatogr A 2002; 943:263-74. [PMID: 11833646 DOI: 10.1016/s0021-9673(01)01462-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Significant advances in metal ion analysis by capillary zone electrophoresis (CZE) have occurred as a consequence of using metal complexes with various organic and inorganic ligands. Metal-ligand complexes that contribute to metal speciation in solution have also gained the attention of researchers. An understanding of the molecular properties that control the separation and further insight into the migration mechanism call for a systematic analysis of relationships between migration parameters and charge and size characteristics of metal complexes. To perform such an investigation, a number multiparametric migration models derived from a generally valid equation for electrophoretic mobility as a function of charge density were developed. The models operating with tabular or readily calculated structural descriptors (in particular, metal atom electronegativity or effective charge) as well as with the formal charge and ligand number were evaluated using numerous sets of experimental migration data for inorganic and organic ligand complexes. Consistent--in a great many instances--approximation results confirm the separation mechanism for metal complexes in CZE as governed basically by differences in charge-to-size parameters, present a valuable and convincing selection of such parameters, possessing a definite physical meaning, and owing to the general validity of the multivariate regression approach, open new possibilities in its application to more complex (i.e., electrokinetic chromatographic) systems.
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Affiliation(s)
- Andrei R Timerbaev
- Vernadsky Institute of Geochemistry and Analytical Chemistry, Russian Academy of Sciences, Moscow.
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Ali I, Aboul-Enein HY. DETERMINATION OF METAL IONS IN WATER, SOIL, AND SEDIMENT BY CAPILLARY ELECTROPHORESIS. ANAL LETT 2002. [DOI: 10.1081/al-120015519] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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35
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Liu YM, Liu EB, Cheng JK. Ultrasensitive chemiluminescence detection of sub-fM level Co(II) in capillary electrophoresis. J Chromatogr A 2001; 939:91-7. [PMID: 11806549 DOI: 10.1016/s0021-9673(01)01329-2] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
A method of on-line ultrasensitive chemiluminescence detection with capillary electrophoresis for Co(II) is reported. Using our newly developed capillary electrophoresis with chemiluminescence detection system and novel mixing mode of the reagents, the effects of field-amplified injection on detection limits of metal ions were studied in detail. The sub-fM level (1.3 x 10(-16) M, 1.6 x 10(-24) mol, 1 molecule) detection of cobalt ions in ultradilute solution was performed. The catalytic behavior of the chemiluminescence reaction of luminol and hydrogen peroxide by cobalt ions and the reaction conditions, such as the concentration of luminol, H2O2, and pH of chemiluminescence reagent were investigated. The separation of fM level Co(II) and trace amounts of Ni(II) was performed successfully.
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Affiliation(s)
- Y M Liu
- Department of Chemistry, Wuhan University, China
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Hirokawa T, Okamoto H, Ikuta N. Operational modes for transient isotachophoretic preconcentration-capillary zone electrophoresis and detectable concentration of rare earth ions. Electrophoresis 2001; 22:3483-9. [PMID: 11669530 DOI: 10.1002/1522-2683(200109)22:16<3483::aid-elps3483>3.0.co;2-o] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Operational modes for transient isotachophoretic preconcentration capillary zone electrophoresis (tr-ITP-CZE) were studied by using 5 microM and 0.5 microM rare earth mixtures as analytes in comparison with field-enhanced sample stacking. After examination of several operational modes for tr-ITP, it was found that tr-ITP effectively occured even if both the leading electrolyte and the terminating electrolyte were injected after the sample plug. This was explained as the result of a field-enhanced stacking for both sample components and the leading and terminating ions. The observed theoretical plate numbers were 4-20 times higher than those obtained by normal stacking; and the estimated low limit of detectable concentration of rare-earth elements (REE) was ca. 0.1 microM which was 2.5 times lower compared to normal stacking. For the 0.5 microM sample, a concentration factor of 20 000 could be achieved after only tr-ITP.
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Affiliation(s)
- T Hirokawa
- Department of Applied Chemistry, Graduate School of Engineering, Hiroshima University, Higashi-hiroshima, Japan.
