1
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Fluorescein isothiocyanate stability in different solvents. MONATSHEFTE FUR CHEMIE 2021. [DOI: 10.1007/s00706-021-02852-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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2
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Moon BJ, Kim SJ, Lee A, Oh Y, Lee SK, Lee SH, Kim TW, Hong BH, Bae S. Structure-controllable growth of nitrogenated graphene quantum dots via solvent catalysis for selective C-N bond activation. Nat Commun 2021; 12:5879. [PMID: 34620858 PMCID: PMC8497556 DOI: 10.1038/s41467-021-26122-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Accepted: 09/10/2021] [Indexed: 11/10/2022] Open
Abstract
Photophysical and photochemical properties of graphene quantum dots (GQDs) strongly depend on their morphological and chemical features. However, systematic and uniform manipulation of the chemical structures of GQDs remains challenging due to the difficulty in simultaneous control of competitive reactions, i.e., growth and doping, and the complicated post-purification processes. Here, we report an efficient and scalable production of chemically tailored N-doped GQDs (NGs) with high uniformity and crystallinity via a simple one-step solvent catalytic reaction for the thermolytic self-assembly of molecular precursors. We find that the graphitization of N-containing precursors during the formation of NGs can be modulated by intermolecular interaction with solvent molecules, the mechanism of wh ich is evidenced by theoretical calculations and various spectroscopic analyses. Given with the excellent visible-light photoresponse and photocatalytic activity of NGs, it is expected that the proposed approach will promote the practical utilization of GQDs for various applications in the near future. Photophysical and photochemical features of graphene quantum dots (GQDs) strongly depend on their chemical nature that remains challenging to be controlled in a systematic and uniform manner. Here the authors report an efficient solvent-catalyst-aided growth of chemically tailored N-doped GQDs.
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Affiliation(s)
- Byung Joon Moon
- Functional Composite Materials Research Center, Korea Institute of Science and Technology, Wanju-gun, Jeollabuk-do, 55324, Republic of Korea.,Department of Chemistry, Seoul National University, Seoul, 08826, Republic of Korea
| | - Sang Jin Kim
- Functional Composite Materials Research Center, Korea Institute of Science and Technology, Wanju-gun, Jeollabuk-do, 55324, Republic of Korea
| | - Aram Lee
- Functional Composite Materials Research Center, Korea Institute of Science and Technology, Wanju-gun, Jeollabuk-do, 55324, Republic of Korea
| | - Yelin Oh
- Functional Composite Materials Research Center, Korea Institute of Science and Technology, Wanju-gun, Jeollabuk-do, 55324, Republic of Korea
| | - Seoung-Ki Lee
- School of Materials Science and Engineering, Pusan National University, Busan, 46241, Republic of Korea
| | - Sang Hyun Lee
- The School of Chemical Engineering, Chonnam National University, Gwangju, 61186, Republic of Korea
| | - Tae-Wook Kim
- Department of Flexible and Printable Electronics, Jeonbuk National University, Jeonju-si, Jeollabuk-do, 54896, Republic of Korea
| | - Byung Hee Hong
- Department of Chemistry, Seoul National University, Seoul, 08826, Republic of Korea.,Graphene Research Center, Advanced Institute of Convergence Technology, Seoul National University, Suwon-si, Gyeonggi-do, 16229, Republic of Korea
| | - Sukang Bae
- Functional Composite Materials Research Center, Korea Institute of Science and Technology, Wanju-gun, Jeollabuk-do, 55324, Republic of Korea.
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3
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Twenty years of amino acid determination using capillary electrophoresis: A review. Anal Chim Acta 2021; 1174:338233. [DOI: 10.1016/j.aca.2021.338233] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Revised: 01/14/2021] [Accepted: 01/16/2021] [Indexed: 12/28/2022]
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4
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Singh J, Mehta A. Rapid and sensitive detection of mycotoxins by advanced and emerging analytical methods: A review. Food Sci Nutr 2020; 8:2183-2204. [PMID: 32405376 PMCID: PMC7215233 DOI: 10.1002/fsn3.1474] [Citation(s) in RCA: 81] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2019] [Revised: 01/20/2020] [Accepted: 01/22/2020] [Indexed: 01/24/2023] Open
Abstract
Quantification of mycotoxins in foodstuffs is extremely difficult as a limited amount of toxins are known to be presented in the food samples. Mycotoxins are secondary toxic metabolites, made primarily by fungal species, contaminating feeds and foods. Due to the presence in globally used grains, it is an unpreventable problem that causes various acute and chronic impacts on human and animal health. Over the previous few years, however, progress has been made in mycotoxin analysis studies. Easier techniques of sample cleanup and advanced chromatographic approaches have been developed, primarily high-performance liquid chromatography. Few extremely sophisticated and adaptable tools such as high-resolution mass spectrometry and gas chromatography-tandem MS/MS have become more important. In addition, Immunoassay, Advanced quantitative techniques are now globally accepted for mycotoxin analysis. Thus, this review summarizes these traditional and highly advance methods and their characteristics for evaluating mycotoxins.
