1
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Zhang L, Tan QG, Fan JQ, Sun C, Luo YT, Liang RP, Qiu JD. Microfluidics for chiral separation of biomolecules. Trends Analyt Chem 2022. [DOI: 10.1016/j.trac.2022.116842] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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2
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Kochetkov KA, Bystrova NA, Pavlov PA, Oshchepkov MS, Oshchepkov AS. Microfluidic Asymmetrical Synthesis and Chiral Analysis. J IND ENG CHEM 2022. [DOI: 10.1016/j.jiec.2022.08.025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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3
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Abstract
Background::
Nano level chiral separation is necessary and demanding in the development
of the drug, genomic, proteomic, and other chemical and the environmental sciences. Few drugs exist
in human body cells for some days at nano level concentrations, that are out of the jurisdiction of the
detection by standard separation techniques. Likewise, the separation and identification of xenobiotics
and other environmental contaminants (at nano or low levels) are necessary for our healthiness.
Discussion:
Conclusion:
This article will be beneficial for chiral chromatographers, academicians, pharmaceutical
industries, environmental researchers and Government regulation authorities.
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Affiliation(s)
- Al Arsh Basheer
- State University of New York, Flint Entrance, Amherst, NY 14260, Buffalo, United States
| | - Iqbal Hussain
- Department of General Studies, Jubail Industrial College, Jubail Industrial City, Jubail, Saudi Arabia
| | - Marcus T. Scotti
- Cheminformatics Laboratory - Postgraduate Program in Natural Products and Synthetic Bioactive, Federal University of Paraiba-Campus I, 58051-970, Joao Pessoa, PB, Brazil
| | - Luciana Scotti
- Teaching and Research Management - University Hospital, Cheminformatics Laboratory - Postgraduate Program in Natural Products and Synthetic Bioactive, Federal University of Paraiba-Campus I, 58051-970, Joao Pessoa, PB, Brazil
| | - Imran Ali
- Department of Chemistry, College of Sciences, Taibah University, Al-Medina Al-Munawara - 41477, Saudi Arabia
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4
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Fanali S, Chankvetadze B. Some thoughts about enantioseparations in capillary electrophoresis. Electrophoresis 2019; 40:2420-2437. [PMID: 31081552 DOI: 10.1002/elps.201900144] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2019] [Revised: 04/22/2019] [Accepted: 04/23/2019] [Indexed: 12/20/2022]
Abstract
In this overview the goal of the authors was to analyze from the historical perspective the reasons of success and failure of chiral capillary electrophoresis. In addition, the current trends are analyzed, unique advantages of capillary electrophoresis are highlighted and some future directions are discussed.
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Affiliation(s)
- Salvatore Fanali
- School in Natural Science and Engineering, University of Verona, Verona, Italy
| | - Bezhan Chankvetadze
- Institute of Physical and Analytical Chemistry, School of Exact and Natural Sciences, Tbilisi State University, Tbilisi, Georgia
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5
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Piendl SK, Raddatz CR, Hartner NT, Thoben C, Warias R, Zimmermann S, Belder D. 2D in Seconds: Coupling of Chip-HPLC with Ion Mobility Spectrometry. Anal Chem 2019; 91:7613-7620. [DOI: 10.1021/acs.analchem.9b00302] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Sebastian K. Piendl
- Institute of Analytical Chemistry, Leipzig University, Linnéstraße 3, 04103 Leipzig, Germany
| | - Christian-Robert Raddatz
- Leibniz University Hannover, Institute of Electrical Engineering and Measurement Technology, Department of Sensors and Measurement Technology, Appelstrasse 9A, 30167 Hannover, Germany
| | - Nora T. Hartner
- Institute of Analytical Chemistry, Leipzig University, Linnéstraße 3, 04103 Leipzig, Germany
| | - Christian Thoben
- Leibniz University Hannover, Institute of Electrical Engineering and Measurement Technology, Department of Sensors and Measurement Technology, Appelstrasse 9A, 30167 Hannover, Germany
| | - Rico Warias
- Institute of Analytical Chemistry, Leipzig University, Linnéstraße 3, 04103 Leipzig, Germany
| | - Stefan Zimmermann
- Leibniz University Hannover, Institute of Electrical Engineering and Measurement Technology, Department of Sensors and Measurement Technology, Appelstrasse 9A, 30167 Hannover, Germany
| | - Detlev Belder
- Institute of Analytical Chemistry, Leipzig University, Linnéstraße 3, 04103 Leipzig, Germany
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6
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Patel DC, Wahab MF, O'Haver TC, Armstrong DW. Separations at the Speed of Sensors. Anal Chem 2018; 90:3349-3356. [PMID: 29437379 DOI: 10.1021/acs.analchem.7b04944] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The virtue of chemical sensors is speed and analyte specificity. The response time to generate an analytical signal typically varies from ∼1 to 20 s, and they are generally limited to a single analyte. Chemical sensors are significantly affected by multiple interferents, matrix effects, temperature, and can vary widely in sensitivity depending on the sensor format. Separation-based analyses remove matrix effects and interferents and are compatible with multiple analytes. However, the speed of such analyses has not been commensurate with traditional sensors until now. Beds of very small size with optimal geometry, containing core-shell particles of judicious immobilized selectors, can be used in an ultrahigh-flow regime, thereby providing subsecond separations of up to 10 analytes. Short polyether ether ketone lined stainless steel columns of various geometries were evaluated to determine the optimal bed geometry for subsecond analysis. Coupling these approaches provides subsecond-based detection and quantitation of multiple chiral and achiral species, including nucleotides, plant hormones, acids, amino acid derivatives, and sedatives among a variety of other compounds. The subsecond separations were reproducible with 0.9% RSD on retention times and showed consistent performance with 0.9% RSD on reduced plate height in van Deemter curves. A new powerful signal processing algorithm is proposed that can further enhance separation outputs and optical spectra without altering band areas on more complex separations such as 10 peaks under a second.
