WorldWideScience

Sample records for capillary electrophoresis instrumentation

  1. Field-portable Capillary Electrophoresis Instrument with Conductivity Detection

    International Nuclear Information System (INIS)

    In this paper a novel capillary electrophoresis chip (CEC) is presented with integrated platinum electrodes and simplified conductivity detector. CEC is fabricated by the method of mechanical modification with probe on organic glass. Capillary electrophoresis chip can rapidly completed ion separation by simulation of concentration distribution and zone-broadening. Detection circuit is simple which can detect pA order current. This system has those advantages such as small volume, low power consumption and linearity, and well suit for field analysis

  2. Capillary electrophoresis

    International Nuclear Information System (INIS)

    After a short historical introduction, the different modes of separation in capillary electrophoresis are explained and illustrated by practical examples. In addition, the most important parameters that can be used to optimize the selectivity of the separation, are discussed. (author) 27 refs.; 8 figs

  3. Analysis of organic molecules using the Mars Organic Analyzer, a portable, automated microfabricated capillary electrophoresis instrument

    OpenAIRE

    Stockton, Amanda Michelle

    2010-01-01

    The search for signs of past or present extraterrestrial life requires autonomous instrumentation capable of robust and highly sensitive in situ analysis of a broad range of organic compound classes. The Mars Organic Analyzer (MOA) is a portable microchip capillary electrophoresis (&muCE) instrument developed for highly sensitive chemical biomarker analysis. This thesis expands the capabilities of the MOA to highly-sensitive analysis of PAHs, aldehydes, ketones, and carboxylic acids in conv...

  4. Serum proteins analysis by capillary electrophoresis

    OpenAIRE

    Uji, Yoshinori; Okabe, Hiroaki

    2001-01-01

    The purpose of this study was to evaluate the efficacy of multi-capillary electrophoresis instrument in clinical laboratory. An automated clinical capillary electrophoresis system was evaluated for performing serum proteins electrophoresis and immuno-fixation electrophoresis by subtraction. In this study the performance of capillary electrophoresis was compared with the cellulose acetate membrane electrophoresis and agarose gel immunofixation electrophoresis for serum proteins. The results of...

  5. Advances in capillary electrophoresis

    International Nuclear Information System (INIS)

    In the 1980s, capillary electrophoresis (CE) developed rapidly into a first-class analytical separation technique. Its advances in instru-mentation and method development will not only enhance or complement existing mature separation techniques such as liquid chromatography and conventional slab gel electrophoresis, but will also severely challenge these separation methods. A brief overview of most striking achievement of CE in the 1980s is given, which illustrates the challenge to liquid chromatography and conventional slab gel electrophoresis, and some detailed discussions are presented to highlight the advantages of CE. New developments in CE that can be expected for the 1990s include especially column technology, separation chemistry and instrumentation, which will serve further to diversify and improve the applicability of this technique in areas which are poorly addressed by other separation methods. This paper considers and speculates on the technological advancements that can be expected to emerge for CE in the 1990s. (author). 95 refs.; 14 figs

  6. Instrumental development of novel detection and separation methods for capillary electrophoresis

    Energy Technology Data Exchange (ETDEWEB)

    Garner, T.

    1993-07-01

    After a general introduction, this thesis is divided into 3 parts: indirect fluorescence detection of sugars separated by capillary zone electrophoresis with visible laser excitation, absorption detection in capillary electrophoresis by fluorescence energy transfer, and increased selectivity for electrochromatography by dynamic ion exchange.

  7. Analytical potentialities of an AI-05 instrument for capillary electrophoresis in the determination of metal cations

    International Nuclear Information System (INIS)

    The analytical potentialities of an AI-05 instrument for capillary zone electrophoresis were examined using the determination of alkali, alkaline earth, and transition metal cations as an example. The plot of the analytical signal of Sr2+ against the concentration of the sample was linear within the range 1 x 10-5 - 1 x 10-4 M. The phenomenon of discrimination of the ionic composition of a sample in the electromigration method of sample injection is discussed. The time taken to separate a mixture of metal cations (M = K, Na, Mg, Sr, Ca, Cd, Co, Ni and Zn) was 16 min

  8. Correlating molar masses of nitrocelluloses with their intrinsic viscosities measured using capillary electrophoresis instrumentation.

    Science.gov (United States)

    Alinat, Elodie; Delaunay, Nathalie; Archer, Xavier; Gareil, Pierre

    2015-09-01

    Specific viscosities for a set of six nitrocellulose (NC) standards comprising three different mass-average molar masses (between 20,000 and 300,000 g mol(-1)) of two different nitrogen contents (11.2 and 12.1%) were measured at 20 °C in tetrahydrofuran, using capillary electrophoresis instrumentation as a bench-top viscometer in frontal mode. Intrinsic viscosities were derived applying Huggins' and Kraemer's models, showing excellent convergence of both models at infinitely diluted polymer concentration. Good overall consistency was shown between viscosity data experimentally acquired by this new protocol and the mass-average molar masses provided by the manufacturers. This simple protocol should be of interest for a better understanding of the solvent interaction given by this complex polymer, and beyond this, for tailoring NC solutions devoted to film deposition, and for the determination of mass-average molar masses of unknown NC samples. PMID:26005144

  9. Laser induced fluorescence and Raman spectroscopy in capillary electrophoresis as an possible instrument for extraterrestrial life signs detection.

    Science.gov (United States)

    Mikhail, Gorlenko; Cheptcov, Vladimir; Anton, Maydykovskiy; Eugeniy, Vasilev

    The one of a significant aims in extraterrestrial exploration is a seeking for a life traces in a open space and planetary objects. Complex composition and unknown origin of suspected signs of life required у new analytical approaches and technical solutions. The promising assai here can be Laser induced fluorescence and Raman spectroscopy methods. The combined instrument developed by our team reveal the advantage of capillary electrophoresis assays in a junction with laser induced fluorescence detection technology. We optimized excitation configuration of fluorescence in capillary electrophoresis to reduce pumping laser power up to 1 mW and decrease background scattering. The improvement of the device sensitivity at poor sample concentration we achieved by incorporating fluorescence flow-through cuvette into spectrometer. That allows to simplify setup, to minimize weight and increase reproducibility of measurements. The device has been tasted in complex organic chemical mixes and microbial strains differentiation tasks. 3d multinational spectra allow us to increase the spectra information loads in comparison with ordinary capillary electrophoresis approaches. Possible updating the device with Raman approach can even furthermore multiple the differentiation power of the instrument. The analytical module developed using this approach can be potentially effectively used in extraterrestrial researches as a payload of the future spacecraft.

  10. Biomedical applications of capillary electrophoresis

    Science.gov (United States)

    Kartsova, L. A.; Bessonova, E. A.

    2015-08-01

    The review deals with modern analytical approaches used in capillary electrophoresis for solving medical and biological problems: search for biomarkers of various diseases and rapid diagnosis based on characteristic profiles of biologically active compounds by capillary electrophoresis with mass spectrometric detection; monitoring of the residual drugs in biological fluids for evaluating the efficiency of drug therapy; testing of the enantiomeric purity of pharmaceutical products; the use of novel materials as components of stationary and pseudo-stationary phases in capillary electrophoresis and capillary electrochromatography to increase the selectivity of separation of components of complex matrices; and identification of various on-line preconcentration techniques to reduce the detection limits of biologically active analytes. A topical trend in capillary electrophoresis required in clinical practice, viz., the design of microfluidic systems, is discussed. The bibliography includes 173 references.

  11. DNA Sequencing Using capillary Electrophoresis

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Barry Karger

    2011-05-09

    The overall goal of this program was to develop capillary electrophoresis as the tool to be used to sequence for the first time the Human Genome. Our program was part of the Human Genome Project. In this work, we were highly successful and the replaceable polymer we developed, linear polyacrylamide, was used by the DOE sequencing lab in California to sequence a significant portion of the human genome using the MegaBase multiple capillary array electrophoresis instrument. In this final report, we summarize our efforts and success. We began our work by separating by capillary electrophoresis double strand oligonucleotides using cross-linked polyacrylamide gels in fused silica capillaries. This work showed the potential of the methodology. However, preparation of such cross-linked gel capillaries was difficult with poor reproducibility, and even more important, the columns were not very stable. We improved stability by using non-cross linked linear polyacrylamide. Here, the entangled linear chains could move when osmotic pressure (e.g. sample injection) was imposed on the polymer matrix. This relaxation of the polymer dissipated the stress in the column. Our next advance was to use significantly lower concentrations of the linear polyacrylamide that the polymer could be automatically blown out after each run and replaced with fresh linear polymer solution. In this way, a new column was available for each analytical run. Finally, while testing many linear polymers, we selected linear polyacrylamide as the best matrix as it was the most hydrophilic polymer available. Under our DOE program, we demonstrated initially the success of the linear polyacrylamide to separate double strand DNA. We note that the method is used even today to assay purity of double stranded DNA fragments. Our focus, of course, was on the separation of single stranded DNA for sequencing purposes. In one paper, we demonstrated the success of our approach in sequencing up to 500 bases. Other

  12. Nonlinear waves in capillary electrophoresis

    OpenAIRE

    Ghosal, Sandip; Chen, Zhen

    2012-01-01

    Electrophoretic separation of a mixture of chemical species is a fundamental technique of great usefulness in biology, health care and forensics. In capillary electrophoresis the sample migrates in a microcapillary in the presence of a background electrolyte. When the ionic concentration of the sample is sufficiently high, the signal is known to exhibit features reminiscent of nonlinear waves including sharp concentration ‘shocks’. In this paper we consider a simplified model consisting of a ...

  13. Non-Aqueous Capillary Electrophoresis

    Science.gov (United States)

    Szumski, Michał; Buszewski, Bogusław

    Non-aqueous capillary electrophoresis and capillary electrochromatography are special variants of these techniques. Here, organic solvents or their mixtures with or without dissolved electrolytes are used as separation buffer or mobile phase, respectively. The most important features of non-aqueous systems are: better solubility of more hydrophobic ionic substances (many natural products) than in water, much less current and Joule heating allows for using highly concentrated buffers and/or larger capillary internal diameters, polar interactions are enhanced in organic solvents which is often highly advantageous in chiral separation systems. This chapter presents most frequently used solvents, their properties, as well as shows pH* scale which is often used in non-aqueous systems.

  14. Capillary electrophoresis electrospray ionization mass spectrometry interface

    Science.gov (United States)

    Smith, Richard D.; Severs, Joanne C.

    1999-01-01

    The present invention is an interface between a capillary electrophoresis separation capillary end and an electrospray ionization mass spectrometry emitter capillary end, for transporting an anolyte sample from a capillary electrophoresis separation capillary to a electrospray ionization mass spectrometry emitter capillary. The interface of the present invention has: (a) a charge transfer fitting enclosing both of the capillary electrophoresis capillary end and the electrospray ionization mass spectrometry emitter capillary end; (b) a reservoir containing an electrolyte surrounding the charge transfer fitting; and (c) an electrode immersed into the electrolyte, the electrode closing a capillary electrophoresis circuit and providing charge transfer across the charge transfer fitting while avoiding substantial bulk fluid transfer across the charge transfer fitting. Advantages of the present invention have been demonstrated as effective in providing high sensitivity and efficient analyses.

  15. Novel absorption detection techniques for capillary electrophoresis

    Energy Technology Data Exchange (ETDEWEB)

    Xue, Y.

    1994-07-27

    Capillary electrophoresis (CE) has emerged as one of the most versatile separation methods. However, efficient separation is not sufficient unless coupled to adequate detection. The narrow inner diameter (I.D.) of the capillary column raises a big challenge to detection methods. For UV-vis absorption detection, the concentration sensitivity is only at the {mu}M level. Most commercial CE instruments are equipped with incoherent UV-vis lamps. Low-brightness, instability and inefficient coupling of the light source with the capillary limit the further improvement of UV-vis absorption detection in CE. The goals of this research have been to show the utility of laser-based absorption detection. The approaches involve: on-column double-beam laser absorption detection and its application to the detection of small ions and proteins, and absorption detection with the bubble-shaped flow cell.

  16. Electromigration dispersion in Capillary Electrophoresis

    CERN Document Server

    Chen, Zhen; 10.1007/s11538-011-9708-7

    2012-01-01

    In a previous paper (S. Ghosal and Z. Chen Bull. Math. Biol. 2010, vol. 72, pg. 2047) it was shown that the evolution of the solute concentration in capillary electrophoresis is described by a nonlinear wave equation that reduced to Burger's equation if the nonlinearity was weak. It was assumed that only strong electrolytes (fully dissociated) were present. In the present paper it is shown that the same governing equation also describes the situation where the electrolytic buffer consists of a single weak acid (or base). A simple approximate formula is derived for the dimensionless peak variance which is shown to agree well with published experimental data.

  17. Microbeam-coupled capillary electrophoresis

    International Nuclear Information System (INIS)

    Within the first few microseconds following a charged particle traversal of a cell, numerous oxygen and nitrogen radicals are formed along the track. Presented here is a method, using capillary electrophoresis, for simultaneous measurement, within an individual cell, of specific reactive oxygen species, such as the superoxide radical (O2-*) as well as the native and oxidised forms of glutathione, an ubiquitous anti-oxidant that assists the cell in coping with these species. Preliminary data are presented as well as plans for integrating this system into the charged particle microbeam at Columbia University. (authors)

  18. Capillary electrophoresis theory and practice

    CERN Document Server

    Grossman, Paul D

    1992-01-01

    This book is designed to be a practical guide, used by wide audience, including those new to CE, those more experienced, routine users, those interested in technology development, and those involved with applications research. References have been emphasized to allow the reader to explore the detailed specifics and theoretical foundations.This book draws together the rapidly evolving, diverse, and multidisciplinary subject of capillary electrophoresis (CE). It is designed as a practical guide to be used by a wide audience, including those new to CE as well as more experienced users. T

  19. High sensitivity radiation detector for capillary electrophoresis

    International Nuclear Information System (INIS)

    Capillary electrophoresis is an important new instrumental technique capable of high resolution separation and analysis of small quantities of nucleotides, amino acids, peptides, and proteins with very high efficiency and throughput. The unprecedented sensitivity of this technique will be useful for such new applications as in vivo labeling and identification of trace substances and single cell work. The principle limitation of this technique for radiolabeled molecules has been identified as the sensitivity of the detector, primarily due to the small sample volume (32P-labeled biomolecules with unprecedented sensitivity. This detector can be easily retrofitted into existing CE apparatus

  20. Simple semi-automated portable capillary electrophoresis instrument with contactless conductivity detection for the determination of β-agonists in pharmaceutical and pig-feed samples.

    Science.gov (United States)

    Nguyen, Thi Anh Huong; Pham, Thi Ngoc Mai; Doan, Thi Tuoi; Ta, Thi Thao; Sáiz, Jorge; Nguyen, Thi Quynh Hoa; Hauser, Peter C; Mai, Thanh Duc

    2014-09-19

    An inexpensive, robust and easy to use portable capillary electrophoresis instrument with miniaturized high-voltage capacitively coupled contactless conductivity detection was developed. The system utilizes pneumatic operation to manipulate the solutions for all flushing steps. The different operations, i.e. capillary flushing, interface rinsing, and electrophoretic separation, are easily activated by turning an electronic switch. To allow the analysis of samples with limited available volume, and to render the construction less complicated compared to a computer-controlled counterpart, sample injection is carried out hydrodynamically directly from the sample vial into the capillary by manual syphoning. The system is a well performing solution where the financial means for the highly expensive commercial instruments are not available and where the in-house construction of a sophisticated automated instrument is not possible due to limited mechanical and electronic workshop facilities and software programming expertise. For demonstration, the system was employed successfully for the determination of some β-agonists, namely salbutamol, metoprolol and ractopamine down to 0.7ppm in pharmaceutical and pig-feed sample matrices in Vietnam. PMID:25115456

  1. Capillary Electrophoresis coupled with Automated Fraction Collection

    OpenAIRE

    Huge, Bonnie Jaskowski; Flaherty, Ryan; Dada, Oluwatosin O.; Dovichi, Norman J.

    2014-01-01

    A fraction collector based on a drop-on-demand ink-jet printer was developed to interface capillary zone electrophoresis with a 96 well microtiter plate. We first evaluated the performance of the collector by using capillary zone electrophoresis to analyze a 1 mM solution of tetramethylrhodamine; a fluorescent microtiter plate reader was then used to detect the analyte and characterize fraction carryover between wells. Relative standard deviation in peak height was 20% and the relative standa...

  2. Portable capillary electrophoresis instrument with contactless conductivity detection for on-site analysis of small volumes of biological fluids.

    Science.gov (United States)

    Greguš, Michal; Foret, František; Kubáň, Petr

    2016-01-01

    A novel, easy to use and portable capillary electrophoretic instrument for injection of small volumes of biological fluids equipped with contactless conductivity detection was constructed. The instrument is lightweight (parts including a tablet computer are accommodated in a plastic briefcase with dimensions 20 cm × 33 cm × 17 cm (w × l × h), allows hydrodynamic injection of small sample volumes and can continuously operate for at least 10 hours. The semi-automated hydrodynamic sample injection is accomplished via a specially designed PMMA interface that is able to repeatedly inject sample aliquots from a sample volume as low as 10 μL, with repeatability of peak areas below 5%. The developed interface and the instrument were optimized for the injection of biological fluids. Practical utility was demonstrated on the determination of formate in blood serum samples from acute methanol intoxication patients and on the analysis of ionic profile (nitrosative stress markers, including nitrite and nitrate) in the exhaled breath condensate from one single exhalation. PMID:26709071

  3. Analytical biotechnology: Capillary electrophoresis and chromatography

    International Nuclear Information System (INIS)

    The papers describe the separation, characterization, and equipment required for the electrophoresis or chromatography of cyclic nucleotides, pharmaceuticals, therapeutic proteins, recombinant DNA products, pheromones, peptides, and other biological materials. One paper, On-column radioisotope detection for capillary electrophoresis, has been indexed separately for inclusion on the data base

  4. Capillary electrophoresis - electrospray ionization mass spectrometry in small diameter capillaries

    Energy Technology Data Exchange (ETDEWEB)

    Wahl, J.H.; Goodlett, D.R.; Udseth, H.R.; Smith, R.D.

    1992-06-01

    Methods (such as small inner diameter capillaries) are being explored to increase analyte sensitivity in capillary electrophoresis- electrospray ionization/mass spectroscopy(CE-ESI/MS). Results are reported for melittin in a protein mixture, with 10 to 100 {mu}m ID capillaries; and for a mixture of aprotinin, cytochrome c, myoglobin, and carbonic anhydrase, with 5 to 50 {mu}m ID capillaries. It is shown that an increase in solute sensitivity occurs when small ID capillaries ({lt} 20 {mu}m) are used in CE-ESI/MS for both a peptide and a protein mixture. 3 figs. (DLC)

  5. A New Conductivity Detector for Capillary Electrophoresis

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A new conductivity detector for capillary electrophoresis consisting of an electrochemical cell and a conductive meter was developed. In the cell, the microelectrode and capillary were inserted through the cell wall and fixed by screws and sealing ring, the ends of microelectrode and capillary were located by a guide with two cross holes. LOD for K+ was 1.5×10-5 mol/L.

  6. Cytokine Analysis by Immunoaffinity Capillary Electrophoresis

    OpenAIRE

    Mendonca, Mark; Kalish, Heather

    2013-01-01

    Immunoaffinity capillary electrophoresis (ICE) is a powerful tool used to detect and quantify target proteins of interest in complex biological fluids. The target analyte is captured and bound to antibodies immobilized onto the wall of a capillary, labeled in situ with a fluorescent dye, eluted and detected online using laser-induced fluorescence following electrophoretic separation. Here, we illustrate how to construct an immunoaffinity capillary and utilize it to run ICE in order to capture...

  7. Simultaneous determination of rare earth elements in ore and anti-corrosion coating samples using a portable capillary electrophoresis instrument with contactless conductivity detection.

    Science.gov (United States)

    Nguyen, Thi Anh Huong; Nguyen, Van Ri; Le, Duc Dung; Nguyen, Thi Thanh Binh; Cao, Van Hoang; Nguyen, Thi Kim Dung; Sáiz, Jorge; Hauser, Peter C; Mai, Thanh Duc

    2016-07-29

    The employment of an in-house-made capillary electrophoresis (CE) instrument with capacitively coupled contactless conductivity detection (C(4)D) as a simple and inexpensive solution for simultaneous determination of many rare earth elements (REEs) in ore samples from Vietnam, as well as in anti-corrosion coating samples is reported. 14 REEs (La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu) were determined using an electrolyte composed of 20mM arginine and 10mM α-hydroxyisobutyric acid adjusted to pH 4.2 with acetic acid. The best detection limit achieved was 0.24mg/L using the developed CE-C(4)D method. Good agreement between results from CE-C(4)D and the confirmation method (ICP-MS) was achieved, with a coefficient of determination (r(2)) for the two pairs of data of 0.998. PMID:27363736

  8. Laser-based ultraviolet absorption detection in capillary electrophoresis

    International Nuclear Information System (INIS)

    Laser-based UV absorption in capillary electrophoresis is demonstrated. The use of vacuum photodiodes and an all-electronic noise canceller provides adequate baseline stability despite the large inherent intensity noise in UV lasers. A 4-fold improvement in the detection limit is achieved in comparison to that of commercial instruments. The main advantage here is the better optical coupling with small capillary tubes, maximizing the available optical pathlength for absorption

  9. Microfluidic chip-capillary electrophoresis devices

    CERN Document Server

    Fung, Ying Sing; Du, Fuying; Guo, Wenpeng; Ma, Tongmei; Nie, Zhou; Sun, Hui; Wu, Ruige; Zhao, Wenfeng

    2015-01-01

    Capillary electrophoresis (CE) and microfluidic chip (MC) devices are relatively mature technologies, but this book demonstrates how they can be integrated into a single, revolutionary device that can provide on-site analysis of samples when laboratory services are unavailable. By introducing the combination of CE and MC technology, Microfluidic Chip-Capillary Electrophoresis Devices broadens the scope of chemical analysis, particularly in the biomedical, food, and environmental sciences.The book gives an overview of the development of MC and CE technology as well as technology that now allows

  10. The capillary electrophoresis of the influenza viruses

    Czech Academy of Sciences Publication Activity Database

    Horká, Marie; Kubesová, Anna; Kubíček, O.; Kubíčková, Z.; Rosenbergová, K.; Šlais, Karel

    Tallinn: Tallinn University of Technology, 2009 - (Borissova, M.; Vaher, M.). s. 93 ISBN 978-9985-59-930-3. [Nordic Separation Science Society (NoSSS) International Conference /5./. 26.08.2009-29.08.2009, Tallinn] R&D Projects: GA AV ČR IAAX00310701 Institutional research plan: CEZ:AV0Z40310501 Keywords : capillary isoelectric focusing * capillary electrophoresis * influenza swine and equine viruses Subject RIV: CB - Analytical Chemistry, Separation

  11. Selectivity and detection in capillary electrophoresis

    OpenAIRE

    Khaled, Maha Yehia

    1994-01-01

    This work is a contribution to the minimization of some of the selectivity and detection limitations in capillary electrophoresis. A more practical design of an electrochemical detector is introduced with simultaneous on-line UV detection (1), for the selective detection of a number of pungent and neurological compounds, the piperines and the capsacinoids. Commercially available microelectrodes together with large 25 μm id fused silica capillary columns are used for the fir...

  12. Planetary In Situ Capillary Electrophoresis System (PISCES)

    Science.gov (United States)

    Willis, P. A.; Stockton, A. M.; Mora, M. F.; Cable, M. L.; Bramall, N. E.; Jensen, E. C.; Jiao, H.; Lynch, E.; Mathies, R. A.

    2012-10-01

    We propose to develop PISCES, a 3-kg, 2W, flight-capable microfluidic lab-on-a-chip capillary electrophoresis analyzer capable of ingesting solid, liquid, or gas samples and performing a suite of chemical analyses with parts per trillion sensitivity.

  13. "Getting the best sensitivity from on-capillary fluorescence detection in capillary electrophoresis" - A tutorial.

    Science.gov (United States)

    Galievsky, Victor A; Stasheuski, Alexander S; Krylov, Sergey N

    2016-09-01

    Capillary electrophoresis with Laser-Induced Fluorescence (CE-LIF) detection is being applied to new analytical problems which challenge both the power of CE separation and the sensitivity of LIF detection. On-capillary LIF detection is much more practical than post-capillary detection in a sheath-flow cell. Therefore, commercial CE instruments utilize solely on-capillary CE-LIF detection with a Limit of Detection (LOD) in the nM range, while there are multiple applications of CE-LIF that require pM or lower LODs. This tutorial analyzes all aspects of on-capillary LIF detection in CE in an attempt to identify means for improving LOD of CE-LIF with on-capillary detection. We consider principles of signal enhancement and noise reduction, as well as relevant areas of fluorophore photochemistry and fluorescent microscopy. PMID:27543015

  14. Capillary Electrophoresis in the Presence of Fosfomycin

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Fosfomyein, a sodim salt of cis-(3-methyloxiranyl) phosphonic acid, was used as electrolyte in binary methanol-water media for capillary electrophoresis. The variety of electroosmotic flow with pH*,methanol concentration and ionic strength was investigated. The migration behavior of nine bases was examined under various conditions, and the separation of thymine, cytosine, 5-flurouracil, 4,6-diamino-pyrimidine, purine was accomplished.

  15. Identifying kinetically stable proteins with capillary electrophoresis

    OpenAIRE

    Zhang, Songjie; Xia, Ke; Chung, Wai Keen; Cramer, Steven M; Colón, Wilfredo

    2010-01-01

    Unlike most proteins, which are in equilibrium with partially and globally unfolded conformations, kinetically stable proteins (KSPs) are trapped in their native conformations and are often resistant to harsh environment. Based on a previous correlation between kinetic stability (KS) and a protein's resistance to sodium dodecyl sulfate (SDS), we show here a simple method to identify KSPs by SDS-capillary electrophoresis (CE). Control non-KSPs were fully denatured by SDS and formed protein:SDS...

  16. Sensitivity enhancement in direct coupling of supported liquid membrane extractions to capillary electrophoresis by means of transient isotachophoresis and large electrokinetic injections

    OpenAIRE

    Pantůčková, P. (Pavla); Kubáň, P. (Pavel); Boček, P. (Petr)

    2015-01-01

    Enhanced sensitivity for determination of basic drugs in body fluids was achieved by in-line coupling of extraction across supported liquid membrane (SLM) to large electrokinetic injection and transient isotachophoresis-capillary zone electrophoresis in commercial capillary electrophoresis instrument.

  17. Capillary electrophoresis in pharmaceutical analysis: a survey on recent applications.

    Science.gov (United States)

    Suntornsuk, Leena

    2007-10-01

    Capillary electrophoresis (CE) has a significant role in drug discovery and manufacturing processes and has a potential to grow further, due to new developments that can provide highly sensitive and high throughput analysis. This review illustrates recent applications of CE in pharmaceutical analysis (2005-present). The history, principles, instruments, and conventional modes of CE are briefly described. Applications for drug analysis by various techniques of CE are presented in six tables: capillary zone electrophoresis (CZE) (Table I), micellar electrokinetic chromatography (MEKC) and microemulsion electrokinetic chromatography (MEEKC) (Table II), non-aqueous CE (NACE) (Table III), chiral CE (Table IV), CE-mass spectrometry (MS) microchip CE (Table V), and multiplexed CE (MCE) (Table VI). PMID:17988444

  18. CMOS absorbance detection system for capillary electrophoresis

    International Nuclear Information System (INIS)

    This paper presents a cost-effective portable photodetection system for capillary electrophoresis absorptiometry. By using a CMOS BDJ (buried double p-n junction) detector, a dual-wavelength method for absorbance measurement is implemented. This system includes associated electronics for low-noise pre-amplification and A/D conversion, followed by digital signal acquisition and processing. Two signal processing approaches are adopted to enhance the signal to noise ratio. One is variable time synchronous detection, which optimizes the sensitivity and measuring rate compared to a conventional synchronous detection technique. The other is a statistical approach based on principal component analysis, which allows optimal estimation of detected signal. This system has been designed and tested in capillary electrophoresis conditions. Its operation has been verified with performances comparable to those of a commercialized spectrophotometric system (HP-3D CE). With potential on-chip integration of associated electronics, it may be operated as an integrable detection module for microchip electrophoresis and other microanalysis systems

  19. Analysis of antimicrobial peptides by capillary electrophoresis

    Czech Academy of Sciences Publication Activity Database

    Ehala, Sille; Niederhafner, Petr; Čeřovský, Václav; Řezanka, P.; Sýkora, D.; Král, V.; Kašička, Václav

    Praha : Institute of Organic Chemistry and Biochemistry AS CR, v. v. i, 2011 - (Slaninová, J.), s. 37-40 ISBN 978-80-86241-44-9. - (Collection Symposium Series. 13). [Biologically Active Peptides /12./. Praha (CZ), 27.04.2011-29.04.2011] R&D Projects: GA ČR(CZ) GA203/09/0675; GA ČR(CZ) GA203/08/1428 Institutional research plan: CEZ:AV0Z40550506 Keywords : capillary electrophoresis * antimicrobial peptides * gold nanoparticles Subject RIV: CC - Organic Chemistry

  20. Study of antimicrobial peptides by capillary electrophoresis

    Czech Academy of Sciences Publication Activity Database

    Tůmová, Tereza; Monincová, Lenka; Čeřovský, Václav; Kašička, Václav

    Sofia: Bulgarian Peptide Society, 2015 - (Naydenova, E.; Pajpanova, T.; Danalev, D.), s. 304-305 ISBN 978-619-90427-2-4. [Peptides 2014. European Peptide Symposium /33./. Sofia (BG), 31.08.2014-05.09.2014] R&D Projects: GA ČR(CZ) GAP206/12/0453; GA ČR(CZ) GA13-17224S Institutional support: RVO:61388963 Keywords : peptides * antimicrobial activity * capillary electrophoresis Subject RIV: CB - Analytical Chemistry, Separation http://bulpepsoc.info/wp-content/uploads/2015/06/PEPTIDES-2014-electronic-version.pdf

  1. Sheathless interface for coupling capillary electrophoresis with mass spectrometry

    Science.gov (United States)

    Wang, Chenchen; Tang, Keqi; Smith, Richard D.

    2014-06-17

    A sheathless interface for coupling capillary electrophoresis (CE) with mass spectrometry is disclosed. The sheathless interface includes a separation capillary for performing CE separation and an emitter capillary for electrospray ionization. A portion of the emitter capillary is porous or, alternatively, is coated to form an electrically conductive surface. A section of the emitter capillary is disposed within the separation capillary, forming a joint. A metal tube, containing a conductive liquid, encloses the joint.

  2. Capillary Electrophoresis coupled with Automated Fraction Collection

    Science.gov (United States)

    Huge, Bonnie Jaskowski; Flaherty, Ryan; Dada, Oluwatosin O.; Dovichi, Norman J.

    2014-01-01

    A fraction collector based on a drop-on-demand ink-jet printer was developed to interface capillary zone electrophoresis with a 96 well microtiter plate. We first evaluated the performance of the collector by using capillary zone electrophoresis to analyze a 1 mM solution of tetramethylrhodamine; a fluorescent microtiter plate reader was then used to detect the analyte and characterize fraction carryover between wells. Relative standard deviation in peak height was 20% and the relative standard deviation in migration time was 1%. The mean and standard deviation of the tetramethylrhodamine peak width was 5 ± 1 s and likely limited by the 4-s period between droplet deposition. We next injected a complex mixture of DNA fragments and used real-time PCR to quantify the product in a CE-SELEX experiment. The reconstructed electrophoretic peak was 27 s in duration. Finally, we repeated the experiment in the presence of a 30-μM thrombin solution under CE-SELEX conditions; fractions were collected and next-generation sequencing was used to characterize the DNA binders. Over 25,000 sequences were identified with close matches to known thrombin binding aptamers. PMID:25159411

  3. Capillary electrophoresis coupled with automated fraction collection.

    Science.gov (United States)

    Huge, Bonnie Jaskowski; Flaherty, Ryan J; Dada, Oluwatosin O; Dovichi, Norman J

    2014-12-01

    A fraction collector based on a drop-on-demand ink-jet printer was developed to interface capillary zone electrophoresis with a 96 well microtiter plate. We first evaluated the performance of the collector by using capillary zone electrophoresis to analyze a 1mM solution of tetramethylrhodamine; a fluorescent microtiter plate reader was then used to detect the analyte and characterize fraction carryover between wells. Relative standard deviation in peak height was 20% and the relative standard deviation in migration time was 1%. The mean and standard deviation of the tetramethylrhodamine peak width was 5 ± 1 s and likely limited by the 4-s period between droplet deposition. We next injected a complex mixture of DNA fragments and used real-time PCR to quantify the product in a CE-SELEX experiment. The reconstructed electrophoretic peak was 27 s in duration. Finally, we repeated the experiment in the presence of a 30-µM thrombin solution under CE-SELEX conditions; fractions were collected and next-generation sequencing was used to characterize the DNA binders. Over 25,000 sequences were identified with close matches to known thrombin binding aptamers. PMID:25159411

  4. Capillary Electrophoresis Analysis of Cations in Water Samples: An Experiment for the Introductory Laboratory

    Science.gov (United States)

    Pursell, Christopher J.; Chandler, Bert; Bushey, Michelle M.