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Affiliation(s)
- Jyoti Singh
- Department of Integrative BiologySchool of Biosciences and TechnologyVellore Institute of TechnologyVelloreIndia
| | - Alka Mehta
- Department of Integrative BiologySchool of Biosciences and TechnologyVellore Institute of TechnologyVelloreIndia
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5
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YAMAMOTO S, NISHIDA N, KINOSHITA M, SUZUKI S. On-Line Derivatization and Concentration of Aspartic Acid Using <i>In Situ</i> Photopolymerized Carboxylic Acid Type Polyacrylamide Gels as a Permselective Preconcentrator. CHROMATOGRAPHY 2018. [DOI: 10.15583/jpchrom.2018.012] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
| | | | | | - Shigeo SUZUKI
- Faculty of Pharmaceutical Sciences, Kindai University
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6
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Mahfuz M, Gazi MA, Hossain M, Islam MR, Fahim SM, Ahmed T. General and advanced methods for the detection and measurement of aflatoxins and aflatoxin metabolites: a review. TOXIN REV 2018. [DOI: 10.1080/15569543.2018.1514638] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Affiliation(s)
- Mustafa Mahfuz
- Nutrition and Clinical Services Division, International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b), Dhaka, Bangladesh
| | - Md. Amran Gazi
- Nutrition and Clinical Services Division, International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b), Dhaka, Bangladesh
| | - Muttaquina Hossain
- Nutrition and Clinical Services Division, International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b), Dhaka, Bangladesh
| | | | - Shah Mohammad Fahim
- Nutrition and Clinical Services Division, International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b), Dhaka, Bangladesh
| | - Tahmeed Ahmed
- Nutrition and Clinical Services Division, International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b), Dhaka, Bangladesh
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7
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Fung FM, Su M, Feng HT, Li SFY. Extraction, separation and characterization of endotoxins in water samples using solid phase extraction and capillary electrophoresis-laser induced fluorescence. Sci Rep 2017; 7:10774. [PMID: 28883632 PMCID: PMC5589922 DOI: 10.1038/s41598-017-11232-x] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2017] [Accepted: 08/21/2017] [Indexed: 02/08/2023] Open
Abstract
This study focuses on one of the key environmental threats, endotoxins, also known as lipopolysaccharides (LPS). A capillary electrophoresis method in combination with laser induced fluorescence (LIF) detection was developed for the analysis of endotoxins from 16 different bacterial strains. LPSs were derivatized with the amino-reactive fluorescent dye, fluorescein isothiocyanate (FITC), separated by capillary zone electrophoresis (CZE) under the optimized conditions with the use of 50 mM sodium tetraborate buffer (pH 9.30), and detected by LIF detector. To improve the sensitivity of CZE-LIF detection for the determination of trace amounts of endotoxins and to remove possible interference materials in environmental samples, a solid phase extraction (SPE) pre-concentration technique was applied successfully. The SPE targeted at polysaccharide moieties of LPSs and showed LPS enrichment effects too. CE migration time could also reveal the O-antigen chain lengths of LPSs. This CE method and SPE pretreatment showed linearity at 99.84%, and repeatabilities at 8.44% and 11.0% for endotoxins from E. Coli O55:B5 and E. Coli O26:B6. The limit of detection (LOD) could reach around 5 ng/mL at optimized condition. The method was applied successfully to the determination of LPS levels in tap water and wastewater, and demonstrated sensitive, reproducible and reliable results.
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Affiliation(s)
- Fun Man Fung
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore, 117543 Singapore
- Institute for Application of Learning Science and Educational Technology (ALSET), University Hall, Lee Kong Chian Wing UHL #05–01D, 21 Lower Kent Ridge Road, Singapore, 119077 Singapore
| | - Min Su
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore, 117543 Singapore
| | - Hua-tao Feng
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore, 117543 Singapore
- NUS Environmental Research Institute, National University of Singapore, T-Lab Building, 5A Engineering Drive 1, Singapore, 117411 Singapore
| | - Sam Fong Yau Li
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore, 117543 Singapore
- NUS Environmental Research Institute, National University of Singapore, T-Lab Building, 5A Engineering Drive 1, Singapore, 117411 Singapore
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8
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Nehmé R, Atieh C, Fayad S, Claude B, Chartier A, Tannoury M, Elleuch F, Abdelkafi S, Pichon C, Morin P. Microalgae amino acid extraction and analysis at nanomolar level using electroporation and capillary electrophoresis with laser-induced fluorescence detection. J Sep Sci 2016; 40:558-566. [DOI: 10.1002/jssc.201601005] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2016] [Revised: 10/25/2016] [Accepted: 10/26/2016] [Indexed: 11/09/2022]
Affiliation(s)
- Reine Nehmé
- Institut de Chimie Organique et Analytique (ICOA); Université d'Orléans; Orléans France
| | - Carla Atieh
- Institut de Chimie Organique et Analytique (ICOA); Université d'Orléans; Orléans France
| | - Syntia Fayad
- Institut de Chimie Organique et Analytique (ICOA); Université d'Orléans; Orléans France
| | - Bérengère Claude
- Institut de Chimie Organique et Analytique (ICOA); Université d'Orléans; Orléans France
| | - Agnès Chartier
- Institut de Chimie Organique et Analytique (ICOA); Université d'Orléans; Orléans France
| | - Mona Tannoury
- Département de Biologie, Faculté des Sciences II; Université Libanaise; Fanar Liban
| | - Fatma Elleuch
- Biotechnologie des algues, Département de Génie biologique, Ecole Nationale d'Ingénieurs de Sfax; University of Sfax; Tunisia
- Centre de Biophysique moléculaire; et Université d'Orléans; France
| | - Slim Abdelkafi
- Biotechnologie des algues, Département de Génie biologique, Ecole Nationale d'Ingénieurs de Sfax; University of Sfax; Tunisia
| | - Chantal Pichon
- Centre de Biophysique moléculaire; et Université d'Orléans; France
| | - Philippe Morin
- Institut de Chimie Organique et Analytique (ICOA); Université d'Orléans; Orléans France
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9
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Chiral separations for d -amino acid analysis in biological samples. J Pharm Biomed Anal 2016; 130:100-109. [DOI: 10.1016/j.jpba.2016.06.054] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2016] [Revised: 06/29/2016] [Accepted: 06/30/2016] [Indexed: 11/20/2022]
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10
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Feliciano RP, Heintz JA, Krueger CG, Vestling MM, Reed JD. Fluorescent labeling of cranberry proanthocyanidins with 5-([4,6-dichlorotriazin-2-yl]amino)fluorescein (DTAF). Food Chem 2014; 166:337-345. [PMID: 25053065 DOI: 10.1016/j.foodchem.2014.06.031] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2014] [Revised: 06/05/2014] [Accepted: 06/06/2014] [Indexed: 10/25/2022]
Abstract
A novel methodology was developed to elucidate proanthocyanidins (PAC) interaction with extra-intestinal pathogenic Escherichia coli (ExPEC). PAC inhibit ExPEC invasion of epithelial cells and, therefore, may prevent transient gut colonization, conferring protection against subsequent extra-intestinal infections, such as urinary tract infections. Until now PAC have not been chemically labeled with fluorophores. In this work, cranberry PAC were labeled with 5-([4,6-dichlorotriazin-2-yl]amino) fluorescein (DTAF), detected by high-performance liquid chromatography with diode-array detection and characterized by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS). We report single and double fluorescent-labeled PAC with one or two chlorine atoms displaced from DTAF in alkaline pH via nucleophilic substitution. Fluorescent labeling was confirmed by fragmentation experiments using MALDI-TOF/TOF MS. Fluorescent labeled PAC were able to promote ExPEC agglutination when observed with fluorescence microscopy. DTAF tagged PAC may be used to trace the fate of PAC after they agglutinate ExPEC and follow PAC-ExPEC complexes in cell culture assays.