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Affiliation(s)
- Darshan C Patel
- Department of Chemistry and Biochemistry , University of Texas at Arlington , Arlington , Texas 76019 , United States
| | - M Farooq Wahab
- Department of Chemistry and Biochemistry , University of Texas at Arlington , Arlington , Texas 76019 , United States
| | - Thomas C O'Haver
- Department of Chemistry and Biochemistry , University of Maryland at College Park , College Park , Maryland 20742 , United States
| | - Daniel W Armstrong
- Department of Chemistry and Biochemistry , University of Texas at Arlington , Arlington , Texas 76019 , United States
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7
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Patel DC, Wahab MF, Armstrong DW, Breitbach ZS. Advances in high-throughput and high-efficiency chiral liquid chromatographic separations. J Chromatogr A 2016; 1467:2-18. [DOI: 10.1016/j.chroma.2016.07.040] [Citation(s) in RCA: 119] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Revised: 07/13/2016] [Accepted: 07/15/2016] [Indexed: 01/08/2023]
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8
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Wahab MF, Wimalasinghe RM, Wang Y, Barhate CL, Patel DC, Armstrong DW. Salient Sub-Second Separations. Anal Chem 2016; 88:8821-6. [PMID: 27529503 DOI: 10.1021/acs.analchem.6b02260] [Citation(s) in RCA: 71] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Sub-second liquid chromatography in very short packed beds is demonstrated as a broad proof of concept for chiral, achiral, and HILIC separations of biologically important molecules. Superficially porous particles (SPP, 2.7 μm) of different surface chemistries, namely, teicoplanin, cyclofructan, silica, and quinine, were packed in 0.5-cm-long columns for separating different classes of compounds. Several issues must be addressed to obtain the maximum performance of 0.5 cm columns with reduced plate heights of 2.6 to 3.0. Modified UHPLC hardware can be used to obtain sub-second separations provided extra-column dispersion is minimized and sufficient data acquisition rates are used. Further, hardware improvements will be needed to take full advantage of faster separations. The utility of power transform, which is already employed in certain chromatography detectors, is shown to be advantageous for sub-second chromatography. This approach could prove to be beneficial in fast screening and two-dimensional liquid chromatography.
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Affiliation(s)
- M Farooq Wahab
- Department of Chemistry and Biochemistry, University of Texas at Arlington , Arlington, Texas 76019, United States
| | - Rasangi M Wimalasinghe
- Department of Chemistry and Biochemistry, University of Texas at Arlington , Arlington, Texas 76019, United States
| | - Yadi Wang
- Department of Chemistry and Biochemistry, University of Texas at Arlington , Arlington, Texas 76019, United States
| | - Chandan L Barhate
- Department of Chemistry and Biochemistry, University of Texas at Arlington , Arlington, Texas 76019, United States
| | - Darshan C Patel
- Department of Chemistry and Biochemistry, University of Texas at Arlington , Arlington, Texas 76019, United States
| | - Daniel W Armstrong
- Department of Chemistry and Biochemistry, University of Texas at Arlington , Arlington, Texas 76019, United States
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9
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Krone KM, Warias R, Ritter C, Li A, Acevedo-Rocha CG, Reetz MT, Belder D. Analysis of Enantioselective Biotransformations Using a Few Hundred Cells on an Integrated Microfluidic Chip. J Am Chem Soc 2016; 138:2102-5. [DOI: 10.1021/jacs.5b12443] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Karin M. Krone
- Institute
of Analytical Chemistry, University of Leipzig, Linnéstrasse 3, 04103 Leipzig, Germany
| | - Rico Warias
- Institute
of Analytical Chemistry, University of Leipzig, Linnéstrasse 3, 04103 Leipzig, Germany
| | - Cornelia Ritter
- Faculty
of Chemistry, Philipps-Universität Marburg, Hans-Meerwein-Strasse, 35032 Marburg, Germany
| | - Aitao Li
- Faculty
of Chemistry, Philipps-Universität Marburg, Hans-Meerwein-Strasse, 35032 Marburg, Germany
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470 Mülheim/Ruhr, Germany
| | - Carlos G. Acevedo-Rocha
- Faculty
of Chemistry, Philipps-Universität Marburg, Hans-Meerwein-Strasse, 35032 Marburg, Germany
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470 Mülheim/Ruhr, Germany
| | - Manfred T. Reetz
- Faculty
of Chemistry, Philipps-Universität Marburg, Hans-Meerwein-Strasse, 35032 Marburg, Germany
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470 Mülheim/Ruhr, Germany
| | - Detlev Belder
- Institute
of Analytical Chemistry, University of Leipzig, Linnéstrasse 3, 04103 Leipzig, Germany
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10
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Regalado EL, Welch CJ. Pushing the speed limit in enantioselective supercritical fluid chromatography. J Sep Sci 2015; 38:2826-32. [DOI: 10.1002/jssc.201500270] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2015] [Revised: 05/22/2015] [Accepted: 05/25/2015] [Indexed: 11/05/2022]
Affiliation(s)
- Erik L. Regalado
- Process & Analytical Chemistry; Merck Research Laboratories; Rahway NJ USA
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11