    2004-01-01

    Capillary electrophoresis is gradually working its way into the undergraduate laboratory curriculum. Typically, experiments utilizing this newer technology have been introduced into analytical or instrumental courses. The authors of this article have introduced an experiment into the introductory laboratory that utilizes capillary electrophoresis…

  5. Analysis of organic acids in Macedonian wines by capillary electrophoresis

    OpenAIRE

    Jancovska, Maja; Ivanova, Violeta; Gulaboski, Rubin; Belder, Detlev

    2013-01-01

    Capillary electrophoresis as a separation technique can be applied for analysis of organic acids in white and red wines, providing high resolution separation of the analytes. Organic acids such as of tartaric, malic, lactic citric and succinic acids have been analysed in many Macedonian red and white wines by capillary electrophoresis, and results have been discussed.

  6. Nicked-sleeve interface for two-dimensional capillary electrophoresis

    OpenAIRE

    Flaherty, Ryan J.; Huge, Bonnie J.; Bruce, Spencer M.; Dada, Oluwatosin O.; Dovichi, Norman J.

    2013-01-01

    We report an improved interface for two-dimensional capillary electrophoresis. This interface is based on capillary tubing and a Plexiglas chip, both of which were milled using a micro-dicing saw. The interface was evaluated and compared to a traditional interface design for both pseudo one-dimensional and two-dimensional capillary electrophoresis. We observe less than 70% transfer efficiency for the traditional design and greater than 90% transfer efficiency with this new interface.

  7. Differentiation of enantiomers by capillary electrophoresis.

    Science.gov (United States)

    Scriba, Gerhard K E

    2013-01-01

    Capillary electrophoresis (CE) has matured to one of the major liquid phase enantiodifferentiation techniques since the first report in 1985. This can be primarily attributed to the flexibility as well as the various modes available including electrokinetic chromatography (EKC), micellar electrokinetic chromatography (MEKC), and microemulsion electrokinetic chromatography (MEEKC). In contrast to chromatographic techniques, the chiral selector is mobile in the background electrolyte. Furthermore, a large variety of chiral selectors are available that can be easily combined in the same separation system. In addition, the migration order of the enantiomers can be adjusted by a number of approaches. In CE enantiodifferentiations the separation principle is comparable to chromatography while the principle of the movement of the analytes in the capillary is based on electrophoretic phenomena. The present chapter will focus on mechanistic aspects of CE enantioseparations including enantiomer migration order and the current understanding of selector-selectand structures. Selected examples of the basic enantioseparation modes EKC, MEKC, and MEEKC will be discussed. PMID:23666080

  8. Validation of STR typing by capillary electrophoresis.

    Science.gov (United States)

    Moretti, T R; Baumstark, A L; Defenbaugh, D A; Keys, K M; Brown, A L; Budowle, B

    2001-05-01

    With the use of capillary electrophoresis (CE), high-resolution electrophoretic separation of short tandem repeat (STR) loci can be achieved in a semiautomated fashion. Laser-induced detection of fluorescently labeled PCR products and multicolor analysis enable the rapid generation of multilocus DNA profiles. In this study, conditions for typing PCR-amplified STR loci by capillary electrophoresis were investigated using the ABI Prism 310 Genetic Analyzer (Applied Biosystems). An internal size standard was used with each run to effectively normalize mobility differences among injections. Alleles were designated by comparison to allelic ladders that were run with each sample set. Multiple runs of allelic ladders and of amplified samples demonstrate that allele sizes were reproducible, with standard deviations typically less than 0.12 bases for fragments up to 317 bases in length (largest allele analyzed) separated in a 47 cm capillary. Therefore, 99.7% of all alleles that are the same length should fall within the measurement error window of +/- 0.36 bases. Microvariants of the tetranucleotide repeats were also accurately typed by the analytical software. Alleles differing in size by one base could be resolved in two-donor DNA mixtures in which the minor component comprised > or = 5% of the total DNA. Furthermore, the quantitative data format (i.e., peak amplitude) can in some instances assist in determining individual STR profiles in mixed samples. DNA samples from previously typed cases (typed for RFLP, AmpliType PM+DQA1, and/or D1S80) were amplified using AmpFlSTR Profiler Plus and COfiler and were evaluated using the ABI Prism 310. Most samples yielded typable results. Compared with previously determined results for other loci, there were no discrepancies as to the inclusion or exclusion of suspects or victims. CE thus provides efficient separation, resolution, sensitivity and precision, and the analytical software provides reliable genotyping of STR loci. The

  9. Fabricating PFPE Membranes for Capillary Electrophoresis

    Science.gov (United States)

    Lee, Michael C.; Willis, Peter A.; Greer, Frank; Rolland, Jason

    2009-01-01

    A process has been developed for fabricating perfluoropolyether (PFPE) membranes that contain microscopic holes of precise sizes at precise locations. The membranes are to be incorporated into laboratory-on-a-chip microfluidic devices to be used in performing capillary electrophoresis. The present process is a modified version of part of the process, described in the immediately preceding article, that includes a step in which a liquid PFPE layer is cured into solid (membrane) form by use of ultraviolet light. In the present process, one exploits the fact that by masking some locations to prevent exposure to ultraviolet light, one can prevent curing of the PFPE in those locations. The uncured PFPE can be washed away from those locations in the subsequent release and cleaning steps. Thus, holes are formed in the membrane in those locations. The most straightforward way to implement the modification is to use, during the ultraviolet-curing step, an ultraviolet photomask similar to the photomasks used in fabricating microelectronic devices. In lieu of such a photomask, one could use a mask made of any patternable ultraviolet-absorbing material (for example, an ink or a photoresist).

  10. Strongly nonlinear waves in capillary electrophoresis

    Science.gov (United States)

    Chen, Zhen; Ghosal, Sandip

    2012-05-01

    In capillary electrophoresis, sample ions migrate along a microcapillary filled with a background electrolyte under the influence of an applied electric field. If the sample concentration is sufficiently high, the electrical conductivity in the sample zone could differ significantly from the background. Under such conditions, the local migration velocity of sample ions becomes concentration-dependent, resulting in a nonlinear wave that exhibits shocklike features. If the nonlinearity is weak, the sample concentration profile, under certain simplifying assumptions, can be shown to obey Burgers’ equation [Ghosal and Chen, Bull. Math. Biol.BMTBAP0092-824010.1007/s11538-010-9527-2 72, 2047 (2010)], which has an exact analytical solution for arbitrary initial condition. In this paper, we use a numerical method to study the problem in the more general case where the sample concentration is not small in comparison to the concentration of background ions. In the case of low concentrations, the numerical results agree with the weakly nonlinear theory presented earlier, but at high concentrations, the wave evolves in a way that is qualitatively different.

  11. Capillary Electrophoresis as a Fundamental Probe of Polymer Dynamics

    OpenAIRE

    Phillies, George D. J.

    2011-01-01

    Capillary electrophoresis has long been been recognized as a powerful analytic tool. Here it is demonstrated that the same capillary electrophoretic experiments also reveal dynamic properties of the polymer solutions being used as the support medium. The dependence of the electrophoretic mobility on the size of the probe and the properties of the matrix polymers shows a unity of behavior between electrophoresis and other methods of studying polymer properties.

  12. Study of Streptavidin-Modified Quantum Dots by Capillary Electrophoresis

    Czech Academy of Sciences Publication Activity Database

    Stanisavljevic, M.; Janů, L.; Šmerková, K.; Křížková, S.; Pizúrová, Naděžda; Ryvolová, M.; Adam, V.; Hubálek, J.; Kizek, R.

    2013-01-01

    Roč. 76, 7-8 (2013), s. 335-343. ISSN 0009-5893 Institutional support: RVO:68081723 Keywords : Capillary electrophoresis * Gel electrophoresis * Avidin-biotin technology * Oligonucleotide * Nanoparticle * quantum dots Subject RIV: CE - Biochemistry Impact factor: 1.370, year: 2013

  13. Integration of amperometric sensors for microchip capillary electrophoresis application

    International Nuclear Information System (INIS)

    Capillary electrophoresis is a technique for the separation and analysis of chemical compounds. Techniques adopted from the microchip technology knowledge have led to recent developments of electrophoresis system with integration on microchip. Microchip Capillary Electrophoresis (μCE) systems offer a series of advantages as easy integration for Lab-on-a-chip applications, high performance, portability, speed, minimal solvent and sample requirements. A new technological challenge aims at the development of an economic modular microchip capillary electrophoresis systems using separable and independent units concerning the sensor. In this project we worked on the development of an interchangeable amperometric sensor in order to provide a solution to such electrode passivation and facilitating the use of tailored sensors for specific analyte detection besides. Fluidic chips have been machined from cyclic olefin polymer pallets (Zeonor) using a micro-injection molding machine.

  14. Design and operation of a portable scanner for high performance microchip capillary array electrophoresis

    Science.gov (United States)

    Scherer, James R.; Liu, Peng; Mathies, Richard A.

    2010-11-01

    We have developed a compact, laser-induced fluorescence detection scanner, the multichannel capillary array electrophoresis portable scanner (McCAEPs) as a platform for electrophoretic detection and control of high-throughput, integrated microfluidic devices for genetic and other analyses. The instrument contains a confocal optical system with a rotary objective for detecting four different fluorescence signals, a pneumatic system consisting of two pressure/vacuum pumps and 28 individual addressable solenoid valves for control of on-chip microvalves and micropumps, four Polymerase Chain Reaction (PCR) temperature control systems, and four high voltage power supplies for electrophoresis. The detection limit of the instrument is ˜20 pM for on-chip capillary electrophoresis of fluorescein dyes. To demonstrate the system performance for forensic short tandem repeat (STR) analysis, two experiments were conducted: (i) electrophoretic separation and detection of STR samples on a 96-lane microfabricated capillary array electrophoresis microchip. Fully resolved PowerPlex® 16 STR profiles amplified from 1 ng of 9947A female standard DNA were successfully obtained; (ii) nine-plex STR amplification, sample injection, separation, and fluorescence detection of 100-copy 9948 male standard DNA in a single integrated PCR- capillary electrophoresis microchip. These results demonstrate that the McCAEPs can be used as a versatile control and detection instrument that operates integrated microfluidic devices for high-performance forensic human identification.

  15. Approach to analysis of single nucleotide polymorphisms by automated constant denaturant capillary electrophoresis

    International Nuclear Information System (INIS)

    Melting gel techniques have proven to be amenable and powerful tools in point mutation and single nucleotide polymorphism (SNP) analysis. With the introduction of commercially available capillary electrophoresis instruments, a partly automated platform for denaturant capillary electrophoresis with potential for routine screening of selected target sequences has been established. The aim of this article is to demonstrate the use of automated constant denaturant capillary electrophoresis (ACDCE) in single nucleotide polymorphism analysis of various target sequences. Optimal analysis conditions for different single nucleotide polymorphisms on ACDCE are evaluated with the Poland algorithm. Laboratory procedures include only PCR and electrophoresis. For direct genotyping of individual SNPs, the samples are analyzed with an internal standard and the alleles are identified by co-migration of sample and standard peaks. In conclusion, SNPs suitable for melting gel analysis based on theoretical thermodynamics were separated by ACDCE under appropriate conditions. With this instrumentation (ABI 310 Genetic Analyzer), 48 samples could be analyzed without any intervention. Several institutions have capillary instrumentation in-house, thus making this SNP analysis method accessible to large groups of researchers without any need for instrument modification

  16. The coupling of capillary electrophoresis-inductively coupled plasma mass spectrometer as a speciation instrument for actinides at trace level; Le couplage electrophorese capillaire-spectrometre de masse a source plasma en tant qu'instrument de speciation des actinides a l'etat de traces

    Energy Technology Data Exchange (ETDEWEB)

    Delorme, A

    2004-07-01

    An interface between the separation technique (capillary electrophoresis) and the analytical technique (Inductively Coupled Plasma - Mass Spectrometer) was developed. In that sense, bibliographic and parametric studies allowed to define necessary conditions for the good working of both techniques. The results obtained led to the realisation of an interface capillary electrophoresis / ICP-MS (CE / ICP-MS). This one was experimentally validated on classical separations (alkalis / earth-alkalis and lanthanides) and the detection limit of the analytical system was determined equal to 4 x 10{sup -11} mol.L{sup -1} for plutonium. This result exhibits a gain in detection limit of a factor higher than 10{sup 4} compared to the capillary electrophoresis in standard detection (UV). The studies were made in order to check the capacity of the CE / ICP-MS coupling as a speciation instrument for actinides at trace level and to define the associated analytical procedures. The coupling turned out to be a suited instrument for the determination of absolute electrophoretic mobilities at infinite dilution (physico-chemical property which allows to predict the migration time of an ion under an electrical field in a given electrolyte), for the determination of thermodynamic constants and for the separation of different actinide oxidation states in solution. (author)

  17. Use of capillary electrophoresis as a method development tool for classical gel electrophoresis

    OpenAIRE

    Sutton, Richard M. C.; Gratz, Samuel R.; Stalcup, Apryll M.

    1998-01-01

    Capillary electrophoresis (CE) was used to optimize the buffer pH, ionic strength and sulfated cyclodextrin concentrations for enantiomeric separation of piperoxan. These enantioseparation conditions were then applied to a classical gel electrophoresis system. Binding constants of the sulfated beta-cyclodextrin–piperoxan couple were approximated using CE and the effects of organic solvents on the system were also investigated.

  18. Use of capillary electrophoresis and indirect detection to quantitate in-capillary enzyme-catalyzed microreactions.

    Science.gov (United States)

    Zhang, Y; el-Maghrabi, M R; Gomez, F A

    2000-04-01

    The use of capillary electrophoresis and indirect detection to quantify reaction products of in-capillary enzyme-catalyzed microreactions is described. Migrating in a capillary under conditions of electrophoresis, plugs of enzyme and substrate are injected and allowed to react. Capillary electrophoresis is subsequently used to measure the extent of reaction. This technique is demonstrated using two model systems: the conversion of fructose-1,6-bisphosphate to dihydroxyacetone phosphate and glyceraldehyde-3-phosphate by fructose-biphosphate aldolase (ALD, EC 4.1.2.13), and the conversion of fructose-1,6-bisphosphate to fructose-6-phosphate by fructose-1,6-bisphospatase (FBPase, EC 3.1.3.11). These procedures expand the use of the capillary as a microreactor and offer a new approach to analyzing enzyme-mediated reactions. PMID:10892022

  19. Capillary electrophoresis and isotachophoresis employed for physicochemical characterization of peptides

    Czech Academy of Sciences Publication Activity Database

    Kašička, Václav; Šolínová, Veronika; Koval, Dušan; Ibrahim, A.; Cottet, H.

    Natal: -, 2014. s. 41. [ITP & LACE 2014. International Symposium on Electro- and Liquid Phase-Separation Techniques /21./ and Latin-American Symposium on Biotechnology, Biomedical, Biopharmaceutical, and Industrial Applications of Capillary Electrophoresis and Microchip Technology /20./. 04.10.2014-08.10.2014, Natal] R&D Projects: GA ČR(CZ) GAP206/12/0453; GA ČR(CZ) GA13-17224S Grant ostatní: GA AV ČR(CZ) M200551207 Institutional support: RVO:61388963 Keywords : capillary electrophoresis * peptides * electrophoretic mobility Subject RIV: CB - Analytical Chemistry, Separation

  20. Application of capillary electrophoresis in forensic science: Analysis of fireworks

    Czech Academy of Sciences Publication Activity Database

    Eliáš, Milan; Maier, V.; Knob, R.

    Olomouc: Faculty of Science, Palacký University Olomouc, 2012 - (Maier, V.; Ševčík, J.), s. 90-91 ISBN 978-80-244-3115-4. ISSN 0232-0061. [International Symposium Advances in Chromatography and Electrophoresis and Chiranal. Olomouc (CZ), 11.06.2012-14.06.2012] Institutional support: RVO:61388963 Keywords : capillary zone electrophoresis * metal cations * fireworks Subject RIV: CB - Analytical Chemistry, Separation

  1. Optimized photonic crystal fibers supporting efficient capillary electrophoresis

    Science.gov (United States)

    Calcerrada, M.; García-Ruiz, C.; Roy, P.; Gonzalez-Herraez, M.

    2013-05-01

    In this paper we present preliminary results on the use of Photonic Crystal Fibers (PCFs) in a conventional capillary electrophoresis system to separate and detect fluorescent species. PCFs show interesting advantages over conventional capillaries for this application, including larger surface-to-volume ratio and potential for higher resolution with comparable sensitivity. Our results illustrate some of these advantages, and we point out the need for stringent tolerances in the fabrication of specific PCFs for this application.

  2. Separation and quantification of cellulases and hemicellulases by capillary electrophoresis

    DEFF Research Database (Denmark)

    Jørgensen, Henning; Kutter, Jörg Peter; Olsson, Lisbeth

    2003-01-01

    . Current methods are limited in their ability to quantify all of these enzymes when all are present simultaneously in a mixture. Five different cellulases (two cellobiohydrolases and three endoglucanases) and one hemicellulase (endoxylanase) were separated using capillary electrophoresis (CE) in a fused...... silica capillary at pH values close to neutral. The improvement of the separation of these six proteins by the addition of alpha, omega-diaminoalkanes with chain lengths from three to seven carbon units was investigated. Dynamically coating the capillary with 1,3-diaminopropane resulted in separation of...

  3. Rapid inorganic ion analysis using quantitative microchip capillary electrophoresis

    NARCIS (Netherlands)

    Vrouwe, Elwin X.; Lüttge, Regina; Olthuis, Wouter; Berg, van den Albert

    2006-01-01

    Rapid quantitative microchip capillary electrophoresis (CE) for online monitoring of drinking water enabling inorganic ion separation in less than 15s is presented. Comparing cationic and anionic standards at different concentrations the analysis of cationic species resulted in non-linear calibratio

  4. Study of Oxidation of Glutathione by Capillary Electrophoresis

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A capillary electrophoresis method for the separation and quantification of reduced glutathione (GSH) and oxidized glutathione (GSSG) was developed. A baseline separation was achieved within five minutes. The effects of time and the concentrations of hydrogen peroxide (H2O2) on the oxidation of GSH were investigated.

  5. Capillary electrophoresis application in metal speciation and complexation characterization

    Science.gov (United States)

    Capillary electrophoresis is amenable to the separation of metal ionic species and the characterization of metal-ligand interactions. This book chapter reviews and discusses three representative case studies in applications of CE technology in speciation and reactions of metal with organic molecules...

  6. Design of a fraction collector for capillary array electrophoresis

    Czech Academy of Sciences Publication Activity Database

    Minarik, M.; Klepárník, Karel; Gilar, M.; Foret, František; Miller, A. W.; Sosic, Z.; Karger, B. L.

    2002-01-01

    Roč. 23, č. 1 (2002), s. 35-42. ISSN 0173-0835 R&D Projects: GA ČR GA203/00/0772 Institutional research plan: CEZ:AV0Z4031919 Keywords : fraction collector * capillary array electrophoresis * DNA analysis Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 4.325, year: 2002

  7. Determination of acidity constants of antimicrobial peptides by capillary electrophoresis

    Czech Academy of Sciences Publication Activity Database

    Tůmová, Tereza; Monincová, Lenka; Čeřovský, Václav; Kašička, Václav

    2015-01-01

    Roč. 44, Suppl 1 (2015), S130. ISSN 0175-7571. [EBSA European Biophysics Congress /10./. 18.07.2015-22.07.2015, Dresden] R&D Projects: GA ČR(CZ) GA13-17224S Institutional support: RVO:61388963 Keywords : acidity constant * antimicrobial peptides * capillary electrophoresis Subject RIV: CB - Analytical Chemistry, Separation

  8. Application of capillary electrophoresis in agricultural and soil chemistry research

    Science.gov (United States)

    As a modern analytical technique, capillary electrophoresis (CE) has become an attractive method for characterizing molecules wit high structural complexity and a wide range of molecular weights. CE can be used to analyze many natural chemical components such as acids, biogenic amines, peptides, pro...

  9. An improved interface for capillary zone electrophoresis-mass spectrometry

    International Nuclear Information System (INIS)

    We have recently developed an improved electrospray ionization interface for capillary electrophoresis mass-spectrometry (CZE-MS). Our initial interface employed a vacuum deposited metal film at the exit of the capillary to make an electrical contact with he eluting buffer and establish the electrospray field gradient. This interface did, however, impose significant limitations on the range of capillary electrophoretic (CE) separations that could be performed. To circumvent these limitations, an interface that does not require a metalized tip was designed nd developed. In the new approach, the electrical contact at the column exit is made through a flowing liquid sheath. The principal advantage of this interface is that it allows operation with a much broader range of electrophoresis conditions. The sheath flow can be readily varied in both composition and volume. An electrospray ionization spectrum is given for a previously intractable buffer solution. 5 refs., 2 figs

  10. Acupuncture Sample Injection for Microchip Capillary Electrophoresis and Electrokinetic Chromatography.

    Science.gov (United States)

    Ha, Ji Won; Hahn, Jong Hoon

    2016-05-01

    A simple nanoliter-scale injection technique was developed for polydimethylsiloxane (PDMS) microfluidic devices to form the well-defined sample plugs in microfluidic channels. Sample injection was achieved by performing acupuncture on a channel with a needle and applying external pressure to a syringe. This technique allowed us to achieve reproducible injection of a 3-nL segment into a microchannel for PDMS microchip-based capillary electrophoresis (CE). Capillary zone electrophoresis (CZE) and capillary electrochromatography (CEC) with bead packing were successfully performed by applying a single potential in the most simplified straight channel. The advantages of this acupuncture injection over the electrokinetic injection in microchip CE include capability of minimizing sample loss and voltage control hardware, capability of serial injections of different sample solutions into a same microchannel, capability of injecting sample plugs into any position of a microchannel, independence on sample solutions during the loading step, and ease in making microchips due to the straight channel, etc. PMID:27056036

  11. Joule heating effects in capillary electrophoresis - designing electrophoretic microchips

    Directory of Open Access Journals (Sweden)

    D. Witkowski

    2009-12-01

    Full Text Available Purpose: Computer simulations are widely used for designing, which contributes to a cheaper equipment developing process. In the last years computer simulations have begun to be also applied in different instances of microfluidics, especially in microchip electrophoresis (where an electrophoresis process takes place in the microcapillaries manufactured on the surface of the small plate which is interesting for us. However, there are no many commercial programs enabling simulations of microfluidics. The programs existing in the market are recently developed as microscale brings new possibilities but also unpredictable effects and challenging problems. The aim of this paper is to develop a mature technique helpful in designing electrophoretic microchips [1-4].Design/methodology/approach: Temperature distributions occurring during capillary electrophoresis because of Joule heating effects will be calculated with use of the CoventorWare™ software.Findings: Computer simulations with the model of capillary, with the same geometry as the real one, are presented. Numerical simulation results are compared with the real data from the capillary electrophoresis process.Practical implications: This is the first step to create a reliable tool for designing microfluidic devices.Originality/value: This comparison shows an ability of the CoventorWare™ software to design electrophoretic microchips.

  12. An axial approach to detection in capillary electrophoresis

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, J.A.

    1993-05-01

    Our approach involves on-axis illumination of the compounds inside the capillary detection region and is applied to absorbance and fluorescence detection. Absorbance measurements were made by focussing an incident laser beam into one capillary end; by using signals collected over the entire length of analyte band, this enhances the analytical path length of conventional absorbance detection 60x. This instrument offers a 15x improvement in detection limits. Three fluorescence detection experiments are discussed, all of which involve insertion of an optical fiber into capillary. The first uses a high refractive index liquid phase to obtain total internal reflectance along capillary axis, this reducing light scatter. The second uses a charge-coupled device camera for simultaneous imaging of a capillary array (this may be useful in genome sequencing, etc.). The third is a study of fluid motion inside the capillary under pressure-driven and electroosmotic flow. The thesis is divided into four parts. Figs, tabs.

  13. Capillary zone electrophoresis for the analysis of glycoforms of cellobiohydrolase

    OpenAIRE

    Gupta R, Baldock S J, Fielden P R, Prest J E, Grieve B D

    2011-01-01

    Cellobiohydrolase (CBH) is an important enzyme for the conversion of lignocellulosic biomass to ethanol. This work separated the glycoforms of CBH possessing different numbers of neutral mannoses using capillary zone electrophoresis (CZE) in a 50 mM, pH 7.5 phosphate buffer. The method analysed CBH in an intact form using a polyacrylamide coated fused silica capillary without requiring additives or labelling of the enzyme. The migration time of the major peak was found to be 21.6 ± 0.1 min (n...

  14. Study of separation of PAMAM dendrimers by capillary electrophoresis

    Czech Academy of Sciences Publication Activity Database

    Sedláková, Pavla; Svobodová, Jana; Mikšík, Ivan; Tomás, H.

    Paris : Ecole Supérieure de Physique et Chimie Industrielles de Paris, 2006. s. 59-59. [ITP 2006 - International Symposium on Capillary Electroseparation Techniques /15./. 28.08.2006-30.08.2006, Paris] R&D Projects: GA MŠk(CZ) 1M0510; GA ČR(CZ) GA203/05/2539; GA ČR(CZ) GA203/06/1044 Institutional research plan: CEZ:AV0Z50110509 Keywords : dendrimer * capillary electrophoresis Subject RIV: CB - Analytical Chemistry, Separation

  15. Determination of Na and Al Ions in Semiconductor Cleaning Solution Using Capillary Electrophoresis

    International Nuclear Information System (INIS)

    The most common process chemical used in the manufacturing process is a standard cleaning (SC) solution, a mixture of ammonia and hydrogen peroxide in deionized water. Since the purity of the SC solution used in the process has been required to the level of sub-ppb range, accurate and reliable determination of ionic contaminants becomes increasingly difficult. In order to satisfy the requirement of impurity control, inductively coupled plasma-mass spectrometer (ICP-MS), graphite furnace atomic absorption spectrometer (GFAAS), and ion chromatography (IC) are currently the most common analytical instruments used in the process. However, those instruments are not designed for on-line monitoring but rather for off-line analysis. Recently, separation and detection of various particles, such as cells and nanoparticles, with capillary electrophoresis (CE) was reported, although the application of CE has been mostly limited to organic or biological samples. Capillary electrophoresis has been emerging as an alternative to ICPAES and AAS for trace metal analysis

  16. Capillary zone electrophoresis and capillary isotachophoresis applied to physicochemical characterization of oligo- and polypeptides

    Czech Academy of Sciences Publication Activity Database

    Kašička, Václav; Šolínová, Veronika; Tůmová, Tereza; Koval, Dušan; Ibrahim, A.; Chamieh, J.; Cottet, H.

    Helsinki: -, 2015. L4B. [International Symposium on Electro- and Liquid Phase-Separation Techniques (ITP2015) /22./ and Nordic Separation Science Symposium (NoSSS2015) /8./. 30.08.2015-03.09.2015, Helsinki] R&D Projects: GA ČR(CZ) GA13-17224S Institutional support: RVO:61388963 Keywords : capillary electrophoresis * capillary isotachophoresis * effective charge Subject RIV: CB - Analytical Chemistry, Separation

  17. Contactless conductivity detector for microchip capillary electrophoresis

    Science.gov (United States)

    Pumera, Martin; Wang, Joseph; Opekar, Frantisek; Jelinek, Ivan; Feldman, Jason; Lowe, Holger; Hardt, Steffen; Svehla, D. (Principal Investigator)

    2002-01-01

    A microfabricated electrophoresis chip with an integrated contactless conductivity detection system is described. The new contactless conductivity microchip detector is based on placing two planar sensing aluminum film electrodes on the outer side of a poly(methyl methacrylate) (PMMA) microchip (without contacting the solution) and measuring the impedance of the solution in the separation channel. The contactless route obviates problems (e.g., fouling, unwanted reactions) associated with the electrode-solution contact, offers isolation of the detection system from high separation fields, does not compromise the separation efficiency, and greatly simplifies the detector fabrication. Relevant experimental variables, such as the frequency and amplitude of the applied ac voltage or the separation voltage, were examined and optimized. The detector performance was illustrated by the separation of potassium, sodium, barium, and lithium cations and the chloride, sulfate, fluoride, acetate, and phosphate anions. The response was linear (over the 20 microM-7 mM range) and reproducible (RSD = 3.4-4.9%; n = 10), with detection limits of 2.8 and 6.4 microM (for potassium and chloride, respectively). The advantages associated with the contactless conductivity detection, along with the low cost of the integrated PMMA chip/detection system, should enhance the power and scope of microfluidic analytical devices.

  18. Anion analysis using capillary electrophoresis in the Halden reactor

    International Nuclear Information System (INIS)

    A significant investment has been made over the last decade in water chemistry analysis capability at the Halden Reactor, reflecting both the need to maintain system reliability and to provide chemical analyses for the increasing number of corrosion and chemistry-related experiments being performed in the reactor. Control of concentrations of anionic species (chloride, sulphate and nitrate) is of crucial importance in reducing the potential of stainless steel components to undergo stress corrosion cracking. Currently at Halden, samples must be taken from the coolant in the reactor itself, several auxiliary systems and approximately 10 test loop systems. Previously, anion analyses were performed using ion chromatography. In 1996, this technique was superseded by capillary electrophoresis since the latter has several advantages over the former, including speed of analysis. This paper will present operational experience of using capillary electrophoresis from two different suppliers. A discussion of the advantages and disadvantages of the technique over ion chromatography is included. (author)

  19. Separation of Trivalent Actinides from Lanthanides Using a Capillary Electrophoresis

    International Nuclear Information System (INIS)

    A separation of 241Am(III) from 152,154Eu(III) was carried out using a capillary electrophoresis technique in a mixed solvent (CH3OH/H2O) system containing thiocyanate ion. First, the formation constants (βn) between thiocyanate ion and Eu(III) or Am(III) were investigated in the mixed solvent solutions by a back-extraction technique using bis (2-ethylhexyl) hydrogen phosphate-toluene. The mean charges calculated on the basis of the data of βn for Eu(III) were comparatively higher than those for Am(III). Based on the differences between the mean charges of Eu(III) and Am(III), separations for Am(III)/Eu(III) by means of capillary electrophoresis technique were tried in the (H+, Na+)(SCN-, ClO4-) mixed solvent solutions. It was proved that Am(III) was completely separated from Eu(III). (authors)

  20. Capillary electrophoresis microchip coupled with on-line chemiluminescence detection

    International Nuclear Information System (INIS)

    In the present work, chemiluminescence detection was integrated with capillary electrophoresis microchip. The microchip was designed on the principle of flow-injection chemiluminescence system and capillary electrophoresis. It has three main channels, five reservoirs and a detection cell. As model samples, dopamine and catechol were separated and detected using a permanganate chemiluminescent system on the prepared microchip. The samples were electrokinetically injected into the double-T cross section, separated in the separation channel, and then oxidized by chemiluminescent reagent delivered by a home-made micropump to produce light in the detection cell. The electroosmotic flow could be smoothly coupled with the micropump flow. The detection limits for dopamine and catechol were 20.0 and 10.0 μM, respectively. Successful separation and detection of dopamine and catechol demonstrated the distinct advantages of integration of chemiluminescent detection on a microchip for rapid and sensitive analysis

  1. Capillary Electrophoresis-based Methodology Development for Biomolecule Analysis

    OpenAIRE

    Li, Ni

    2011-01-01

    Capillary electrophoresis (CE) is a separation tool with wide applications in biomolecule analysis. Fast and high-resolution separation requiring minute sample volumes is advantageous to study multiple components in biological samples. Flexible modes and methods can be developed. In this thesis, I focus on developing and applying novel CE methods to study multi-target nucleic acid sensing with high sensitivity (Part I) and interactions between multiple components, i.e. proteins, nanoparticles...

  2. Chiral capillary electrophoresis separations of charged helical molecules

    Czech Academy of Sciences Publication Activity Database

    Koval, Dušan; Severa, Lukáš; Teplý, Filip; Kašička, Václav

    New Orleans: -, 2014. P1309. [HPLC 2014. International Symposium on High Performance Liquid Phase Separations and Related Techniques /41./. 11.05.2014-15.05.2014, New Orleans] R&D Projects: GA ČR GA13-19213S; GA ČR GA13-32974S Grant ostatní: AV ČR(CZ) M200551208 Institutional support: RVO:61388963 Keywords : helquats * capillary electrophoresis * chiral separation Subject RIV: CB - Analytical Chemistry, Separation

  3. Chiral separation of helical dyes by capillary electrophoresis

    Czech Academy of Sciences Publication Activity Database

    Koval, Dušan; Reyes Gutierrez, Paul Eduardo; Jirásek, Michael; Severa, Lukáš; Novotná, P.; Teplý, Filip; Kašička, Václav

    Geneva: -, 2015. s. 275. [HPLC 2015. International Symposium on High Performance Liquid Phase Separations and Related Techniques /42./. 21.06.2015-25.06.2015, Geneva] R&D Projects: GA ČR GA13-32974S; GA ČR GA13-19213S Institutional support: RVO:61388963 Keywords : capillary electrophoresis * chiral separation * helicene * sulfated cyclodextrin * cationic dye Subject RIV: CB - Analytical Chemistry, Separation

  4. Automation and integration of multiplexed on-line sample preparation with capillary electrophoresis for DNA sequencing

    Energy Technology Data Exchange (ETDEWEB)

    Tan, H.