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Affiliation(s)
- Rodrigo P Feliciano
- University of Wisconsin-Madison, Dept. of Food Science, 1605 Linden Drive, Madison, WI 53706, USA; University of Wisconsin-Madison, Reed Research Group, Dept. Animal Sciences, 1675 Observatory Drive, Madison, WI 53706, USA
| | - Joseph A Heintz
- Biological & Biomaterials Preparation, Imaging & Characterization Facility, Dept. Animal Sciences, 1675 Observatory Drive, Madison, WI 53706, USA
| | - Christian G Krueger
- University of Wisconsin-Madison, Reed Research Group, Dept. Animal Sciences, 1675 Observatory Drive, Madison, WI 53706, USA; Complete Phytochemical Solutions, LLC, 317 South Street, Cambridge, WI 53523, USA
| | - Martha M Vestling
- University of Wisconsin-Madison, Dept. of Chemistry, 1101 University Ave., Madison, WI 53706, USA
| | - Jess D Reed
- University of Wisconsin-Madison, Reed Research Group, Dept. Animal Sciences, 1675 Observatory Drive, Madison, WI 53706, USA; Complete Phytochemical Solutions, LLC, 317 South Street, Cambridge, WI 53523, USA.
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11
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Liu K, Wang L. Enantioseparations of amino acids by capillary array electrophoresis with 532nm laser induced fluorescence detection. J Chromatogr A 2013; 1295:142-6. [DOI: 10.1016/j.chroma.2013.04.058] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2012] [Revised: 03/25/2013] [Accepted: 04/17/2013] [Indexed: 02/06/2023]
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12
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Wagner Z, Tábi T, Zachar G, Csillag A, Szökő É. Comparison of quantitative performance of three fluorescence labels in CE/LIF analysis of aspartate and glutamate in brain microdialysate. Electrophoresis 2011; 32:2816-22. [DOI: 10.1002/elps.201100032] [Citation(s) in RCA: 13] [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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13
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14
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Szökő É, Tábi T. Analysis of biological samples by capillary electrophoresis with laser induced fluorescence detection. J Pharm Biomed Anal 2010; 53:1180-92. [DOI: 10.1016/j.jpba.2010.07.045] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2010] [Revised: 07/23/2010] [Accepted: 07/27/2010] [Indexed: 12/26/2022]
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15
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Li H, Yan ZY. Analysis of amino acid neurotransmitters in hypothalamus of rats during cerebral ischemia-reperfusion by microdialysis and capillary electrophoresis. Biomed Chromatogr 2010; 24:1185-92. [DOI: 10.1002/bmc.1425] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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16
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Zhang N, Zhang HS, Wang H. Separation of free amino acids and catecholamines in human plasma and rabbit vitreous samples using a new fluorogenic reagent 3-(4-bromobenzoyl)-2-quinolinecarboxaldehyde with CE-LIF detection. Electrophoresis 2009; 30:2258-65. [DOI: 10.1002/elps.200800667] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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17
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Zhang N, Zhao YZ, Zhang HS, Wang H. Sensitive determination of aliphatic amines by high-performance liquid chromatography with a new fluorogenic probe 3-(4-fluorinebenzoyl)-2-quinoline carboxaldehyde. J Sep Sci 2008; 31:38-46. [DOI: 10.1002/jssc.200700341] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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18
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Wang J, Zhang Y, Wang L, Bai J. Capillary array electrophoresis for the research of racemization reaction of l-amino acids. J Chromatogr A 2007; 1144:279-82. [PMID: 17292905 DOI: 10.1016/j.chroma.2007.01.084] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2006] [Revised: 01/17/2007] [Accepted: 01/25/2007] [Indexed: 10/23/2022]
Abstract
Research to the racemization reaction of L-amino acids is performed through a laboratory-made 16-channel capillary array electrophoresis. The impact factors such as catalyst, solvent, and reactive time which influenced the racemization reaction are screened, the experimental results proved that the capillary array electrophoresis is qualified as combinatorial enantiomeric screening system.
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Affiliation(s)
- Jun Wang
- Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, China.
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19
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Horká M, Růzicka F, Horký J, Holá V, Slais K. Capillary isoelectric focusing of proteins and microorganisms in dynamically modified fused silica with UV detection. J Chromatogr B Analyt Technol Biomed Life Sci 2006; 841:152-9. [PMID: 16765111 DOI: 10.1016/j.jchromb.2006.05.013] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2006] [Revised: 05/04/2006] [Accepted: 05/08/2006] [Indexed: 11/15/2022]
Abstract
We suggest a method for the reproducible and efficient capillary isoelectric focusing of proteins and microorganisms in the pH gradient 3-10. The method involves the segmental injection of the simple ampholytes, the solution of the selected electrolytes, and the sample mixture of bioanalytes and carrier ampholytes to the fused silica capillaries dynamically modified by poly(ethylene glycol), PEG 4000, which is added to the catholyte, the anolyte and injected solutions. In order to receive the reproducible results, the capillaries were rinsed by the mixture of acetone/ethanol between analyses. For the tracing of the pH gradients the low-molecular-mass pI markers were used. The simple proteins and the mixed cultures of microorganisms, Saccharomyces cerevisiae CCM 8191, Escherichia coli CCM 3954, Candida albicans CCM 8180, Candida parapsilosis, Candida krusei, Staphylococcus aureus, Streptococcus agalactiae CCM 6187, Enterococcus faecalis CCM 4224, Staphylococcus epidermidis CCM 4418 and Stenotrophomonas maltophilia, were focused and separated by the method suggested. The minimum detectable number of microbial cells was 5x10(2) to 1x10(3) with on-column UV detection at 280 nm.
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Affiliation(s)
- Marie Horká
- Institute of Analytical Chemistry, Academy of Sciences of the Czech Republic, Veverí 97, 611 42 Brno, Czech Republic.
