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Skinner CD. Fiber optic illumination of a poly(dimethylsiloxane) sheath flow cuvette for diode laser induced fluorescence detection in capillary electrophoresis. Electrophoresis 2015; 36:502-8. [DOI: 10.1002/elps.201400437] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2014] [Revised: 10/15/2014] [Accepted: 10/16/2014] [Indexed: 11/06/2022]
Affiliation(s)
- Cameron D. Skinner
- Department of Chemistry and Biochemistry; Concordia University; Montréal QC Canada
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2
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Abdul Keyon AS, Guijt RM, Bolch CJ, Breadmore MC. Droplet Microfluidics for Postcolumn Reactions in Capillary Electrophoresis. Anal Chem 2014; 86:11811-8. [DOI: 10.1021/ac5033963] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Aemi S. Abdul Keyon
- Australian
Centre for Research on Separation Science, School of Physical Sciences, University of Tasmania, GPO Box 252-75, Hobart, Tasmania 7001, Australia
- Pharmacy
School of Medicine, Australian Centre for Research on Separation Science, University of Tasmania, GPO Box 252-26, Hobart, Tasmania 7001, Australia
- National
Centre for Marine Conservation and Resource Sustainability, Australian
Maritime College, University of Tasmania, 7250, Launceston, Tasmania Australia
- Department
of Chemistry, Faculty of Science, Universiti Teknologi Malaysia, 81310, Johor Bahru, Johor Malaysia
| | - Rosanne M. Guijt
- Pharmacy
School of Medicine, Australian Centre for Research on Separation Science, University of Tasmania, GPO Box 252-26, Hobart, Tasmania 7001, Australia
| | - Christopher J. Bolch
- National
Centre for Marine Conservation and Resource Sustainability, Australian
Maritime College, University of Tasmania, 7250, Launceston, Tasmania Australia
| | - Michael C. Breadmore
- Australian
Centre for Research on Separation Science, School of Physical Sciences, University of Tasmania, GPO Box 252-75, Hobart, Tasmania 7001, Australia
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Dada OO, Huge BJ, Dovichi NJ. Simplified sheath flow cuvette design for ultrasensitive laser induced fluorescence detection in capillary electrophoresis. Analyst 2012; 137:3099-101. [PMID: 22606689 PMCID: PMC3371152 DOI: 10.1039/c2an35321k] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We present a design for a sheath-flow cuvette that uses a relatively inexpensive quartz cuvette. The cuvette has a high optical quality square flow chamber that is fused to quartz tubes at each end. PEEK/TEFZEL fittings hold and seal the quartz flow chamber without putting strain on the cuvette. The performance of the cuvette is evaluated as a laser-induced fluorescence detector for capillary electrophoresis. The cuvette produces mass detection limits of 50 yoctomoles (30 copies) for 5-carboxyl tetramethylrhodamine (5 TAMRA SE) with a separation efficiency of 400,000 theoretical plates.
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Affiliation(s)
- Oluwatosin O Dada
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, USA
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4
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Xu H, Weber SG. Effect of an open tube in series with a packed capillary column on liquid chromatographic performance. The influence of particle diameter, temperature, and system pressure. J Chromatogr A 2009; 1216:1346-52. [PMID: 19150071 PMCID: PMC2663968 DOI: 10.1016/j.chroma.2008.12.060] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2008] [Revised: 12/16/2008] [Accepted: 12/22/2008] [Indexed: 10/21/2022]
Abstract
A postcolumn reactor or a simple open tube connecting a capillary column to, for example, a mass spectrometer affects the performance of a capillary liquid chromatography system in two ways: stealing pressure from the column and adding band-spreading. This effect is especially intolerable in fast separations. Our calculations show that in the presence of a 25 microm radius postcolumn reactor, column (50 microm radius) efficiency (number of theoretical plates) is severely reduced by more than 75% with a t(0) of 10s and a particle diameter from 1 to 5 microm for unretained solutes at room temperature. Therefore, it is necessary to minimize the reactor's effect and to improve the column efficiency by optimizing postcolumn conditions. We derived an equation that defines the observed number of theoretical plates (N(obs)) taking into account the two effects stated above, which is a function of the maximum pressure P(m), the particle diameter d(p), the reactor radius a(r), the column radius a(c), the desired dead time t(0), the column temperature T and zone capacity factor k''. Poppe plots were obtained by calculations using this equation. The results show that for a t(0) shorter than 18s, a P(m) of 4000 psi, and a d(p) of 1.7 microm, a 5 microm radius reactor has to be used. Such a small reactor is difficult to fabricate. Fortunately, high temperature helps to minimize the reactor effect so that reactors with manageable radius (larger than 12.5 microm) can be used in many practical conditions. Furthermore, solute retention diminishes the influence of a postcolumn reactor. Thus, a 12.5 microm reactor supersedes a 5 microm reactor for retained solutes even at a t(0) of 5s (k''>3.8, or k'>2.0).