    1999-03-31

    The purpose of this research is to develop a multiplexed sample processing system in conjunction with multiplexed capillary electrophoresis for high-throughput DNA sequencing. The concept from DNA template to called bases was first demonstrated with a manually operated single capillary system. Later, an automated microfluidic system with 8 channels based on the same principle was successfully constructed. The instrument automatically processes 8 templates through reaction, purification, denaturation, pre-concentration, injection, separation and detection in a parallel fashion. A multiplexed freeze/thaw switching principle and a distribution network were implemented to manage flow direction and sample transportation. Dye-labeled terminator cycle-sequencing reactions are performed in an 8-capillary array in a hot air thermal cycler. Subsequently, the sequencing ladders are directly loaded into a corresponding size-exclusion chromatographic column operated at {approximately} 60 C for purification. On-line denaturation and stacking injection for capillary electrophoresis is simultaneously accomplished at a cross assembly set at {approximately} 70 C. Not only the separation capillary array but also the reaction capillary array and purification columns can be regenerated after every run. DNA sequencing data from this system allow base calling up to 460 bases with accuracy of 98%.

  5. Conductivity detection for conventional and miniaturised capillary electrophoresis systems.

    Science.gov (United States)

    Guijt, Rosanne M; Evenhuis, Christopher J; Macka, Miroslav; Haddad, Paul R

    2004-12-01

    Since the introduction of capillary electrophoresis (CE), conductivity detection has been an attractive means of detection. No additional chemical properties are required for detection, and no loss in sensitivity is expected when miniaturising the detector to scale with narrow-bore capillaries or even to the microchip format. Integration of conductivity and CE, however, involves a challenging combination of engineering issues. In conductivity detection the resistance of the solution is most frequently measured in an alternating current (AC) circuit. The influence of capacitors both in series and in parallel with the solution resistance should be minimised during conductivity measurements. For contact conductivity measurements, the positioning and alignment of the detection electrodes is crucial. A contact conductivity detector for CE has been commercially available, but was withdrawn from the market. Microfabrication technology enables integration and precise alignment of electrodes, resulting in the popularity of conductivity detection in microfluidic devices. In contactless conductivity detection, the alignment of the electrodes with respect to the capillary is less crucial. Contactless conductivity detection (CCD) was introduced in capillary CE, and similar electronics have been applied for CCD using planar electrodes in microfluidic devices. A contactless conductivity detector for capillaries has been commercialised recently. In this review, different approaches towards conductivity detection in capillaries and chip-based CE are discussed. In contrast to previous reviews, the focus of the present review is on the technological developments and challenges in conductivity detection in CE. PMID:15597418

  6. Quantification of nucleotides by ICPMS: coupling of ICPMS with capillary electrophoresis or capillary HPLC

    International Nuclear Information System (INIS)

    Full text: Quantification of nucleotides in small volumes of biological samples has eagerly been demanded. A method using ICPMS coupled with capillary electrophoresis or capillary liquid chromatography is reported. A new interface system, which consists of a double tube nebulizer inserted with a fused silica capillary tube and a cylinder mini-chamber with a sheath gas inlet, was designed. Moreover, the surface conditions of the sampling and skimmer cones, and the introduction of H2 gas into the plasma were found to significantly improve the signal/background ratio for phosphorus determination at m/z 31. (author)

  7. Demonstrating Chemical and Analytical Concepts in the Undergraduate Laboratory Using Capillary Electrophoresis and Micellar Electrokinetic Chromatography

    Science.gov (United States)

    Palmer, Christopher P.

    1999-11-01

    This paper describes instrumental analysis laboratory exercises that utilize capillary electrophoresis and micellar electrokinetic chromatography to demonstrate several analytical and chemical principles. Alkyl parabens (4-hydroxy alkyl benzoates), which are common ingredients in cosmetic formulations, are separated by capillary electrophoresis. The electrophoretic mobilities of the parabens can be explained on the basis of their relative size. 3-Hydroxy ethylbenzoate is also separated to demonstrate the effect of substituent position on the acid dissociation constant and the effect this has on electrophoretic mobility. Homologous series of alkyl benzoates and alkyl phthalates (common plasticizers) are separated by micellar electrokinetic chromatography at four surfactant concentrations. This exercise demonstrates the separation mechanism of micellar electrokinetic chromatography, the concept of chromatographic phase ratio, and the concepts of micelle formation. A photodiode array detector is used in both exercises to demonstrate the advantages and limitations of the detector and to demonstrate the effect of pH and substituent position on the spectra of the analytes.

  8. [Does bilirubin interfere with capillary electrophoresis of serum proteins?].

    Science.gov (United States)

    Hellara, Ilhem; Fekih, Ons; Triki, Sonia; Elmay, Ahlem; Neffati, Fadoua; Najjar, Mohamed Fadhel

    2014-01-01

    Capillary electrophoresis of serum proteins is a fast, reliable and simple technique, but many interference exist. The objective of our work is to study the interference of bilirubin on this technique; 70 icteric sera were analysed on Capillarys ™ (Sebia). A second electrophoresis was performed on 40 samples after bilirubin photodegradation. The bilirubin and serum proteins were determinated respectively by Jendrassik and Grof and biuret methods on Konélab 20i ™ (Thermo Electron Corporation). We found abnormal spreading of the albumin fraction of the anode side wich constitute sometimes an isolated fraction in the traditional area of pre-albumin migration. This fraction varies from 2.0 ± 2.0% (0.0 to 7.3%) or 0.98 ± 1.53 g/L (0 to 5.3 g/L) and it seems to be related to the direct bilirubin since, following overloading sera with a solution of bilirubin, no further fraction was recovered. An average decrease of bilirubin after photodegradation of 58 ± 17% (26-89%) is followed by a decrease in the same order 64 ± 38% (10-100%) of the additional fraction. Acetate cellulose electrophoresis of the same samples showed no variation. The high bilirubin levels seem modify slightly the electrophoretic profile. However the impact of the interference on the interpretation of electrophoretic trace is negligible. PMID:24492101

  9. An enhanced capillary electrophoresis method for characterizing natural organic matter.

    Science.gov (United States)

    Cottrell, Barbara A; Cheng, Wei Ran; Lam, Buuan; Cooper, William J; Simpson, Andre J

    2013-02-21

    Natural organic matter (NOM) is ubiquitous and is one of the most complex naturally occurring mixtures. NOM plays an essential role in the global carbon cycle; atmospheric and natural water photochemistry; and the long-range transport of trace compounds and contaminants. There is a dearth of separation techniques capable of resolving this highly complex mixture. To our knowledge, this is the first reported use of ultrahigh resolution counterbalance capillary electrophoresis to resolve natural organic matter. The new separation strategy uses a low pH, high concentration phosphate buffer to reduce the capillary electroosmotic flow (EOF). Changing the polarity of the electrodes reverses the EOF to counterbalance the electrophoretic mobility. Sample stacking further improves the counterbalance separation. The combination of these conditions results in an electropherogram comprised up to three hundred peaks superimposed on the characteristic "humic hump" of NOM. Fraction collection, followed by three-dimensional emission excitation spectroscopy (EEMs) and UV spectroscopy generated a distinct profile of fluorescent and UV absorbing components. This enhanced counterbalance capillary electrophoresis method is a potentially powerful technique for the characterization and separation of NOM and complex environmental mixtures in general. PMID:23289095

  10. Capacitively coupled contactless conductivity detection and sequential injection analysis in capillary electrophoresis and capillary electro-chromatography

    OpenAIRE

    Mai, Thanh Duc

    2011-01-01

    This thesis focuses on the applications of capacitively coupled contactless conductivity detection (C4D) in capillary electrophoresis (CE) hybridized with high-performance liquid chromatography (HPLC), i.e. in capillary electrochromatography and pressure-assisted capillary electrophoresis, as well as on the development and applications of an extension of CE-C4D with sequential injection analysis (SIA). At first, the in-house built C4D was used for electro-chromatographic determinations of...

  11. Mecanismos de Separação em Eletroforese Capilar Separation Mechanisms in Capillary Electrophoresis

    OpenAIRE

    Tavares, Marina F. M.

    1997-01-01

    Since its inception in the 80's, capillary electrophoresis has matured into a well established technique for the separation and analysis of complex samples. One of its strongest aspects is the ability to handle materials from a diversity of chemical classes, ranging from few to millions of Daltons. This is only possible because several modes of electrophoresis can be performed in a single capillary format. In this work, relevant aspects of capillary zone electrophoresis in its three modes (fr...

  12. Separation of Aminobenzoic Acids by Gold Nanoparticle modified Capillary Electrophoresis

    Institute of Scientific and Technical Information of China (English)

    YAN,Hongtao; LI,Tuo; GUO,Yanli

    2009-01-01

    A novel method for the separation of aminobenzoic acids by capillary electrophoresis was developed.The capillary was modified with gold nanoparticles.The effect of gold nanoparticles on the resolution and selectivity of separation was investigated.The influence of separation voltage,pH and buffer concentration on the separation of aminobenzoic acids was also examined.It was found that the presence of gold nanoparticles improved the precision of the analysis and increased the separation efficiency.Under the optimized experiment conditions,aminobenzoic acids were separated and determined.Linearity was established over the concentration range 0.5-40 μg·mL-1 with correlation coefficients of 0.9978-0.9992.The detection limits (S/N = 3) were from 0.1 to 0.5 μg·mL-1.

  13. Separation and determination of some carboxylic acids by capillary electrophoresis

    Energy Technology Data Exchange (ETDEWEB)

    Sladkov, V.; Fourest, B

    2006-07-01

    Separation and determination of some organic acids, mono-carboxylic (formic and acetic), dicarboxylic (oxalic and tartaric), tricarboxylic (citric) acids and aromatic acids (phtalic, benzoic, mellitic and trimellitic), by capillary electrophoresis are reviewed. The method development parameters, such as separation and injection mode, are discussed. Special attention is paid to the comparison of different detection types (spectroscopic and electrochemical). The optimisation of the carrier electrolyte composition (choice of carrier electrolyte, effect of pH, ionic strength, electro-osmotic flow modifier) is treated. Different additives (alkali-earth and transition metal ions, cyclodextrins and alcohol), which are often used for improving organic acid separation, are also considered. (authors)

  14. A New Denoising Technique for Capillary Electrophoresis Signals

    Institute of Scientific and Technical Information of China (English)

    王瑛; 莫金垣

    2002-01-01

    Capillary electrophoresis(CE) is a powerful analytical tool in chemistry,Thus,it is valuable to solve the denoising of CE signals.A new denoising method called MWDA which emplosy Mexican Hat wavelet is presented ,It is an efficient chemometrics technique and has been applied successfully in processing CE signals ,Useful information can be extractred even from signals of S/N=1 .After denoising,the peak positions are unchanged and the relative errors of peak height are less than 3%.

  15. PNEUMATIC MICROVALVE FOR ELECTROKINETIC SAMPLE PRECONCENTRATION AND CAPILLARY ELECTROPHORESIS INJECTION

    Energy Technology Data Exchange (ETDEWEB)

    Cong, Yongzheng; Rausch, Sarah J.; Geng, Tao; Jambovane, Sachin R.; Kelly, Ryan T.

    2014-10-27

    Here we show that a closed pneumatic microvalve on a PDMS chip can serve as a semipermeable membrane under an applied potential, enabling current to pass through while blocking the passage of charged analytes. Enrichment of both anionic and cationic species has been demonstrated, and concentration factors of ~70 have been achieved in just 8 s. Once analytes are concentrated, the valve is briefly opened and the sample is hydrodynamically injected onto an integrated microchip or capillary electrophoresis (CE) column. In contrast to existing preconcentration approaches, the membrane-based method described here enables both rapid analyte concentration as well as high resolution separations.

  16. Enantiomeric Separation of Meptazinol Hydrochloride by Capillary Electrophoresis

    Institute of Scientific and Technical Information of China (English)

    YUYun-qiu; CHENYan; LINi; QIUZhui-bai

    2004-01-01

    Aim To establish a capillary electrophoresis method for enantiomerie separation of meptazinol hydrochloride. Methods The separation conditions such as cyclodextrin(CD)type, buffer pH, concentration of 2,3,6-O-triInethyl-β-cyclodextrin and organic additives were optimized. An optimum concentration was 30 mmol·L-1 phosphate (pH 7.02)with 10% (W/V) TM-β-CD and 2% acetonitrile. Results Basehne resolution of the enantiomer was readily achieved using 2,3,6-O-trimethyl-β-cyclodextrin. Conclusion This is a convenient method for fast enantiomeric resolution of meptazinol hydrochloride.

  17. Subtracting Technique of Baselines for Capillary Electrophoresis Signals

    Institute of Scientific and Technical Information of China (English)

    WANG Ying; MO Jin-yuan; CHEN Zuan-guang; GAO Yan

    2004-01-01

    The drifting baselines of capillary electrophoresis affect the veracity of analysis greatly. This paper presents Threshold Fitting Technique(TFT) so as to subtract the baselines from the original signals and emendate the signals. In TFT, wav elet and curve fitting technique are applied synthetically, thresholds are decided by the computer automatically. Many experiments of signal processing indicate that TFT is simple for being used, there are few man-induced factors, and the results are satisfactory. TFT can be applied for noisy signals without any pre-processing.

  18. Capillary electrophoresis coupled with electrochemiluminescence for determination of cloperastine hydrochloride

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Objective To investigate the electrochemiluminescence (ECL) behavior of cloperastine hydrochloride. Methods ECL intensity of tris (2,2′-bipyridyl) rutheniumo(Ⅱ) was enhanced, the method for the determination of cloperastine hydrochloride was established using capillary electrophoresis (CE) coupled with electrochemilumolinescence (ECL) detection. Results Under the optimum conditions, ECL intensity varied linearly with cloperastine hydrochloride concentration from 7.0×10-6g/mL to 1.0×10-4g/mL. The detection l...

  19. Chiral capillary electrophoresis separations of charged helical molecules

    Czech Academy of Sciences Publication Activity Database

    Koval, Dušan; Severa, Lukáš; Reyes Gutierrez, Paul Eduardo; Teplý, Filip; Kašička, Václav

    Praha: Ústav organické chemie a biochemie AV ČR, v.v.i, 2014. s. 206. ISBN 978-80-86241-52-4. [Chirality 2014. International Symposium on Chiral Discrimination /26./. 27.07.2014-30.07.2014, Praha] R&D Projects: GA ČR GA13-19213S; GA ČR GA13-32974S Grant ostatní: GA AV ČR(CZ) M200551208 Institutional support: RVO:61388963 Keywords : helquats * capillary electrophoresis * chiral separation Subject RIV: CB - Analytical Chemistry, Separation

  20. Ligand-assisted capillary electrophoresis separations of the lanthanides

    International Nuclear Information System (INIS)

    Capillary electrophoresis is used with simple organic ligands added to the electrolyte matrix to achieve separation of the individual lanthanide cations. Results for acetate (AC-) and malonate (MA-) yield good resolution for the lighter lanthanides, but not the heavier lanthanides. In contrast, α-hydroxyisobutyrate (HIB-) gives complete resolution for all of the lanthanide cations. These results are related to the complexation chemistry between the lanthanides and the ligands across the lanthanide series. In addition, preliminary results for lanthanide separations using AC- in mixed methanol:water solvent systems are provided. The presence of methanol improves resolution but slows the separation. (author)

  1. Separation and determination of some carboxylic acids by capillary electrophoresis

    International Nuclear Information System (INIS)

    Separation and determination of some organic acids, mono-carboxylic (formic and acetic), dicarboxylic (oxalic and tartaric), tricarboxylic (citric) acids and aromatic acids (phtalic, benzoic, mellitic and trimellitic), by capillary electrophoresis are reviewed. The method development parameters, such as separation and injection mode, are discussed. Special attention is paid to the comparison of different detection types (spectroscopic and electrochemical). The optimisation of the carrier electrolyte composition (choice of carrier electrolyte, effect of pH, ionic strength, electro-osmotic flow modifier) is treated. Different additives (alkali-earth and transition metal ions, cyclodextrins and alcohol), which are often used for improving organic acid separation, are also considered. (authors)

  2. Analysis and characterization of antimicrobial peptides by capillary electrophoresis

    Czech Academy of Sciences Publication Activity Database

    Tůmová, Tereza; Monincová, Lenka; Čeřovský, Václav; Kašička, Václav

    Brno : Institute of Analytical Chemistry AS CR, 2014 - (Foret, F.; Křenková, J.; Drobníková, I.; Guttman, A.; Klepárník, K.), s. 71-74 ISBN 978-80-904959-2-0. [CECE 2014. International Interdisciplinary Meeting on Bioanalysis /11./. Brno (CZ), 20.10.2014-22.10.2014] R&D Projects: GA ČR(CZ) GAP206/12/0453; GA ČR(CZ) GA13-17224S Institutional support: RVO:61388963 Keywords : capillary electrophoresis * halictines * physico-chemical parameters Subject RIV: CB - Analytical Chemistry, Separation

  3. STUDY OF CAPILLARY ELECTROPHORESIS ON MICROCHIP BASED ON MEMS

    Institute of Scientific and Technical Information of China (English)

    WangMing; LiWei; 等

    2002-01-01

    Using a standard photolithographical procedure,chenmical wet etching and thermal diffusion bonding technology,a chemical analysis device for Capillary Electrophoresis(CE) has been microfabricated on a planar glass substrate with a cross-column geometry.The channels on the microchip substrate are about 50um deep and 150um wide.By employing amino acids derived from 2,4-DiNitroFluoroBenzen(DNFB) on CE chip channels,the sample manipulating system is studied based on the principle of electrodynamics.

  4. Probing Antigen-Antibody Interaction Using Fluorescence Coupled Capillary Electrophoresis

    OpenAIRE

    Pengju Jiang; Jiang Xia; Jingyan Li; Cheli Wang; Yue Zhang; Lin Qiu; Jianhao Wang

    2013-01-01

    In this report, the use of fluorescence detection coupled capillary electrophoresis (CE-FL) allowed us to fully characterize the antigen-antibody interaction. CE-FL allowed separation of unbound quantum dots (QDs) and ligand bound QDs and also revealed an ordered assembly of biomolecules on QDs. Further, we observed FRET from QDs donor to DyLight acceptor, which were covalently conjugated with human IgG and goat anti-human IgG, respectively. The immunocomplex was formed and the mutual affinit...

  5. Miniaturized movable contactless conductivity detection cell for capillary electrophoresis.

    Science.gov (United States)

    Macka, Miroslav; Hutchinson, Joseph; Zemann, Andreas; Shusheng, Zhang; Haddad, Paul R

    2003-06-01

    A miniaturized capacitively coupled contactless conductivity detector (mini-C(4)D) cell has been designed which is small enough to allow it to slide along the effective capillary length inside the capillary cassette of an Agilent capiillary electrophoresis system (CE) (or other CE brand of similar construction), including the possibility of positioning it close to the point of optical detection (4 cm), or even putting two such detector cells in one cassette. The cell was tested and the performance characteristics (noise, sensitivity, and peak width) were compared with those obtained with the previously used large C(4)D cell. No significant differences were observed. The mini-C(4)D was used in simultaneous separations of common cations and anions where its advantage over a larger C(4)D cell is the ability to vary the point of detection with the mini-C(4)D cell continuously at any point along the capillary length, so that the optimum apparent selectivity can be chosen. Other applications include providing a convenient second point of detection in addition to photometric detection, such as to measure accurately the linear velocity of a zone, or to allow placement of two mini-C(4)D cells in one capillary cassette simultaneously. PMID:12858387

  6. On-column radioisotope detection for capillary electrophoresis

    International Nuclear Information System (INIS)

    Three on-line radioactivity detection schemes for capillary electrophoresis are described. The first detector system utilizes a commercially available semiconductor device positioned external to the separation channel and responding directly to impinging γ or high-energy β radiation. The second detector system utilizes a commercially available plastic scintillator material and a cooled photomultiplier tube operated in the photon counting mode. The third detector system utilizes a plastic scintillator material and two room-temperature photomultiplier tubes operated in the coincidence counting mode. The system performance and detector efficiency are evaluated for each of the detection schemes using synthetic mixtures of 32P-labeled sample molecules. The detection limits are determined to be in the low nanocurie range for separations performed under standard conditions (an injected sample quantity of 1 nanocurie corresponds to 110 x 10-18 moles of 32P). The lower limit of detection is extended to the sub-nanocurie level by using flow (voltage) programming to increase the residence time of labeled sample components in the detection volume. The separation of 32P-labeled oligonucleotide mixtures using polyacrylamide gel-filled capillaries and on-line radioisotope detection is also presented. When desired, the residence time can be made almost arbitrarily long by freezing the contents of the capillary, permitting autoradiograms to be recorded. This last technique is applied to gel-filled capillaries and provides a detection sensitivity of a few DPM per separated component, corresponding to subattomole amounts of radiolabel

  7. Ergot alkaloids as chiral selectors in capillary electrophoresis and other electromigration methods

    Czech Academy of Sciences Publication Activity Database

    Sinibaldi, M.; Messina, A.; Stodůlková, Eva; Flieger, Miroslav

    2010-01-01

    Roč. 1, č. 3 (2010), s. 233-243. ISSN 0976-5514 Institutional research plan: CEZ:AV0Z50200510 Keywords : capillary electrophoresis * capillary electrochromatography * chiral analysis Subject RIV: CB - Analytical Chemistry, Separation

  8. Capillary electrophoresis in tapered capillary manufactured by etching with sub-supercritical water

    Czech Academy of Sciences Publication Activity Database

    Karásek, Pavel; Horká, Marie; Šlais, Karel; Roth, Michal; Planeta, Josef

    Messina : Chromaleont S.r.L, 2012 - (Sandra, P.; Mondello, L.). s. 254 [International Symposium on Capillary Chromatography /36./ and GC x GC Symposium /9./. 27.5.2012-01.06.2012, Riva del Garda] R&D Projects: GA ČR(CZ) GAP206/11/0138; GA ČR(CZ) GAP106/12/0522; GA MV VG20112015021 Institutional research plan: CEZ:AV0Z40310501 Keywords : electrophoresis in tapered capillaries * supercritical water * complex samples Subject RIV: CB - Analytical Chemistry, Separation

  9. Direct coupling of supported liquid membranes to capillary electrophoresis for analysis of complex samples: A tutorial

    OpenAIRE

    Kubáň, P. (Pavel); Boček, P. (Petr)

    2013-01-01

    This tutorial provides an overview of direct coupling of extraction techniques based on supported liquid membranes to capillary electrophoresis for treatment and subsequent analysis of complex samples.

  10. An air-pressure-free elastomeric valve for integrated nucleic acid analysis by capillary electrophoresis

    Science.gov (United States)

    Jung, Wooseok; Barrett, Matthew; Brooks, Carla; Rivera, Andrew; Birdsell, Dawn N.; Wagner, David M.; Zenhausern, Frederic

    2015-12-01

    We present a new elastomeric valve for integrated nucleic acid analysis by capillary electrophoresis. The valve functions include metering to capture a designated volume of biological sample into a polymerase chain reaction (PCR) chamber, sealing to preserve the sample during PCR cycling, and transfer of the PCR-products and on-chip formamide post-processing for the analysis of DNA fragments by capillary gel electrophoresis. This new valve differs from prior art polydimethylsiloxane (PDMS) valves in that the valve is not actuated externally by air-pressure or vacuum so that it simplifies a DNA analysis system by eliminating the need for an air-pressure or vacuum source, and off-cartridge solenoid valves, control circuit boards and software. Instead, the new valve is actuated by a thermal cycling peltier assembly integrated within the hardware instrument that tightly comes in contact with a microfluidic cartridge for thermal activation during PCR, so that it spontaneously closes the valve without an additional actuator system. The valve has bumps in the designated locations so that it has a self-alignment that does not require precise alignment of a valve actuator. Moreover, the thickness of the new valve is around 600 μm with an additional bump height of 400 μm so that it is easy to handle and very feasible to fabricate by injection molding compared to other PDMS valves whose thicknesses are around 30-100 μm. The new valve provided over 95% of metering performance in filling the fixed volume of the PCR chamber, preserved over 97% of the sample volume during PCR, and showed very comparable capillary electrophoresis peak heights to the benchtop assay tube controls with very consistent transfer volume of the PCR-product and on-chip formamide. The new valve can perform a core function for integrated nucleic acid analysis by capillary electrophoresis.

  11. An air-pressure-free elastomeric valve for integrated nucleic acid analysis by capillary electrophoresis

    International Nuclear Information System (INIS)

    We present a new elastomeric valve for integrated nucleic acid analysis by capillary electrophoresis. The valve functions include metering to capture a designated volume of biological sample into a polymerase chain reaction (PCR) chamber, sealing to preserve the sample during PCR cycling, and transfer of the PCR-products and on-chip formamide post-processing for the analysis of DNA fragments by capillary gel electrophoresis. This new valve differs from prior art polydimethylsiloxane (PDMS) valves in that the valve is not actuated externally by air-pressure or vacuum so that it simplifies a DNA analysis system by eliminating the need for an air-pressure or vacuum source, and off-cartridge solenoid valves, control circuit boards and software. Instead, the new valve is actuated by a thermal cycling peltier assembly integrated within the hardware instrument that tightly comes in contact with a microfluidic cartridge for thermal activation during PCR, so that it spontaneously closes the valve without an additional actuator system. The valve has bumps in the designated locations so that it has a self-alignment that does not require precise alignment of a valve actuator. Moreover, the thickness of the new valve is around 600 μm with an additional bump height of 400 μm so that it is easy to handle and very feasible to fabricate by injection molding compared to other PDMS valves whose thicknesses are around 30–100 μm. The new valve provided over 95% of metering performance in filling the fixed volume of the PCR chamber, preserved over 97% of the sample volume during PCR, and showed very comparable capillary electrophoresis peak heights to the benchtop assay tube controls with very consistent transfer volume of the PCR-product and on-chip formamide. The new valve can perform a core function for integrated nucleic acid analysis by capillary electrophoresis. (paper)

  12. Determination of glycyrrhizin in liqueurs by on-line coupled capillary isotachophoresis with capillary zone electrophoresis.

    Science.gov (United States)

    Kvasnicka, Frantisek; Voldrich, Michal; Vyhnálek, Josef

    2007-10-26

    An on-line coupled capillary isotachophoresis-capillary zone electrophoresis method for the determination of glycyrrhizin in liqueurs is described. The optimised electrolyte system was 5 mM HCl+11 mM epsilon-aminocaproic acid+0.05% hydroxyethylcellulose+30% methanol (leading electrolyte), 5 mM caproic acid+30% methanol (terminating electrolyte) and 20 mM caproic acid+10 mM histidine+0.1% hydroxyethylcellulose+30% methanol (background electrolyte). Method characteristics, i.e., linearity (20-500 ng/ml), accuracy (recovery 99+/-4%), intra-assay repeatability (2%), intermediate repeatability (3.8%) and detection limit (8 ng/ml) were determined. Speed of analysis, low laboriousness, high sensitivity and low-running cost are the typical attributes of the capillary isotachophoresis-capillary zone electrophoresis method. Developed method was successfully applied to analysis of liqueurs with liquorice extract and some foods (sweets and food supplements) containing liquorice. Found levels of glycyrrhizin in liqueurs, sweets and food supplements varied between 1-16 mg/l, 850-1050 mg/kg and 1.6-1.8 g/kg, respectively. PMID:17875310

  13. Chiral Separation of Indapamide Enantiomers by Capillary Electrophoresis

    Directory of Open Access Journals (Sweden)

    Amelia Tero-Vescan

    2014-05-01

    Full Text Available Purpose: Indapamide is probably the most frequently prescribed diuretic drug, generally being used for the treatment of hypertension. It contains a chiral center in its molecule; is marketed as a racemic mixture; but there are rather few studies regarding the pharmacokinetic and the pharmacological effect differences of the two enantiomers. Our aim was the development of a simple, rapid and precise analytical procedure for the chiral separation of indapamide enantiomers. Methods: In this study capillary zone electrophoresis was used for the enantiomeric separation of indapamide using a systematic screening approach involving different native and derivatized; neutral and charged cyclodextrines as chiral selectors. The effects of pH value and composition of the background electrolyte, capillary temperature, running voltage and injection parameters have been investigated. Results: After preliminary analysis a charged derivatized CD, sulfobuthyl ether- β-CD, proved to be the optimum chiral selector for the enantioseparation. Using a buffer solution containing 25 mM disodium hydrogenophosphate – 25 mM sodium didydrogenophosphate and 5 mM sulfobuthyl ether- β-CD as chiral selector at a pH - 7, a voltage of + 25 kV, temperature 15°C and UV detection at 242 nm, we succeeded in the separation of the two enantiomers in approximately 6 minutes, with a resolution of 4.30 and a separation factor of 1.08. Conclusion: Capillary zone electrophoresis using cyclodextrines as chiral selectors proved to be a suitable method for the enantioseparation of indapamide. Our method is rapid, specific, reliable, and cost-effective and can be proposed for laboratories performing indapamide routine analysis.

  14. Microfabricated capillary electrophoresis amino acid chirality analyzer for extraterrestrial exploration

    Science.gov (United States)

    Hutt, L. D.; Glavin, D. P.; Bada, J. L.; Mathies, R. A.

    1999-01-01

    Chiral separations of fluorescein isothiocyanate-labeled amino acids have been performed on a microfabricated capillary electrophoresis chip to explore the feasibility of using such devices to analyze for extinct or extant life signs in extraterrestrial environments. The test system consists of a folded electrophoresis channel (19.0 cm long x 150 microns wide x 20 microns deep) that was photolithographically fabricated in a 10-cm-diameter glass wafer sandwich, coupled to a laser-excited confocal fluorescence detection apparatus providing subattomole sensitivity. Using a sodium dodecyl sulfate/gamma-cyclodextrin pH 10.0 carbonate electrophoresis buffer and a separation voltage of 550 V/cm at 10 degrees C, baseline resolution was observed for Val, Ala, Glu, and Asp enantiomers and Gly in only 4 min. Enantiomeric ratios were determined for amino acids extracted from the Murchison meteorite, and these values closely matched values determined by HPLC. These results demonstrate the feasibility of using microfabricated lab-on-a-chip systems to analyze extraterrestrial samples for amino acids.

  15. Towards the development of an integrated capillary electrophoresis optical biosensor.

    Science.gov (United States)

    Bossi, Alessandra; Castelletti, Laura; Piletsky, Sergey A; Turner, Anthony P F; Righetti, Pier Giorgio

    2003-10-01

    Extending the previous preliminary study on the construction of a capillary electrophoresis (CE)/sensor for the detection of reducing analytes, we focus the interest on the simultaneous detection of redox active species, which are important indicators of the oxidative damage in tissues, of food preservation, and of pollution. The CE/sensor was built by modifying the detector-portion of the capillary with the redox-sensitive polymer polyaniline (PANI). The analyte is detected by monitoring the changes in optical absorption of the PANI film. The CE/sensor was tested, with good results, with ascorbic acid, glutathione (GSH), as well as with compounds with very close similarity (ascorbic and isoascorbic acid). The kinetics of oxidation and reduction of PANI were evaluated. Further a PANI/CE-biological sensor was developed by coupling an enzyme, glucose oxidase (GOD), to the PANI-modified portion of the capillary. The stability of the immobilized GOD and the sensitivity of the CE/biosensor were studied, by using glucose as test analyte in concentrations within the physiological range. The results indicate that the CE/biosensor had good stability (more than 75% of original activity retained after 30 operational days), manufacturing reproducibility and a sensing range convenient for monitoring physiological glucose (1-24 mM). PMID:14595682

  16. Determination of Enantiomeric Excess of Glutamic Acids by Lab-made Capillary Array Electrophoresis

    Institute of Scientific and Technical Information of China (English)

    Jun WANG; Kai Ying LIU; Li WANG; Ji Ling BAI

    2006-01-01

    Simulated enantiomeric excess of glutamic acid was determined by a lab-made sixteen-channel capillary array electrophoresis with confocal fluorescent rotary scanner. The experimental results indicated that the capillary array electrophoresis method can accurately determine the enantiomeric excess of glutamic acid and can be used for high-throughput screening system for combinatorial asymmetric catalysis.

  17. Carbon Fiber-gold/mercury Dual-electrode Detection for Capillary Electrophoresis

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A carbon fiber-gold/mercury dual-electrode for capillary electrophoresis is constructed. Cysteine, glutathione, ascorbic acid and uric acid can be detected simultaneously and selectively at the dual-electrode, respectively. The capillary electrophoresis / dual-electrode detection system has been used to determine these compounds in human blood samples.