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Yokoyama T, Macka M, Haddad PR. Determination of association constants of inorganic ions with C12- and C14-alkyldimethylammoniopropane sulfonate zwitterionic surfactants using capillary electrochromatography. Anal Chim Acta 2001. [DOI: 10.1016/s0003-2670(01)01177-1] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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38
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Hirokawa T, Okamoto H, Ikuta N. Operational modes for transient isotachophoretic preconcentration-capillary zone electrophoresis and detectable concentration of rare earth ions. Electrophoresis 2001. [DOI: 10.1002/1522-2683(200109)22:16%3c3483::aid-elps3483%3e3.0.co;2-o] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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39
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Timerbaev AR. Element speciation analysis by capillary electrophoresis: what are the hints on becoming a standard analytical methodology? Anal Chim Acta 2001. [DOI: 10.1016/s0003-2670(01)00788-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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41
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Breadmore MC, Macka M, Avdalovic N, Haddad PR. On-capillary ion-exchange preconcentration of inorganic anions in open-tubular capillary electrochromatogrpahy with elution using transient-isotachophoretic gradient. 2. Characterization of the isotachophoretic gradient. Anal Chem 2001; 73:820-8. [PMID: 11248899 DOI: 10.1021/ac0010577] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Diffuse transient-isotachophoretic boundaries can be used as an elution gradient of increasing eluotropic strength to elute inorganic anions that have been preconcentrated on an open-tubular ion-exchange stationary phase prior to electrophoretic separation. The generation and characteristics of these gradients for elution after preconcentration have been investigated. The gradients are generated by placing a low-mobility, weak ion-exchange competing anion in the capillary (weak electrolyte, WE), and a high-mobility, strong ion-exchange competing anion in the electrolyte vials (strong electrolyte, SE). Application of voltage establishes a diffuse boundary with the composition changing from the weak anion to the strong anion. Comparison of elution gradients generated with different electrolyte systems was accomplished by comparing the eluotropic strength (a function of eluent concentration, ion-exchange selectivity coefficient, and charge) and the shape of the profile as it changes from WE to SE. The ion-exchange selectivity coefficient of the SE competing anion is important in establishing a sharp change in elution strength. A large difference in mobility between the WE and SE competing anions gives an SE with a higher final eluotropic strength, but the slope of the gradient is shallower. This results in a reduction in the efficiency of analyte focusing. To ensure maximum focusing efficiency, the WE and SE electrolytes should be selected such that the SE has the highest possible eluotropic strength for a given concentration of WE. The SE competing anion should also have a sufficiently low electrophoretic mobility to ensure focusing for the maximum number of analytes, and the mobility difference between the WE and SE competing anions should be as small as possible.
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Virtanen P, Korpela T, Paavilainen S. Capillary electrophoresis in determination of inorganic anions in microbial fermentation processes; comparison with high-performance liquid chromatography. J Sep Sci 2001. [DOI: 10.1002/1615-9314(20010201)24:2<141::aid-jssc141>3.0.co;2-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Abstract
This survey gives an overview of recent derivatization protocols, starting from 1996, in combination with capillary electrophoresis (CE). Derivatization is mainly used for enhancing the detection sensitivity of CE, especially in combination with laser-induced fluorescence. Derivatization procedures are classified in tables in pre-, on- and postcapillary arrangements and, more specifically, arranged into functional groups being derivatized. The amine and reducing ends of saccharides are reported most frequently, but examples are also given for derivatization of thiols, hydroxyl, carboxylic, and carbonyl groups, and inorganic ions. Other reasons for derivatization concern indirect chiral separations, enhancing electrospray characteristics, or incorporation of a suitable charge into the analytes. Special attention is paid to the increasing field of research using on-line precapillary derivatization with CE and microdialysis for in vivo monitoring of neurotransmitter concentrations. The on-capillary derivatization can be divided in several approaches, such as the at-inlet, zone-passing and throughout method. The postcapillary mode is represented by gap designs, and membrane reactors, but especially the combination of separation, derivatization and detection on a chip is a new emerging field of research. This review, which can be seen as a sequel to our earlier reported review covering the years 1991-1995, gives an impression of current derivatization applications and highlights new developments in this field.
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Affiliation(s)
- J C Waterval
- Universiteit Utrecht, Faculty of Pharmacy, The Netherlands
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Abstract
Advances in the fundamental studies and methodology of capillary electrophoresis (CE) as applied to metal ion analysis over the last two years are reviewed, with the objective of providing the interested reader with a state-of-the-art picture of technique's potentialities in the area. In particular, novel strategies for separation selectivity control and CE system innovations designed to enhance the detection sensitivity are described. In addition, a brief overview of the primary metal analytes and samples for which the technique appears to be best suited is given. The current limitations of the technique regarding most of all the implementation for routine use are considered along with the approaches on how they could be addressed. Finally, some pointers as to the likely trends in the future research are discussed.
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Affiliation(s)
- A R Timerbaev
- Vernadsky Institute of Geochemistry and Analytical Chemistry, Russian Academy of Sciences, Moscow.
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45
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Solid-phase extraction and subsequent capillary zone electrophoresis of trace metal ions as soluble dithiocarbamate complexes. Chromatographia 2000. [DOI: 10.1007/bf02490800] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Mayrhofer K, Zemann AJ, Schnell E, Bonn GK. Capillary Electrophoresis and Contactless Conductivity Detection of Ions in Narrow Inner Diameter Capillaries. Anal Chem 1999; 71:3828-33. [DOI: 10.1021/ac990019o] [Citation(s) in RCA: 86] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Karl Mayrhofer
- Institute of Analytical Chemistry and Radiochemistry, Leopold-Franzens-University of Innsbruck, Innrain 52a, A-6020 Innsbruck, Austria
| | - Andreas J. Zemann
- Institute of Analytical Chemistry and Radiochemistry, Leopold-Franzens-University of Innsbruck, Innrain 52a, A-6020 Innsbruck, Austria
| | - Erhard Schnell
- Institute of Analytical Chemistry and Radiochemistry, Leopold-Franzens-University of Innsbruck, Innrain 52a, A-6020 Innsbruck, Austria
| | - Günther K. Bonn
- Institute of Analytical Chemistry and Radiochemistry, Leopold-Franzens-University of Innsbruck, Innrain 52a, A-6020 Innsbruck, Austria
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