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Affiliation(s)
- Hongjuan Xu
- Department of Chemistry, University of Pittsburgh, 219 Parkman Avenue, Pittsburgh, PA 15260, USA
| | - Stephen G. Weber
- Department of Chemistry, University of Pittsburgh, 219 Parkman Avenue, Pittsburgh, PA 15260, USA
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Xu Z, Esumi T, Ikuta N, Hirokawa T. High-sensitive analysis of DNA fragments by capillary gel electrophoresis using transient isotachophoresis preconcentration and fluorescence detection. J Chromatogr A 2009; 1216:3602-5. [PMID: 19211105 DOI: 10.1016/j.chroma.2009.01.066] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2008] [Revised: 01/21/2009] [Accepted: 01/23/2009] [Indexed: 01/15/2023]
Abstract
In this report aimed on further development of a high-sensitivity capillary gel electrophoresis (CGE) method for analysis of DNA fragments, we firstly explored online transient isotachophoresis (tITP) preconcentration combined with fluorescence detection (FD). The fluorescence signal (excitation: 488 nm; emission: 590 nm) was generated using the intercalating dye of ethidium bromide (EB). It was found when the leading electrolyte (LE) was injected behind the sample zone, such a special tITP mode has significant advantages to solve the bubble formation issue and to improve the analytical performance stability. Two standard DNA samples, a 50 bp DNA step ladder and the phiX174/HaeIII digest, were used to evaluate the qualitative and quantitative abilities of the tITP-FD approach. A highly diluted sample (10,000-fold in the water, e.g. the phiX174/HaeIII digest diluted from 500 microg/ml to the 50 ng/ml level) was enriched and detected; the LOD was down to 0.09 ng/ml for the 72 bp fragment, apparently improved more than 1000-fold in comparison with UV detection. Although the RSD of peak areas (n=3) was around 15.5% for the sample was electrokinetically injected, good linearity of peak area response showed that the proposed method is suitable for quantitative analysis.