  18. VIII All-Russian symposium on molecular liquid chromatography and capillary electrophoresis. Program. Summary of reports

    International Nuclear Information System (INIS)

    Program and summary of reports of the VIII All-Russian symposium on molecular liquid chromatography and capillary electrophoresis are performed. The meeting took place 15-19 October, 2001 in Moscow. Many problems of liquid and ion exchange chromatography, capillary electrophoresis, thin-layer chromatography have been discussed extensively. Reports covering properties of sorbents and devices for chromatography are incorporated in the collection

  19. A novel covalent coating of capillaries for capillary electrophoresis coupled to matrix assisted laser desorption ionization

    International Nuclear Information System (INIS)

    Capillary electrophoresis (CE) offers the advantage of flexibility and method development. It excels in the area of separation of ions, chiral, polar, and biological compounds (especially proteins and peptides). Masking the active sites on the inner surface of a bare fused-silica capillary wall is often necessary for CE separations of basic compounds, proteins and peptides. The use of capillary surface coatings is an approach to prevent adsorption phenomena and improve the repeatability of these analytes. In this work, new capillary coatings consisting of (I) derivatized polystyrene nanoparticles (PS) and (II) derivatized fullerenes, were investigated for the analysis of peptides and protein digest by CE. The coated capillaries showed excellent run-to-run and batch-to-batch reproducibility (RSD of migration time ≤ 0.5 % for run to run and ≤ 9.5 % for batch-to-batch experiments). Furthermore, the capillaries offer high stability from pH 2.0 up to pH 10.0. The actual potential of the coated capillaries was tested by combining CE with matrix-assisted laser desorption ionisation (MALDI) mass spectrometry (MS) for analysing complex samples, such as peptides, whereas the overall performance of the CE-MALDI-TOF-MS system was investigated by analysing a five protein digest mixture. Subsequently, the peak list (peptide mass fingerprint) generated from the mass spectra of each fraction was entered into the Swiss Prot database in order to search for matching tryptic fragments using the Mascot software. The sequence coverage of analysed proteins was between 36-68%. The established technology benefits from the synergism of high separation efficiency and the structure selective identification via MS. (author)

  20. The new approach of standardization of capillary electrophoresis

    Institute of Scientific and Technical Information of China (English)

    LI; Hua; WANG; Kang; JOSEF; Havel

    2005-01-01

    In this paper, we develope the new standardization methods to eliminate the influence in capillary electrophoresis (CE). The markers were used to determine the basis position and then correct the data of sample by the migration time of standard sample, and make the migration time of samples consistent with the standard sample by the criterion of the marker. The problem of time transition was corrected in this way. Then according to the peak height or peak area of the marker in the sample (peak height was used here) compared with the standard sample, the sample data was zoomed appropriately. The absorbance error was made to be correct.The wavelet de-noise method was also used to make the data smooth and get a good baseline.

  1. Probing Antigen-Antibody Interaction Using Fluorescence Coupled Capillary Electrophoresis

    Directory of Open Access Journals (Sweden)

    Pengju Jiang

    2013-09-01

    Full Text Available In this report, the use of fluorescence detection coupled capillary electrophoresis (CE-FL allowed us to fully characterize the antigen-antibody interaction. CE-FL allowed separation of unbound quantum dots (QDs and ligand bound QDs and also revealed an ordered assembly of biomolecules on QDs. Further, we observed FRET from QDs donor to DyLight acceptor, which were covalently conjugated with human IgG and goat anti-human IgG, respectively. The immunocomplex was formed and the mutual affinity of the antigen and antibody brought QDs and DyLight close enough to allow FRET to occur. This novel CE-based technique can be easily extended to other FRET systems based on QDs and may have potential application in the detection of antibodies.

  2. Applications of capillary electrophoresis in DNA mutation analysis of genetic disorders.

    OpenAIRE

    Le, H; Fung, D.; Trent, R.J.

    1997-01-01

    AIM: To facilitate DNA mutation analysis by use of capillary electrophoresis. METHODS: The usefulness and applications of capillary electrophoresis in DNA fragment sizing and sequencing were evaluated. RESULTS: DNA mutation testing in disorders such as cystic fibrosis, Huntington disease, alpha thalassaemia, and hereditary fructose intolerance were undertaken effectively. However, sizing the (CAG)n repeat in the case of Huntington disease was a potential problem when using capillary electroph...

  3. Affinity capillary electrophoresis method for investigation of bile salts complexation with sulfobutyl ether-ß-cyclodextrin

    DEFF Research Database (Denmark)

    Østergaard, Jesper; Jensen, Henrik; Holm, Rene

    2012-01-01

    influence on the ionic strength of the background electrolyte when the cyclodextrin is used in capillary electrophoresis. Mobility-shift affinity capillary methods for investigation of the complexation of taurocholate and taurochenodeoxycholate with the negatively charged cyclodextrin derivative applying...... constant power and ionic strength conditions as well as constant voltage and varying ionic strength were investigated. A new approach for the correction of background electrolyte ionic strength was developed. Mobility-shift affinity capillary electrophoresis experiments obtained at constant voltage and...

  4. Automated dual capillary electrophoresis system with hydrodynamic injection for the concurrent determination of cations and anions

    International Nuclear Information System (INIS)

    Highlights: • Concurrent determination of cations and anions was carried out by electrophoretic separation. • Optimized conditions for each class of analystes was possible by using separate capillaries. • Simultaneous hydrodynamic injection was carried out. • Pneumatic actuation was used for flushing and sample handling. • The denitrification of drinking water was successfully demonstrated. - Abstract: The capillary electrophoresis instrument developed for the concurrent determination of cations and anions features two separate capillaries and individual detectors to allow independent optimization for each group of ions. The capillaries are joined in a common injector block. The sample is drawn into the injector with a small membrane pump and automated simultaneous injection into both capillaries is achieved by pressurization of the fluid with compressed air. Flushing of the injector and of the capillaries with the background electrolyte is also carried out automatically by the same means. The buffer consisted of 12 mM histidine and 2 mM 18-crown-6 adjusted to pH 4 with acetic acid and was suitable for the contactless conductivity detection employed. The system was optimized for the determination of cationic NH4+ and anionic NO3− and NO2−, and linear calibration curves from about 20 μM up to about 1.5 mM were obtained for these ions. In a test run over 8 h, the reproducibility for the peak areas was within ±7%. For demonstration, the instrument was successfully applied to the concurrent monitoring of the concentrations of the three ions during the biological removal of ammonium from contaminated groundwater in a sequencing batch reactor, where NO3− and NO2− are formed as intermediate products

  5. Automated dual capillary electrophoresis system with hydrodynamic injection for the concurrent determination of cations and anions

    Energy Technology Data Exchange (ETDEWEB)

    Pham, Thi Thanh Thuy; Mai, Thanh Duc [University of Basel, Department of Chemistry, Spitalstrasse 51, Basel 4056 (Switzerland); Centre for Environmental Technology and Sustainable Development (CETASD), Hanoi University of Science, Nguyen Trai Street 334, Hanoi (Viet Nam); Nguyen, Thanh Dam [Centre for Environmental Technology and Sustainable Development (CETASD), Hanoi University of Science, Nguyen Trai Street 334, Hanoi (Viet Nam); Sáiz, Jorge [Department of Analytical Chemistry, Physical Chemistry and Chemical Engineering – University of Alcalá, Ctra. Madrid-Barcelona km 33.6, Alcalá de Henares, Madrid 28871 (Spain); Pham, Hung Viet, E-mail: phamhungviet@hus.edu.vn [Centre for Environmental Technology and Sustainable Development (CETASD), Hanoi University of Science, Nguyen Trai Street 334, Hanoi (Viet Nam); Hauser, Peter C., E-mail: Peter.Hauser@unibas.ch [University of Basel, Department of Chemistry, Spitalstrasse 51, Basel 4056 (Switzerland)

    2014-09-02

    Highlights: • Concurrent determination of cations and anions was carried out by electrophoretic separation. • Optimized conditions for each class of analystes was possible by using separate capillaries. • Simultaneous hydrodynamic injection was carried out. • Pneumatic actuation was used for flushing and sample handling. • The denitrification of drinking water was successfully demonstrated. - Abstract: The capillary electrophoresis instrument developed for the concurrent determination of cations and anions features two separate capillaries and individual detectors to allow independent optimization for each group of ions. The capillaries are joined in a common injector block. The sample is drawn into the injector with a small membrane pump and automated simultaneous injection into both capillaries is achieved by pressurization of the fluid with compressed air. Flushing of the injector and of the capillaries with the background electrolyte is also carried out automatically by the same means. The buffer consisted of 12 mM histidine and 2 mM 18-crown-6 adjusted to pH 4 with acetic acid and was suitable for the contactless conductivity detection employed. The system was optimized for the determination of cationic NH{sub 4}{sup +} and anionic NO{sub 3}{sup −} and NO{sub 2}{sup −}, and linear calibration curves from about 20 μM up to about 1.5 mM were obtained for these ions. In a test run over 8 h, the reproducibility for the peak areas was within ±7%. For demonstration, the instrument was successfully applied to the concurrent monitoring of the concentrations of the three ions during the biological removal of ammonium from contaminated groundwater in a sequencing batch reactor, where NO{sub 3}{sup −} and NO{sub 2}{sup −} are formed as intermediate products.

  6. Rapid capillary coating by epoxy-poly-(dimethylacrylamide): Performance in capillary zone electrophoresis of protein and polystyrene carboxylate

    Czech Academy of Sciences Publication Activity Database

    Chiari, M.; Cretich, M.; Šťastná, Miroslava; Radko, S. P.; Chrambach, A.

    2001-01-01

    Roč. 22, č. 4 (2001), s. 656-659. ISSN 0173-0835 Institutional research plan: CEZ:AV0Z4031919 Keywords : capillary coating * capillary zone electrophoresis * proteins Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 4.282, year: 2001

  7. Determination of Amino Acids in Single Human Lymphocytes after On-capillary Derivatization by Capillary Zone Electrophoresis with Electrochemical Detection

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Amino acids in individual human lymphocytes were determined by capillary zone electrophoresis with electrochemical detection after on-capillary derivatization. In order to inject cells easily, a cell injector was designed. Four amino acids (serine, alanine, taurine, and glycine) in single human lymphocytes have been identified. Quantitation has been accomplished through the use of calibration curves.

  8. Capillary zone electrophoresis and packed capillary column liquid chromatographic analysis of recombinant human interleukin-4.

    Science.gov (United States)

    Bullock, J

    1993-02-24

    Capillary zone electrophoresis (CZE) and packed capillary column liquid chromatography (micro-LC) have been applied to the analysis of the recombinant human protein interleukin-4 (rhIL-4). Separations for both the parent protein and its enzymatic digest were developed for the purpose of characterizing protein purity and identity. CZE separations of the intact protein were investigated over the pH range of 4.5 to 8.0 using uncoated fused silica capillaries. Gradient reversed-phase micro-LC was performed using 0.32 mm packed capillary columns at flow-rates of 5-6 microliters/min. Emphasis was placed on the ability of these methods to separate close structural variants and degradation products of the protein. Peptide mapping of the tryptic digest of rhIL-4 using a combination of CZE and micro-LC provided complimentary high resolution methods for establishing protein identity. Reproducible separations were achieved using sub-picomol amounts of sample. The advantages and problems encountered with these two techniques for characterizing rhIL-4 were assessed. PMID:8450025

  9. Capillary electrophoresis: Imaging of electroosmotic and pressure driven flow profiles in fused silica capillaries

    Science.gov (United States)

    Williams, George O., Jr.

    1996-01-01

    This study is a continuation of the summer of 1994 NASA/ASEE Summer Faculty Fellowship Program. This effort is a portion of the ongoing work by the Biophysics Branch of the Marshall Space Flight Center. The work has focused recently on the separation of macromolecules using capillary electrophoresis (CE). Two primary goals were established for the effort this summer. First, we wanted to use capillary electrophoresis to study the electrohydrodynamics of a sample stream. Secondly, there was a need to develop a methodology for using CE for separation of DNA molecules of various sizes. In order to achieve these goals we needed to establish a procedure for detection of a sample plug under the influence of an electric field Detection of the sample with the microscope and image analysis system would be helpful in studying the electrohydrodynamics of this stream under load. Videotaping this process under the influence of an electric field in real time would also be useful. Imaging and photography of the sample/background electrolyte interface would be vital to this study. Finally, detection and imaging of electroosmotic flow and pressure driven flow must be accomplished.

  10. Streamlined sign-out of capillary protein electrophoresis using middleware and an open-source macro application

    Directory of Open Access Journals (Sweden)

    Gagan Mathur

    2014-01-01

    Full Text Available Background: Interfacing of clinical laboratory instruments with the laboratory information system (LIS via "middleware" software is increasingly common. Our clinical laboratory implemented capillary electrophoresis using a Sebia; Capillarys-2™ (Norcross, GA, USA instrument for serum and urine protein electrophoresis. Using Data Innovations Instrument Manager, an interface was established with the LIS (Cerner that allowed for bi-directional transmission of numeric data. However, the text of the interpretive pathology report was not properly transferred. To reduce manual effort and possibility for error in text data transfer, we developed scripts in AutoHotkey, a free, open-source macro-creation and automation software utility. Materials and Methods: Scripts were written to create macros that automated mouse and key strokes. The scripts retrieve the specimen accession number, capture user input text, and insert the text interpretation in the correct patient record in the desired format. Results: The scripts accurately and precisely transfer narrative interpretation into the LIS. Combined with bar-code reading by the electrophoresis instrument, the scripts transfer data efficiently to the correct patient record. In addition, the AutoHotKey script automated repetitive key strokes required for manual entry into the LIS, making protein electrophoresis sign-out easier to learn and faster to use by the pathology residents. Scripts allow for either preliminary verification by residents or final sign-out by the attending pathologist. Conclusions: Using the open-source AutoHotKey software, we successfully improved the transfer of text data between capillary electrophoresis software and the LIS. The use of open-source software tools should not be overlooked as tools to improve interfacing of laboratory instruments.

  11. Determination of dioxopromethazine hydrochloride by capillary electrophoresis with electrochemiluminescence detection

    International Nuclear Information System (INIS)

    The paper presents a rapid method for the determination of dioxopromethazine hydrochloride (DPZ), an antihistamine drug, by the capillary electrophoresis with electrochemiluminescene detection (CE-ECL) using tris(2,2'-bipyridyl)ruthenium(II) (Ru(bpy)32+) reagent. This CE-ECL detection method has high sensitivity, good selectivity and reproducibility for DPZ analysis. Under the optimized conditions: separation capillary, 38 cm length (25 μm i.d.); sample injection, 10 s at 8 kV; separation voltage, 12.5 kV; running buffer, 20 mmol L-1 sodium phosphate of pH 6.0; detection potential, 1.15 V; 50 mmol L-1 of phosphate buffer (pH 7.14) containing 5 mmol L-1 of Ru(bpy)32+ in ECL detection cell, the detection limit of DPZ was 0.05 μmol L-1 (S/N = 3). The linear range extended from 5 to 100 μmol L-1. The linear curve obtained was Y = 181.62 + 9.28X with a correlation coefficient of 0.9970. The relative standard deviations of the ECL intensity and the migration time for six continuous injections of 5 μmol L-1 DPZ were 3.7% and 0.92%, respectively. The CE-ECL method was applied to analyze DPZ in real samples including tablets, rat serum and human urine, and satisfactory results were obtained without interference from samples matrix. The CE-ECL technique was proved to be a potential method for the detection of DPZ in clinic analysis

  12. Analysis of Soft Drinks: UV Spectrophotometry, Liquid Chromatography, and Capillary Electrophoresis

    Science.gov (United States)

    McDevitt, Valerie L.; Rodriguez, Alejandra; Williams, Kathryn R.

    1998-05-01

    Instrumental analysis students analyze commercial soft drinks in three successive laboratory experiments. First, UV multicomponent analysis is used to determine caffeine and benzoic acid in Mello YelloTM using the spectrophotometer's software and manually by the simultaneous equations method. The following week, caffeine, benzoic acid and aspartame are determined in a variety of soft drinks by reversed-phase liquid chromatography using 45% methanol/55% aqueous phosphate, pH 3.0, as the mobile phase. In the third experiment, the same samples are analyzed by capillary electrophoresis using a pH 9.4 borate buffer. Students also determine the minimum detection limits for all three compounds by both LC and CE. The experiments demonstrate the analytical use and limitations of the three instruments. The reports and prelab quizzes also stress the importance of the chemistry of the three compounds, especially the relationships of acid/base behavior and polarity to the LC and CE separations.

  13. Band broadening of DNA fragments isolated by polyacrylamide gel electrophoresis in capillary electrophoresis.

    Science.gov (United States)

    Kaneta, Takashi; Ogura, Takehito; Yamato, Shuhei; Imasaka, Totaro

    2012-02-01

    Polyacrylamide gel electrophoresis (PAGE) is used frequently for isolation and purification of DNA fragments. In the present study, DNA fragments extracted from polyacrylamide gels showed significant band broadening in capillary electrophoresis (CE). A pHY300PLK (a shuttle vector functioning in Escherichia coli and Bacillus subtilis) marker, which contained nine fragments ranging from 80 to 4870 bp, was separated by PAGE, and each fragment was isolated by phenol/chloroform extraction and ethanol precipitation. After extraction from the polyacrylamide gel, the peaks of the isolated DNA fragments exhibited band broadening in CE, where a linear poly(ethylene oxide) was used as a sieving matrix. The theoretical plate numbers of the DNA fragments contained in the pHY300PLK marker were >10(6) for all the fragments before extraction. However, the DNA fragments extracted from the polyacrylamide gel showed decreased theoretical plate numbers (5-20 times smaller). The degradation of the theoretical plate number was significant for middle sizes of the DNA fragments ranging from 489 to 1360 bp, whereas the largest and smallest fragments (80 and 4870 bp) had no obvious influence. The band broadening was attributed to contamination of the DNA fragments by polyacrylamide fibers during the separation and extraction process. PMID:22258810

  14. Capillary electrophoresis methods for microRNAs assays: A review

    International Nuclear Information System (INIS)

    Highlights: • A review of CE analysis of miRNAs. • Summary of developments and applications of CE systems in miRNA studies. • Applications and development of microchip-based CE for rapid analysis of miRNA. - Abstract: MicroRNAs (miRNAs) are short noncoding RNAs that conduct important roles in many cellular processes such as development, proliferation, differentiation, and apoptosis. In particular, circulating miRNAs have been proposed as biomarkers for cancer, diabetes, cardiovascular disease, and other illnesses. Therefore, determination of miRNA expression levels in various biofluids is important for the investigation of biological processes in health and disease and for discovering their potential as new biomarkers and drug targets. Capillary electrophoresis (CE) is emerging as a useful analytical tool for analyzing miRNA because of its simple sample preparation steps and efficient resolution of a diverse size range of compounds. In particular, CE with laser-induced fluorescence detection is a promising and relatively rapidly developing tool with the potential to provide high sensitivity and specificity in the analysis of miRNAs. This paper covers a short overview of the recent developments and applications of CE systems in miRNA studies in biological and biomedical areas

  15. Capillary electrophoresis methods for microRNAs assays: A review

    Energy Technology Data Exchange (ETDEWEB)

    Ban, Eunmi; Song, Eun Joo, E-mail: ejsong@kist.re.kr

    2014-12-10

    Highlights: • A review of CE analysis of miRNAs. • Summary of developments and applications of CE systems in miRNA studies. • Applications and development of microchip-based CE for rapid analysis of miRNA. - Abstract: MicroRNAs (miRNAs) are short noncoding RNAs that conduct important roles in many cellular processes such as development, proliferation, differentiation, and apoptosis. In particular, circulating miRNAs have been proposed as biomarkers for cancer, diabetes, cardiovascular disease, and other illnesses. Therefore, determination of miRNA expression levels in various biofluids is important for the investigation of biological processes in health and disease and for discovering their potential as new biomarkers and drug targets. Capillary electrophoresis (CE) is emerging as a useful analytical tool for analyzing miRNA because of its simple sample preparation steps and efficient resolution of a diverse size range of compounds. In particular, CE with laser-induced fluorescence detection is a promising and relatively rapidly developing tool with the potential to provide high sensitivity and specificity in the analysis of miRNAs. This paper covers a short overview of the recent developments and applications of CE systems in miRNA studies in biological and biomedical areas.

  16. Capillary electrophoresis-chemiluminescence determination of norfloxacin and prulifloxacin

    Energy Technology Data Exchange (ETDEWEB)

    Yang Zhongju; Wang Xiaoli [College of Chemistry, Beijing Normal University, Beijing 100875 (China); Qin Weidong [College of Chemistry, Beijing Normal University, Beijing 100875 (China)], E-mail: qinwd@bnu.edu.cn; Zhao Huichun [College of Chemistry, Beijing Normal University, Beijing 100875 (China)], E-mail: zhaohuichun@bnu.edu.cn

    2008-08-15

    A capillary electrophoresis (CE)-chemiluminescence (CL) method for determining norfloxacin (NFLX) and prulifloxacin (PFLX) was developed based on the enhanced CL intensity of the cerium(IV)-sulfite-fluoroquinolone (FQ) reaction sensitized by terbium(III). The separation was conducted in buffer composed of 20 mM sodium citrate, 4 mM citric acid and 10 mM sodium sulfite at pH 6.1. The CL reagent solution consisted of 2 mM cerium(IV), 4 mM terbium(III) and 1.1 mM hydrochloric acid. NFLX and PFLX were baseline separated within 11 min with detection limits (S/N = 3) of 0.057 and 0.084 {mu}g mL{sup -1}, respectively. The maximum intra- and inter-day relative standard deviations (R.S.D.s) of migration time of the analytes were less than 4.0% and 4.2%, respectively. The proposed method was applied to detect NFLX and PFLX in fortified urine sample and the results were comparable to high-performance liquid chromatography (HPLC)-UV method. Moreover, the high selectivity of the CL detection and the high-separation efficiency of CE render the method the potential of quick analyzing fluoroquinolones in real complex matrix.

  17. Separation of Purine and Its Derivatives by Capillary Zone Electrophoresis

    Institute of Scientific and Technical Information of China (English)

    ZengBai-zhao; ZhaoFa-qiong

    2003-01-01

    The separation of a group of 17 purine and its derivatives by capillary zone electrophoresis is presented. A systematic approach was used to study the effect of pH, buffer type, organic modifiers, applied potential, sodium dodecyl sulfate (SDS) and cyclodextrins on the separation of these purine derivatives. An ideal condition was found for their separation, which was 30 mmol/L sodium borate buffer (pH 9-9.5), 10% (V/V) methanol buffer modifier and 20 kV. Under this condition, the 17 purine derivatives were baseline separated and the linear correlation coefficient for adenine,uric acid and 2-thioxanthine was 0. 99 over two orders of magnitude. The variation of peak areas was less than 4.6%(n= 5) and that of migration times was in the range of 0%-3%, while the samples were injected hydrodynamically at a height of 15 cm and an injection time of 8-10 s. In addition,alcohol, 1-propanol, 1-butanol and acetonitrile were also effective additives in the separation. However, SDS and various β-cyclodextrin (β-CDs) were found to do no good to their separation.

  18. Separation of Purine and Its Derivatives by Capillary Zone Electrophoresis

    Institute of Scientific and Technical Information of China (English)

    Zeng Bai-zhao; Zhao Fa-qiong

    2003-01-01

    The separation of a group of 17 purine and its derivatives by capillary zone electrophoresis is presented. A systematic approach was used to study the effect of pH, buff-er type, organic modifiers, applied potential, sodium dodecyl sulfate (SDS) and cyclodextrins on the separation of these pu-rine derivatives. An ideal condition was found for their se-paration, which was 30 mmol/L sodium borate buffer (pH 9-9.5), 10% (V/V) methanol buffer modifier and 20 kV. Un-der this condition, the 17 purine derivatives were baseline separated and the linear correlation coefficient for adenine,uric acid and 2-thioxanthine was 0. 99 over two orders of magnitude. The variation of peak areas was less than 4.6 %(n=5) and that of migration times was in the range of 0%-3%, while the samples were injected hydrodynamically at a height of 15 cm and an injection time of 8-10 s. In addition,alcohol, 1-propanol, 1-butanol and acetonitrile were also ef-fective additives in the separation. However, SDS and various β-cyclodextrin (β-CDs) were found to do no good to their se-paration.

  19. Stability measurements of antisense oligonucleotides by capillary gel electrophoresis.

    Science.gov (United States)

    Bruin, G J; Börnsen, K O; Hüsken, D; Gassmann, E; Widmer, H M; Paulus, A

    1995-08-11

    The approach of using antisense oligonucleotides as potential drugs is based on hybridization of a short chemically-modified oligonucleotide with complementary cellular DNA or RNA sequences. A critical question is the stability of chemically modified antisense oligonucleotides in cellular environments. In a model system, resistance against various nucleases was evaluated by capillary gel electrophoresis (CGE). For some of the samples, matrix assisted laser desorption and ionization mass spectrometry (MALDI-MS) was used as an additional analytical tool to perform stability measurements. Using CGE, the enzymatic degradation of single nucleotides from the oligomer can be followed after different incubation times. 10% T polyacrylamide gels give baseline resolution for oligonucleotides ranging between 5 and 30 bases in length. The kinetic influence of a specific nuclease concentration and the antisense oligonucleotide structure on the cleavage reaction are discussed. Also, a simple desalting method to improve the injection efficiency and sensitivity of the method are described. Examples of measurements of chemically modified antisense 19-mers are presented. PMID:7581844

  20. QuShape: Rapid, accurate, and best-practices quantification of nucleic acid probing information, resolved by capillary electrophoresis

    OpenAIRE

    Karabiber, Fethullah; McGinnis, Jennifer L.; Favorov, Oleg V.; Weeks, Kevin M.

    2013-01-01

    Chemical probing of RNA and DNA structure is a widely used and highly informative approach for examining nucleic acid structure and for evaluating interactions with protein and small-molecule ligands. QuShape, described in this paper, is a platform-independent, user-friendly software package that yields quantitative and objective nucleotide reactivity information as resolved by automated high-throughput capillary electrophoresis instruments.

  1. Monitoring Homovanillic Acid and Vanillylmandelic Acid in Human Urine by Capillary Electrophoresis with Electrochemical Detection

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A simple, rapid and low-cost method of separation and determination of homovanillic acid and vanillylmandelic acid in human urine was developed based on capillary zone electrophoresis / amperometric detection with high sensitivity and good resolution.

  2. Capillary Electrophoresis Profiles and Fluorophore Components of Humic Acids in Nebraska Corn and Philippine Rice Soils

    Science.gov (United States)

    As humic substances represent relatively high molecular mass polyelectrolytes containing aromatic, aliphatic and heterocyclic subunits, capillary electrophoresis (CE) has become an attractive method for “finger-print” characterization of humic acids. In addition, fluorescence excitation-emission ma...

  3. Applications of on-line weak affinity interactions in free solution capillary electrophoresis

    DEFF Research Database (Denmark)

    Heegaard, Niels H H; Nissen, Mogens H; Chen, David D Y

    2002-01-01

    The impressive selectivity offered by capillary electrophoresis can in some cases be further increased when ligands or additives that engage in weak affinity interactions with one or more of the separated analytes are added to the electrophoresis buffer. This on-line affinity capillary...... enantiomers and on using capillary electrophoresis to characterize such interactions quantitatively. We describe the equations for binding isotherms, illustrate how selectivity can be manipulated by varying the additive concentrations, and show how the methods may be used to estimate binding constants. On......-line affinity capillary electrophoresis methods are especially valuable for enantiomeric separations and for functional characterization of the contents of biological samples that are only available in minute quantities....

  4. Synthesis and Characterization of Water-Soluble Carboxymethyl-Cyclodextrin Polymer as Capillary Electrophoresis Chiral Selector

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The water-soluble carboxymethyl-cyclodextrin polymer (CM-CD polymer) was synthesized and used as capillary electrophoresis chiral selector.Verrapamil and thiopentorusodium were well separated using CM-CD polymer as chiral selector.

  5. p-Hydrazinobenzenesulfonic Acid Derivatives of Carbohydrates and Their Capillary Zone Electrophoresis

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    p-Hydrazinobenzenesulfonic acid is explored as a novel ultraviolet labeling reagent for capillary electrophoresis (CE) of mono- and disaccharides. The labeling reaction takes less than 10 minutes and introduces both of absorption and charge groups into the sugars.

  6. Recent advances in the analysis of biological particles by capillary electrophoresis

    OpenAIRE

    Kostal, Vratislav; Arriaga, Edgar A.

    2008-01-01

    This review covers research papers published in the years 2005–2007 that describe the application of capillary electrophoresis to the analysis of biological particles such as whole cells, subcellular organelles, viruses and microorganisms.

  7. ANALYSIS OF THE ENANTIOMERS OF CHIRAL PESTICIDES AND OTHER POLLUTANTS IN ENVIRONMENTAL SAMPLES BY CAPILLARY ELECTROPHORESIS

    Science.gov (United States)

    The generic method described here involves typical capillary electrophoresis (CE) techniques, with the addition of cyclodextrin chiral selectors to the electrolyte for enantiomer separation and also, in the case of neutral analytes, the further addition of a micelle forming comp...

  8. Trace analysis of organic ions in ice samples by capillary electrophoresis

    Energy Technology Data Exchange (ETDEWEB)

    Huber, T. [Bern Univ. (Switzerland); Schwikowski, M.; Gaeggeler, H.W. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1997-09-01

    Capillary electrophoresis was tested as a new analytical method for ice samples. Comparisons to ion chromatography were made concerning accuracy, detection limits, reproducibility, necessary sample volume and time consumption. (author) 1 fig., 3 refs.

  9. Determination of Size Distribution of Nano-particles by Capillary Zone Electrophoresis

    Institute of Scientific and Technical Information of China (English)

    Yan XUE; Hai Ying YANG; Yong Tan YANG

    2005-01-01

    A new method was developed for the determination of the size distribution of nano-particles by capillary zone electrophoresis (CZE). Scattering effect of nanoparticles was studied. This method for the determination of size distribution was statistical.

  10. DNA sequencing with capillary electrophoresis and single cell analysis with mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Fung, N.

    1998-03-27

    Since the first demonstration of the laser in the 1960`s, lasers have found numerous applications in analytical chemistry. In this work, two different applications are described, namely, DNA sequencing with capillary gel electrophoresis and single cell analysis with mass spectrometry. Two projects are described in which high-speed DNA separations with capillary gel electrophoresis were demonstrated. In the third project, flow cytometry and mass spectrometry were coupled via a laser vaporization/ionization interface and individual mammalian cells were analyzed. First, DNA Sanger fragments were separated by capillary gel electrophoresis. A separation speed of 20 basepairs per minute was demonstrated with a mixed poly(ethylene oxide) (PEO) sieving solution. In addition, a new capillary wall treatment protocol was developed in which bare (or uncoated) capillaries can be used in DNA sequencing. Second, a temperature programming scheme was used to separate DNA Sanger fragments. Third, flow cytometry and mass spectrometry were coupled with a laser vaporization/ionization interface.

  11. Chiral Separation by Capillary Zone Electrophoresis Used Cyclodextrins and Their Derivatives as Chiral Selector

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    @@ Capillary zone electrophoresis (CZE) is a very pronising analytical technique for the optical isomer resolution of the compounds studied. The drawbacks of the techniques such as HPLC [1] were sophisticated stationary phases and/or the relatively high quantity of the chiral agent in the mobile phase, which do not exist in CZE. The capillary electrophoresis (CE) method can offer advantages on lower consumption of analyte and background electrolyte (BGE), shorter analysis time, and higher efficiencies [2-3

  12. Pathway for Unfolding of Ubiquitin in Sodium Dodecyl Sulfate, Studied by Capillary Electrophoresis

    OpenAIRE

    Schneider, Grégory F.; Shaw, Bryan F.; Lee, Andrew; Carillho, Emanuel; Whitesides, George M.

    2008-01-01

    This paper characterizes the complexes formed by a small protein, ubiquitin (UBI), and a negatively charged surfactant, sodium dodecyl sulfate (SDS), using capillary electrophoresis (CE), circular dichroism (CD), and amide hydrogendeuterium exchange (HDX; as monitored by mass spectroscopy, MS). Capillary electrophoresis of complexes of UBI and SDS, at apparent equilibrium, at concentrations of SDS ranging from sub-micellar and sub-denaturing to micellar and denaturing, revealed multiple compl...

  13. Application of capillary electrophoresis to the characterization of some colloidal particles

    International Nuclear Information System (INIS)

    The advantages of the capillary electrophoresis method, known to be highly selective, have been tested on some standard latex colloids and nanoparticles of thorium phosphate, investigated separately or in mixtures. The results have been compared to those obtained by laser Doppler velocimetry. Both methods appear as complementary: capillary electrophoresis is more efficient to point out very fine particles among others, but is more restricting about the supporting medium. (author). 9 refs., 6 figs., 1 tab

  14. Potentials and Method Improvements of Capillary Zone Electrophoresis for Use in Spelt Breeding Programs

    Science.gov (United States)

    Capillary zone electrophoresis (CZE) in acidic buffer systems is capable of separating cereal storage proteins based on similar separation principles as classical acidic polyacrylamide gel electrophoresis. However, it is faster, its resolution is distinctly higher and data evaluation is much simpler...

  15. ANALYSIS OF ANIONIC METALLIZED AZO AND FORMAZAN DYES BY CAPILLARY ELECTROPHORESIS/MASS SPECTROMETRY

    Science.gov (United States)

    Capillary electrophoresis-mass spectrometry was applied to the separation of several anionic dyes containing copper(II), chromium(III), or cobalt(III) as part of the dye molecule. The dyes were separated using a 110 cmX50 mu m uncoated fused-silica capillary and a 5 mM ammonium a...

  16. Quantification of Carbohydrates in Grape Tissues Using Capillary Zone Electrophoresis

    Science.gov (United States)

    Zhao, Lu; Chanon, Ann M.; Chattopadhyay, Nabanita; Dami, Imed E.; Blakeslee, Joshua J.