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Liang RP, Wang XN, Wang L, Qiu JD. Enantiomeric separation by microchip electrophoresis using bovine serum albumin conjugated magnetic core-shell Fe3 O4 @Au nanocomposites as stationary phase. Electrophoresis 2014; 35:2824-32. [PMID: 25042461 DOI: 10.1002/elps.201400264] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2014] [Revised: 07/06/2014] [Accepted: 07/10/2014] [Indexed: 11/07/2022]
Abstract
In this work, a novel enantioselective MCE was developed employing BSA-conjugated Fe3 O4 @Au nanoparticles (Fe3 O4 @Au NPs) as stationary phase. Fe3 O4 @Au NPs with high magnetic responsively, excellent solubility, and high dispersibility in water were prepared through a sonochemical synthesis strategy. BSA was then immobilized onto the Fe3 O4 @Au NPs surfaces through the well-developed interaction between Au NPs and amine groups of BSA to form Fe3 O4 @Au NPs-BSA conjugates, which were then locally packed into PDMS microchannels with the help of magnets. The resultant Fe3 O4 @Au NPs-BSA conjugates not only have the magnetism of Fe3 O4 NPs that make them easily manipulated by an external magnetic field, but also have the larger surface and excellent biocompatibility of Au shell, which can incorporate much more biomolecules and well maintain their biological activity. In addition, the successful BSA decorations endowed Fe3 O4 @Au NPs-BSA conjugates with pH-tunable water solubility related to the pI of BSA (pI 4.7) and led to enhanced stability against high ionic strength. Compared with the native PDMS microchannel, the modified surfaces exhibited more stable and suppressed electroosmotic mobility, and less nonspecific adsorption toward analytes. Successful separation of chiral amino acids (tryptophan and threonine) and ofloxacin enantiomers demonstrate that the constructed MCE columns own ideal enantioselectivity. The results are expected to open up a new possibility for high-throughput screening of enantiomers with protein targets as well as a new application of magnetic NPs.
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Affiliation(s)
- Ru-Ping Liang
- Department of Chemistry, Nanchang University, Nanchang, P.R. China
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12
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Ohla S, Beyreiss R, Scriba GKE, Fan Y, Belder D. An integrated on-chip sirtuin assay. Electrophoresis 2012; 31:3263-7. [PMID: 22216443 DOI: 10.1002/elps.201000220] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
A microchip-based assay to monitor the conversion of peptide substrates by human recombinant sirtuin 1 (hSIRT1) is presented. For this purpose a fused silica microchip consisting of a microfluidic separation structure with an integrated serpentine micromixer has been used. As substrate for the assay, we used a 9-fluorenylmethoxycarbonyl (Fmoc)-labeled tetrapeptide derived from the amino acid sequence of p53, a known substrate of hSIRT1. The Fmoc group at the N-terminus resulting from solid-phase peptide synthesis enabled deep UV laser-induced fluorescence detection with excitation at 266 nm. The enzymatic reaction of 0.1 U/μL hSIRT1 was carried out within the serpentine micromixer using a 400 μM solution of the peptide in buffer. In order to reduce protein adsorption, the reaction channel was dynamically coated with hydroxypropylmethyl cellulose. The substrate and the deacetylated product were separated by microchip electrophoresis on the same chip. The approach was successfully utilized to screen various SIRT inhibitors.
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Affiliation(s)
- Stefan Ohla
- Institute of University of Leipzig, Analytical Chemistry, Leipzig, Germany
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13
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Beyreiss R, Ohla S, Nagl S, Belder D. Label-free analysis in chip electrophoresis applying deep UV fluorescence lifetime detection. Electrophoresis 2012; 32:3108-14. [PMID: 22102494 DOI: 10.1002/elps.201100204] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Herein we introduce deep UV fluorescence lifetime detection in microfluidics applied for label-free detection and identification of various aromatic analytes in chip electrophoresis. For this purpose, a frequency quadrupled Nd:YAG (neodymium-doped yttrium aluminum garnet) picosecond laser at 266 nm was incorporated into an inverse fluorescence microscope setup with time-correlated single photon counting detection. This allowed recording of photon timing with sub-nanosecond precision. Thereby fluorescence decay curves are gathered on-the-fly and average lifetimes can be determined for each substance in the electropherogram. The aromatic compounds serotonin, propranolol, 3-phenoxy-1,2-propanediol and tryptophan were electrophoretically separated using a fused-silica microchip. Average lifetimes were independently determined for each compound via bi-exponential tail fitting. Time-correlated single photon counting also allows the discrimination of background fluorescence in the time domain. This results in improved signal-to-noise-ratios as demonstrated for the above model analytes. Microchip electrophoretic separations with fluorescence lifetime detection were also performed with a protein mixture containing lysozyme, trypsinogen and chymotrypsinogen emphasizing the potential for biopolymer analysis.