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Affiliation(s)
- Zhongqi Xu
- Department of Applied Chemistry, Graduate School of Engineering, Hiroshima University, Higashi-hiroshima, Japan
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6
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Skinner CD. A PDMS sheath flow cuvette for high-sensitivity LIF measurements in CE. Electrophoresis 2009; 30:372-8. [DOI: 10.1002/elps.200800300] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Determination of kanamycin A, amikacin and tobramycin residues in milk by capillary zone electrophoresis with post-column derivatization and laser-induced fluorescence detection. J Chromatogr B Analyt Technol Biomed Life Sci 2009; 877:333-8. [DOI: 10.1016/j.jchromb.2008.12.011] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2008] [Revised: 09/22/2008] [Accepted: 12/04/2008] [Indexed: 11/20/2022]
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Yu CZ, He YZ, Han F, Fu GN. Post-column reactor of coaxial-gap mode for laser-induced fluorescence detection in capillary electrophoresis. J Chromatogr A 2007; 1171:133-9. [DOI: 10.1016/j.chroma.2007.09.046] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2007] [Revised: 09/14/2007] [Accepted: 09/17/2007] [Indexed: 10/22/2022]
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Affiliation(s)
- Karel Klepárník
- Institute of Analytical Chemistry, Academy of Sciences of the Czech Republic, Veveří 97, CZ-602 00 Brno, Czech Republic
| | - Petr Boček
- Institute of Analytical Chemistry, Academy of Sciences of the Czech Republic, Veveří 97, CZ-602 00 Brno, Czech Republic
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Xu H, Weber SG. Optimization of post-column reactor radius in capillary high performance liquid chromatography Effect of chromatographic column diameter and particle diameter. J Chromatogr A 2006; 1113:116-22. [PMID: 16494886 PMCID: PMC1839062 DOI: 10.1016/j.chroma.2006.01.129] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2005] [Revised: 01/26/2006] [Accepted: 01/30/2006] [Indexed: 11/20/2022]
Abstract
A post-column reactor consisting of a simple open tube (Capillary Taylor Reactor) affects the performance of a capillary LC in two ways: stealing pressure from the column and adding band spreading. The former is a problem for very small radius reactors, while the latter shows itself for large reactor diameters. We derived an equation that defines the observed number of theoretical plates (N(obs)) taking into account the two effects stated above. Making some assumptions and asserting certain conditions led to a final equation with a limited number of variables, namely chromatographic column radius, reactor radius and chromatographic particle diameter. The assumptions and conditions are that the van Deemter equation applies, the mass transfer limitation is for intraparticle diffusion in spherical particles, the velocity is at the optimum, the analyte's retention factor, k', is zero, the post-column reactor is only long enough to allow complete mixing of reagents and analytes and the maximum operating pressure of the pumping system is used. Optimal ranges of the reactor radius (a(r)) are obtained by comparing the number of observed theoretical plates (and theoretical plates per time) with and without a reactor. Results show that the acceptable reactor radii depend on column diameter, particle diameter, and maximum available pressure. Optimal ranges of a(r) become narrower as column diameter increases, particle diameter decreases or the maximum pressure is decreased. When the available pressure is 4000 psi, a Capillary Taylor Reactor with 12 microm radius is suitable for all columns smaller than 150 microm (radius) packed with 2-5 microm particles. For 1 microm packing particles, only columns smaller than 42.5 microm (radius) can be used and the reactor radius needs to be 5 microm.
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Affiliation(s)
- Hongjuan Xu
- Department of Chemistry, University of Pittsburgh, 219 Parkman Avenue, Pittsburgh, PA 15260, USA
| | - Stephen G. Weber
- Department of Chemistry, University of Pittsburgh, 219 Parkman Avenue, Pittsburgh, PA 15260, USA
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11
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Rezenom YH, Lancaster JM, Pittman JL, Gilman SD. Laser ablation construction of on-column reagent addition devices for capillary electrophoresis. Anal Chem 2002; 74:1572-7. [PMID: 12043598 DOI: 10.1021/ac015693w] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A simple and reproducible technique for constructing perfectly aligned gaps in fused-silica capillaries has been developed for postcolumn reagent addition with capillary electrophoresis. This technique uses laser ablation with the second harmonic of a Nd:YAG laser (532 nm) at 13.5 mJ/pulse and a repetition rate of 15 Hz to create these gaps. A capillary is glued to a microscope slide and positioned at the focal point of a cylindrical lens using the focused beam from a laser pointer as a reference. Gaps of 14.0 +/- 2.2 microm (n = 33) at the bore of the capillary are produced with a success rate of 94% by ablation with 400 pulses. This simple method of gap construction requires no micromanipulation under a microscope, hydrofluoric acid etching, or use of column fittings. These structures have been used for reagent addition for postcolumn derivatization with laser-induced fluorescence detection and have been tested for the separation of proteins and amino acids. Detection limits of 6 x 10(-7) and 1 x 10(-8) M have been obtained for glycine and tranferrin, respectively. Separation efficiencies obtained using these gap reactors range from 38,000 to 213,000 theoretical plates.
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Affiliation(s)
- Yohannes H Rezenom
- Department of Chemistry, University of Tennessee, Knoxville 37996-1600, USA
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12
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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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