    2016-01-01

    Soluble sugars play an important role in freezing tolerance in both herbaceous and woody plants, functioning in both the reduction of freezing-induced dehydration and the cryoprotection of cellular constituents. The quantification of soluble sugars in plant tissues is, therefore, essential in understanding freezing tolerance. While a number of analytical techniques and methods have been used to quantify sugars, most of these are expensive and time-consuming due to complex sample preparation procedures which require the derivatization of the carbohydrates being analyzed. Analysis of soluble sugars using capillary zone electrophoresis (CZE) under alkaline conditions with direct UV detection has previously been used to quantify simple sugars in fruit juices. However, it was unclear whether CZE-based methods could be successfully used to quantify the broader range of sugars present in complex plant extracts. Here, we present the development of an optimized CZE method capable of separating and quantifying mono-, di-, and tri-saccharides isolated from plant tissues. This optimized CZE method employs a column electrolyte buffer containing 130 mM NaOH, pH 13.0, creating a current of 185 μA when a separation voltage of 10 kV is employed. The optimized CZE method provides limits-of-detection (an average of 1.5 ng/μL) for individual carbohydrates comparable or superior to those obtained using gas chromatography–mass spectrometry, and allows resolution of non-structural sugars and cell wall components (structural sugars). The optimized CZE method was successfully used to quantify sugars from grape leaves and buds, and is a robust tool for the quantification of plant sugars found in vegetative and woody tissues. The increased analytical efficiency of this CZE method makes it ideal for use in high-throughput metabolomics studies designed to quantify plant sugars. PMID:27379118

  17. Potential of polyE-323 coated capillaries for capillary electrophoresis of lipids.

    Science.gov (United States)

    Martma, Kert; Lindenburg, Petrus W; Habicht, Kaia-Liisa; Vulla, Kaspar; Resik, Kristiin; Kuut, Gunnar; Shimmo, Ruth

    2013-11-22

    In this note the feasibility of a polyamine-based capillary coating, polyE-323, for capillary electrophoresis (CE) of lipids is explored. PolyE-323 has previously been demonstrated to be suitable to suppress analyte-wall interaction of proteins in CE. However, the full applicability range of polyE-323 has not been exploited yet and it might be useful in the analysis of hydrophobic analytes, such as lipids. In this study, the stability of polyE-323 when using highly organic background electrolytes (BGEs), which are needed to solubilize the lipid analytes, was studied. For this, we used three different lipid samples: sphingomyelin, cardiolipin and a lipid extract from a cell culture. The highly organic BGEs that were used in this study consisted of 94.5% of organic solvents and 5.5% of an aqueous buffer. First, the influence of pure acetonitrile, methanol, propylene carbonate, isopropanol and chloroform on the polyE-323 coating was investigated. Then BGEs were developed and tested, using sphingomyelin and cardiolipin as test analytes in CE-UV experiments. After establishing the best BGEs (in terms of analysis time and repeatability) by CE-UV, sphingomyelin was used as a test analyte to demonstrate that method was also suitable for CE with mass-spectrometry detection (CE-MS). The LOD of sphingomyelin was estimated to be 100 nM and its migration time repeatability was 1.3%. The CE-MS analysis was further applied on a lipid extract obtained from human glioblastoma cells, which resulted in the separation and detection of a multitude of putative lipids. The results of our feasibility study indicate that CE systems based on polyE-323 coated capillaries and highly organic BGEs are promising for fast electromigration-based analysis of lipids. PMID:24011728

  18. Evaluation of The Interaction between Netropsin and Double Stranded DNA by Capillary Zone Electrophoresis

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Capillary zone electrophoresis (CZE) was applied to study the interaction between netropsin and a 14mer double stranded DNA (dsDNA). The binding constant of this interaction calculated from Scatchard plot was (1.07±0.10)×105 (mol/L)-1. The binding stoichiometry was 1:1. The use of polyacrylamide coated capillary showed better effect in the analysis of DNA than noncoated capillary.

  19. Modification of resolution in capillary electrophoresis for protein profiling in identification of genetic modification in foods

    OpenAIRE

    Latoszek, A.; Cifuentes, Alejandro

    2011-01-01

    The capillary electrophoresis with UV detection was employed for protein profiling in extracts from maize and soybeans. Modifications of back-ground electrolyte and coating the capillary wall with polybrene was employed in order to decrease the protein adsorption on the capillary walls. The obtained protein profiles were compared for transgenic and non-transgenic variants, showing in some cases significant changes that might be employed for identification of genetic modifications ...

  20. Exploring chip-capillary electrophoresis-laser-induced fluorescence field-deployable platform flexibility: Separations of fluorescent dyes by chip-based non-aqueous capillary electrophoresis

    Czech Academy of Sciences Publication Activity Database

    Nuchtavorn, N.; Smejkal, Petr; Breadmore, M. C.; Guijt, R. M.; Doble, P.; Bek, F.; Foret, František; Suntornsuk, L.; Macka, M.

    2013-01-01

    Roč. 1286, APR (2013), s. 216-221. ISSN 0021-9673 R&D Projects: GA ČR(CZ) GBP206/12/G014 Institutional support: RVO:68081715 Keywords : microfluidic chip CE * capillary electrophoresis * NACE * LIF detection Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 4.258, year: 2013

  1. Capillary zone electrophoresis analysis and detection of mid-spectrum biological warfare agents. Suffield memorandum No. 1463

    Energy Technology Data Exchange (ETDEWEB)

    Boulet, C.A.

    1995-12-31

    Mid-spectrum biological warfare agents such as proteins, peptides, and toxins are often difficult to analyze and often require individually developed assay methods for detection and identification. In this regard, capillary electrophoresis is an important, emerging technique for separation and quantitation of peptides and proteins, providing separation efficiencies up to two orders of magnitude greater than high performance liquid chromatography. The technique can also analyze a broad range of compounds, has a simple instrument design which can be automated, and has low sample volume requirements. In this study, a highly efficient and reproducible capillary zone electrophoresis method was developed to separate and identify a series of nine peptides of defense interest including bradykinin, leucine enkephalin, and oxytocin. The paper demonstrates three strategies which could be used in a fully automated field detection and identification system for unknown peptides.

  2. Determination of anions with an on-line capillary electrophoresis method; Anionien on-line maeaeritys kapillaarielektroforeesilla - MPKT 10

    Energy Technology Data Exchange (ETDEWEB)

    Siren, H.; Saerme, T.; Kotiaho, T.; Hiissa, T.; Savolahti, P.; Komppa, V. [VTT Chemical Technology, Espoo (Finland)

    1998-12-31

    The aim of the study was to set-up an on-line capillary electrophoresis method for determination of anions in process waters of pulp and paper industry with exporting the results to the process control system of the mill. The quantification is important, since it will give information about the possible causes of precipitation. In recent years, the capillary electrophoresis (CE) due to its high separation efficiency has been shown as a method to take into consideration when analyzing chemical species ranging from small inorganic anions to different macromolecules. Many compounds are not easily detected in their native state, why analysis methods must be developed to improve their detection. Especially, small inorganic and organic anions which do not have chromophores are not sensitive enough for direct-UV detection. In such analyses the anions are mostly detected with indirect-UV technique. Capillary electrophoresis instruments are used to analyze samples in off-line, which seldom represent the situation in process. Therefore, on-line instrument technology with autoanalyzing settings will be needed in quality control. The development of a fully automatic capillary electrophoresis system is underway in co-operation with KCL (The Finnish Pulp and Paper Research Institute). In our research, we have first concentrated on the determination of sulphate in waters of paper industry. The method used for detection of sulphate is based on indirect-UV detection with CE, where the background electrolyte (BGE) is an absorbing mixture of secondary amines. The whole procedure for quantification of sulphate is performed within 15 minutes, after which a new sample is analyzed automatically. The only sample pretreatment is filtration, which is necessary before analysis. The concentrations of sulphate in process waters tested were between 300 and 800 ppm. Our tests show that a simultaneous determination of chloride, sulphate, nitrate, nitrite, sulphite, carbonate and oxalate is also

  3. Determination of methicillin-resistant and methicillin-susceptible Staphylococcus aureus bacteria in blood by capillary zone electrophoresis

    OpenAIRE

    Horká, M. (Marie); Tesařová, M. (Marie); Karásek, P. (Pavel); Růžička, F.; Holá, V.; Sittová, M.; Roth, M

    2015-01-01

    We used capillary zone electrophoresis in supercritical water-etched and modified fused silica capillaries to separate methicillin-resistant and methicillin-susceptible Staphylococcus aureus bacteria from clinical samples of whole blood.

  4. Polymer mediated capillary electrophoresis with attenuated total reflectance infrared microspectroscopy detection

    International Nuclear Information System (INIS)

    Polymer mediated capillary electrophoresis (CE) using poly(diallyldimethylammonium chloride) (PDDAC) in the electrolyte with end-column single reflection attenuated total internal reflectance (ATR) Fourier transform infrared (FT-IR) microspectroscopy is presented. The terminus of the capillary is placed ∼1 μm from the internal reflectance element (IRE), at the focus of the ATR infrared microscope. Electrophoretic separations of benzenesulfonate, 1-naphthalenesulfonate and 1,5-naphthalenesulfonate in a NaCl and PDDAC electrolyte using either -11 or -15 kV are demonstrated with the CE-ATR FT-IR spectra providing identification of these compounds. Running electrolyte salt concentrations in the 0.85-1.7 M range are required due to the 50-80 mg mL-1 sample concentrations. Increasing the NaCl salt concentration improves peak resolution but also increases analysis time. A PDDAC concentration as low as 0.0075% can facilitate the separation of the aromatic sulfonates while maintaining reasonable electroosmotic flow. Etching of the germanium IRE by the applied current, which can affect the intensity of the infrared beam, is corrected by fabrication of a plastic mounting post for the IRE to prevent current conduction through the IR instrument

  5. DNA sequencing method using laser-induced fluorescence and capillary gel electrophoresis

    International Nuclear Information System (INIS)

    A postelectrophoresis capillary scanning method for increasing the throughput of DNA sequencing has been developed. The method features a spatially and temporally separated arrangement between capillary gel electrophoresis separation of DNA sequencing fragments and the visualization of the separation pattern. Fluorescently labeled DNA sequencing fragments are produced in enzymatic chain-termination reactions and separated by capillary with a transparent polymer coating. The capillary containing all bands of the fragments is then scanned longitudinally with laser beams. The DNA sequence is determined by analyzing the four-color band patterns. The innerwall of the capillary is coated with linear polyacrylamide. The capillary can be used repeatedly by refilling it with crosslinked polyacrylamide gel which can be easily removed out using a HPLC pump. Scanning time of less than 7 s has been achieved and a sequence of about 400 bases can be determined per scan.

  6. An integrated multiple capillary array electrophoresis system for high-throughput DNA sequencing

    Energy Technology Data Exchange (ETDEWEB)

    Lu, X.

    1998-03-27

    A capillary array electrophoresis system was chosen to perform DNA sequencing because of several advantages such as rapid heat dissipation, multiplexing capabilities, gel matrix filling simplicity, and the mature nature of the associated manufacturing technologies. There are two major concerns for the multiple capillary systems. One concern is inter-capillary cross-talk, and the other concern is excitation and detection efficiency. Cross-talk is eliminated through proper optical coupling, good focusing and immersing capillary array into index matching fluid. A side-entry excitation scheme with orthogonal detection was established for large capillary array. Two 100 capillary array formats were used for DNA sequencing. One format is cylindrical capillary with 150 {micro}m o.d., 75 {micro}m i.d and the other format is square capillary with 300 {micro}m out edge and 75 {micro}m inner edge. This project is focused on the development of excitation and detection of DNA as well as performing DNA sequencing. The DNA injection schemes are discussed for the cases of single and bundled capillaries. An individual sampling device was designed. The base-calling was performed for a capillary from the capillary array with the accuracy of 98%.

  7. Improved dual photometric-contactless conductometric detector for capillary electrophoresis

    International Nuclear Information System (INIS)

    A new design of a dual, UV photometric - contactless conductometric detector is described. The separation capillary with an optical window created is pressed onto two semitubular electrodes, 3 mm wide and 2 mm apart. The electrodes form the detection cell of the contactless conductometric detector. An optical fiber, placed in the gap between the conductometric electrodes, brings radiation from the source. The radiation that passes through the separation capillary is recorded by a large-area photodiode. The optical fiber and the photodiode operate the photometric cell which is between the conductometric electrodes. The detector thus permits simultaneous photometric and conductometric detection in the same place of the capillary, while exchanging of the separation capillary is easy and without effect on the detector geometry and performance

  8. Recent achievements in characterization of chiral helical molecules by capillary electrophoresis

    Czech Academy of Sciences Publication Activity Database

    Koval, Dušan; Růžička, Martin; Severa, Lukáš; Vávra, Jan; Reyes Gutierrez, Paul Eduardo; Teplý, Filip; Kašička, Václav

    Sao Bernardo do Campo: Grupo VLS Print Solution, 2015 - (Guzman, N.; Tavares, M.). s. 56 [LACE 2015. Latin-American Symposium on Biotechnology , Biomedical, Biopharmaceutical, and Industrial Applications of Capillary Electrophoresis and Microchip Technology /21./. 05.12.2015-08.12.2015, Cartagena] R&D Projects: GA ČR GA13-32974S; GA ČR(CZ) GA13-17224S; GA ČR GA13-19213S; GA ČR(CZ) GA15-01948S Institutional support: RVO:61388963 Keywords : helquats * chiral molecules * capillary electrophoresis Subject RIV: CB - Analytical Chemistry, Separation

  9. A New Dual-electrode and Multi-channel Electrochemical DetectionSystem for Capillary Electrophoresis

    Institute of Scientific and Technical Information of China (English)

    Bing Yi YANG; Jin Yuan MO; Rong LAI

    2004-01-01

    A new type of dual-electrode and multi-channel electrochemical detection technology for capillary electrophoresis is described in this paper. Two detectors(the amperometric detector and the conductometric detector)or two conductometric detectors are connected to the same capillary electrophoresis system. The whole system possesses the advantages of the two electrochemical detectors including sparing time,improving the analytical speed and expanding the sample range.The working electrode and detector cell are handled easily.The system was applied to sample detection with satisfactory results.

  10. Chiral Separation by Capillary Zone Electrophoresis Used Cyclodextrins and Their Derivatives as Chiral Selector

    Institute of Scientific and Technical Information of China (English)

    HOU; JingGuo

    2001-01-01

    Capillary zone electrophoresis (CZE) is a very pronising analytical technique for the optical isomer resolution of the compounds studied. The drawbacks of the techniques such as HPLC [1] were sophisticated stationary phases and/or the relatively high quantity of the chiral agent in the mobile phase, which do not exist in CZE. The capillary electrophoresis (CE) method can offer advantages on lower consumption of analyte and background electrolyte (BGE), shorter analysis time, and higher efficiencies [2-3]  ……

  11. Development of fully automated quantitative capillary electrophoresis with high accuracy and repeatability.

    Science.gov (United States)

    Xu, Yuan; Ling, Bang-Zan; Zhu, Wen-Jun; Yao, Dong; Zhang, Lin; Wang, Yan; Yan, Chao

    2016-03-01

    A quantitative capillary electrophoresis (qCE) was developed by utilizing a rotary type of nano-volume injector, an autosampler, and a thermostat with cooling capacity. The accuracy and precision were greatly improved compared with conventional capillary electrophoresis. The 10 nL volume accuracy was guaranteed by the carefully designed nano-injector with an accurate internal loop. The system repeatability (precision) in terms of RSD test sample. We believe that this fully automated qCE system has the potential to be employed broadly in quality control and quality assurance in the pharmaceutical industry. PMID:26174138

  12. Analysis of hydrosoluble organic chelating agents. Potentialities of capillary electrophoresis and ionic chromatography

    International Nuclear Information System (INIS)

    Capillary electrophoresis and ion exchange chromatography are good techniques for the determination of organic chelating agents as mono or poly-carboxylates. Ion exchange chromatography allows to obtain very high sensitivities (a few μg/L). Capillary electrophoresis generates practically none analytical waste; this technique is then very interesting for nuclear industry. This microanalysis technique has been here carried out for the determination of organic chelating agents in leaching water of an old waste for which an important release rate of radio-toxic metals had been found. Thus, formate and especially acetate ions have been correlated with this unusual behaviour

  13. New adventures in chiral separation of helical molecules by capillary electrophoresis

    Czech Academy of Sciences Publication Activity Database

    Koval, Dušan; Reyes Gutierrez, Paul Eduardo; Severa, Lukáš; Jirásek, Michael; Teplý, Filip; Kašička, Václav

    Natal: -, 2014. s. 80. [ITP & LACE 2014. International Symposium on Electro- and Liquid Phase-Separation Techniques /21./ and Latin-American Symposium on Biotechnology, Biomedical, Biopharmaceutical, and Industrial Applications of Capillary Electrophoresis and Microchip Technology /20./. 04.10.2014-08.10.2014, Natal] R&D Projects: GA ČR(CZ) GA13-17224S; GA ČR GA13-32974S; GA ČR GA13-19213S Institutional support: RVO:61388963 Keywords : helquats * capillary electrophoresis * chiral separation Subject RIV: CB - Analytical Chemistry, Separation

  14. On-line X-ray fluorescence detection for capillary electrophoresis separations

    International Nuclear Information System (INIS)

    In these investigations, capillary electrophoresis with on-line X-ray fluorescence detection (CE-XRF) has been demonstrated for the first time. The insertion of a polyethylene sample cell between fused-silica capillary segments enabled continuous XRF detection during electrophoresis with minimal additional band broadening. Detection limits in the 10-4 M range are currently feasible for the CE-XRF separation of metal complexes, and design advances will enhance detectability to the 10-5-10-6 M range, permitting studies of important environmental and biological samples

  15. Analysis and purification of biologically active peptides by capillary and free-flow electrophoresis

    Czech Academy of Sciences Publication Activity Database

    Kašička, Václav; Sázelová, Petra; Šolínová, Veronika; Koval, Dušan

    Olomouc: Palacký University, 2013 - (Blattná, J.; Horna, A.; Macka, M.). s. 46-46 ISBN 978-80-7395-546-5. [INDC 2013. International Nutrition and Diagnostics Conference /13./. 26.08.2013-29.08.2013, Olomouc] R&D Projects: GA ČR(CZ) GAP206/12/0453; GA ČR GA13-17224S Institutional support: RVO:61388963 Keywords : biopeptides * capillary electrophoresis * free-flow electrophoresis Subject RIV: CB - Analytical Chemistry, Separation

  16. Recent developments and applications of capillary and microchip electrophoresis in proteomic and peptidomic analyses

    Czech Academy of Sciences Publication Activity Database

    Štěpánová, Sille; Kašička, Václav

    2016-01-01

    Roč. 39, č. 1 (2016), s. 198-211. ISSN 1615-9306 R&D Projects: GA ČR(CZ) GA13-17224S; GA ČR(CZ) GA15-01948S Institutional support: RVO:61388963 Keywords : capillary electrophoresis * mass spectrometry * microchip electrophoresis * peptidomics * proteomics Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 2.737, year: 2014

  17. Assay of Histamine in Single Mast Cells by Capillary Zone Electrophoresis with Electrochemical Detection

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Capillary zone electrophoresis was employed for the analysis of histamine in single rat peritoneal mast cells using an amperometric detector. In this method, individual mast cells and then 0.02 mol/L NaOH as a lysing solution are injected into the front end of the separation capillary. A cell injector was constructed for easy injection of single cells. Histamine in single mast cells has been identified and quantified.

  18. Capillary electrophoresis and isoelectric focusing methods for diagnostics of diabetes and control of the therapy

    Czech Academy of Sciences Publication Activity Database

    Koval, Dušan; Kašička, Václav; Cottet, H.

    Riga: -, 2011. s. 46-46. [Conference of the Nordic Separation Science Society /6./. 24.08.2011-27.08.2011, Riga] R&D Projects: GA ČR(CZ) GA203/08/1428; GA ČR GP203/09/P485 Institutional research plan: CEZ:AV0Z40550506 Keywords : capillary electrophoresis * capillary isoelectric focusing * hemoglobin Subject RIV: CB - Analytical Chemistry, Separation

  19. Detecção eletroquímica em eletroforese capilar Electrochemical detection in capillary electrophoresis

    OpenAIRE

    José Alberto Fracassi da Silva

    2003-01-01

    This review focuses the development of electrochemical detection systems coupled to capillary electrophoresis. Conductometric, amperometric, voltametric, and potentiometric modes of detection are reviewed. The positioning of the electrodes, interferences of high electric field, and the materials employed in the fabrication and modification of the electrodes are discussed. The advantages of the use of electrochemical detection with capillary electrophoresis, regarding to the sensitivity and se...

  20. Separation and quantification of cellulases and hemicellulases by capillary electrophoresis

    DEFF Research Database (Denmark)

    Jørgensen, Henning; Kutter, Jörg Peter; Olsson, Lisbeth

    2003-01-01

    Cellulases and hemicellulases are two classes of enzymes produced by filamentous fungi and secreted into the cultivation medium. Both classes of enzymes consist of a subset of classes of which the fungi produce several enzymes with varying molecular mass and pI but similar enzymatic activities...... silica capillary at pH values close to neutral. The improvement of the separation of these six proteins by the addition of alpha, omega-diaminoalkanes with chain lengths from three to seven carbon units was investigated. Dynamically coating the capillary with 1,3-diaminopropane resulted in separation of...

  1. Assay of phenolic compounds in red wine by on-line combination of capillary isotachophoresis with capillary zone electrophoresis

    Czech Academy of Sciences Publication Activity Database

    Hamoudová, R.; Urbánek, Marek; Pospíšilová, M.; Polášek, M.

    2004-01-01

    Roč. 1032, 1-2 (2004), s. 281-287. ISSN 0021-9673 R&D Projects: GA MZd NL7689 Grant ostatní: GA FR VŠ(CZ) G6/2995/2003 Institutional research plan: CEZ:AV0Z4031919 Keywords : wine * food analysis * isotachophoresis * capillary zone electrophoresis Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 3.359, year: 2004

  2. Capillary electrophoresis of conidia from cultivated microscopic filamentous fungi

    Czech Academy of Sciences Publication Activity Database

    Horká, Marie; Růžička, F.; Kubesová, Anna; Holá, V.; Šlais, Karel

    2009-01-01

    Roč. 81, č. 10 (2009), s. 3997-4004. ISSN 0003-2700 R&D Projects: GA AV ČR IAAX00310701 Institutional research plan: CEZ:AV0Z40310501 Keywords : capillary electromigration techniques * optimization of the separation * microscopic filamentous fungi Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 5.214, year: 2009

  3. Nanospray interfacing for capillary electrophoresis-mass spectrometry

    Czech Academy of Sciences Publication Activity Database

    Foret, František; Křenková, Jana; Týčová, Anna; Klepárník, Karel

    Messina: Chromaleont S.r.L, 2016 - (Mondello, L.; Dugo, P.). s. 117-117 ISBN 978-88-941816-0-9. [ISCC /40./ and GC×GC Symposium /13./. 29.05.2016-03.06.2016, Riva del Garda] Institutional support: RVO:68081715 Keywords : CE/MS * microfabricated liquid junction/sprayer module * electrospray ionization * separation capillaries Subject RIV: CB - Analytical Chemistry, Separation

  4. Assessment of genetic diversity in Saccharum using SSR markers and capillary electrophoresis

    Science.gov (United States)

    This study was conducted to assess the genetic diversity amongst 12 Saccharum clones from 3 species using SSR markers and CE (capillary electrophoresis). Genomic DNA of 12 sugarcane cultivars was amplified with 19 SSR primer pairs. A total of 229 bands generated with a size range between 100 and 26...

  5. Transient isotachophoresis in carrier ampholyte-based capillary electrophoresis for protein analysis

    Czech Academy of Sciences Publication Activity Database

    Busnel, J. M.; Descroix, S.; Godfrin, D.; Hennion, M. C.; Kašička, Václav; Peltre, G.

    2006-01-01

    Roč. 27, č. 18 (2006), s. 3591-3598. ISSN 0173-0835 Institutional research plan: CEZ:AV0Z40550506 Keywords : carrier ampholyte-based capillary electrophoresis * transient isotachophoresis * proteins Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 4.101, year: 2006

  6. Characterization of the Interaction between Bovine Serum Albumin and Lomefloxacin by Capillary Zone Electrophoresis

    Institute of Scientific and Technical Information of China (English)

    Ming GUO; Qing Sen YU; Jian Wei YAN; Fei TAN; Guo Zheng MA

    2004-01-01

    Three capillary zone electrophoresis (CZE) methods of the frontal analysis (FA), vacancy peak (VP) and simplified Hummel-Dreyer (SHD) were applied to investigate interaction between bovine serum albumin (BSA) and lomefloxacin, the experimental condition was established after a large number of tests. Based on the site-binding model, the binding parameters were measured according to the site model by Scatchard.

  7. Gold Nanoparticles Enhanced Microchip Capillary Electrophoresis for Detection of Serum Lipoprotein

    Institute of Scientific and Technical Information of China (English)

    WANG Hua; WANG DaXin; CAO Li; CHEN Xia

    2009-01-01

    @@ We describe here the use of gold nanoparticles (AuNPs) in conjunction with chip-based capillary electrophoresis (CE) to improve the selectivity between lipoprotein fractions and increase the efficiency of the separation.AuNPs were added into the running buffer to manipulate solution and control the electroosmotic flow (EOF).

  8. Capillary Electrophoresis and Fluorescence Excitation-Emission Matrix Characterization of Soil Mobile and Calcium Humates

    Science.gov (United States)

    Capillary electrophoresis (CE) and Excitation-emission matrix (EEM) fluorescence spectroscopy have been used in natural organic matter (NOM) studies. The mutual relevance of data collected from each of the two methods provides novel insight into the correlation of complex NOM fluorescence spectra to...

  9. SIMULTANEOUS DTERMINATION OF CHROMATE AND AROMATIC HYDROCARBONS IN ENVIRONMENTAL SAMPLES BY CAPILLARY ELECTROPHORESIS

    Science.gov (United States)

    An analytical method was developed to determine simultaneously, the inorganic anion CrO2-4, and organic aromatic compounds including benzoate, 2-Cl-benzoate, phenol, m-cresol and o-/p-cresol by capillary electrophoresis (CE). Chromate and the aromatics were separated in a relativ...

  10. Capillary electrophoresis of FITC labeled amino acids with laser-induced fluorescence detection

    Institute of Scientific and Technical Information of China (English)

    党福全; 陈义

    1999-01-01

    FITC labeled amino acids have been separated using a home-huilt capillary electrophoresis with a laserinduced fluorescence detection (CE-LIF) system. Seventeen peaks can now be generated from the twenty common amino acids. The key conditions lie in the optimization of pH, buffer electrolytes and buffer additives.

  11. Capillary electrophoresis of the mycotoxin zearalenone using cyclodextrin-enhanced fluorescence

    Science.gov (United States)

    Certain of the cyclodextrins are capable of significantly enhancing the native fluorescence of the estrogenic mycotoxin zearalenone (ZEN). Twenty-two cyclodextrins (CDs) were screened for their ability to enhance the fluorescence of ZEN in a capillary electrophoresis-laser induced fluorescence (CE-...

  12. Determination of the specific activities of methionine sulfoxide reductase A and B by capillary electrophoresis

    Science.gov (United States)

    A capillary electrophoresis (CE) method for the determination of methionine sulfoxide reductase A and methionine sulfoxide reductase B activities in mouse liver is described. The method is based on detection of the 4-(dimethylamino)azobenzene-4’-sulfonyl derivative of L-methionine (dabsyl Met), the ...

  13. On-Line Multichannel Raman Spectroscopic Detection System For Capillary Zone Electrophoresis

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    An on-line multichannel Raman spectroscopic detection system for capillary electrophoresis was established by using an Ar+ laser and a cryogenically cooled ICCD. Resonant excitation Raman spectra of methyl red and methyl orange were employed to test the system. The result shows that it could yield on-line electrophoretogram and time series of Raman spectra.

  14. Study of Oxidation of Glutathione Treated with Hypochlorous Acid by Capillary Electrophoresis

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Capillary electrophoresis (CE) method was developed for the separation and quantification of reduced glutathione (GSH), oxidized glutathione (GSSG) and glutathione sulphonic acid (GSO3H). Baseline separation was obtained within five minutes. The effects of reaction time and molar ratio of hypochlorous acid (HOCI) to GSH on the oxidation of GSH were investigated.

  15. Disposable pen-shaped capillary gel electrophoresis cartridge for fluorescence detection of bio-molecules

    Science.gov (United States)

    Amirkhanian, Varoujan; Tsai, Shou-Kuan

    2014-03-01

    We introduce a novel and cost-effective capillary gel electrophoresis (CGE) system utilizing disposable pen-shaped gelcartridges for highly efficient, high speed, high throughput fluorescence detection of bio-molecules. The CGE system has been integrated with dual excitation and emission optical-fibers with micro-ball end design for fluorescence detection of bio-molecules separated and detected in a disposable pen-shaped capillary gel electrophoresis cartridge. The high-performance capillary gel electrophoresis (CGE) analyzer has been optimized for glycoprotein analysis type applications. Using commercially available labeling agent such as ANTS (8-aminonapthalene-1,3,6- trisulfonate) as an indicator, the capillary gel electrophoresis-based glycan analyzer provides high detection sensitivity and high resolving power in 2-5 minutes of separations. The system can hold total of 96 samples, which can be automatically analyzed within 4-5 hours. This affordable fiber optic based fluorescence detection system provides fast run times (4 minutes vs. 20 minutes with other CE systems), provides improved peak resolution, good linear dynamic range and reproducible migration times, that can be used in laboratories for high speed glycan (N-glycan) profiling applications. The CGE-based glycan analyzer will significantly increase the pace at which glycoprotein research is performed in the labs, saving hours of preparation time and assuring accurate, consistent and economical results.

  16. Interfacing capillary electrophoresis with inductively coupled plasma mass spectrometry by direct injection nebulization for selenium speciation

    DEFF Research Database (Denmark)

    Bendahl, Lars; Gammelgaard, Bente; Jons, O.;

    2001-01-01

    A demountable direct injection high efficiency nebulizer operating at low sample uptake rates was developed and used for coupling of capillary electrophoresis (CE) with inductively coupled plasma mass spectrometry (ICP-MS). When the nebulizer was used for continuous sample introduction, detection...

  17. Congophilicity (Congo red affinity) of different beta2-microglobulin conformations characterized by dye affinity capillary electrophoresis

    DEFF Research Database (Denmark)

    Heegaard, N H; Sen, J W; Nissen, Mogens Holst

    2000-01-01

    The amyloidogenic protein beta-microglobulin was characterized by affinity capillary electrophoresis (CE). CE could separate conformational variants of beta2-microglobulin and with the amyloid-specific dye Congo red as a buffer additive it was possible to measure different Congo red-affinities of...

  18. Advances in capillary electrophoresis : In-line preconcentration for biomedical analysis. Impurity profiling of heparin

    NARCIS (Netherlands)

    van der Hoorn, Y.H.

    2015-01-01

    Capillary electrophoresis (CE) has shown to be highly suitable for the analysis of polar and ionogenic compounds in biomedical and pharmaceutical samples. Separation with CE is based on the charge-to-size ratio of analytes. The application of CE for bioanalysis may be hindered by its relatively low

  19. Trace determination of perchlorate using electromembrane extraction and capillary electrophoresis with capacitively coupled contactless conductivity detection

    Czech Academy of Sciences Publication Activity Database

    Kiplagat, I.K.; Doan, T.K.O.; Kubáň, Pavel; Boček, Petr

    2011-01-01

    Roč. 32, č. 21 (2011), s. 3008-3015. ISSN 0173-0835 R&D Projects: GA ČR GAP206/10/1219 Institutional research plan: CEZ:AV0Z40310501 Keywords : electromembrane extraction * perchlorate * capillary electrophoresis Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 3.303, year: 2011

  20. Elimination of matrix effects in analyses of trace metabolites in body fluids by capillary electrophoresis

    Czech Academy of Sciences Publication Activity Database

    Křivánková, Ludmila

    Dubai : Eureka Science Ltd, 2008. -. [International Conference on Drug Design & Discovery /1./. 04.02.2008-07.02.2008, Dubai ] R&D Projects: GA AV ČR IAA400310703 Institutional research plan: CEZ:AV0Z40310501 Keywords : capillary zone electrophoresis * isotachophoresis * drugs and their metabolites Subject RIV: CB - Analytical Chemistry, Separation

  1. Urine Metabolite Profiling of Human Colorectal Cancer by Capillary Electrophoresis Mass Spectrometry Based on MRB

    Directory of Open Access Journals (Sweden)

    Jin-Lian Chen

    2012-01-01

    (P<0.05. Conclusion. The technique of capillary electrophoresis mass spectrometry based on MRB could reveal the significant metabolic alterations during progression of colorectal cancer, and the method is feasible and may be useful for the early diagnosis of colorectal cancer.