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Affiliation(s)
- Reinhild Beyreiss
- University of Leipzig, Institute of Analytical Chemistry, Leipzig, Germany
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14
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Facile fabrication of an interface for online coupling of microchip CE to surface plasmon resonance. Bioanalysis 2012; 4:373-9. [DOI: 10.4155/bio.12.4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Background: The aim was to develop a simple route to coupling microchip CE (MCE) to surface plasmon resonance (SPR). MCE is a microfluidic technology that utilizes microfabrication techniques to connect interacting fluid reservoirs. Its advantages include rapid analysis (typically seconds), easy integration of multiple analytical steps and parallel operation. SPR detects changes in refractive index within a short distance from the surface of a thin metal film as variations in light intensity reflected from the back of the film and, thus, does not require labeling. There is a great demand for developing hyphenated techniques like MCE–SPR that are fast, sensitive and inexpensive to analyze biological materials. Materials & Methods: The separation channel and flow cell exist as overlapping regions constructed during the microchip production and buffer solution was delivered mechanically. Such a design has successfully isolated the electrical field inherent in the MCE from the SPR detector. Consequently, the potential interference to the SPR signal (or modulation of the density of surface plasmons at the gold chip) is circumvented. Results: The limits of detection for bovine serum albumin and sodium fluorescein were determined to be 7.5 µM and 3.1 mM, respectively. Conclusion: The technique described, herein, has been successfully applied in the separation of two species. The method offers the advantages of a near zero connection dead volume, electrical shielding from the separation voltage and minimization of the mass transfer effect.
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15
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Huang Y, Shi M, Zhao S, Liang H. Trace analysis of d-tyrosine in biological samples by microchip electrophoresis with laser induced fluorescence detection. J Chromatogr B Analyt Technol Biomed Life Sci 2011; 879:3203-7. [DOI: 10.1016/j.jchromb.2011.01.033] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2010] [Revised: 01/23/2011] [Accepted: 01/27/2011] [Indexed: 01/09/2023]
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16
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Nagl S, Schulze P, Ohla S, Beyreiss R, Gitlin L, Belder D. Microfluidic chips for chirality exploration. Anal Chem 2011; 83:3232-8. [DOI: 10.1021/ac200150w] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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17
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Qu P, Lei J, Sheng J, Zhang L, Ju H. Simultaneous multiple enantioseparation with a one-pot imprinted microfluidic channel by microchip capillary electrochromatography. Analyst 2011; 136:920-6. [DOI: 10.1039/c0an00559b] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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18
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Chip electrophoresis of active banana ingredients with label-free detection utilizing deep UV native fluorescence and mass spectrometry. Anal Bioanal Chem 2010; 399:1853-7. [DOI: 10.1007/s00216-010-4557-z] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2010] [Revised: 11/11/2010] [Accepted: 12/01/2010] [Indexed: 10/18/2022]
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19
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Herrero M, Simó C, García-Cañas V, Fanali S, Cifuentes A. Chiral capillary electrophoresis in food analysis. Electrophoresis 2010; 31:2106-14. [DOI: 10.1002/elps.200900770] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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20
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Fritzsche S, Hoffmann P, Belder D. Chip electrophoresis with mass spectrometric detection in record speed. LAB ON A CHIP 2010; 10:1227-1230. [PMID: 20445873 DOI: 10.1039/c000349b] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
We demonstrate that the combination of high speed separations on chip with a fast mass spectrometer enables electrophoretic separations with full mass spectra registration within a second. This was accomplished by coupling a microfluidic glass chip with an integrated nanospray emitter to a fast time of flight mass spectrometer working at 100 Hz for data acquisition. Applying field strengths up to 5800 V cm(-1) we achieved separations of model analytes such as pharmaceuticals and peptides with subsequent acquisition of full mass spectra within one second or slightly more.
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Affiliation(s)
- Stefanie Fritzsche
- Institute of Analytical Chemistry, University of Leipzig, Linnéstr. 3, 04103, Leipzig, Germany
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21
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Guihen E, O'Connor WT. Capillary and microchip electrophoresis in microdialysis: recent applications. Electrophoresis 2010; 31:55-64. [PMID: 20039293 DOI: 10.1002/elps.200900467] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The theme of this review is to highlight the importance of microscale electrophoretic-based separation systems in microdialysis (microD). The ability of CE and MCE to yield very rapid and highly efficient separations using just nanolitre volumes of microdialysate samples will also be discussed. Recent advances in this area will be highlighted, by illustration of some exciting new applications while the need for further innovation will be covered. The first section briefly introduces the concept of microD sampling coupled with electrophoresis-based separation and the inherent advantages of this approach. The following section highlights some specific applications of CE separations in the detection of important biomarkers such as low-molecular-weight neurotransmitters, amino acids, and other molecules that are frequently encountered in microD. Various detection modes in CE are outlined and some of the advantages and drawbacks thereof are discussed. The last section introduces the concepts of micro-total analysis systems and the coupling of MCE and microD. Some of the latest innovations will be illustrated. The concluding section reflects on the future of this important chemical alliance between microD and CE/MCE.
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Affiliation(s)
- Elizabeth Guihen
- Graduate Entry Medical School and Materials and Surface Science Institute, University of Limerick, Limerick, Ireland.