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20
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Wang J, Wang L, Bai J. Separation of Different Enantiomeric Amino Acids by Capillary Array Electrophoresis. ANAL LETT 2006. [DOI: 10.1080/00032710600669002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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21
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Ho YH, Wu HL. Micellar electrokinetic capillary chromatographic method for the separation and quantitation of multiple amino acids as naphthoxy derivatives in pharmaceutical formulations. Electrophoresis 2006; 27:2300-9. [PMID: 16786479 DOI: 10.1002/elps.200500810] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The MEKC method is described for the quantitative analysis of 17 amino acids (AA) in pharmaceutical products. The method is based on simply derivatizing the AA with (2-naphthoxy)acetyl chloride under mild conditions. The resulting derivatives were separated by MEKC with borate buffer (35 mM; pH 9.50) including 150 mM SDS at the applied voltage of 25 kV in an uncoated capillary (effective length, 40 cm) and monitored by UV at 230 nm. The detection limits of the amino acid derivatives were in the range of 3.0-8.0 microM (S/N = 3, injection 5.0 s, 6 895 Pa). The precision (RSD) and accuracy (relative error) of the method for intra- and interday analyses of the analytes are all below 5.2%. The amino acid derivatives are stable at room temperature for 33 h studied and the molar absorptivity of the alanine derivative (used as a model) is stable over a wide pH range of 3.00-12.00. This is favorable for monitoring the derivatives in various pH by CE or LC. Application of the method to the analysis of multiple AA in a liquid injection formulation proved satisfactory.
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Affiliation(s)
- Yu-Hsiang Ho
- Graduate Institute of Pharmaceutical Sciences, Kaohsiung Medical University, Kaohsiung, Taiwan
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22
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Horká M, Růzicka F, Holá V, Slais K. Capillary isoelectric focusing of microorganisms in the pH range 2–5 in a dynamically modified FS capillary with UV detection. Anal Bioanal Chem 2006; 385:840-6. [PMID: 16791563 DOI: 10.1007/s00216-006-0508-0] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2005] [Revised: 04/18/2006] [Accepted: 04/21/2006] [Indexed: 10/24/2022]
Abstract
The isoelectric points of many microbial cells lie within the pH range spanning from 1.5 to 4.5. In this work, we suggest a CIEF method for the separation of cells according to their isoelectric points in the pH range of 2-5. It includes the segmental injection of the sample pulse composed of the segment of the selected simple ampholytes, the segment of the bioanalytes and the segment of carrier ampholytes into fused silica capillaries dynamically modified by poly(ethylene glycole). This polymer dissolved in the catholyte, in the anolyte and in the injected sample pulse was used for a prevention of the bioanalyte adsorption on the capillary surface and for the reduction of the electroosmotic flow. Between each focusing run, the capillaries were washed with the mixture of acetone/ethanol to achieve the reproducible and efficient CIEF. In order to trace of pH gradients, low-molecular-mass pI markers were used. The mixed cultures of microorganisms, Escherichia coli CCM 3954, Candida albicans CCM 8180, Candida parapsilosis, Candida krusei, Candida glabrata, Candida tropicalis, CCM 8223, Proteus vulgaris, Klebsiela pneumoniae, Staphylococcus aureus CCM 3953, Streptococcus agalactiae CCM 6187, Enterococcus faecalis CCM 4224 and Staphylococcus epidermidis CCM 4418, were focused and separated by the CIEF method suggested here. This CIEF method enables the separation and detection of the microbes from the mixed cultures within several minutes. The minimum detectable number of microbial cells was less than 10(3).
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Affiliation(s)
- Marie Horká
- Institute of Analytical Chemistry, Academy of Sciences of the Czech Republic, Veverí 97, 61142, Brno, Czech Republic.
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23
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Cao L, Wang H, Ma M, Zhang H. Determination of biogenic amines in HeLa cell lysate by 6-oxy-(N-succinimidyl acetate)-9-(2'-methoxycarbonyl) fluorescein and micellar electrokinetic capillary chromatography with laser-induced fluorescence detection. Electrophoresis 2006; 27:827-36. [PMID: 16411271 DOI: 10.1002/elps.200500301] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
An MEKC-LIF method using 6-oxy-(N-succinimidyl acetate)-9-(2'-methoxy-carbonyl) fluorescein (SAMF) newly synthesized in our lab as a labeling reagent for the separation and determination of eight typical biogenic amines was proposed. After careful study of the derivatization condition such as pH value, reagent concentration, temperature, and reaction time, derivatization reaction was accomplished as quickly as 10 min with stable yield. Optimal separation of SAMF-labeled amines was achieved with a running buffer (pH 9.3) containing 30 mM boric acid, 25 mM SDS, and 20% v/v ACN. The proposed method allowed biogenic amines to be determined with LODs as low as 0.25-2.5 nmol/L and RSD values from 0.4 to 4.5%. The present method has been successfully used to monitor biogenic amines in HeLa cells and fish samples. This study exploits the potential of MEKC-LIF with SAMF labeling as a tool for monitoring biogenic amines involved in complex physiological and behavioral processes in various matrices.
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Affiliation(s)
- Liwei Cao
- Department of Chemistry, Wuhan University, Wuhan, PR China
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24
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Wang W, Li C, Li Y, Hu Z, Chen X. Rapid and ultrasensitive determination of ephedrine and pseudoephedrine derivatizated with 5-(4,6-dichloro-s-triazin-2-ylamino) fluorescein by micellar electrokinetic chromatography with laser-induced fluorescence detection. J Chromatogr A 2006; 1102:273-9. [PMID: 16297394 DOI: 10.1016/j.chroma.2005.10.015] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2005] [Revised: 09/20/2005] [Accepted: 10/11/2005] [Indexed: 11/22/2022]
Abstract
This paper presents a micellar electrokinetic chromatography method with laser-induced fluorescence detection to analyze ephedrine (E) and pseudoephedrine (PE) after derivatizated with 5-(4,6-dichloro-s-triazin-2-ylamino) fluorescein. The optimum derivatization conditions were: 0.05 M Na2CO(3/NaHCO3 (pH 9.5), reaction time 30 min at 45 degrees C, molar ratio of DTAF to E and PE mixture 20:1. The baseline separation was achieved within 8 min with running buffer composed of 20 mM borate+20 mM SDS+15% acetonitrile (v/v) (adjusted pH 9.8), and applied voltage of 20 kV. Good linearity relationships (correlation coefficients: 0.9906 for E and 0.9941 for PE) between the peak heights and concentration of the analytes were obtained (2.5-50 ngmL(-1)). The detection limits for E and PE were 3.85 x 10(-4) and 1.41 x 10(-4)ngmL(-1), respectively, which indicated that the proposed method surpassed other chromatographic alternatives in terms of limit of detection by at least 10(3) folds. The method was applied to the analysis of the two alkaloids in ephedra herb plants and its preparations with recoveries in the range of 89.6-107.0%.