  2. Determination of acid dissociation constants of triazole fungicides by pressure assisted capillary electrophoresis

    Czech Academy of Sciences Publication Activity Database

    Konášová, R.; Jaklová Dytrtová, Jana; Kašička, Václav

    Ljubljana: National Institute of Chemistry, 2015 - (Vovk, I.; Glavnik, V.; Albreht, A.). s. 102 ISBN 978-961-6104-28-9. [ISSS 2015. International Symposium on Separation Sciences /21./. 30.06.2015-03.07.2015, Ljubljana] Institutional support: RVO:61388963 Keywords : solvent effect * stability constant * affinity capillary electrophoresis Subject RIV: CB - Analytical Chemistry, Separation

  3. Characterization of IHSS Natural Organic Matter by Capillary Electrophoresis and Flourescence Spectroscopy

    Science.gov (United States)

    Capillary electrophoresis (CE) and fluorescence spectroscopy have recently been used in natural organic matter (NOM) studies. In this study, we characterized fulvic acids (5), humic acids (6) and unprocessed NOM (2) samples obtained from the International Humic Substances Society (IHSS) using these ...

  4. Recent advances in combination of capillary electrophoresis with mass spectrometry: Methodology and theory

    Czech Academy of Sciences Publication Activity Database

    Klepárník, Karel

    2015-01-01

    Roč. 36, č. 1 (2015), s. 159-179. ISSN 0173-0835 R&D Projects: GA ČR(CZ) GA14-28254S Institutional support: RVO:68081715 Keywords : capillary electrophoresis * electrospray * mass spectrometry * Microfluidic devices Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 3.028, year: 2014

  5. Capillary electrophoresis study on phase of mixed micelles and its role in transport phenomena of particles

    Czech Academy of Sciences Publication Activity Database

    Oszwaldowski, S.; Kubáň, Pavel

    2015-01-01

    Roč. 864, March (2015), s. 85-93. ISSN 0003-2670 R&D Projects: GA ČR(CZ) GA13-05762S Institutional support: RVO:68081715 Keywords : capillary electrophoresis * mixed micelles * nanoparticles Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 4.513, year: 2014

  6. Capillary electrophoresis in an extended nanospray tip-electrospray as an electrophoretic column

    Czech Academy of Sciences Publication Activity Database

    Týčová, Anna; Foret, František

    2015-01-01

    Roč. 1388, APR (2015), s. 274-279. ISSN 0021-9673 R&D Projects: GA ČR(CZ) GBP206/12/G014 Institutional support: RVO:68081715 Keywords : mass spectrometry * interface * separation * capillary electrophoresis Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 4.169, year: 2014

  7. Capillary Electrophoresis and Fluorescence Excitation-Emission Matrix Spectroscopy for Characterization of Humic Substances

    Science.gov (United States)

    Capillary electrophoresis (CE) and fluorescence spectroscopy have been used in natural organic matter (NOM) studies. In this study, we characterized five fulvic acids, six humic acids and two unprocessed NOM samples obtained from the International Humic Substances Society (IHSS) using these two ana...

  8. Self-aligning subatmospheric hybrid liquid junction electrospray interface for capillary electrophoresis

    Czech Academy of Sciences Publication Activity Database

    Křenková, Jana; Klepárník, Karel; Grym, Jakub; Luksch, Jaroslav; Foret, František

    2016-01-01

    Roč. 37, č. 3 (2016), s. 414-417. ISSN 0173-0835 R&D Projects: GA ČR(CZ) GBP206/12/G014 Institutional support: RVO:68081715 Keywords : capillary electrophoresis * electrospray interfacing * microfabrication Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 3.028, year: 2014

  9. Comparison of capillary electrophoresis and high performance liquid chromatography methods for caffeine determination in decaffeinated coffee

    Directory of Open Access Journals (Sweden)

    Carolina Schaper Bizzotto

    2013-03-01

    Full Text Available Decaffeinated coffee accounts for 10 percent of coffee sales in the world; it is preferred by consumers that do not wish or are sensitive to caffeine effects. This article presents an analytical comparison of capillary electrophoresis (CE and high performance liquid chromatography (HPLC methods for residual caffeine quantification in decaffeinated coffee in terms of validation parameters, costs, analysis time, composition and treatment of the residues generated, and caffeine quantification in 20 commercial samples. Both methods showed suitable validation parameters. Caffeine content did not differ statistically in the two different methods of analysis. The main advantage of the high performance liquid chromatography (HPLC method was the 42-fold lower detection limit. Nevertheless, the capillary electrophoresis (CE detection limit was 115-fold lower than the allowable limit by the Brazilian law. The capillary electrophoresis (CE analyses were 30% faster, the reagent costs were 76.5-fold, and the volume of the residues generated was 33-fold lower. Therefore, the capillary electrophoresis (CE method proved to be a valuable analytical tool for this type of analysis.

  10. Constant pressure-assisted head-column field-amplified sample injection in combination with in-capillary derivatization for enhancing the sensitivity of capillary electrophoresis.

    Science.gov (United States)

    Yan, Na; Zhou, Lei; Zhu, Zaifang; Zhang, Huige; Zhou, Ximin; Chen, Xingguo

    2009-05-15

    In this work, a novel method combining constant pressure-assisted head-column field-amplified sample injection (PA-HC-FASI) with in-capillary derivatization was developed for enhancing the sensitivity of capillary electrophoresis. PA-HC-FASI uses an appropriate positive pressure to counterbalance the electroosmotic flow in the capillary column during electrokinetic injection, while taking advantage of the field amplification in the sample matrix and the water of the "head column". Accordingly, the analytes were stacked at the stationary boundary between water and background electrolyte. After 600s PA-HC-FASI, 4-fluoro-7-nitro-2,1,3-benzoxadiazole as derivatization reagent was injected, followed by an electrokinetic step (5kV, 45s) to enhance the mixing efficiency of analytes and reagent plugs. Standing a specified time of 10min for derivatization reaction under 35 degrees C, then the capillary temperature was cooled to 25 degrees C and the derivatives were immediately separated and determined under 25 degrees C. By investigating the variables of the presented approach in detail, on-line preconcentration, derivatization and separation could be automatically operated in one run and required no modification of current CE commercial instrument. Moreover, the sensitivity enhancement factor of 520 and 800 together with the detection limits of 16.32 and 6.34pg/mL was achieved for model compounds: glufosinate and aminomethylphosphonic acid, demonstrating the high detection sensitivity of the presented method. PMID:19342058

  11. Gel versus capillary electrophoresis genotyping for categorizing treatment outcomes in two anti-malarial trials in Uganda

    OpenAIRE

    Hubbard Alan E; Dorsey Grant; Gupta Vinay; Rosenthal Philip J; Greenhouse Bryan

    2010-01-01

    Abstract Background Molecular genotyping is performed in anti-malarial trials to determine whether recurrent parasitaemia after therapy represents a recrudescence (treatment failure) or new infection. The use of capillary instead of agarose gel electrophoresis for genotyping offers technical advantages, but it is unclear whether capillary electrophoresis will result in improved classification of anti-malarial treatment outcomes. Methods Samples were genotyped using both gel and capillary elec...

  12. Technology to accelerate pangenomic scanning for unknown point mutations in exonic sequences: cycling temperature capillary electrophoresis (CTCE

    Directory of Open Access Journals (Sweden)

    Bjørheim Jens

    2007-08-01

    Full Text Available Abstract Background Rapid means to discover and enumerate unknown mutations in the exons of human genes on a pangenomic scale are needed to discover the genes carrying inherited risk for common diseases or the genes in which somatic mutations are required for clonal diseases such as atherosclerosis and cancers. The method of constant denaturing capillary electrophoresis (CDCE permitted sensitive detection and enumeration of unknown point mutations but labor-intensive optimization procedures for each exonic sequence made it impractical for application at a pangenomic scale. Results A variant denaturing capillary electrophoresis protocol, cycling temperature capillary electrophoresis (CTCE, has eliminated the need for the laboratory optimization of separation conditions for each target sequence. Here are reported the separation of wild type mutant homoduplexes from wild type/mutant heteroduplexes for 27 randomly chosen target sequences without any laboratory optimization steps. Calculation of the equilibrium melting map of each target sequence attached to a high melting domain (clamp was sufficient to design the analyte sequence and predict the expected degree of resolution. Conclusion CTCE provides practical means for economical pangenomic detection and enumeration of point mutations in large-scale human case/control cohort studies. We estimate that the combined reagent, instrumentation and labor costs for scanning the ~250,000 exons and splice sites of the ~25,000 human protein-coding genes using automated CTCE instruments in 100 case cohorts of 10,000 individuals each are now less than U.S. $500 million, less than U.S. $500 per person.

  13. Capillary electrophoresis with contactless conductivity detection coupled to a sequential injection analysis manifold for extended automated monitoring applications

    International Nuclear Information System (INIS)

    A capillary electrophoresis (CE) instrument with capacitively coupled contactless conductivity detection (C4D) based on a sequential injection analysis (SIA) manifold was refined. Hydrodynamic injection was implemented to avoid a sampling bias by using a split-injection device based on a needle valve for precise adjustment. For safety and reliability, the integrity of the high voltage compartment at the detection end was fully maintained by implementing flushing of the high voltage interface through the capillary. With this set-up, extended fully automated monitoring applications are possible. The system was successfully tested in the field for the determination of the concentration levels of major inorganic cations and anions in a creek over a period of 5 days.

  14. Affinity chromatography and capillary electrophoresis for analysis of the yeast ribosomal proteins

    Directory of Open Access Journals (Sweden)

    Miriam S. Goyder

    2012-04-01

    Full Text Available We present a top down separation platform for yeast ribosomalproteins using affinity chromatography and capillary electrophoresiswhich is designed to allow deposition of proteins ontoa substrate. FLAG tagged ribosomes were affinity purified, andrRNA acid precipitation was performed on the ribosomes followedby capillary electrophoresis to separate the ribosomalproteins. Over 26 peaks were detected with excellent reproducibility(<0.5% RSD migration time. This is the first reportedseparation of eukaryotic ribosomal proteins using capillaryelectrophoresis. The two stages in this workflow, affinity chromatographyand capillary electrophoresis, share the advantagesthat they are fast, flexible and have small sample requirementsin comparison to more commonly used techniques. This methodis a remarkably quick route from cell to separation that hasthe potential to be coupled to high throughput readout platformsfor studies of the ribosomal proteome. [BMB reports2012; 45(4: 233-238

  15. Development of capillary zone electrophoresis-mass spectrometry

    International Nuclear Information System (INIS)

    Recently we described the first on-line combination of CZE with mass spectrometry, which also represented the first reported direct combination of any electrophoretic separation technique with mass spectrometry. This development was based upon the recognition that both ends of the CZE capillary did not have to be immersed in buffer reservoirs, as conventionally practiced. This provided a basis for new detection methods in which the electro-osmotically induced flow could be analyzed at the column terminus. The strong electro-osmotic flow in CZE, which results from the strong zeta potential of most amenable capillary surfaces, is sufficiently large under many conditions to result in elution of ions having both positive and negative electrophoretic mobilities in a single separation. Nonaqueous buffers also allow compounds to be separated which are somewhat less polar than feasible in aqueous systems, effectively providing a range of applications which should overlap with those of SFC

  16. Capillary electrophoresis: Biotechnology for separation of DNA and chromosomes

    Science.gov (United States)

    Williams, George O., Jr.

    1994-01-01

    Electrophoresis has been used for the separation of particles, ions, and molecules for a number of years. The technology for separation and detection of the results has many applications in the life sciences. One of the major goals of the scientific community is to separate DNA molecules and intact chromosomes based upon their different lengths or number of base pairs. This may be achieved by using some of the commercially available and widely used methods, but these processes require a considerable amount of time. The challenge is to achieve separation of intact chromosomes in a short time, preferably in a matter of minutes.

  17. Staining Method for Protein Analysis by Capillary Gel Electrophoresis

    OpenAIRE

    Wu, Shuqing; Lu, Joann J; Wang, Shili; Peck, Kristy L.; Li, Guigen; Liu, Shaorong

    2007-01-01

    A novel staining method and the associated fluorescent dye were developed for protein analysis by capillary SDS-PAGE. The method strategy is to synthesize a pseudo-SDS dye and use it to replace some of the SDS in SDS–protein complexes so that the protein can be fluorescently detected. The pseudo-SDS dye consists of a long, straight alkyl chain connected to a negative charged fluorescent head and binds to proteins just as SDS. The number of dye molecules incorporated with a protein depends on ...

  18. A Novel Polybrene/Chondroitin Sulfate C Double Coated Capillary and Its Application in Capillary Electrophoresis

    Institute of Scientific and Technical Information of China (English)

    DU,Ying-Xiang(杜迎翔); HONDA,Susumu; TAGA,Atsushi; LIU,Wen-Ying(刘文英); SUZUKI,Shigeo

    2002-01-01

    A new capillary coated by double polymer, polybrene/chondroitin sulfate C (P/CC), was developed using a simple procedure. The P/CC double coated capillary showed long lifetime,strong chemical stability and good reproducibility. It endured during more than 100 replicated analyses and was also tolerant to HCl (1 mol/L), NaOH (0.01 mol/L), CH3OH and CH3CN. The P/CC double coated capillary can be applied to basic drug analyses. The adsorption of basic drugs to the capillary wall was suppressed and the peak tailing greatly decreased. The use of the P/CC double coated capillary allowed excelent separation of the enantiomers of some basic drugs by using chondroitin sulfate C as the chiral selector, ami the peak symmetry of basic drugs was further improved under these conditions.

  19. Alignment of capillary electrophoresis-mass spectrometry datasets using accurate mass information.

    Science.gov (United States)

    Nevedomskaya, Ekaterina; Derks, Rico; Deelder, André M; Mayboroda, Oleg A; Palmblad, Magnus

    2009-12-01

    Capillary electrophoresis-mass spectrometry (CE-MS) is a powerful technique for the analysis of small soluble compounds in biological fluids. A major drawback of CE is the poor migration time reproducibility, which makes it difficult to combine data from different experiments and correctly assign compounds. A number of alignment algorithms have been developed but not all of them can cope with large and irregular time shifts between CE-MS runs. Here we present a genetic algorithm designed for alignment of CE-MS data using accurate mass information. The utility of the algorithm was demonstrated on real data, and the results were compared with one of the existing packages. The new algorithm showed a significant reduction of elution time variation in the aligned datasets. The importance of mass accuracy for the performance of the algorithm was also demonstrated by comparing alignments of datasets from a standard time-of-flight (TOF) instrument with those from the new ultrahigh resolution TOF maXis (Bruker Daltonics). PMID:19826795

  20. The development of expeditious and high efficient separation method of trivalent actinides using capillary electrophoresis

    International Nuclear Information System (INIS)

    It has been recognized that separation of trivalent actinides is difficult because their chemical properties are very similar. We have been studied the rapid separation of Am, Cm and Cf by means of capillary electrophoresis (CE). The separation using α-HIBA as a ligand were examined for the various conditions such as pH, length of capillary, and inner diameter of capillary, flow rate to transport, and chemical condition at inner wall capillary. We have previously got the result that the trivalent ion radius of Am and Cm were not lined up the tendency of the lanthanides when we plotted the mobility against the trivalent ion radius. To advance the repeatability, we have been tried to upgrade the injection and the fraction method of CE. We report the automation of fraction preparative isolation and the result of separation of Am, Cm and Cf. (author)

  1. Optimization of electric field strength for DNA sequencing in capillary gel electrophoresis

    Science.gov (United States)

    Luckey, John A.; Smith, Lloyd M.

    1993-06-01

    Since its development, capillary gel electrophoresis has demonstrated the ability to separate DNA sequencing reactions at speeds roughly 25 times as great as conventional slab gel electrophoresis. These increased speeds are the result of using the more efficient dissipation of Joule heating by capillaries. However, to date there have been no studies which quantitate the advantages of disadvantages in operating these gels at high electric field strength. This work addresses this question by investigating the band-broadening of DNA sequencing reactions as they are separated through a fixed distance of gel at field strengths ranging from 50 V/cm to 400 V/cm. It is found that the bandwidths of DNA fragments do decrease with the higher field strengths due to a reduction in diffusional broadening. However, at sufficiently high electric field strengths, the bands begin to broaden again under the influence of an increasing thermal gradient across the diameter of the capillary. The result is an optimum electric field strength in the intermediate range of 100 - 250 V/cm depending on the length of fragments being separated. The relative importance of diffusion and thermal gradients are discussed and used to generate an equation that models the observed band broadening of DNA in capillary gel electrophoresis (CGE).

  2. Gel versus capillary electrophoresis genotyping for categorizing treatment outcomes in two anti-malarial trials in Uganda

    Directory of Open Access Journals (Sweden)

    Hubbard Alan E

    2010-01-01

    Full Text Available Abstract Background Molecular genotyping is performed in anti-malarial trials to determine whether recurrent parasitaemia after therapy represents a recrudescence (treatment failure or new infection. The use of capillary instead of agarose gel electrophoresis for genotyping offers technical advantages, but it is unclear whether capillary electrophoresis will result in improved classification of anti-malarial treatment outcomes. Methods Samples were genotyped using both gel and capillary electrophoresis from randomized trials of artemether-lumefantrine (AL vs. dihydroartemisinin-piperaquine (DP performed in two areas of Uganda: Kanungu, where transmission is moderate, and Apac, where transmission is very high. Both gel and capillary methods evaluated polymorphic regions of the merozoite surface protein 1 and 2 and glutamine rich protein genes. Results Capillary electrophoresis detected more alleles and provided higher discriminatory power than agarose gel electrophoresis at both study sites. There was only moderate agreement between classification of outcomes with the two methods in Kanungu (kappa = 0.66 and poor agreement in Apac (kappa = 0.24. Overall efficacy results were similar when using gel vs. capillary methods in Kanungu (42-day risk of treatment failure for AL: 6.9% vs. 5.5%, p = 0.4; DP 2.4% vs. 2.9%, p = 0.5. However, the measured risk of recrudescence was significantly higher when using gel vs. capillary electrophoresis in Apac (risk of treatment failure for AL: 17.0% vs. 10.7%, p = 0.02; DP: 8.5% vs. 3.4%, p = 0.03. Risk differences between AL and DP were not significantly different whether gel or capillary methods were used. Conclusions Genotyping with gel electrophoresis overestimates the risk of recrudescence in anti-malarial trials performed in areas of high transmission intensity. Capillary electrophoresis provides more accurate outcomes for such trials and should be performed when possible. In areas of moderate transmission

  3. Coupling Immobilized Alkaline Phosphatase-based Automated Diagonal Capillary Electrophoresis to Tandem Mass Spectrometry for Phosphopeptide Analysis

    OpenAIRE

    Mou, Si; Sun, Liangliang; Wojcik, Roza; Dovichi, Norman J.

    2013-01-01

    Automated diagonal capillary electrophoresis is a two-dimensional separation method that incorporates an immobilized enzyme reactor at the distal end of the first capillary and employs identical electrophoretic separation modes in both dimensions. Components undergo a preliminary separation in the first capillary. Fractions are parked in the reactor where some components undergo transformation. The fractions are then periodically transferred to the second capillary and replaced by the next co...

  4. Advances in Automation and Throughput of the Mars Organic Analyzer Microchip Capillary Electrophoresis System

    Science.gov (United States)

    Haldeman, B. J.; Skelley, A. M.; Scherer, J. R.; Jayarajah, C.; Mathies, R. A.

    2005-12-01

    We have previously demonstrated the design, construction and testing of a portable microchip capillary electrophoresis (CE) instrument called the Mars Organic Analyzer (MOA) for analysis of amino acids and amine containing organic molecules (1). This instrument is designed to accept organic compounds isolated from samples by sublimation or by subcritical water extraction, to label the amine groups with fluorescamine, and to perform high resolution electrophoretic analysis. The CE instrument has shown remarkable robustness during successful field tests last year in the Panoche Valley, CA (1) and more recently in the Atacama Desert, Chile (2). For successful operation on Mars, however, it is necessary to operate autonomously and to analyze large numbers of samples, blanks, and standards. Toward this end we present here two advances in the MOA system that test key aspects of an eventual flight prototype. First, we have developed an automated microfluidic system and method for the autonomous loading, running and cleaning of the CE chip on the single channel MOA instrument. The integration of microfabricated PDMS valves and pumps with all-glass separation channels in a multilayer design enabled creation of structures for complex fluidic routing. Twenty sequential analyses of an amino acid standard were performed with an automated cleaning procedure between runs. In addition, dilutions were performed on-chip, and blanks were run to demonstrate the elimination of carry-over from run to run. These results demonstrate an important advance of the technology readiness level of the MOA. Second, we have designed, constructed and successfully tested a lab version of the multichannel instrument we initially proposed for the MSL opportunity. The portable Multi-Channel Mars Organic Analyzer (McMOA, 25 by 30 by 15 cm), was designed to sequentially interrogate eight radially oriented CE separation channels on a single wafer. Since each channel can be used to analyze 20 or more

  5. Quantitation of Leishmania lipophosphoglycan repeat units by capillary electrophoresis.

    Science.gov (United States)

    Barron, Tamara L; Turco, Salvatore J

    2006-04-01

    The glycosylphosphatidylinositol (GPI)-anchored lipophosphoglycan (LPG) of Leishmania is the dominant cell surface glycoconjugate of these pathogenic parasites. LPG is structurally characterized by a series of phosphoglycan repeat units. Determining the number of repeat units per LPG molecule has proven difficult using current technologies, such as mass spectrometry. As an alternative method to quantitate the number of repeat units in LPG, a procedure based on capillary electrophoretic analysis of the proportion of mannose to 2,5-anhydromannose (derived from the nonacetylated glucosamine of the GPI anchor of LPG) was developed. The CE-based technique is sensitive and relatively rapid compared to GC-MS-based protocols. Its application was demonstrated in quantitating the number of LPG repeat units from several species of Leishmania as well as from two life-cycle stages of these organisms. PMID:16310310

  6. Application of capillary and free-flow electrophoresis in the development of peptide-based pharmaceuticals

    Czech Academy of Sciences Publication Activity Database

    Kašička, Václav; Koval, Dušan; Šolínová, Veronika; Sázelová, Petra; Barth, Tomislav; Hlaváček, Jan; Slaninová, Jiřina

    Bratislava: Slovak University of Technology, 2008 - (Sádecká, J.), L09/1-L09/4 ISSN 1335-5236. [International Conference Analytical Methods and Human Health /17./. Nový Smokovec (SK), 20.10.2008-23.10.2008] R&D Projects: GA ČR(CZ) GA203/06/1044; GA ČR GA203/08/1428 Institutional research plan: CEZ:AV0Z40550506 Keywords : capillary electrophoresis * free-flow electrophoresis * peptide-based pharmaceuticals Subject RIV: CB - Analytical Chemistry, Separation

  7. Determination of iodide in samples with complex matrices by hyphenation of capillary isotachophoresis and zone electrophoresis

    Czech Academy of Sciences Publication Activity Database

    Pantůčková, Pavla; Urbánek, Marek; Křivánková, Ludmila

    Olomouc: Palacký University, 2007 - (Petr, J.; Znaleziona, J.; Ranc, V.; Vítková, K.). s. 134 ISBN 978-80-244-1705-9. [Advances in Chromatography and Electrophoresis 2007 & CHIRANAL 2007. 24.06.2007-27.06.2007, Olomouc] R&D Projects: GA ČR GA203/05/2106; GA AV ČR IAA400310703 Institutional research plan: CEZ:AV0Z40310501 Keywords : hyphenation of capillary isotachophoresis and zone electrophoresis * iodide Subject RIV: CB - Analytical Chemistry, Separation

  8. Capillary electrophoresis employed for quantitative characterization of peptide interactions with small ions and cyclodextrins

    Czech Academy of Sciences Publication Activity Database

    Kašička, Václav; Ehala, Sille; Šolínová, Veronika; Schimperková, Tereza; Sázelová, Petra; Koval, Dušan; Makrlík, E.

    Olomouc : Palacký University Olomouc, 2010, s. 37-38. ISBN 978-80-244-2470-5. - (Acta Universitatis Palackianae Olomucensis Facultas Rerum Naturalium. Chemica. 47S). [International Symposium Advances in Chromatography and Electrophoresis & Chiranal 2010. Olomouc (CZ), 08.02.2010-11.02.2010] R&D Projects: GA ČR(CZ) GA203/08/1428; GA ČR(CZ) GA203/09/0675 Institutional research plan: CEZ:AV0Z40550506 Keywords : capillary affinity electrophoresis * valinomycin * peptide interactions Subject RIV: CB - Analytical Chemistry, Separation

  9. Study of DNA oligonucleotides interactions with ethidium bromide by partial-filling affinity capillary electrophoresis

    Czech Academy of Sciences Publication Activity Database

    Růžička, Martin; Koval, Dušan; Kašička, Václav

    Olomouc: Palacký University, 2014 - (Maier, V.; Ševčík, J.), s. 194-195 ISBN 978-80-244-3950-1. ISSN 0232-0061. [Advances in Chromatography and Electrophoresis & Chiranal 2014. Olomouc (CZ), 10.02.2014-14.02.2014] R&D Projects: GA ČR(CZ) GAP206/12/0453; GA ČR(CZ) GA13-17224S; GA ČR GA13-32974S Institutional support: RVO:61388963 Keywords : affinity capillary electrophoresis * binding constant * oligonucleotide Subject RIV: CB - Analytical Chemistry, Separation

  10. A validated capillary electrophoresis method for simultaneous determination of ezetimibe and atorvastatin in pharmaceutical formulations

    OpenAIRE

    AlShehri, Mona M.

    2011-01-01

    A simple, precise, and sensitive capillary electrophoresis technique coupled with a diode array detector has been developed for the separation and simultaneous determination of ezetimibe and atorvastatin in pharmaceutical formulations. Separation of both ezetimibe and atorvastatin was achieved utilizing fused silica capillary (58 cm × 75 μm ID) and background electrolyte solution that consisted of phosphate buffer (2.5 mM, pH 6.7): methanol (70:30 v/v). The proposed method was validated by te...

  11. Determination of acid dissociation constant of 20 coumarin derivatives by capillary electrophoresis using the amine capillary and two different methodologies.

    Science.gov (United States)

    Nowak, Paweł Mateusz; Woźniakiewicz, Michał; Piwowarska, Monika; Kościelniak, Paweł

    2016-05-13

    In this work capillary electrophoresis has been used to determine acid dissociation constant of 20 structurally diverse coumarin derivatives. For a majority of compounds pKa value has been determined for the first time. The obtained values vary between 4.16-9.10pH unit, pointing to the interesting structure-acidity relationships. The amine permanently coated capillary has been applied for that purpose, because it has turned out to be more effective in pKa determination than the bare silica and other coated capillaries, ensuring good precision and shorter migration times. A traditional methodology relying on measurements in a broad pH range and fitting of a sigmoidal function has been compared to an alternative simplified approach, reported for the first time, where only two electrophoretic mobility values suffice for pKa estimation. The first value corresponds to the partially ionized form and it is measured experimentally, while the second one to the totally ionized form - it is measured experimentally (two-values method) or estimated directly from molecular mass (one-value method). We show that despite a limited measurements number, the alternative approach may be consistent with the traditional methodology, yielding the relatively low pKa deviation. Its reliability has also been confirmed by the analytical predictions, comprising resolution, migration order, migration times and peaks overlapping. Therefore, combination of the amine capillary with the simplified calculation method is an attractive tool for fast and reliable pKa estimation. PMID:27083264

  12. Determination of phenolic acids in olive oil by capillary electrophoresis.

    Science.gov (United States)

    Buiarelli, Francesca; Di Berardino, Sonia; Coccioli, Franco; Jasionowska, Renata; Russo, Mario Vincenzo

    2004-01-01

    A CZE method for the separation and quantitation of phenolic acids (cinnamic, syringic, p-coumaric, vanillic, caffeic, 3,4-dihydroxyphenylacetic, protocatechuic), extracted from extra virgin olive oil, was developed. The sample preparation involved the LLE and SPE extraction methods. CE separation was performed in a fused silica capillary of I.D.= 50microm using as a BGE 40 mM borate buffer at pH=9.2. The separation voltage was 18kV with corresponding current of 27-28 microA. Detection was accomplished with UV-detector at lambda=200nm. The proposed method was fully validated. A good repeatability of migration time (RSD% ranged from 0.81 to 1.63) and of corrected peak area (RSD% from 2.89 to 5.77) was obtained. The linearity of detector response in the range from 5 to 50 ppm was checked, obtaining the correlation coefficient R2 values in the range: 0.9919-0.9997. Some phenolic acids in real oil samples were detected and quantified with the proposed method. PMID:15506620

  13. Analysis of flavonoids by capillary zone electrophoresis with electrokinetic supercharging.

    Science.gov (United States)

    Zhong, Hao; Yao, Qingqiang; Breadmore, Michael C; Li, Yumei; Lu, Yuanqi

    2011-11-01

    On-line concentration via Electrokinetic Supercharging (EKS) was used to enhance the sensitivity of the capillary electrophoretic separation of the four flavonoids naringenin, hesperetin, naringin and hesperidin. Separation conditions, including the background electrolyte pH and concentration, the length and choice of terminator and the electrokinetic injection time were optimized. The optimum conditions were: a background electrolyte of 30 mM sodium tetraborate (pH 9.5) containing 5% (v/v) of methanol, electrokinetic injection of the sample (130 s, -10 kV) followed by hydrodynamic injecting of 100 mM 2-(cyclohexylamino)ethanesulfonic acid (CHES) (17 s, 0.5 psi) as terminator, and separation with -20 kV. Under these conditions the four flavonoids could be separated with a sample-to-sample time of 15 min and detection limits from 2.0 to 6.8 ng mL(-1). When compared to a conventional hydrodynamic injection the sensitivity was enhanced between 824 and 1515 times which is 7.6-16 times higher than other CE methods for the on-line concentration of flavonoids. The applicability of the developed method was demonstrated by the detection of the four flavonoids in an aqueous extract of Clematis hexapetala pall. PMID:21949941

  14. Ultrafast Capillary Electrophoresis Isolation of DNA Aptamer for the PCR Amplification-Based Small Analyte Sensing

    Directory of Open Access Journals (Sweden)

    Emmanuelle eFiore

    2015-08-01

    Full Text Available Here, we report a new homogeneous DNA amplification-based aptamer assay for small analyte sensing. The aptamer of adenosine chosen as the model analyte was split into two fragments able to assemble in the presence of target. Primers were introduced at extremities of one fragment in order to generate the amplifiable DNA component. The amount of amplifiable fragment was quantifiable by Real-Time Polymerase Chain Reaction (RT-PCR amplification and directly reliable on adenosine concentration. This approach combines the very high separation efficiency and the homogeneous format (without immobilization of capillary electrophoresis and the sensitivity of real time PCR amplification. An ultrafast isolation of target-bound split aptamer (60 s was developed by designing a capillary electrophoresis input/ouput scheme. Such method was successfully applied to the determination of adenosine with a LOD of 1 µM.

  15. Simultaneous determination of five flavonoids in saussurea involucrata by capillary electrophoresis

    International Nuclear Information System (INIS)

    A method of determination of five flavonoids in Saussurea involucrata by beta-cyclodextrin modified capillary zone electrophoresis has been developed.The effects of buffer pH and buffer concentration, applied voltage and beta-CD concentrations on the separation were systematically investigated. The optimum condition providing baseline separation of all compounds within 8 min was obtained in the 20 mmol per liter borax buffer (pH 9.2), 20 kV applied voltage and 8 mmol per liter beta-CD. The linearity, detection limits, limits of quantification, reproducibility and recovery were satisfactory. The beta-cyclodextrin modified capillary zone electrophoresis method proposed here has been satisfactorily employed to analyze S. involucrate samples. (author)

  16. Ultrafast Capillary Electrophoresis Isolation of DNA Aptamer for the PCR Amplification-Based Small Analyte Sensing

    Science.gov (United States)

    Fiore, Emmanuelle; Dausse, Eric; Dubouchaud, Hervé; Peyrin, Eric; Ravelet, Corinne

    2015-08-01

    Here, we report a new homogeneous DNA amplification-based aptamer assay for small analyte sensing. The aptamer of adenosine chosen as the model analyte was split into two fragments able to assemble in the presence of target. Primers were introduced at extremities of one fragment in order to generate the amplifiable DNA component. The amount of amplifiable fragment was quantifiable by Real-Time Polymerase Chain Reaction (RT-PCR) amplification and directly reliable on adenosine concentration. This approach combines the very high separation efficiency and the homogeneous format (without immobilization) of capillary electrophoresis and the sensitivity of real time PCR amplification. An ultrafast isolation of target-bound split aptamer (60 s) was developed by designing a capillary electrophoresis input/ouput scheme. Such method was successfully applied to the determination of adenosine with a LOD of 1 µM.

  17. A New Immunoassay Method by Capillary Electrophoresis with Enhanced Chemiluminescence Detection

    Institute of Scientific and Technical Information of China (English)

    Jiao Ning WANG; Ji Cun REN

    2005-01-01

    This paper described a new immunoassay method by capillary electrophoresis with enhanced chemiluminescence (CL) detection system based on luminol-hydrogen peroxide reaction catalyzed by horseradish peroxides (HRP). Using para-iodophenol as a CL enhancer, the detection limit of about 1×10-12 mol/L for HRP was achieved, which corresponded to 1.32×10-5U/mL. In optimal conditions, the free HRP-labeled CA125 antibody (Ab*) and the bound enzyme-labeled complex (Ab*-Ag) were well separated by capillary electrophoresis within 4 min.The assay was successfully used to determine the contents of CA125 in human sera, which were associated with ovarian cancer, and the recoveries of the standard addition experiments were 96 to109 %.