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22
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Mikus P, Maráková K. Advanced CE for chiral analysis of drugs, metabolites, and biomarkers in biological samples. Electrophoresis 2010; 30:2773-802. [PMID: 19653234 DOI: 10.1002/elps.200900173] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
An analysis of recent trends indicates that CE can show real advantages over chromatographic methods in ultratrace enantioselective determination of biologically active compounds in complex biological matrices. It is due to high separation efficiency and many applicable in-capillary electromigration effects in CE (countercurrent migration, stacking effects) enhancing significantly (enantio)separability and enabling effective sample preparation (preconcentration, purification, analyte derivatization). Other possible on-line combinations of CE, such as column coupled CE-CE techniques and implementation of nonelectrophoretic techniques (extraction, membrane filtration, flow injection) into CE, offer additional approaches for highly effective sample preparation and separation. CE matured to a highly flexible and compatible technique enabling its hyphenation with powerful detection systems allowing extremely sensitive detection (e.g. LIF) and/or structural characterization of analytes (e.g. MS). Within the last decade, more as well as less conventional analytical on-line approaches have been effectively utilized in this field and their practical potentialities are demonstrated on many new application examples in this article. Here, three basic areas of (enantioselective) drug bioanalysis are highlighted and supported by a brief theoretical description of each individual approach in a compact review structure (to create integrated view on the topic), including (i) progressive enantioseparation approaches and new enantioselective agents, (ii) in-capillary sample preparation (preconcentration, purification, derivatization), and (iii) detection possibilities related to enhanced sensitivity and structural characterization.
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Affiliation(s)
- Peter Mikus
- Department of Pharmaceutical Analysis and Nuclear Pharmacy, Faculty of Pharmacy, Comenius University, Bratislava, Slovak Republic.
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23
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McMullen JP, Jensen KF. Integrated microreactors for reaction automation: new approaches to reaction development. ANNUAL REVIEW OF ANALYTICAL CHEMISTRY (PALO ALTO, CALIF.) 2010; 3:19-42. [PMID: 20636032 DOI: 10.1146/annurev.anchem.111808.073718] [Citation(s) in RCA: 241] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Applications of microsystems (microreactors) in continuous-flow chemistry have expanded rapidly over the past two decades, with numerous reports of higher conversions and yields compared to conventional batch benchtop equipment. Synthesis applications are enhanced by chemical information gained from integrating microreactor components with sensors, actuators, and automated fluid handling. Moreover, miniaturized systems allow experiments on well-defined samples at conditions not easily accessed by conventional means, such as reactions at high pressure and temperatures. The wealth of synthesis information that could potentially be acquired through use of microreactors integrated with physical sensors and analytical chemistry techniques for online reaction monitoring has not yet been well explored. The increased efficiency resulting from use of continuous-flow microreactor platforms to automate reaction screening and optimization encourages a shift from current batchwise chemical reaction development to this new approach. We review advances in this new area and provide application examples of online monitoring and automation.
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Affiliation(s)
- Jonathan P McMullen
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, 02139, USA.
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24
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Qu P, Lei J, Ouyang R, Ju H. Enantioseparation and Amperometric Detection of Chiral Compounds by in Situ Molecular Imprinting on the Microchannel Wall. Anal Chem 2009; 81:9651-6. [DOI: 10.1021/ac902201a] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Affiliation(s)
- Ping Qu
- Key Laboratory of Analytical Chemistry for Life Science (Ministry of Education of China), Department of Chemistry, Nanjing University, Nanjing 210093, P. R. China
| | - Jianping Lei
- Key Laboratory of Analytical Chemistry for Life Science (Ministry of Education of China), Department of Chemistry, Nanjing University, Nanjing 210093, P. R. China
| | - Ruizhuo Ouyang
- Key Laboratory of Analytical Chemistry for Life Science (Ministry of Education of China), Department of Chemistry, Nanjing University, Nanjing 210093, P. R. China
| | - Huangxian Ju
- Key Laboratory of Analytical Chemistry for Life Science (Ministry of Education of China), Department of Chemistry, Nanjing University, Nanjing 210093, P. R. China
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25
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Abstract
This paper summarizes the history of chiral separations done by using electromigration methods with CDs. Several enantioresolution mechanisms and a wide number of chiral selectors have been applied to the separation of optical isomers by CE. Among them inclusion-complexation with CDs or their derivatives played a very important role in CE. Since the beginning our group was involved in studying method optimization for enantiomer resolution by using these chiral selectors. One of our publications was the basis for further development in the field, at least for us. New chiral selectors, development of theory, new methodological approaches and a wide number of practical applications are the main results achieved in the last almost 25 years using CE as an enantioseparative technique.
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Affiliation(s)
- Salvatore Fanali
- Institute of Chemical Methodologies, National Council of Research, Area della Ricerca di Roma I, Monterotondo Scalo (Rome), Italy.