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Affiliation(s)
- Weiping Wang
- Department of Chemistry, Lanzhou University, Lanzhou 730000, PR China
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25
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Orejuela E, Silva M. Rapid and sensitive determination of phosphorus-containing amino acid herbicides in soil samples by capillary zone electrophoresis with diode laser-induced fluorescence detection. Electrophoresis 2005; 26:4478-85. [PMID: 16259012 DOI: 10.1002/elps.200500290] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
A straightforward and sensitive method has been developed for the analysis of phosphorus-containing amino acid herbicides (glufosinate and aminomethylphosphonic acid, the major metabolite of glyphosate) in soil samples. For this purpose, the analytical features of two indocyanine fluorescent dyes, sulfoindocyanine succinimidyl ester (Cy5) and 1-ethyl-1-[5-(N-succinimidyl-oxycarbonyl)pentyl]-3,3,3,3-tetramethyl-indodicarbocyanine chloride, as labeling reagents for the determination of these herbicides by CZE with diode LIF detection were investigated. Practical aspects related to the labeling chemistry and CZE separation showed that the two probes behave similarly, Cy5 being the best choice for the determination of these herbicides on account of its higher sensitivity. The optimum procedure includes a derivatization step of the pesticides at 25 degrees C for 30 min and direct injection to CZE analysis, which is conducted within about 14 min using ACN in the running buffer. The lowest detectable analyte concentration ranged from 0.025 to 0.18 microg/L with a precision of 3.6-5.4%. These results indicate that indocyanine fluorescence dyes are useful as rapid and sensitive labels for the determination of these herbicides when compared with typical fluorescein dyes such as FITC and 5-(4,6-dichloro-s-triazin-2-ylamino) fluorescein, because they provide faster labeling reactions even at room temperature and the excess of reagent practically does not interfere the determination. Finally, the Cy5 method was successfully applied to soil samples without a preliminary clean-up procedure, and the herbicides were measured without any interference from coexisting substances. The recoveries of these compounds in these samples at fortification levels of 100-500 ng/g were 90-93%.
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Affiliation(s)
- Eva Orejuela
- Department of Analytical Chemistry, Marie-Curie Building (Annex), Rabanales Campus, University of Cordoba, Cordoba, Spain
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26
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Orejuela E, Silva M. Rapid determination of aniline metabolites of chlorpropham in potatoes by micellar electrokinetic chromatography using negative-charged mixed micelles and laser-induced fluorescence detection. Electrophoresis 2005; 26:2991-8. [PMID: 15995980 DOI: 10.1002/elps.200410330] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
A rapid, reliable method has been developed for the multi-residue analysis of aniline metabolites of chlorpropham in potato samples. The method involves the precolumn derivatization of aniline metabolites with 5-(4,6-dichloro-s-triazin-2-ylamino) fluorescein (DTAF) and their subsequent separation and determination by micellar electrokinetic capillary chromatography with laser-induced fluorescence detection (MEKC-LIF). The optimum procedure includes a derivatization step of the aniline metabolites (3-chloroaniline, 3-chloro-4-hydroxyaniline and 3-chloro-4-methoxyaniline) at 40 degrees C for 40 min and a 5-fold dilution prior to MEKC analysis, which is conducted within about 7 min using negative-charged mixed micelles (SDS/Triton X-100) in the running buffer. Under these conditions, the DTAF-anilines were readily detected at 0.3-3.1 microg/L level with a precision of 4.8-6.4%. These results indicate that negative-charged mixed surfactant MEKC-LIF is useful as a selective, rapid, and sensitive tool for the determination of these anilines and surpasses other electrophoretic alternatives based on the use of fluorescein-isothiocyanate (FITC) as label reagent. Finally, the potato matrix showed no significant effects on the derivatization and determination of these analytes, since the analytical figures of merit for the real samples were similar to those obtained in aqueous solutions, and the average recovery at fortification levels of 10-250 microg/kg was over 97%.
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Affiliation(s)
- Eva Orejuela
- Department of Analytical Chemistry, Marie-Curie Building (Annex), Rabanales Campus, University of Cordoba, Spain
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27
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Lacroix M, Poinsot V, Fournier C, Couderc F. Laser-induced fluorescence detection schemes for the analysis of proteins and peptides using capillary electrophoresis. Electrophoresis 2005; 26:2608-21. [PMID: 15948219 DOI: 10.1002/elps.200410414] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Over the past few years, a large number of studies have been prepared that describe the analysis of peptides and proteins using capillary electrophoresis (CE) and laser-induced fluorescence (LIF). These studies have focused on two general goals: (i) development of automatic, selective and quick separation and detection of mixtures of peptides or proteins; (ii) generation of new methods of quantitation for very low concentrations (nm and subnanomolar) of peptides. These two goals are attained with the use of covalent labelling reactions using a variety of dyes that can be readily excited by the radiation from a commonly available laser or via the use of noncovalent labelling (immunoassay using a labelled antibody or antigen or noncovalent dye interactions). In this review article, we summarize the works which were performed for protein and peptide analysis via CE-LIF.
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Affiliation(s)
- Marlene Lacroix
- Laboratoire des IMRCP, UMR 5623, ERT 1046, Université Paul Sabatier, Toulouse, France
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28
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Cao LW, Wang H, Li JS, Zhang HS. 6-Oxy-(N-succinimidyl acetate)-9-(2'-methoxycarbonyl)fluorescein as a new fluorescent labeling reagent for aliphatic amines in environmental and food samples using high-performance liquid chromatography. J Chromatogr A 2005; 1063:143-51. [PMID: 15700466 DOI: 10.1016/j.chroma.2004.11.093] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
6-Oxy-(N-succinimidyl acetate)-9-(2'-methoxycarbonyl)fluorescein (SAMF), a new fluorescein-based amine-reactive fluorescent probe was well designed, synthesized and used as a pre-column derivatizing reagent for the determination of aliphatic amines in HPLC. It exhibited relatively pH-independent fluorescence (pH 4-9) and excellent photostability. The derivatization was performed at room temperature in 6min. On a C18 column, the derivatives of SAMF with eight aliphatic amines were baseline separated in 28 min with a mobile phase of methanol-water (57:43, v/v) containing 10 mmol l(-1) pH 5.0, H3Cit3-NaOH buffer. With fluorescent detection at lambda(ex)/lambda(em) = 484/516 nm, the detection limit could reach 2-320 fmol (signal-to-noise = 3), which was equivalent to or better than the detection limits obtained from other analytical methods of aliphatic amines. The proposed method has been applied to the determination of the aliphatic amines in environmental and food samples such as lake water, red wine, white wine, and cheese with satisfying recoveries varying from 95 to 106%.