  18. Electrospray ionization phenomena and the interface of capillary electrophoresis and mass spectrometry

    International Nuclear Information System (INIS)

    Recently a new electrospray ionization interface for capillary electrophoresis-mass spectroscopy (CE-MS) has been developed. The interface uses a sheath flow of liquid to make electrical contact at the CZE terminus, thus defining both the CZE and electrospray field gradients. Ions created by the ESI process are sampled through a 1 mm nozzle into a region mechanically pumped at 50 L/s using a single-stage roots blower. The ions entering this region are sampled through a 2 mm dia skimmer orifice located 0.5 cm behind the nozzle orifice. Ions passing through the skimmer enter a radio frequency focusing quadrupole. This region is pumped by a cryopump. A mixture of four quaternary phosphonium salts is used to illustrate capillary electrophoresis separations with mass spectroscopy and their uses. 2 figs

  19. Effect of Separation Temperature on Structure Specific Glycan Migration in Capillary Electrophoresis.

    Science.gov (United States)

    Guttman, Andras; Kerekgyarto, Marta; Jarvas, Gabor

    2015-12-01

    Temperature dependent differential migration shifts were studied in capillary electrophoresis between linear (maltooligosaccharides) and branched (sialylated, neutral and core fucosylated biantennary IgG glycans) carbohydrates. Background electrolytes without as well as with low and high molecular weight additives (ethylene glycol, linear polyacrylamide and poly(ethylene oxide)) were investigated for this phenomena in the temperature range of 20-50 °C. Glucose unit (GU) value shifts were observed with increasing temperature for the all IgG glycans both in additive-free and additive-containing background electrolytes, emphasizing the importance of tight temperature control during glycosylation analysis by capillary electrophoresis. The activation energy concept was applied to understand the structure specific electrophoretic migration of the different sugar molecules. Activation energy values were derived from the slopes of the Arrhenius plots of logarithmic mobility vs reciprocal absolute temperature and compared for the linear and branched sugars as well as for the various background electrolyte additives. PMID:26544759

  20. Capillary electrophoresis as a tool for screening aptamer with high affinity and high specificity to ricin

    Institute of Scientific and Technical Information of China (English)

    TANG Jijun; XIE Jianwei; SHAO Ningsheng; GUO Lei; YAN Yan

    2007-01-01

    Aptamers which specifically recognize target sare selected from random oligonucleotide library using systematic evolution of ligands by exponential enrichment(SELEX). In this paper, capillary electrophoresis (CE) as a separation approach has been introduced to SELEX pro-cedure. The high efficiency of CE gives rise to greatly shorten the selection procedure. The results from enzyme-linked assay and dot blot experiment show that an enrichment pool has been obtained after four rounds selection, which can specifically recognize riein.

  1. An accessible micro-capillary electrophoresis device using surface-tension-driven flow

    OpenAIRE

    Mohanty, Swomitra K; Warrick, Jay; Gorski, Jack; Beebe, David J.

    2009-01-01

    We present a rapidly fabricated micro-capillary electrophoresis chip that utilizes surface-tension-driven flow for sample injection and extraction of DNA. Surface-tension-driven flow (i.e. passive pumping) injects a fixed volume of sample that can be predicted mathematically. Passive pumping eliminates the need for tubing, valves, syringe pumps, and other equipment typically needed for interfacing with microelectrophoresis chips. This method requires a standard micropipette to load samples be...

  2. Determination of chlorophenols in environmental samples using electromembrane extraction and capillary electrophoresis

    OpenAIRE

    Šlampová, Andrea

    2013-01-01

    Combination of electromembrane extraction (EME) with capillary electrophoresis (CE) was used for determination of trace level chlorophenols (CPs) in environmental water samples. The analytes were transported across supported liquid membrane (SLM), composed of 1-ethyl-2-nitrobenzene (ENB), by the application of electrical field. A driving force of 150 V was applied to extract the analytes from neutral sample (donor solution) into strongly alkaline acceptor solutions. The acceptor soluti...

  3. Determination of Dissociation Constants of Complicated Compounds by Capillary Zone Electrophoresis

    Institute of Scientific and Technical Information of China (English)

    YANG, Geng-Liang; WANG, De-Xian; SUN, Su-Fang; LIU, Hai-Xing; MA, Jian-Jun

    2001-01-01

    In this work,the whole theoretical metods forthe determinaion ofpKa1 and pKa2 of complicated complicated compounds are proposed by capillary zone electrophoresis.The pka values areachieved by non-linear regression analysis by takiny into consideration the effect of activity coefficient.This is the first report on determining the dissociation constants of gastrodin,magnolol,honkiol,puercetin,curcumin,diethylstilbestrol,diehylstilbestrol,4acetamidophenol,eugenol and paeonol.

  4. Evaluation of carrier ampholyte-based capillary electrophoresis for separation of peptides and peptide mimetics

    Czech Academy of Sciences Publication Activity Database

    Koval, Dušan; Busnel, J. M.; Hlaváček, Jan; Jiráček, Jiří; Kašička, Václav; Peltre, G.

    2008-01-01

    Roč. 29, č. 18 (2008), s. 3759-3767. ISSN 0173-0835 R&D Projects: GA ČR(CZ) GA203/06/1044; GA ČR GA203/06/1272; GA ČR GA203/08/1428 Institutional research plan: CEZ:AV0Z40550506 Keywords : capillary electrophoresis * carrier ampholytes * peptides Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 3.509, year: 2008

  5. Analyses of Phytohormones in Coconut (Cocos Nucifera L.) Water Using Capillary Electrophoresis-Tandem Mass Spectrometry

    OpenAIRE

    Swee Ngin Tan; Jean Wan Hong Yong; Liya Ge

    2014-01-01

    Capillary electrophoresis (CE) coupled with mass spectrometry (MS) or tandem mass spectrometry (MS/MS) is reported as an alternative and potentially useful method for the simultaneous analysis of various classes of phytohormones with diversified structures, including indole-3-acetic acid (IAA), indole-3-butyric acid (IBA), abscisic acid (ABA), gibberellic acid (GA), zeatin (Z), N6-benzyladenine (BA), α-naphthaleneacetic acid (NAA) and 2,4-dichlorophenoxyacetic acid (2,4-D). The key to the CE-...

  6. Photodeposited silver nanoparticles for on-column surface-enhanced Raman spectrometry detection in capillary electrophoresis

    Czech Academy of Sciences Publication Activity Database

    Přikryl, Jan; Klepárník, Karel; Foret, František

    2012-01-01

    Roč. 1226, - (2012), s. 43-47. ISSN 0021-9673 R&D Projects: GA ČR GA203/08/1680; GA ČR(CZ) GAP301/11/2055; GA MŠk LC06023 Institutional research plan: CEZ:AV0Z40310501 Keywords : SERS * capillary electrophoresis * photodeposition Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 4.612, year: 2012

  7. Aggregate of Amphiphilic Block Copolymer as a Pseudo-Stationary Phase in Capillary Electrophoresis

    OpenAIRE

    Nakamura, Tohru; OHKI, Akira; Mishiro, Masaki; Tsuyashima, Osamu; Maeda, Shigeru; ナカムラ, トオル; オオキ, アキラ; ミシロ, マサキ; ツヤシマ, オサム; マエダ, シゲル; 中村, 透; 大木, 章; 艶島, 修; 前田, 滋

    1999-01-01

    The use of an aggregate of amphiphilic block copolymer 1, which consists of poly[(N-acetylimino)ethylene] and poly[(N-pentanoylimino)ethylene], for a pseudo-stationary phase in capillary electrophoresis has been examined. From gel-filtration chromatography, the aggregate from 1 (1-AG) was found to incorporate phenol. When the running solution contains 1-AG and sodium dodecyl sulfate (SDS), the electrophoretic mobility becomes nearly zero. Thus, it is found that when 1-AG and SDS are added to ...

  8. Electromembrane extraction of heavy metal cations followed by capillary electrophoresis with capacitively coupled contactless conductivity detection

    Czech Academy of Sciences Publication Activity Database

    Kubáň, Pavel; Strieglerová, Lenka; Gebauer, Petr; Boček, Petr

    2011-01-01

    Roč. 32, č. 9 (2011), s. 1025-1032. ISSN 0173-0835 R&D Projects: GA ČR GA203/08/1536; GA ČR GAP206/10/1219; GA AV ČR IAA400310703 Institutional research plan: CEZ:AV0Z40310501 Keywords : capillary electrophoresis * electromembrane extraction * heavy metal cations Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 3.303, year: 2011

  9. DNA Separation by Capillary Electrophoresis with Ultraviolet Detection using Mixed Synthetic Polymers

    Institute of Scientific and Technical Information of China (English)

    Qian WANG; Xu XU

    2003-01-01

    The mixtures of two polymers, poly (N,N-dimethylacrylamide) (PDMA) and polyvinylpyrrolidone (PVP) were synthesized and used as the separation medium for double-stranded and single-stranded DNA fragments by capillary electrophoresis with UV detector. On optimal conditions, 2%w/v PDMA ( 2%w/v PVP can be used to separate the doublet 123/124bp in pBR322/Hae III Markers.

  10. Chiral Separation of Ibuprofen and Terbutaline by Nonaqueous Capillary Electrophoresis with Conductance Detection

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    In the nonaqueous N,N-dimethylformamide medium, the chiral drugs ibuprofen and terbutaline were successfully separated with sulfonyl-β-cyclodextrin(s-β-CD) as the chiral selector by capillary electrophoresis with conductance detection. The comparison of the effects of three CDS(β-CD, diethylic-β-CD, sulfonyl-β-CD) on the chiral separation was made and the resolution mechanism was proposed.

  11. Determination of Caffeine in Beverages by Capillary Zone Electrophoresis: An Experiment for the Undergraduate Analytical Laboratory

    Science.gov (United States)

    Conte, Eric D.; Barry, Eugene F.; Rubinstein, Harry

    1996-12-01

    Certain individuals may be sensitive to specific compounds in comsumer products. It is important to quantify these analytes in food products in order to monitor their intake. Caffeine is one such compound. Determination of caffeine in beverages by spectrophotometric procedures requires an extraction procedure, which can prove time-consuming. Although the corresponding determination by HPLC allows for a direct injection, capillary zone electrophoresis provides several advantages such as extremely low solvent consumption, smaller sample volume requirements, and improved sensitivity.

  12. Analysis of ecstasy tablets using capillary electrophoresis with capacitively coupled contactless conductivity detection.

    Science.gov (United States)

    Porto, Suely K S S; Nogueira, Thiago; Blanes, Lucas; Doble, Philip; Sabino, Bruno D; do Lago, Claudimir L; Angnes, Lúcio

    2014-11-01

    A method for the identification of 3,4-methylenedioxymethamphetamine (MDMA) and meta-chlorophenylpiperazine (mCPP) was developed employing capillary electrophoresis (CE) with capacitively coupled contactless conductivity detection (C(4) D). Sample extraction, separation, and detection of "Ecstasy" tablets were performed in caffeine, lidocaine, and cocaine. Separation was performed in <90 sec. The advantages of using C(4) D instead of traditional CE-UV methods for in-field analysis are also discussed. PMID:25039689

  13. Physicochemical and Biopharmaceutical Characterisation of Small Drug Molecules by Capillary Electrophoresis

    OpenAIRE

    Örnskov, Eivor

    2004-01-01

    Capillary Electrophoresis (CE) was explored as a means for physicochemical and biopharmaceutical characterisation of small drug molecules. Special attention was paid to the characterisation of acid-base and lipophilic properties of drug compounds by analysing their migration behaviour in different CE systems. The thesis comprises an overview of the field together with separate studies on the different topics. The utility of CE for the determination of pKa of labile drug compounds was investig...

  14. Multi-target PCR analysis by capillary electrophoresis and laser-induced fluorescence

    Science.gov (United States)

    Lu, Wei; Han, Dai-Shu; Yuan, Ju; Andrieu, Jean-Marie

    1994-03-01

    Quantitative analysis of polymerase chain reaction (PCR) amplified HIV-1 DNA or cDNA fragments is attained using an automated system that combines capillary-gel electrophoresis (CGE) for high-efficiency separation and laser-induced fluorescence (LIF) for high-sensitivity detection. This system enables the detection of PCR-amplified multiple target DNA or cDNA in the same tube by a single injection with high precision.

  15. Determination of uric acid in plasma and allantoic fluid of chicken embryos by capillary electrophoresis

    Czech Academy of Sciences Publication Activity Database

    Matějčková, J.; Tůma, P.; Samcová, E.; Zemanová, Zdeňka

    2007-01-01

    Roč. 30, č. 12 (2007), s. 1947-1952. ISSN 1615-9306 R&D Projects: GA ČR(CZ) GA304/04/0972 Grant ostatní: GA ČR(CZ) GA203/07/0896 Institutional research plan: CEZ:AV0Z50110509 Keywords : capillary electrophoresis * microsamples of plasma * uric acid Subject RIV: CE - Biochemistry Impact factor: 2.632, year: 2007

  16. Capillary Electrophoresis Mass Spectrometry based Detection of Drugs and Neurotransmitters in Drosophila Brain

    OpenAIRE

    Phan, Nhu T. N.; Hanrieder, Jörg; Berglund, E. Carina; Ewing, Andrew G.

    2013-01-01

    Capillary electrophoresis coupled to mass spectrometry has been used to determine the in vivo concentrations of the neuroactive drug, methylphenidate, and a metabolite in the heads of the fruit fly, Drosophila melanogaster. These concentrations, evaluated at the site of action, the brain, have been correlated with orally administrated methylphenidate. Drosophila melanogaster has a relatively simple nervous system but possesses high order brain functions similar to humans; thus it has been use...

  17. Further development of capillary electrophoresis for the quantitative determination of small inorganic anions

    OpenAIRE

    King, Marion

    2003-01-01

    Factors influencing the separation and indirect UV absorbance detection of common inorganic anions using capillary zone electrophoresis (CZE) have been investigated. Initially a number of different aspects of indirect background electrolyte (BGE) systems were studied, with the resultant observations indicating the requirements of an 'ideal' BGE system for the separation and detection of common inorganic anions in water samples. In addition to the above the correct use of buffers within BGE us...

  18. Capillary affinity electrophoresis and ab initio calculation studies on complexation of valinomycin with Na+ ion

    Czech Academy of Sciences Publication Activity Database

    Ehala, Sille; Dybal, Jiří; Makrlík, E.; Kašička, Václav

    2009-01-01

    Roč. 32, č. 4 (2009), s. 597-604. ISSN 1615-9306 R&D Projects: GA ČR(CZ) GA203/06/1044; GA ČR(CZ) GA203/08/1428; GA AV ČR 1ET400500402 Institutional research plan: CEZ:AV0Z40550506; CEZ:AV0Z40500505 Keywords : capillary affinity electrophoresis * valinomycin * ab initio calculation Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 2.551, year: 2009

  19. Separation and structure-mobility relationship study of cyclic antimicrobial peptides by capillary zone electrophoresis

    Czech Academy of Sciences Publication Activity Database

    Tůmová, Tereza; Monincová, Lenka; Čeřovský, Václav; Kašička, Václav

    Helsinki: -, 2015. YS5. [International Symposium on Electro- and Liquid Phase-Separation Techniques (ITP2015) /22./ and Nordic Separation Science Symposium (NoSSS2015) /8./. 30.08.2015-03.09.2015, Helsinki] R&D Projects: GA ČR(CZ) GA15-01948S Institutional support: RVO:61388963 Keywords : structure-mobility relationship * antimicrobial peptides * capillary electrophoresis Subject RIV: CB - Analytical Chemistry, Separation

  20. Affinity capillary electrophoresis and density functional theory employed for characterization of (bio)molecular interactions

    Czech Academy of Sciences Publication Activity Database

    Kašička, Václav; Ehala, Sille; Růžička, Martin; Dybal, Jiří; Toman, Petr

    Salzburg: Society of Analytical Chemistry, 2014. OR28. [ISC 2014. International Symposium on Chromatography /30./. 14.09.2014-18.09.2014, Salzburg] R&D Projects: GA ČR(CZ) GAP206/12/0453; GA ČR(CZ) GA13-17224S Institutional support: RVO:61388963 ; RVO:61389013 Keywords : affinity capillary electrophoresis * density functional theory * biomolecular complexes Subject RIV: CB - Analytical Chemistry, Separation

  1. Separation of Am(III), Cm(III), and Cf(III) using capillary electrophoresis

    International Nuclear Information System (INIS)

    Trivalent actinides Am(III), Cm(III), and Cf(III) were successfully separated for the first time using capillary electrophoresis in 2-hydroxyisobutyric acid/acetic acid. It was found that the ionic radius was primarily important for separation of trivalent actinides as well as lanthanides in this condition. The stability constants of the Am(III) complexes with 2-hydroxyisobutyrate were estimated using the correlations between the molar fraction ratio of lanthanides and their ionic radii. (orig.)

  2. Affinity capillary electrophoresis applied to investigation of complexes of acyclic nucleoside phosphonates with beta-cyclodextrin

    Czech Academy of Sciences Publication Activity Database

    Šolínová, Veronika; Mikysková, Hana; Kaiser, Martin Maxmilian; Janeba, Zlatko; Holý, Antonín; Kašička, Václav

    Ljubljana: National Institute of Chemistry, 2015 - (Vovk, I.; Glavnik, V.; Albreht, A.). s. 127 ISBN 978-961-6104-28-9. [ISSS 2015. International Symposium on Separation Sciences /21./. 30.06.2015-03.07.2015, Ljubljana] R&D Projects: GA ČR(CZ) GA13-17224S; GA MV VG20102015046 Institutional support: RVO:61388963 Keywords : acyclic nucleoside phosphonates * complexes * capillary electrophoresis Subject RIV: CB - Analytical Chemistry, Separation

  3. Determination of acid dissociation constants of triazole fungicides by pressure assisted capillary electrophoresis

    Czech Academy of Sciences Publication Activity Database

    Konášová, Renáta; Jaklová Dytrtová, Jana; Kašička, Václav

    2015-01-01

    Roč. 1408, Aug 21 (2015), s. 243-249. ISSN 0021-9673 R&D Projects: GA ČR(CZ) GA13-17224S; GA ČR GP13-21409P Institutional support: RVO:61388963 Keywords : triazole fungicides * acid dissociation constant * pK(a) * capillary electrophoresis * ionic mobility Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 4.169, year: 2014

  4. Affinity Capillary Electrophoresis Applied to Investigation of Noncovalent Interactions of (Bio)molecules

    Czech Academy of Sciences Publication Activity Database

    Kašička, Václav; Růžička, Martin; Konášová, Renáta; Koval, Dušan; Čížková, Martina; Teplý, Filip

    Geneva: -, 2015. s. 66-67. [HPLC 2015. International Symposium on High Performance Liquid Phase Separations and Related Techniques /42./. 21.06.2015-25.06.2015, Geneva] R&D Projects: GA ČR(CZ) GA13-17224S; GA ČR GA13-32974S; GA ČR GA13-19213S Institutional support: RVO:61388963 Keywords : affinity capillary electrophoresis * binding constant * DNA * oligophenylenes * dibenzo-18-crown-6-ether Subject RIV: CB - Analytical Chemistry, Separation

  5. Investigation of [Gly6]-antamanide complexes with small cations by capillary affinity electrophoresis

    Czech Academy of Sciences Publication Activity Database

    Pangavhane, Sachinkumar; Kašička, Václav

    Helsinki: -, 2015. P2. [International Symposium on Electro- and Liquid Phase-Separation Techniques (ITP2015) /22./ and Nordic Separation Science Symposium (NoSSS2015) /8./. 30.08.2015-03.09.2015, Helsinki] R&D Projects: GA ČR(CZ) GA15-01948S Institutional support: RVO:61388963 Keywords : antamanide * complexes * affinity capillary electrophoresis Subject RIV: CB - Analytical Chemistry, Separation

  6. Determination of apparent binding constants of complexes of acyclic nucleoside phosphonates with cyclodextrins by capillary electrophoresis

    Czech Academy of Sciences Publication Activity Database

    Šolínová, Veronika; Kaiser, Martin Maxmilian; Lukáč, Miloš; Janeba, Zlatko; Kašička, Václav

    Salzburg: Society of Analytical Chemistry, 2014. P510. [ISC 2014. International Symposium on Chromatography /30./. 14.09.2014-18.09.2014, Salzburg] R&D Projects: GA ČR(CZ) GAP206/12/0453; GA ČR(CZ) GA13-17224S; GA MV VG20102015046 Institutional support: RVO:61388963 Keywords : acyclic nucleoside phosphonates * capillary electrophoresis * binding constant Subject RIV: CB - Analytical Chemistry, Separation

  7. Cyclodextrine Screening for the Chiral Separation of Amlodipine Enantiomers by Capillary Electrophoresis

    OpenAIRE

    Gabriel Hancu; Monica Budău; Lajos Kristóf Kántor; Anca Cârje

    2015-01-01

    Purpose: Amlodipine is a long acting, dihydropyridine type calcium channel blocker frequently used in the treatment of hypertension and coronary insufficiency. The calcium channel blocking activity resides primarily in the S-amlodipine enantiomer, while R-amlodipine is a potent inhibitor of smooth muscle cell migration. Methods: In this study capillary electrophoresis was applied for the enantiomeric separation of amlodipine using different native and derivatized; neutral and charged cyclo...

  8. Development of a capillary electrophoresis method for the simultaneous determination of cephalosporins

    OpenAIRE

    Hancu Gabriel; Kelemen Hajnal; Rusu Aura; Gyéresi Árpád

    2013-01-01

    A rapid and simple capillary electrophoresis method has been developed for the simultaneous determination of six extensively used cephalosporin antibiotics (cefaclor, cefadroxil, cefalexin, cefuroxim, ceftazidim, ceftriaxon). The determination of cephalosporins was performed at a pH 6.8, using a 25 mM phospate - 25 mM borate mixed buffer, + 25 kV voltage at a temperature of 25 °C. We achieved a baseline separation in approximately 10 minutes. The separation resolution was increased by a...

  9. Polyethylene Oxide (PEO) and Polyethylene Glycol (PEG) Polymer Sieving Matrix for RNA Capillary Electrophoresis

    OpenAIRE

    Yamaguchi, Yoshinori; Li, Zhenqing; Zhu, Xifang; Liu, Chenchen; Zhang, Dawei; Dou, Xiaoming

    2015-01-01

    The selection of sieving polymer for RNA fragments separation by capillary electrophoresis is imperative. We investigated the separation of RNA fragments ranged from 100 to 10,000 nt in polyethylene glycol (PEG) and polyethylene oxide (PEO) solutions with different molecular weight and different concentration. We found that the separation performance of the small RNA fragments (4000 nt) deteriorated in PEG/PEO solutions when the concentration was above 1.0%/0.6%, respectively. By double logar...

  10. Experimental assessment of electromigration properties of background electrolytes in capillary zone electrophoresis

    Czech Academy of Sciences Publication Activity Database

    Boušková, Eva; Presutti, C.; Gebauer, Petr; Fanali, S.; Beckers, J. L.; Boček, Petr

    2004-01-01

    Roč. 25, č. 2 (2004), s. 355-359. ISSN 0173-0835 R&D Projects: GA ČR GA203/02/0023; GA ČR GA203/01/0401; GA AV ČR IAA4031103 Institutional research plan: CEZ:AV0Z4031919 Keywords : borate buffers * capillary zone electrophoresis * electromigration properties Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 3.743, year: 2004

  11. Determination of Enantiomeric Purity of n-Pyrrolidinyl Phenylpropanol by Capillary Electrophoresis Using b-Cyclodextrin Polymer as Chiral Selector

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Enantiomer of n-pyrrolidinyl phenylpropanol was studied by capillary electrophoresis using b-cyclodextrin polymer as chiral selector. We determined the enantiomeric excess value of n-pyrrolidinyl phenylpropanol with RSD 0.48%.

  12. Physico-chemical characterization of liposomes and drug substance-liposome interactions in pharmaceutics using capillary electrophoresis and electrokinetic chromatography

    DEFF Research Database (Denmark)

    Franzen, Ulrik; Østergaard, Jesper

    2012-01-01

    electrophoresis and liposome electrokinetic chromatography for the characterization of liposomes in a pharmaceutical context. Capillary electrophoretic techniques have been used for the measurement of electrophoretic mobility, which provides information on liposome surface charge, size and membrane permeability...... of liposomes. The use of liposome electrokinetic chromatography and capillary electrophoresis for determination of liposome/water partitioning and characterization of drug-liposome interactions is reviewed. A number of studies indicate that capillary electrophoresis may have a role in the...... characterization of liposome drug delivery systems, e.g., for the investigation of encapsulation efficiency and drug leakage. The well-known characteristics of capillary electrophoresis, i.e., low sample volume requirement, high separation efficiency in aqueous media without a stationary phase, minimal sample...

  13. Steroid determination in fish plasma using capillary electrophoresis

    Science.gov (United States)

    Bykova, L.; Archer-Hartmann, S. A.; Holland, L.A.; Iwanowicz, L.R.; Blazer, V.S.

    2010-01-01

    A capillary separation method that incorporates pH-mediated stacking is employed for the simultaneous determination of circulating steroid hormones in plasma from Perca flavescens (yellow perch) collected from natural aquatic environments. The method can be applied to separate eight steroid standards: progesterone, 17α,20β-dihydroxypregn-4-en-3-one, 17α-hydroxyprogesterone, testosterone, estrone, 11-ketotestosterone, ethynyl estradiol, and 17β-estradiol. Based on screening of plasma, the performance of the analytical method was determined for 17α,20β-dihydroxypregn-4-en-3-one, testosterone, 11-ketotestosterone, and 17β-estradiol. The within-day reproducibility in migration time for these four steroids in aqueous samples was ≤2%. Steroid quantification was accomplished using a calibration curve obtained with external standards. Plasma samples from fish collected from the Choptank and Severn Rivers, Maryland, USA, stored for up to one year were extracted with ethyl acetate and then further processed with anion exchange and hydrophobic solid phase extraction cartridges. The recovery of testosterone and 17β-estradiol from yellow perch plasma was 84 and 85%, respectively. Endogenous levels of testosterone ranged from 0.9 to 44 ng/ml, and when detected 17α,20β-dihydroxypregn-4-en-3-one ranged from 5 to 34 ng/ml. The reported values for testosterone correlated well with the immunoassay technique. Endogenous concentrations of 17β-estradiol were ≤1.7 ng/ml. 11-Ketotestosterone was not quantified because of a suspected interferant. Higher levels of 17α,20β-dihydroxypregn-4-en-3-one were found in male and female fish in which 17β-estradiol was not detected. Monitoring multiple steroids can provide insight into hormonal fluctuations in fish.

  14. Determination of acid dissociation constants of warfarin and hydroxywarfarins by capillary electrophoresis.

    Science.gov (United States)

    Nowak, Paweł; Olechowska, Paulina; Mitoraj, Mariusz; Woźniakiewicz, Michał; Kościelniak, Paweł

    2015-08-10

    In this work the acid dissociation constants--pKa of warfarin and its all important oxidative metabolites have been determined by capillary electrophoresis-based methods. It has resulted in a complete description of two acid-base dissociation equilibria, yet not investigated experimentally for phase I metabolites of warfarin. The capillary electrophoresis (CE) method based on the relation between effective electrophoretic mobilities and pH has proven to be a suitable tool for pKa determination, while the spectrophotometric (CE-DAD) and the internal standard methods (IS-CE), have appeared to be promising alternative approaches. The CE-DAD approach based on the change in absorbance spectra between the acidic and basic forms is a combination between capillary electrophoresis and spectrophotometric titration, and yields very consistent values of pKa1 with CE. The IS-CE, in turn, enables an estimation of pKa1 and pKa2 from only two analytical runs, however, less accurate than CE and CE-DAD. The Debye-Hückel model has been confirmed experimentally as a good predictor of pKa values at various ionic strengths. Therefore, it has been used in determination of thermodynamic pKa1 and pKa2, referring to the zero ionic strength. The results are important from the analytical, pharmacological, and theoretical points of view. PMID:25968611

  15. Characterization and Study of Transgenic Cultivars by Capillary and Microchip Electrophoresis

    Science.gov (United States)

    Domínguez Vega, Elena; Marina, Maria Luisa

    2014-01-01

    Advances in biotechnology have increased the demand for suitable analytical techniques for the analysis of genetically modified organisms. Study of the substantial equivalence, discrimination between transgenic and non-transgenic cultivars, study of the unintended effects caused by a genetic modification or their response to diverse situations or stress conditions (e.g., environmental, climatic, infections) are some of the concerns that need to be addressed. Capillary electrophoresis (CE) is emerging as an alternative to conventional techniques for the study and characterization of genetically modified organisms. This article reviews the most recent applications of CE for the analysis and characterization of transgenic cultivars in the last five years. Different strategies have been described depending on the level analyzed (DNA, proteins or metabolites). Capillary gel electrophoresis (CGE) has shown to be particularly useful for the analysis of DNA fragments amplified by PCR. Metabolites and proteins have been mainly separated using capillary zone electrophoresis (CZE) using UV and MS detection. Electrophoretic chips have also proven their ability in the analysis of transgenic cultivars and a section describing the new applications is also included. PMID:25535077

  16. Sensitive detection of malachite green and crystal violet by nonlinear laser wave mixing and capillary electrophoresis.

    Science.gov (United States)

    Maxwell, Eric J; Tong, William G

    2016-05-01

    An ultrasensitive label-free antibody-free detection method for malachite green and crystal violet is presented using nonlinear laser wave-mixing spectroscopy and capillary zone electrophoresis. Wave-mixing spectroscopy provides a sensitive absorption-based detection method for trace analytes. This is accomplished by forming dynamic gratings within a sample cell, which diffracts light to create a coherent laser-like signal beam with high optical efficiency and high signal-to-noise ratio. A cubic dependence on laser power and square dependence on analyte concentration make wave mixing sensitive enough to detect molecules in their native form without the use of fluorescent labels for signal enhancement. A 532nm laser and a 635nm laser were used for malachite green and crystal violet sample excitation. The use of two lasers of different wavelengths allows the method to simultaneously detect both analytes. Selectivity is obtained through the capillary zone electrophoresis separation, which results in characteristic migration times. Measurement in capillary zone electrophoresis resulted in a limit of detection of 6.9×10(-10)M (2.5×10(-19)mol) for crystal violet and 8.3×10(-11)M (3.0×10(-20)mol) for malachite green at S/N of 2. PMID:26998858

  17. Characterization and Study of Transgenic Cultivars by Capillary and Microchip Electrophoresis

    Directory of Open Access Journals (Sweden)

    Elena Domínguez Vega

    2014-12-01

    Full Text Available Advances in biotechnology have increased the demand for suitable analytical techniques for the analysis of genetically modified organisms. Study of the substantial equivalence, discrimination between transgenic and non-transgenic cultivars, study of the unintended effects caused by a genetic modification or their response to diverse situations or stress conditions (e.g., environmental, climatic, infections are some of the concerns that need to be addressed. Capillary electrophoresis (CE is emerging as an alternative to conventional techniques for the study and characterization of genetically modified organisms. This article reviews the most recent applications of CE for the analysis and characterization of transgenic cultivars in the last five years. Different strategies have been described depending on the level analyzed (DNA, proteins or metabolites. Capillary gel electrophoresis (CGE has shown to be particularly useful for the analysis of DNA fragments amplified by PCR. Metabolites and proteins have been mainly separated using capillary zone electrophoresis (CZE using UV and MS detection. Electrophoretic chips have also proven their ability in the analysis of transgenic cultivars and a section describing the new applications is also included.

  18. A covalent modified hydrophilic capillary for enhanced capillary electrophoresis of biopolymers

    Institute of Scientific and Technical Information of China (English)

    Lian Guo Shan; Xue Yu; Yin Mao Wei; Xiao Hui Zheng; Jian Bin Zheng

    2009-01-01

    δ-Gluconolactone was covalently coupled to aminopropyl derivatized capillary,which created hydrophilic brushes on the inner wall of the capillary.The coated capillary was shown to generate a stable electroosmotic flow(EOF)in the investigated pH range of 2.0-9.0 and to suppress effectively the adsorption of proteins.And it enabled separation of some biopolymer mixtures including basic proteins,DNA and tryptic digested bovine serum albumin(BSA)within 15 min with efficiencies up to 450,000 plates/m.The intra-and inter-day reproducibility of the coating referring to the retention times of proteins were satisfactory with mean relative standard deviations(R.S.D.)of 0.8 and 1.7%,respectively.

  19. Feasibility of applying the new improved PCR/LDR/capillary electrophoresis on prenatal diagnosis of fetal beta thalassaemia

    OpenAIRE

    Liao, Xi; Yi, Ping; Zheng, Ying-Ru; Yu, Li-Li; Zhong, Xiao-Lin; Yin-hu HUANG; Han, Lei; Yu-juan ZHU; LI Li

    2014-01-01

    Objective  To investigate the feasibility of applying new improved polymerase chain reaction (PCR)/ligase detection reaction (LDR)/capillary electrophoresis to the prenatal diagnosis of fetal β thalassemia from maternal plasma. Methods  The mixture of different concentrations of normal DNA and trace β-thalassemia mutation heterozygous DNA were used for PCR, and the amplification products obtained thereafter were used for LDR. The ligation product was detected by capillary electrophoresis to d...