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26
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Nagl S, Schulze P, Ludwig M, Belder D. Progress in microchip enantioseparations. Electrophoresis 2009; 30:2765-72. [DOI: 10.1002/elps.200900153] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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27
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Ikai T, Okamoto Y. Structure Control of Polysaccharide Derivatives for Efficient Separation of Enantiomers by Chromatography. Chem Rev 2009; 109:6077-101. [DOI: 10.1021/cr8005558] [Citation(s) in RCA: 347] [Impact Index Per Article: 23.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Affiliation(s)
- Tomoyuki Ikai
- EcoTopia Science Institute, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603, Japan, and College of Material Science and Chemical Engineering, Harbin Engineering University, 145 Nantong St. Harbin 150001, P. R. China
| | - Yoshio Okamoto
- EcoTopia Science Institute, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603, Japan, and College of Material Science and Chemical Engineering, Harbin Engineering University, 145 Nantong St. Harbin 150001, P. R. China
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28
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Huang Y, Shi M, Zhao S. Quantification of D
-Asp and D
-Glu in rat brain and human cerebrospinal fluid by microchip electrophoresis. J Sep Sci 2009; 32:3001-6. [DOI: 10.1002/jssc.200900026] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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29
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Kirschner DL, Green TK. Separation and sensitive detection of D
-amino acids in biological matrices. J Sep Sci 2009; 32:2305-18. [DOI: 10.1002/jssc.200900101] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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30
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Zhang G, Qian C, Xu Y, Feng X, Du W, Liu BF. Open tubular CEC in a microfluidic chip for rapid chiral recognition. J Sep Sci 2009; 32:374-80. [DOI: 10.1002/jssc.200800507] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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31
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Guihen E, Hogan AM, Glennon JD. High-speed microchip electrophoresis method for the separation of (R,S)-naproxen. Chirality 2009; 21:292-8. [DOI: 10.1002/chir.20575] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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32
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Danger G, Ross D. Chiral separation with gradient elution isotachophoresis for futurein situextraterrestrial analysis. Electrophoresis 2008; 29:4036-44. [DOI: 10.1002/elps.200700950] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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33
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Chiral separation by capillary electromigration techniques. J Chromatogr A 2008; 1204:140-56. [DOI: 10.1016/j.chroma.2008.07.071] [Citation(s) in RCA: 208] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2008] [Revised: 06/27/2008] [Accepted: 07/08/2008] [Indexed: 11/19/2022]
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34
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Juvancz Z, Kendrovics RB, Iványi R, Szente L. The role of cyclodextrins in chiral capillary electrophoresis. Electrophoresis 2008; 29:1701-12. [PMID: 18421743 DOI: 10.1002/elps.200700657] [Citation(s) in RCA: 107] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The members of the enantiomeric pairs frequently show rather different biological effects, so their chiral selective synthesis, pharmacological studies and analysis are necessary. CE has unique advantages in chiral analysis. The most frequently used chiral selectors are CDs in this field. This paper gives a short view on the advantages on CE in direct chiral separations, emphasizing the role of CDs. The reason for the broad selectivity spectra of CDs is discussed in detail. The physical background of chiral selective separations is briefly shown in CE. Their interaction mechanisms are shortly defined. The general trend of their use is statistically evaluated. Most frequently used CDs and CD derivatives are characterized. Advantages of ionizable CDs and single-isomer derivatives are shown. The general trend of their use is established.
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Affiliation(s)
- Zoltán Juvancz
- Department of Environmental Engineering, Budapest Tech. Polytechnical Institution, Budapest, Hungary.
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35
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Danger G, Ross D. Development of a temperature gradient focusing method for in situ extraterrestrial biomarker analysis. Electrophoresis 2008; 29:3107-14. [DOI: 10.1002/elps.200700778] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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36
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Gao Y, Luo Y, Qin J, Lin B. A multichannel electrophoresis microchip platform for rapid chiral selector screening. Electrophoresis 2008; 29:1918-23. [DOI: 10.1002/elps.200700384] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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37
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Wu D, Qin J, Lin B. Electrophoretic separations on microfluidic chips. J Chromatogr A 2008; 1184:542-59. [PMID: 18207148 PMCID: PMC7094303 DOI: 10.1016/j.chroma.2007.11.119] [Citation(s) in RCA: 148] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2007] [Revised: 11/17/2007] [Accepted: 11/30/2007] [Indexed: 02/07/2023]
Abstract
This review presents a brief outline and novel developments of electrophoretic separation in microfluidic chips. Distinct characteristics of microchip electrophoresis (MCE) are discussed first, in which sample injection plug, joule heat, channel turn, surface adsorption and modification are introduced, and some successful strategies and recognized conclusions are also included. Important achievements of microfluidic electrophoresis separation in small molecules, DNA and protein are then summarized. This review is aimed at researchers, who are interested in MCE and want to adopt MCE as a functional unit in their integrated microsystems.
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Affiliation(s)
| | - Jianhua Qin
- Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China
| | - Bingcheng Lin
- Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China
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38
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18 Coupling CE and microchip-based devices with mass spectrometry. ACTA ACUST UNITED AC 2008. [DOI: 10.1016/s0149-6395(07)00018-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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39
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Kuswandi B, Nuriman, Huskens J, Verboom W. Optical sensing systems for microfluidic devices: A review. Anal Chim Acta 2007; 601:141-55. [PMID: 17920386 DOI: 10.1016/j.aca.2007.08.046] [Citation(s) in RCA: 244] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2007] [Revised: 08/22/2007] [Accepted: 08/23/2007] [Indexed: 10/22/2022]
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40
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Chankvetadze B. Enantioseparations by using capillary electrophoretic techniques. The story of 20 and a few more years. J Chromatogr A 2007; 1168:45-70; discussion 44. [PMID: 17765908 DOI: 10.1016/j.chroma.2007.08.008] [Citation(s) in RCA: 203] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2007] [Revised: 07/27/2007] [Accepted: 08/02/2007] [Indexed: 11/29/2022]
Abstract
This paper provides the author's insight on the past, present and future of performing enantioseparations using capillary electrophoretic (CE) techniques. These techniques are discussed from the historical point of view, as well as based on their potential as the separation techniques of today and the future. The overview covers mechanistic as well as practical aspects of CE techniques.