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Affiliation(s)
- Li-Wei Cao
- Department of Chemistry, Wuhan University, Wuhan 430072, China
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29
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Cao L, Wang H, Zhang H. Analytical potential of 6-oxy-(N-succinimidyl acetate)-9-(2'-methoxycarbonyl) fluorescein for the determination of amino compounds by capillary electrophoresis with laser-induced fluorescence detection. Electrophoresis 2005; 26:1954-62. [PMID: 15818574 DOI: 10.1002/elps.200410227] [Citation(s) in RCA: 21] [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
The analytical potential of a fluorescein analogue, 6-oxy-(N-succinimidyl acetate)-9-(2'-methoxycarbonyl) fluorescein (SAMF), for the first time synthesized in our laboratory, as a labeling reagent for the labeling and determination of amino compounds by capillary electrophoresis (CE) with laser-induced fluorescence (LIF) detection was investigated. Biogenic monoamines and amino acids were chosen as model analytes to evaluate the analytical possibilities of this approach. The derivatization conditions and separation parameters for the biogenic amines were optimized in detail. The derivatization was performed at 30 degrees C for 6 min in boric acid buffer (pH 8.0). The derivatives were baseline-separated in 15 min with 25 mM boric acid running buffer (pH 9.0), containing 24 mM SDS and 12.5% v/v acetonitrile. The concentration detection limit for biogenic amines reaches 8 x 10(-11) mol.L(-1) (signal-to-noise ratio = 3). The application of CE in the analysis of the SAMF-derivatized amino acids was also exploited. The optimal running buffer for amino acids suggested that weak acidic background electrolyte offered better separation than the basic one. The proposed method was applied to the determination of biogenic amines in three different beer samples with satisfying recoveries varying from 92.8% to 104.8%. Finally, comparison of several fluorescein-based probes for amino compounds was discussed. With good labeling reaction, excellent photostability, pH-independent fluorescence (pH 4-9), and the resultant widely suited running buffer pH, SAMF has a great prospect in the determination of amino compounds in CE.
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Affiliation(s)
- Liwei Cao
- Department of Chemistry, Wuhan University, Wuhan 430072, China
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30
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Liu X, Li DF, Wang Y, Lu YT. Determination of 1-aminocyclopropane-1-carboxylic acid in apple extracts by capillary electrophoresis with laser-induced fluorescence detection. J Chromatogr A 2004; 1061:99-104. [PMID: 15633749 DOI: 10.1016/j.chroma.2004.10.067] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
A rapid and sensitive method for the determination of 1-aminocyclopropane-1-carboxylic acid (ACC) in apple tissues has been described. This method is based on the derivatization of ACC with 3-(2-furoyl)quinoline-2-carboxaldehyde (FQ), and separation and quantification of the resulting FQ-ACC derivative by capillary electrophoresis coupled to laser-induced fluorescence detection (CE-LIF). Our results indicated that ACC derivatized with FQ could be well separated from other interfering amino acids using 20 mM borate buffer (pH 9.35) containing 40 mM sodium dodecyl sulfate and 10 mM Brij 35. The linearity of ACC was determined in the range from 0.05 to 5 microM with a correlation of 0.9967. The concentration detection limit for ACC was 10 nM (signal-to-noise = 3). The sensitivity and selectivity of this described method allows the analysis of ACC in crude apple extracts without extra purification and enrichment procedure.
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Affiliation(s)
- Xin Liu
- Key Laboratory of MOE for Plant Developmental Biology, College of Life Sciences, Wuhan University, Wuhan 430072, PR China
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31
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Separation of fluorescent derivatives of hydroxyl-containing small molecules on a microfluidic chip. Anal Chim Acta 2004. [DOI: 10.1016/j.aca.2003.09.067] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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32
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Dong CH, Yang ST, Yang ZA, Zhang L, Gui JF. A C-type lectin associated and translocated with cortical granules during oocyte maturation and egg fertilization in fish. Dev Biol 2004; 265:341-54. [PMID: 14732397 DOI: 10.1016/j.ydbio.2003.08.028] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Oocyte maturation and egg fertilization in both vertebrates and invertebrates are marked by orchestrated cytoplasmic translocation of secretory vesicles known as cortical granules. It is thought that such redistribution of cellular content is critical for asymmetrical cell division during early development, but the mechanism and regulation of the process is poorly understood. Here we report the identification, purification and cDNA cloning of a C-type lectin from oocytes of a freshwater fish species gibel carp (Carassius auratus gibelio). The purified protein has been demonstrated to have lectin activity and to be a Ca(2+)-dependent C-type lectin by hemagglutination activity assay. Immunocytochemistry revealed that the lectin is associated with cortical granules, gradually translocated to the cell surface during oocyte maturation, and discharged to the egg envelope upon fertilization. Interestingly, the lectin becomes phosphorylated on threonine residues upon induction of exocytosis by fertilization and returns to its original state after morula stage of embryonic development, suggesting that this posttranslational modification may represent a critical molecular switch for early embryonic development.
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Affiliation(s)
- Cai-Hua Dong
- State Key Laboratory of Freshwater Ecology and Biotechnology, Wuhan Center for Developmental Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
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33
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Siméon N, Myers R, Bayle C, Nertz M, Stewart JK, Couderc F. Some applications of near-ultraviolet laser-induced fluorescence detection in nanomolar- and subnanomolar-range high-performance liquid chromatography or micro-high-performance liquid chromatography. J Chromatogr A 2001; 913:253-9. [PMID: 11355820 DOI: 10.1016/s0021-9673(00)01234-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
In this work we present some applications of near-UV laser-induced fluorescence (LIF) with micro-HPLC (microHPLC) and HPLC. To test the sensitivity of the detection, we used pyrene and aflatoxins, because both of these molecules exhibit native fluorescence. Then we studied catecholamines derivatized with 1,2-diphenylethylenediamine. The results show that we were able to reach better sensitivity levels than previously described in LIF studies. For catecholamines, a 50-fold increase in sensitivity compared to conventional fluorescence was obtained. These results indicate that LIF detection associated with HPLC or microHPLC can be used to detect very low concentrations of substances that can be excited in the near-UV range after labeling at nanomolar concentrations.