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Affiliation(s)
- Bezhan Chankvetadze
- Institute of Chemistry, School of Exact and Natural Sciences and Molecular Recognition and Separation Science Laboratory, Tbilisi State University, Chavchavadze Ave. 1, 0128 Tbilisi, Georgia.
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41
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Abstract
Microfluidic devices have been widely used to derivatize, separate, and detect amino acids employing many different strategies. Virtually zero-dead volume interconnections and fast mass transfer in small volume microchannels enable dramatic increases in on-chip derivatization reaction speed, while only minute amounts of sample and reagent are needed. Due to short channel path, fast subsecond separations can be carried out. With sophisticated miniaturized detectors, the whole analytical process can be integrated on one platform. This article reviews developments of lab-on-chip technology in amino acid analysis, it shows important design features such as sample preconcentration, precolumn and postcolumn amino acid derivatization, and unlabeled and labeled amino acid detection with focus on advanced designs. The review also describes important biomedical and space exploration applications of amino acid analysis on microfluidic devices.
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Affiliation(s)
- Martin Pumera
- ICYS, National Institute for Materials Science, Tsukuba, Japan.
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42
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Kirschner DL, Jaramillo M, Green TK. Enantioseparation and stacking of Cyanobenz[f]isoindole-amino acids by reverse polarity capillary electrophoresis and sulfated beta-cyclodextrin. Anal Chem 2007; 79:736-43. [PMID: 17222044 DOI: 10.1021/ac061725+] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A capillary electrophoresis method with laser-induced fluorescence detection for the chiral separation of cyanobenz[f]isoindole (CBI) derivatives of amino acids was developed and optimized. The enantioseparations are accomplished with sulfated beta-CD (S-beta-CD) as chiral selector at low pH and reverse polarity. BGE conditions were optimized for CBI-serine and then applied to other CBI-amino acids. Baseline resolution of 13 CBI-amino acids was achieved using a single BGE formulation of 2 wt % S-beta-CD in 25 mM phosphate buffer at pH 2.00 and a voltage of -30 kV. pH is the most critical BGE parameter affecting resolution. At 2 wt % S-beta-CD, CBI-serine enantiomers are baseline-resolved at pH 2.00 but no resolution is obtained at pH 3.00. l-Glutamate, l-aspartate and d-serine are simultaneously quantified in the microdialysate of an arctic ground squirrel to illustrate the application to biological samples. Dilute solutions of the CBI-amino acids in water can be stacked by hydrodynamic injection with a 100-fold improvement in signal-to-noise ratio without loss of chiral resolution. The stacking is proposed to consist of field-amplified migration, pH-mediated stacking, and sweeping by S-beta-CD. The limit of detections for CBI-dl-serine and CBI-dl-glutamate are determined as 0.20 and 0.30 nM, respectively. The stacking method was not applicable to the high ionic strength microdialysates.
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Affiliation(s)
- Daniel L Kirschner
- Department of Chemistry & Biochemistry, Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, Alaska 99775, USA
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43
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Gübitz G, Schmid MG. Advances in chiral separation using capillary electromigration techniques. Electrophoresis 2007; 28:114-26. [PMID: 17136739 DOI: 10.1002/elps.200600411] [Citation(s) in RCA: 93] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
This review gives an overview of recent developments in CZE, EKC, and CEC covering the literature since the year 2004. Since there appeared a special issue on applications, this review focuses on the progress in electromigration techniques and new methodological developments. New techniques, new chiral selectors as well as new chiral stationary phases for CEC are discussed.
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Affiliation(s)
- Gerald Gübitz
- Department of Pharmaceutical Chemistry, Institute of Pharmaceutical Sciences, Karl-Franzens-University, Graz, Austria.
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44
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Vlčková M, Stettler AR, Schwarz MA. Microchip Affinity Capillary Electrophoresis: Applications and Recent Advances. J LIQ CHROMATOGR R T 2007. [DOI: 10.1080/10826070600574754] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Affiliation(s)
- Markéta Vlčková
- a Universität Basel, Departement Chemie , Basel, Switzerland
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45
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Götz S, Karst U. Recent developments in optical detection methods for microchip separations. Anal Bioanal Chem 2007; 387:183-92. [PMID: 17031620 PMCID: PMC7080113 DOI: 10.1007/s00216-006-0820-8] [Citation(s) in RCA: 124] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2006] [Revised: 08/18/2006] [Accepted: 08/31/2006] [Indexed: 10/26/2022]
Abstract
This paper summarizes the features and performances of optical detection systems currently applied in order to monitor separations on microchip devices. Fluorescence detection, which delivers very high sensitivity and selectivity, is still the most widely applied method of detection. Instruments utilizing laser-induced fluorescence (LIF) and lamp-based fluorescence along with recent applications of light-emitting diodes (LED) as excitation sources are also covered in this paper. Since chemiluminescence detection can be achieved using extremely simple devices which no longer require light sources and optical components for focusing and collimation, interesting approaches based on this technique are presented, too. Although UV/vis absorbance is a detection method that is commonly used in standard desktop electrophoresis and liquid chromatography instruments, it has not yet reached the same level of popularity for microchip applications. Current applications of UV/vis absorbance detection to microchip separations and innovative approaches that increase sensitivity are described. This article, which contains 85 references, focuses on developments and applications published within the last three years, points out exciting new approaches, and provides future perspectives on this field.
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Affiliation(s)
- Sebastian Götz
- Chemical Analysis Group and MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands
| | - Uwe Karst
- Chemical Analysis Group and MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands
- Present Address: Institute of Inorganic and Analytical Chemistry, University of Münster, Corrensstr. 30, 48149 Münster, Germany
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46
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Götz S, Revermann T, Karst U. Quantitative on-chip determination of taurine in energy and sports drinks. LAB ON A CHIP 2007; 7:93-7. [PMID: 17180210 DOI: 10.1039/b609739a] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
A new method for the quantitative determination of taurine in beverages by microchip electrophoresis was developed. A rapid and simple sample preparation procedure, only including two dilution steps and the addition of the fluorogenic labeling reagent NBD-Cl (4-chloro-7-nitrobenzofurazan), is applied. Using a home-built wavelength-resolved fluorescence detector, the separation and determination of the taurine derivative could be achieved in only 12 s, while the additional spectral information was utilized to ensure peak purity. Spanning from 0.1 to 50 mmol L(-1), the linear dynamic range of the applied method was adapted to the apparent contents in common taurine containing beverages. The smallest detectable amount of the taurine derivative actually injected into the separation channel was as low as 60 amol. The method was successfully validated by an independent liquid chromatographic method.
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Affiliation(s)
- Sebastian Götz
- University of Twente, Chemical Analysis Group and MESA+ Institute for Nanotechnology, P.O. Box 217, 7500 AE Enschede, The Netherlands
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47
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Liu X, Liu X, Liang A, Shen Z, Zhang Y, Dai Z, Xiong B, Lin B. Studying protein-drug interaction by microfluidic chip affinity capillary electrophoresis with indirect laser-induced fluorescence detection. Electrophoresis 2006; 27:3125-8. [PMID: 16807938 DOI: 10.1002/elps.200500890] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
We developed a microfluidic chip-affinity CE method based on indirect LIF detection to study protein-drug interactions. The interaction between heparin and BSA was quantitatively studied, as a model system. In our method, sodium fluorescein was chosen as background, and redistilled water as marker to monitor EOF. The electrophoretic mobility changes of BSA were measured, with various concentrations of heparin added to the running buffer. Each run was completed within 80 s. The binding constant was determined to be (1.24 +/- 0.05) x 10(3) M(-1), which was in good agreement with that reported in the literature.
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Affiliation(s)
- Xiaojun Liu
- Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023, P. R. China
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48
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Weng X, Bi H, Liu B, Kong J. On-chip chiral separation based on bovine serum albumin-conjugated carbon nanotubes as stationary phase in a microchannel. Electrophoresis 2006; 27:3129-35. [PMID: 16807934 DOI: 10.1002/elps.200500840] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
A novel method of chiral separation based on protein-stationary phase immobilized in a poly(methyl methacrylate) microfluidic chip was developed. BSA conjugated with the shortened carboxylic single-walled carbon nanotubes (SWNTs) was employed as the chiral selector. Successful separation of tryptophan enantiomers was achieved in less than 70 s with a resolution factor of 1.35 utilizing a separation length of 32 mm. This is the first example of chiral separation based on SWNTs-BSA conjugates as stationary phase immobilized in microchip channel. The stability of the stationary phase in the channel was examined by microchip electrophoresis with laser-induced fluorescence detection. Factors that influenced the chiral separation resolution were examined. Under the optimized conditions, the proposed modified chip revealed adequate repeatability concerning run-to-run. These results show that the use of SWNTs-BSA conjugates within microfluidic channels hold great promise for a variety of analytical schemes.
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Affiliation(s)
- Xuexiang Weng
- Department of Chemistry, Fudan University, Shanghai 200433, P. R. China
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49
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Van Eeckhaut A, Michotte Y. Chiral separations by capillary electrophoresis: Recent developments and applications. Electrophoresis 2006; 27:2880-95. [PMID: 16688697 DOI: 10.1002/elps.200500375] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
This paper provides an overview of the different classes of chiral selectors that are used in CE. The main properties of every class are described, together with the mechanism of enantioseparation. Newly introduced selectors are also discussed. Pharmaceutical and biomedical applications published from January 2004 till March 2005 are summarized.
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Affiliation(s)
- Ann Van Eeckhaut
- Department of Pharmaceutical Chemistry, Drug Analysis and Drug Information, Pharmaceutical Institute, Vrije Universiteit Brussel, Brussels, Belgium
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50
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Affiliation(s)
- Timothy J Ward
- Millsaps College, 1701 North State Street, Box 150306, Jackson, Mississippi, USA.
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