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34
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Molina M, Silva M. Simultaneous determination of phosphorus-containing amino acid-herbicides by nonionic surfactant micellar electrokinetic chromatography with laser-induced fluorescence detection. Electrophoresis 2001; 22:1175-81. [PMID: 11358144 DOI: 10.1002/1522-2683()22:6<1175::aid-elps1175>3.0.co;2-8] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The potential of micellar electrokinetic chromatography (MEKC) with laser-induced fluorescence (LIF) detection for the separation and determination of phosphorus-containing amino acid-herbicides (glufosinate and glyphosate), and aminomethylphosphonic acid (the major metabolite of glyphosate), involving derivatization with fluorescein isothiocyanate (FITC) isomer I, was investigated. Different variables that affect derivatization (pH, FITC concentration, time and temperature) and separation (pH and concentration of the buffer, kind and concentration of surfactants and applied voltage) were studied. The analysis was conducted within about 8 min and the use of the nonionic surfactant Triton X-100 improved the selectivity, thus indirectly enhancing sensitivity by shifting of the interfering peaks of the FITC excess. Dynamic ranges of 2.0-3,000 microg/L, limits of detection at microgram or submicrogram-per-liter level, and relative standard deviations from 4.7 to 6.4% were obtained. The ensuing method--nonionic surfactant MEKC-- is a useful choice for the determination of these herbicides as it provides limits of detection similar or lower than those reported by existing chromatographic alternatives without the use of an additional preconcentration technique such as solid-phase extraction. The separation of a mixture of nine FITC-derivatized amino acids, selected as target compounds, was also carried out to assess the discrimination power of the nonionic surfactant MEKC method for the analysis of closely related anionic analytes.
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Affiliation(s)
- M Molina
- Department of Analytical Chemistry and Ecology, University of Córdoba, Spain
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35
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Reetz M, Kühling K, Deege A, Hinrichs H, Belder D. Super-Hochdurchsatz-Screening von enantioselektiven Katalysatoren mittels parallelisierter Kapillarelektrophorese. Angew Chem Int Ed Engl 2000. [DOI: 10.1002/1521-3757(20001103)112:21<4049::aid-ange4049>3.0.co;2-n] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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36
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Reetz M, Kühling K, Deege A, Hinrichs H, Belder D. Super-High-Throughput Screening of Enantioselective Catalysts by Using Capillary Array Electrophoresis. Angew Chem Int Ed Engl 2000; 39:3891-3893. [DOI: 10.1002/1521-3773(20001103)39:21<3891::aid-anie3891>3.0.co;2-1] [Citation(s) in RCA: 171] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2000] [Indexed: 11/10/2022]
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37
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Oguri S. Electromigration methods for amino acids, biogenic amines and aromatic amines. JOURNAL OF CHROMATOGRAPHY. B, BIOMEDICAL SCIENCES AND APPLICATIONS 2000; 747:1-19. [PMID: 11103896 DOI: 10.1016/s0378-4347(00)00092-x] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Methods of electromigration in laboratory apparatus of small-bore size have recently undergone development at a remarkably rapid pace, leading to a variety of new analytical techniques. One such technique is called "capillary electrophoresis" (CE), which is further classified on the basis of electromigration mode, viz., "capillary zone electrophoresis" (CZE), which, in turn, has several variations. This review aims to give a short overview of the various electromigration methods for amino compounds by using CE. Firstly, this review briefly summarizes the detection methods employed for detection of monoamines and polyamines by CE for both native and derivative forms. Next, current CE methods are described, and their applications to detection of amino acids, biogenic amines, aromatic amines, including heteroaromatic amines and their enantiomers, are introduced from representative papers. Finally, new methods for single-cell analysis and microchip CE techniques are focused on.
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Affiliation(s)
- S Oguri
- Department of Home Economics, Aichi-Gakusen University, Okazaki City, Japan
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38
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Couderc F, Caussé E, Bayle C. Drug analysis by capillary electrophoresis and laser-induced fluorescence. Electrophoresis 1998; 19:2777-90. [PMID: 9870374 DOI: 10.1002/elps.1150191605] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
This review briefly presents the different laser-induced fluorescence detectors, outlines the different dyes used to derivatize molecules which are used with capillary electrophoresis/laser-induced fluorescence (CE-LIF), and provides an overview and current status of CE-LIF in drug analysis.
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Affiliation(s)
- F Couderc
- Université Paul Sabatier, Laboratoire de Biologie Moléculaire Eucaryotes, Toulouse, France.
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39
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Ramseier A, von Heeren F, Thormann W. Analysis of fluorescein isothiocyanate derivatized amphetamine and analogs in human urine by capillary electrophoresis in chip-based and fused-silica capillary instrumentation. Electrophoresis 1998; 19:2967-75. [PMID: 9870397 DOI: 10.1002/elps.1150191628] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Amines can easily be derivatized with fluorescein isothiocyanate isomer I (FITC) and analyzed by capillary electrophoresis (CE) using alkaline buffers with or without dodecyl sulfate micelles. This paper reports the CE analysis of FITC-derivatized amphetamine, methamphetamine, 3,4-methylenedioxymethamphetamine and beta-phenylethylamine in human urine using chip-based and fused-silica capillary instrumentation with laser-induced fluorescence detection. Data obtained via direct labeling of fortified urine are compared to those generated after FITC labeling of urinary extracts that were prepared by solid-phase extraction using a copolymer phase. For a urine volume of 5 mL with a "spiked amine": FITC ratio of 1:250, the latter approach was found to provide a sensitivity that is relevant for toxicological drug screening and confirmation (about 200 ng/mL urine). With direct labeling of 10 microL urine that was alkalinized and diluted for derivatization, the limit of identification was determined to be about 10 microg/mL, a value that is too high for practical purposes. Compared to fused-silica capillaries, electrophoresis in microstructures is shown to provide faster separations and higher efficiencies without loss of accuracy and precision.
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Affiliation(s)
- A Ramseier
- Department of Clinical Pharmacology, University of Bern, Switzerland
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40
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Dabek-Zlotorzynska E, Maruszak W. Determination of dimethylamine and other low-molecular-mass amines using capillary electrophoresis with laser-induced fluorescence detection. JOURNAL OF CHROMATOGRAPHY. B, BIOMEDICAL SCIENCES AND APPLICATIONS 1998; 714:77-85. [PMID: 9746237 DOI: 10.1016/s0378-4347(98)00070-x] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The potential of capillary electrophoresis (CE) with laser-induced fluorescence (LIF) detection for the separation and determination of dimethylamine (DMA) and other low-molecular-mass amines involving precolumn derivatization with fluorescein isothiocyanate isomer I (FITC) was investigated. Different variables that affect derivatization (pH, FITC concentration, reaction time and temperature) and separation (buffer concentration, addition of various organic modifiers, applied voltage and length of capillary) were studied. The linearity, reproducibility and reliability of the method were evaluated. The estimated instrumental detection limit for a 2-s pressure injection of the FITC-DMA derivative was 50 pg/ml (10(-9) M), using LIF detection with excitation and emission wavelengths of 488 nm and 520 nm, respectively. However, for practical reasons, a minimum of 5 ng/ml DMA should be subjected to the derivatization. The applicability of the described method to the extract of atmospheric aerosol samples was demonstrated.
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Affiliation(s)
- E Dabek-Zlotorzynska
- Analysis and Air Quality Division, Environmental Technology Centre, Environment Canada, Ottawa, Ontario
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41
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Enlund AM, Schmidt S, Westerlund D. Detectability improvements in capillary zone electrophoresis by combining single capillary isotachophoretic preconcentration and frequency doubled argon ion laser-induced fluorescence detection. Electrophoresis 1998; 19:707-11. [PMID: 9629903 DOI: 10.1002/elps.1150190518] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Due to the small path length and low injection volume the concentration limit of detection is comparatively poor in capillary electrophoresis (CZE) with UV detection. This limitation can be overcome by means of preconcentration methods and/or improved detection techniques. This paper describes a strategy where isotachophoresis (ITP) is used to preconcentrate a new cholinesterase inhibitor (NXX-066) prior to a capillary zone electrophoresis analysis in the same single capillary. A hydrodynamic backpressure is used to prevent the analyte from migrating out of the capillary. Laser-induced fluorescence (LIF) is used to further increase the detectability. The total gain in detectability with ITP-CZE-LIF compared to CZE-UV was at least 5500-fold, and it is possible to determine NXX-066 at the 1 nM level. The ITP-CZE method was further evaluated for two beta-blockers; the mean coefficient of variation of the peak areas was 3.4% and the linearity of the calibration plots was satisfying.
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Affiliation(s)
- A M Enlund
- Analytical Pharmaceutical Chemistry, Uppsala University Biomedical Center, Sweden
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42
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Abstract
The current status in the analysis of amino acids using capillary electrophoresis is addressed. This area of biological analysis has received increased attention with more than 200 articles being published in the last five years. This review discusses pre-, post-, and on-column derivatization techniques used to tag amino acids providing a detectable moiety. Several separation methodologies which provided resolution for large sets of amino acids are presented. An overview of advances in the enantiomeric resolution methodologies for amino acids is given. Both direct and indirect enantiomeric separation schemes are summarized. Recent advances in detection strategies for both derivatized and underivatized amino acids are presented. Applications utilizing amino acid analysis by capillary electrophoresis are described. This review covers articles published between 1991 and 1996.
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Affiliation(s)
- J T Smith
- Department of Physical Sciences, Southeastern Oklahoma State University, Durant 74701-0609, USA.
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43
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Abstract
This review surveys the use of micelles as separation media in chromatography and electrophoresis. Applications to pharmaceuticals whose molecular masses are relatively small are focused on in this review. In high-performance liquid chromatography (HPLC), chromatography using micelles and reversed-phase stationary phases such as octadecylsilylized silica gel (ODS) columns is known as micellar liquid chromatography (MLC). The main application of MLC to pharmaceutical analysis is the same as in ion-pair chromatography using alkylsulfonate or tetraalkylammonium. In most cases, selectivity is much improved compared with other short alkyl chain ion-pairing agents such as pentanesulfonate or octanesulfonate. Direct plasma/serum injection can be successful in MLC. Separation of small ions is also successful by using gel filtration columns and micellar solutions. In electrophoresis, especially capillary electrophoresis (CE), micelles are used as pseudo-stationary phases in capillary zone electrophoresis (CZE). This mode is called micellar electrokinetic chromatography (MEKC). Most of the drug analysis can be performed by using the MEKC mode because of its wide applicability. Enantiomer separation, separation of amino acids and closely related peptides, separation of very complex mixtures, determination of drugs in biological samples etc. as well as separation of electrically neutral drugs can be successfully achieved by MEKC. Microemulsion electrokinetic chromatography (MEEKC), in which surfactants are also used in forming the microemulsion, is successful for the separation of electrically neutral drugs as in MEKC. This review mainly describes the typical applications of MLC and MEKC for the analysis of pharmaceuticals.
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Affiliation(s)
- H Nishi
- Analytical Research Laboratory, Tanabe Seiyaku Co., Osaka, Japan
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44
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Muijselaar PG, Otsuka K, Terabe S. Micelles as pseudo-stationary phases in micellar electrokinetic chromatography. J Chromatogr A 1997; 780:41-61. [PMID: 9335128 DOI: 10.1016/s0021-9673(97)00632-8] [Citation(s) in RCA: 80] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
This review article describes some general comments on micellar electrokinetic chromatography (MEKC) from the viewpoint of pseudo-stationary phases and presents a compiled list of surfactants used for MEKC, prepared from published papers. We tried to give comments on some typical surfactants from the practical point of view.
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Affiliation(s)
- P G Muijselaar
- Faculty of Science, Himeji Institute of Technology, Hyogo, Japan
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Rodriguez I, Lee H, Li S. Separation of biogenic amines by micellar electrokinetic chromatography. J Chromatogr A 1996. [DOI: 10.1016/0021-9673(96)00422-0] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Abstract
Micellar electrokinetic chromatography (MEKC) has become a popular mode among several capillary electromigration techniques. Most drug analyses can be performed by using MEKC because of its wide applicability. Enantiomer separation, separation of closely related peptides and isotopic compounds, separation of very complex mixtures, determination of drugs in the biological samples, etc., can be successfully achieved by MEKC. This review surveys typical applications of MEKC analysis. Recent advances in MEKC, especially with pseudo-stationary phases, are described. Modes of electrokinetic chromatography including MEKC, a separation theory of MEKC and selectivity manipulation in MEKC are also briefly mentioned.
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Affiliation(s)
- H Nishi
- Analytical Research Laboratory, Tanabe Seiyaku Co., Ltd., Osaka, Japan
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