  20. Affinity capillary electrophoresis applied to quantitative evaluation of non-covalent peptide interactions with metal ions and cyclodextrins

    Czech Academy of Sciences Publication Activity Database

    Kašička, Václav; Ehala, Sille; Šolínová, Veronika; Schimperková, Tereza; Sázelová, Petra; Makrlík, E.

    Sevilla : CSIC, 2009. s. 35-35. [Latin American Symposium on Biotechnology, Biomedical, Biopharmaceutical and Industrial Applications of Capillary Electrophoresis and Microchip Technology /15./. 02.10.2009-06.10.2009, Sevilla] R&D Projects: GA ČR(CZ) GA203/08/1428 Grant ostatní: GA ČR(CZ) GA203/09/0675 Institutional research plan: CEZ:AV0Z40550506 Keywords : affinity capillary electrophoresis * peptide interactions * cyclodextrin s Subject RIV: CB - Analytical Chemistry, Separation

  1. Restriction Enzyme Pattern Analysis of Mycobacteria DNA by Capillary Electrophoresis with Laser-induced Fluorescence Detection

    Institute of Scientific and Technical Information of China (English)

    Li Yuanqian; Wang Guoqing; Mi Jianping; Zhou Ying; Zeng Hongyan; Zhang Chaowu

    2006-01-01

    A new method for rapidly detecting restriction enzyme patterns of Mycobacterium DNA using capillary electrophoresis with laser-induced fluorescence detection (CE-LIFD)was developed.Polymerase chain reaction was used to amplify a 439-bp fragment of a 65,000-kDa(Mr)heat shock protein gene(hsp65)of Mycobacterium.After digesting amplification products by BstEII and HaeIII,patterns of enzyme cleavage products were detected by both CE-LIFD and agarose gel electrophoresis(AGE),respectively.Experimental parameters of CE were optimized.Restriction enzyme patterns of Mycobacterium DNA were detected in optimum electrophoresis conditions:a coated capillary column with a length of 50 cm and an internal diameter of 100 μm,an electrophoresis buffer of 45 mmol/1 Tris-boric acid-ethylenediaminetetraacetic acid,and a running voltage of 11 kV.The restriction enzyme patterns for eight species of mycobacteria were studied.Relative standard deviations of the relative migration times of DNA segments were<3.6%.Compared with AGE,CE is more outstanding in resolution and detection time,and it can be applied as a more effective means to DNA restriction enzyme pattern analysis.

  2. Development of novel separation techniques for biological samples in capillary electrophoresis

    Energy Technology Data Exchange (ETDEWEB)

    Chang, H.T.

    1994-07-27

    This dissertation includes three different topics: general introduction of capillary electrophoresis (CE); gradient in CE and CE in biological separations; and capillary gel electrophoresis (CGE) for DNA separation. Factors such as temperature, viscosity, pH, and the surface of capillary walls affecting the separation performance are demonstrated. A pH gradient between 3.0 and 5.2 is useful to improve the resolution among eight different organic acids. A flow gradient due to the change in the concentration of surfactant, which is able to coat to the capillary wall to change the flow rate and its direction, is also shown as a good way to improve the resolution for organic compounds. A temperature gradient caused by joule heat is shown by voltage programming to enhance the resolution and shorten the separation time for several phenolic compounds. The author also shows that self-regulating dynamic control of electroosmotic flow in CE by simply running separation in different concentrations of surfactant has less matrix effect on the separation performance. One of the most important demonstrations in this dissertation is that the author proposes on-column reaction which gives several advantages including the use of a small amount of sample, low risk of contamination, and time saving and kinetic features. The author uses this idea with laser induced fluorescence (LIF) as a detection mode to detect an on-column digestion of sub-ng of protein. This technique also is applied to single cell analysis in the group.

  3. Improving the reproducibility in capillary electrophoresis by incorporating current drift in mobility and peak area calculations

    DEFF Research Database (Denmark)

    Petersen, Nickolaj J.; Hansen, Steen H

    2012-01-01

    The traditional way of calculating mobility and peak areas in capillary electrophoresis does not take into account the changes in the buffer viscosity at different thermostatic control and that the analytes may accelerate during the individual runs due to Joule heating effects. We present a method...... for accounting for these changes based on the monitored changes in current during the separation. The calculation method requires measuring the initial resistance of the buffer filled capillary, performed using a 0.2 min voltage ramping at the start of a separation. The mobility calculation corrected...... for current drift allowed identification of the tested analytes independent from capillary dimensions, electric field strengths and temperature control. Furthermore, the peak areas become less influenced by the experimental conditions, since the velocities of the analytes passing the detector are...

  4. Analysis of protamine peptides in insulin pharmaceutical formulations by capillary electrophoresis.

    Science.gov (United States)

    Lamalle, Caroline; Servais, Anne-Catherine; Demelenne, Alice; Crommen, Jacques; Fillet, Marianne

    2016-03-01

    Protamines are a group of highly basic peptides that are sometimes added to insulin formulations to prolong the pharmacological action. In this study, different methods were investigated to identify protamine in insulin formulations. Capillary electrophoresis in aqueous and non-aqueous media was tested to separate these peptides with very close amino acid sequences. Different buffers (phosphate or formate, both acidified) and various additives (principally negatively charged and neutral surfactants) were investigated to optimize peptide separation. Finally, a micellar electrokinetic capillary chromatography method using a capillary of 120 cm effective length and an aqueous background electrolyte made up of 100 mM phosphate buffer (pH 2) and 50 mM Thesit® gave the best results, providing the separation of the four major protamine peptides within 25 min. PMID:26829340

  5. On-line wall-free cell for laser-induced fluorescence detection in capillary electrophoresis.

    Science.gov (United States)

    Yu, Chang-Zhu; He, You-Zhao; Xie, Hai-Yang; Gao, Yong; Gan, Wu-Er; Li, Jun

    2009-05-15

    A wall-free detection method based on liquid junction in a capillary gap was proposed for laser-induced fluorescence (LIF) of capillary electrophoresis (CE). The capillary gap of the wall-free cell was fabricated by etching a 10-mm x 50-microm I.D. fused-silica capillary to obtain a polyimide coating sleeve, decoating about 6mm at one end of both 50 microm I.D. separation and liquid junction capillary, inserting the treated capillary ends into the coating sleeve oppositely, fixing the capillaries with a gap distance of 140 microm by epoxy glue and removing the coating sleeve by burning. The theoretical model, experimental results and wall-free cell images indicated that the gap distance and applied voltage were main influence factors on the wall-free detection. Since the wall-free cell increased the absorption light path and avoided the stray light from the capillary wall, it improved the ratio of signal to noise and limit of detection (LOD) of CE-LIF. Three flavin compounds of riboflavin (RF), flavin mononucleotide sodium (FMN) and flavin adenine dinucleotide disodium (FAD) were used to evaluate the wall-free detection method. Compared with on-column cell, the LODs of the wall-free cell were improved 15-, 6- and 9-fold for RF, FMN and FAD, respectively. The linear calibration concentrations of the flavins ranged from 0.005 to 5.0 micromol/L. The column efficiency was in the range from 1.0 x 10(5) to 2.5 x 10(5) plates. The wall-free detection of CE-LIF was applied to the analysis of the flavins in spinach and lettuce leaves. PMID:19329123

  6. CSE-MECC two-dimensional capillary electrophoresis analysis of proteins in the mouse tumor cell (AtT-20) homogenate

    OpenAIRE

    Chen, Xingguo; Fazal, Md. Abul; Dovichi, Norman J.

    2007-01-01

    Two-dimensional capillary electrophoresis was used for the separation of proteins and biogenic amines from the mouse AtT-20 cell line. The first-dimension capillary contained a TRIS-CHES-SDS-dextran buffer to perform capillary sieving electrophoresis, which is based on molecular weight of proteins. The second-dimension capillary contained a TRIS-CHES-SDS buffer for micel1ar electrokinetic capillary chromatography. After a 61 seconds preliminary separation, fractions from the first-dimension c...

  7. A Theoretical Analysis of the Influence of Electroosmosis on the Effective Ionic Mobility in Capillary Zone Electrophoresis

    Science.gov (United States)

    Hijnen, Hens

    2009-01-01

    A theoretical description of the influence of electroosmosis on the effective mobility of simple ions in capillary zone electrophoresis is presented. The mathematical equations derived from the space-charge model contain the pK[subscript a] value and the density of the weak acid surface groups as parameters characterizing the capillary. It is…

  8. Linearity evaluation in absorbance detection: the use of light-emitting diodes for on-capillary detection in capillary electrophoresis.

    Science.gov (United States)

    Macka, M; Andersson, P; Haddad, P R

    1996-12-01

    A model which takes into account both stray light and polychromatic light was used to predict and evaluate linearity in on-capillary detection in capillary electrophoresis (CE). According to the model the stray light is the major factor which determines linearity under typical CE operating conditions. By calculating theoretical absorbance versus concentration plots, the influence of different levels of stray light and polychromatic light on linearity is demonstrated. Experimentally, six light-emitting diodes (LEDs) in the range from 563 to 654 nm were examined as light sources for on-capillary detection in CE. Fitting theoretical curves to measured linearity plots enabled determination of the values of both effective path length and stray light for a particular detection system. The detector linearity for the four LEDs was compared to mercury and tungsten lamps used with interference filters. For potassium permanganate as the test compound, the linear range for a 563 nm LED was two times greater than that for a mercury lamp operated at 546 nm. The relatively poor linearity of the mercury lamp detector is explained by its high level of stray light. The noise of the LED563-based detector was the same as for the mercury lamp, whereas the other LEDs of higher light intensity gave approximately half the noise of the mercury lamp. The lowest noise level of 3 x 10(-5) AU was obtained for the LED at 554 nm (determined at a detector time constant of 0.1 s). PMID:9034772

  9. Coupling Sodium Dodecyl Sulfate–Capillary Polyacrylamide Gel Electrophoresis with MALDI-TOF-MS via a PTFE Membrane

    OpenAIRE

    Lu, Joann J; Zhu, Zaifang; Wang, Wei; Liu, Shaorong

    2011-01-01

    Sodium dodecyl sulfate (SDS)–polyacrylamide gel electrophoresis (PAGE) is a fundamental analytical technique for proteomic research, and SDS–capillary gel electrophoresis (CGE) is its miniaturized version. Compared to conventional slab-gel electrophoresis, SDS-CGE has many advantages such as increased separation efficiency, reduced separation time and automated operation. SDS-CGE is not widely accepted in proteomic research primarily due to the difficulties in identifying the well-resolved pr...

  10. Protein Cross-Linking Capillary Electrophoresis for Protein-Protein Interaction Analysis.

    Science.gov (United States)

    Ouimet, Claire M; Shao, Hao; Rauch, Jennifer N; Dawod, Mohamed; Nordhues, Bryce; Dickey, Chad A; Gestwicki, Jason E; Kennedy, Robert T

    2016-08-16

    Capillary electrophoresis (CE) has been identified as a useful platform for detecting, quantifying, and screening for modulators of protein-protein interactions (PPIs). In this method, one protein binding partner is labeled with a fluorophore, the protein binding partners are mixed, and then, the complex is separated from free protein to allow direct determination of bound to free ratios. Although it possesses many advantages for PPI studies, the method is limited by the need to have separation conditions that both prevent protein adsorption to capillary and maintain protein interactions during the separation. In this work, we use protein cross-linking capillary electrophoresis (PXCE) to overcome this limitation. In PXCE, the proteins are cross-linked under binding conditions and then separated. This approach eliminates the need to maintain noncovalent interactions during electrophoresis and facilitates method development. We report PXCE methods for an antibody-antigen interaction and heterodimer and homodimer heat shock protein complexes. Complexes are cross-linked by short treatments with formaldehyde after reaching binding equilibrium. Cross-linked complexes are separated by electrophoretic mobility using free solution CE or by size using sieving electrophoresis of SDS complexes. The method gives good quantitative results; e.g., a lysozyme-antibody interaction was found to have Kd = 24 ± 3 nM by PXCE and Kd = 17 ± 2 nM using isothermal calorimetry (ITC). Heat shock protein 70 (Hsp70) in complex with bcl2 associated athanogene 3 (Bag3) was found to have Kd = 25 ± 5 nM by PXCE which agrees with Kd values reported without cross-linking. Hsp70-Bag3 binding site mutants and small molecule inhibitors of Hsp70-Bag3 were characterized by PXCE with good agreement to inhibitory constants and IC50 values obtained by a bead-based flow cytometry protein interaction assay (FCPIA). PXCE allows rapid method development for quantitative analysis of PPIs. PMID:27434096

  11. Application of capillary electrophoresis to anion speciation in soil water extracts: 2. Arsenic

    Energy Technology Data Exchange (ETDEWEB)

    Naidu, R.; Smith, J.; McLaren, R.G.; Stevens, D.P.; Sumner, M.E.; Jackson, P.E.

    2000-02-01

    A method has been developed for the speciation of arsenic (AsO{sub 2}{sup {minus}}, AsO{sub 4}{sup 3{minus}}, and dimethylarsinic [DMA]) in natural soil solutions from contaminated sites in Australia. The separation of these anions was achieved by capillary zone electrophoresis (CZE) using a fused silica capillary with a basic chromate buffer and on-column indirect UV detection at 254 nm. Method parameters, such as electrolyte pH, run voltage, and capillary temperature were studied in order to establish suitable analytical conditions. The ideal separation for As(III) and DMA was achieved with a buffer pH of 8.0, a run voltage of 25 kV, and a capillary temperature of 30 C. Under these conditions, As(V) and orthophosphate ions comigrated. However, the use of a chromate buffer at pH 10, a run voltage of 20 kV, and capillary temperature of 20 C led to complete separation of As(V) and phosphate peaks. Results of these investigations together with recovery test data suggest that separation of the As species from soil solutions can be achieved in less than 5 min with detection limits of 0.50, 0.10, and 0.10 mg L{sup {minus}1} for As(III), As(V), and DMA, respectively.

  12. Impact of capillary conditioning and background electrolyte composition on capillary electrophoresis analysis of prostate specific antigen isoforms.

    Science.gov (United States)

    Farina-Gomez, Noemi; Puerta, Angel; Gonzalez, Monica; Diez-Masa, Jose Carlos; de Frutos, Mercedes

    2016-04-22

    Glycoproteins expressed in the human body can experience modifications as result of pathological situations. Detection of those changes can be useful as disease biomarkers. As a result of these modifications, size and/or electrical charge of the glycoprotein can be altered. Migration in capillary zone electrophoresis (CZE) is governed by the size to charge ratio of the analyte and therefore this separation technique can be used to monitor those modifications. At its turn, the alteration of the electrophoretical pattern of a given glycoprotein could be used as disease biomarker. To this aim, high repeatability for separation of a large number of peaks for a given glycoprotein is desirable. For prostate cancer, new markers are needed to decrease the high number of false positive results provided by the biomarkers currently used in clinics. In this sense, CZE methods for analysis of the several prostate specific antigen (PSA) peaks which this glycoprotein exhibit, called isoforms and containing one or more glycoforms, could be useful to study the PSA pattern as prostate cancer marker. In this study two complementary strategies to achieve both lot-to-lot capillary repeatability and high resolution of a large number of PSA isoforms are developed. Better performance and precision have been obtained for capillaries conditioned with HCl than for those conditioned with NaOH. Optimization of the background electrolyte (BGE) pH value to 8.0 and inclusion of 3M urea on its composition were the two factors of highest impact for enhancing resolution of the highest number of PSA peaks. Under the optimized conditions for capillary conditioning and BGE pH and composition, long-term resolution of 10 isoforms of PSA was achieved. Inter-day (n=3) %RSD was 0.55 for the ratio tm/tEOF, 1.15 for μeff, and 5.02 for % Acorr of the PSA peaks. PMID:27018191

  13. Study of the Electrophoretic Behavior of Cephalosporins by Capillary Zone Electrophoresis

    Directory of Open Access Journals (Sweden)

    Gabriel Hancu

    2015-06-01

    Full Text Available Purpose: The aim of the study was the characterization of the electrophoretic behavior of cephalosporins from different generation having different structural characteristics in order to develop a rapid, simple and efficient capillary electrophoretic method for their identification and simultaneous separation from complex mixtures. Methods: Ten cephalosporin derivatives (cefaclor, cefadroxil, cefalexin, cefazolin, cefoxitin, cefuroxime, cefoperazone, cefotaxime, ceftazidime, ceftriaxone were analyzed by capillary zone electrophoresis using different background electrolyte solutions at different pH values. Electrophoretic mobilities of the analytes were calculated, the influence of the electrophoretic parameteres on the separation was established and the analytical conditions were optimized. Results: Taking into consideration their structural and chemical properties cephalosporins can be detected over a pH range between 6 and 10. The best results were obtained using a buffer solution containing 25 mM disodium hydrogenophosphate - 25 mM sodium dihydrogenophosphate, at a pH – 7.00, + 25 kV voltage at a temperature of 25 C, UV detection at 210 nm. Using the optimized analytical conditions we achieved the simultaneous baseline separation for seven cephalosporins in less then 10 minutes. Conclusion: Using the described optimized electrophoretic procedures, capillary electrophoresis can be used for the identification and determination of cephalosporins in formulated pharmaceutical products and for their separation from complex mixtures.

  14. Chiral separation of benzoporphyrin derivative mono- and diacids by laser induced fluorescence-capillary electrophoresis.

    Science.gov (United States)

    Peng, Xuejun; Sternberg, Ethan; Dolphin, David

    2002-01-01

    A method for the separation of benzoporphyrin derivative mono- and diacid (BPDMA, BPDDA) enantiomers by laser induced fluorescence-capillary electrophoresis (LIF-CE) has been developed. By using 300 mM borate buffer, pH 9.2, 25 mM sodium cholate and 10% acetronitrile as electrolyte, +10 kV electrokinetic sampling injection of 2 s and an applied +20 kV voltage across the ends of a 37 cm capillary (30 cm to the detector, 50 microm ID), all six BPD stereoisomers were baseline-separated within 20 min. Formation constants, free electrophoretic and complexation mobilities with borate and cholate were determined based on dynamic complexation capillary electrophoresis theory. The BPD enantiomers can be quantitatively determined in the range of 10(-2)-10(-5) mg mL(-1). The correlation coefficients (r2) of the least-squares linear regression analysis of the BPD enantiomers are in the range of 0.9914-0.9997. Their limits of detection are 2.18-3.5 x 10(-3) mg mL(-1). The relative standard deviations for the separation were 2.90-4.64% (n = 10). In comparison with high-performance liquid chromatography (HPLC), CE has better resolution and efficiency. This separation method was successfully applied to the BPD enantiomers obtained from a matrix of bovine serum and from liposomally formulated material as well as from studies with rat, dog and human microsomes. PMID:11824627

  15. Capillary zone electrophoresis analysis and detection of mid-spectrum biological warfare agents

    Energy Technology Data Exchange (ETDEWEB)

    Boulet, C.A.; Townsley, C.

    1995-04-01

    DRE Suffield has initiated a research program to develop methods and equipment for field detection and laboratory identification of mid-spectrum agents, molecules of biological origin such as proteins, peptides and toxins. In this study, a highly efficient and reproducible capillary zone electrophoresis method was developed to separate and identify a series of nine peptides of defence interest: bradykinin, bradykinin fragment 1-5, substance P,ARG8-vasopressin, luteinizing hormone releasing hormone, bombesin, leucine enkephalin, methionine enkephalin, and oxytocin. Using a 50 micrometer x 47 cm capillary column, 22.5 kV separation voltage and a 100 mM pH 2.5 phosphate buffer, all nine peptide could separated in under 10 minutes. Three strategies, which could be used in a fully automated field detection and identification system, were demonstrated for the identification of unknown peptides: comparison of migration times, comparison of electrophoretic mobilities, and co-injection of multiple reference standards. These experiments demonstrate that a separation based analytical method such as capillary electrophoresis could form the basis of a generic detection system for mid-spectrum protein and peptide toxins.

  16. Capillary electrophoresis separation of vinpocetine and related compounds: prediction of electrophoretic mobilities in partly aqueous media.

    Science.gov (United States)

    Mazák, K; Szakács, Z; Nemes, A; Noszál, B

    2000-07-01

    Offord's equation, a relationship between electrophoretic mobility and charge, size and shape of peptides, has been extended to quantitate the electrophoretic mobility of vinca alkaloids. Partly aqueous protonation constants and the derived theoretical mobilities have been proven to be able to predict experimental electrophoretic mobilities. In practice, seven vincamine derivatives of very low water-solubility were separated by capillary electrophoresis. Buffer total concentration, apparent pH and methanol content, the three most important parameters of the running buffer, were used in triangular resolution mapping to characterize separation. Even though electrophoresis is well known to slow down in partly aqueous media, under our optimized circumstances a baseline separation was achieved within 8 min in each case. PMID:10939454

  17. Capillary electrophoresis of proteins in buffers containing high concentrations of zwitterionic salts.

    Science.gov (United States)

    Bushey, M M; Jorgenson, J W

    1989-10-20

    A method for improving protein separations in capillary zone electrophoresis utilizing high concentrations of zwitterionic buffer additives was examined. Lysozyme and alpha-chymotrypsinogen A were used as test proteins in untreated fused-silica capillaries in buffers of pH ca. 7.0 and 9.0 The zwitterion-containing buffers were compared with buffers containing high ionic salt concentrations and a buffer containing a combination of high ionic salt and high zwitterion concentrations. Over 100,000 theoretical plates were obtained in less than 30 min. for both test proteins in a pH 7 buffer containing both trimethylglycine and potassium sulfate. The advantages and disadvantages of this technique compared with those of other methods used to prevent protein adsorption are discussed. PMID:2592485

  18. Speciation of Tc(IV) in chloride solutions by capillary electrophoresis

    International Nuclear Information System (INIS)

    A method for speciation of Tc(IV) species (TcCl62- and TcCl5(H2O)-) in chloride solutions, using capillary electrophoresis (CE) technique was developed. The proposed method has overcome the difficulties of unstable oxidation states analysis by shortening their travel time in the capillary. TcCl62- and TcCl5(H2O)- were thus separated without being hydrolyzed and polymerized, and their UV/Vis spectra were recorded. With a 1 M HCl/NaCl buffer solution (pH = 1), the electrophoretic mobilities were determined as 5.47 x 10-4 cm2/Vs for TcCl62- and 2.13 x 10-4 cm2/Vs for TcCl5(H2O)- at 25 C. The total analysis time for one run is 12 minutes. (orig.)

  19. On-line coupling of capillary gel electrophoresis with electrospray mass spectrometry for oligonucleotide analysis.

    Science.gov (United States)

    Freudemann, T; von Brocke, A; Bayer, E

    2001-06-01

    Homooligodeoxyribonucleotides differing one nucleotide in length from 12- to 15-mer and from 17- to 20-mer were separated by size with capillary gel electrophoresis (CGE) using an entangled polymer solution in coated capillaries. The resolved components were analyzed by on-line coupling of CGE with electrospray mass spectrometry (ES-MS), denoted as CGE/ES-MS, in the full-scan negative ion detection mode. Baseline separation was achieved for the 12-15-mer oligonucleotide mixtures. Both synthetic phosphodiester oligonucleotide mixtures as well as their phosphorothioate analogues, serving as model compounds for antisense oligonucleotides, could be analyzed by on-line CGE/ES-MS coupling. Terminally phosphorylated and nonphosphorylated synthetic failure sequences could be electrophoretically separated and mass spectrometically characterized as well. This methodology might be a useful tool for synthesis control of phosphodiester oligonucleotides as well as for analysis of phosphorothioate analogues as they are used in antisense drug development. PMID:11403304

  20. Rapid determination of salbutamol in pharmaceutical preparations by chiral capillary electrophoresis

    OpenAIRE

    Ekiert, Ela; García Ruiz, Carmen; García, María A.; Marina Alegre, María Luisa

    2003-01-01

    A fast and simple method of chiral capillary electrophoresis (CE) has been applied to the analysis of salbutamol in different pharmaceutical preparations. Using of a 25 mM acetate buffer (pH 5.0), containing 13.1 mg/mL carboxymethyl- -cyclodextrin (CM- - CD), an applied voltage of 20 kV and a temperature of 25 C, the enantiomers of salbutamol could be separated in about 2 min. Three different pharmaceutical preparations (two syrups, one oral solution, and two kind of tablets) containing a ...

  1. Use of Capillary Electrophoresis in the Study of Interaction between dsDNA and Drug Molecules

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Two 17-mer dsDNA with different sequence characteristics were designed to investigate the binding characteristics of berberine, an anticancer drug with uncertain binding mode, and Hoechst 33258, a model DNA minor groove binder, with dsDNA, respectively by the capillary zone electrophoresis (CZE). Kenndler model analysis revealed that Hoechst 33258 exhibited intermediate affinity with dsDNA, while there was only low affinity and some weak binding preference for AATT-containing to GGCC-containing dsDNA for berberine.

  2. Determination of diastereoisomeric alkaloids in urine by capillary electrophoresis with electrochemiluminescence detection

    Institute of Scientific and Technical Information of China (English)

    Yan Ming Liu; Long Fei Peng; Lin Mei; Li Juan Liu

    2011-01-01

    A new and simple capillary electrophoresis with electrochemiluminescence detection was developed for the separation and the quantification of a pair of diastereoisomeric alkaloids (ephedrine and pseudoephedrine). The limits of detection (S/N = 3) were 4.5 × 10-8 mol/L for ephedrine and 5.2×10-8 mol/L for pseudoephedrine, respectively. The RSDs of migration time and peak area were less than 1.3 and 2.5% (n = 5), respectively. The applicability of the propose method was illustrated in the determination of ephedrine and pseudoephedrine in human urine, ephedrine in nasal drops, and the monitoring of pharmacokinetics for pseudoephedrine.

  3. Potential of surface-enhanced Raman scattering detector for capillary electrophoresis

    Czech Academy of Sciences Publication Activity Database

    Přikryl, Jan; Klepárník, Karel; Foret, František

    Brno: Ústav analytické chemie AV ČR v. v. i., 2011 - (Foret, F.). s. 58 ISBN 978-80-904959-0-6. [International Interdisciplinary Meeting on Bioanalysis /8./. 03.11.2011-04.11.2011, Brno] R&D Projects: GA ČR(CZ) GAP301/11/2055; GA MŠk LC06023; GA ČR GA203/08/1680 Institutional research plan: CEZ:AV0Z40310501 Keywords : SERS * nanoparticle * capillary electrophoresis Subject RIV: CB - Analytical Chemistry, Separation

  4. Studies of Active Ingredients in Cough Syrup by Capillary Zone Electrophoresis with Amperometric Detection

    Institute of Scientific and Technical Information of China (English)

    ZHOU Tian-shu; WANG Ai-fang; WU Fang; SHI Guo-yue; FANG Yu-zhi

    2003-01-01

    The present paper covers a simple, reliable and reproducible method, based on capillary zone electrophoresis(CZE) with amperometric detection(AD), for the separation and the determination of ephedrine hydrochloride, promethazine hydrochloride and codeine phosphate. Under the optimal conditions, the three analytes were base-line separated completely within 16 min. Good linear relationships between the peak heights and the concentrations of the three analytes were obtained with the correlation coefficients better than 0.9993. The method was directly applied to the determination of the active ingredients in pharmaceutical preparations and the assay results were satisfactory.

  5. Capillary electrophoresis with inhibited electrochemiluminescent detection for the trace analysis of epinephrine and dopamine

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    In this paper,a novel electrochemiluminescent (ECL) detection approach was developed for highly sensitive detection of ECL inhibitors based on the ECL inhibition of Ru(bpy)32+/2-(Dibutylamino)ethanol (DBAE) system. A microfluidic ECL detection cell was fabricated to couple with the capillary electrophoresis system,the electrochemical system and the postcolumn injection system. Both Ru(bpy)32+ and DBAE solutions were injected directly to the working electrode surface by a micro-infusion system to obtain a hi...

  6. Capillary electrophoresis with direct chemiluminescence detection for the analysis of catecholamines in human urine

    Institute of Scientific and Technical Information of China (English)

    Cheng Quan Wang; Hui Wang; Yan Ming Liu

    2007-01-01

    A rapid and sensitive method for the analysis of three catecholamines by capillary electrophoresis (CE) with direct chemiluminescence (CL) detection is described. The detection limits (S/N = 3) were 1.3 × 10-8 g/mL for isoprenaline,1.0 × 10-8 g/mL for epinephrine and 2.8 × 10-8 g/mL for dopamine. The proposed method was successfully applied to the analysis of catecholamines in urine samples of cigarette smokers and nonsmokers. The results showed that there is a close relation between the release of dopamine in human body fluids and cigarette smoking/nonsmoking.

  7. Simple and rapid capillary electrophoresis analysis of formate in blood of methanol intoxicated persons

    Czech Academy of Sciences Publication Activity Database

    Pantůčková, Pavla; Kubáň, Pavel; Boček, Petr

    Česká farmaceutická společnost České lékařské společnosti J. E. Purkyně, 2013. s. 126-126. [Syntéza a analýza léčiv /42./. 02.09.2013-05.09.2013, Velké Karlovice] R&D Projects: GA ČR(CZ) GP13-05762S Institutional support: RVO:68081715 Keywords : blood samples * capillary electrophoresis * formate Subject RIV: CB - Analytical Chemistry, Separation

  8. Determination of lithium in lithium-aluminium alloy by capillary electrophoresis

    International Nuclear Information System (INIS)

    A simple and rapid method for the determination of lithium in lithium-aluminium alloy using capillary electrophoresis (CE) is developed. The method separates Li from other metal ions and it does not require prior separation of aluminium, which is major constituent of the alloy. Separation of Li was achieved using BGE of 20mM Imidazole (pH 2) with an applied voltage of 20kV. The precision of the method is better than 10% at 0.5 ppm of Li and LOD is 0.12 ppm. (author)

  9. A new injection method for soil nutrient analysis in capillary electrophoresis

    Science.gov (United States)

    Smolka, M.; Puchberger-Enengl, D.; Bipoun, M.; Fercher, G.; Klasa, A.; Krutzler, C.; Keplinger, F.; Vellekoop, M. J.

    2013-05-01

    We present a new method for the direct injection of liquid sample into a capillary electrophoresis (CE) device. Instead of a double-T injection mechanism, a single inlet provided with a membrane filter is used. From a reservoir on top of this inlet, the liquid directly enters the separation channel through the membrane. The driving force is a short electrical pulse. This avoids an additional sample channel, so that the chip needs only three microfluidic connects and no mechanical sample pumping is demanded. The high injection reproducibility and the comparatively simple setup open up the way for mobile application of soil analysis.

  10. Investigation of Melamine Presence in Canned Tuna Fish by Capillary Zone Electrophoresis Method

    OpenAIRE

    Er Demirhan, Buket; Demirhan, Burak; Yarımkaya Baş, Sezen; Yentür, Gülderen; Bayhan Öktem, Aysel

    2015-01-01

    Melamine is widely used as a chemical in food industry and may lead to kidney damage. The aim of this study was to determine melamine and pH value of 80 canned tuna fish samples of four different brands (A, B, C, D) sold in Ankara, Turkey. Quantitative determination of melamine in canned tuna fish samples was carried out by capillary zone electrophoresis with diode array detector (CZE-DAD). The limits of detection and quantitation for melamine were found to be 0.21 mg kg-1and 0.68 mg kg-1, re...

  11. Rapid diagnosis of methanol poisoning by direct coupling of microextraction techniques to capillary zone electrophoresis

    Czech Academy of Sciences Publication Activity Database

    Pantůčková, Pavla; Kubáň, Pavel; Boček, Petr

    Bratislava: Department of Analytical Chemistry, Faculty of Natural Sciences, Comenius University in Bratislava, 2015, s. 252-253. ISBN 978-80-971179-5-5. [International Conference Analytical Methods and Human Health /20./. Patince (SK), 15.06.2015-18.06.2015] R&D Projects: GA ČR(CZ) GA13-05762S Grant ostatní: GA AV ČR(CZ) R200311404 Institutional support: RVO:68081715 Keywords : methanol poisoning * microextraction techniques * capillary electrophoresis Subject RIV: CB - Analytical Chemistry, Separation

  12. Resolution of a configurationally stable [5]helquat. enantiocomposition analysis of a helicene congener by capillary electrophoresis

    Czech Academy of Sciences Publication Activity Database

    Severa, Lukáš; Koval, Dušan; Novotná, P.; Ončák, M.; Sázelová, Petra; Šaman, David; Slavíček, P.; Urbanová, M.; Kašička, Václav; Teplý, Filip

    2010-01-01

    Roč. 34, č. 6 (2010), s. 1063-1067. ISSN 1144-0546 R&D Projects: GA ČR GA203/09/1614; GA ČR GA203/09/0705; GA ČR(CZ) GA203/08/1428; GA ČR GAP207/10/2391 Institutional research plan: CEZ:AV0Z40550506 Keywords : [5]helquat * capillary electrophoresis * resolution via diastereoisomers Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.631, year: 2010

  13. Investigation of peptide complexes with small cations and cyclodextrins by capillary affinity electrophoresis

    Czech Academy of Sciences Publication Activity Database

    Kašička, Václav; Ehala, Sille; Šolínová, Veronika; Schimperková, Tereza; Sázelová, Petra; Koval, Dušan

    Praha : Institut of organic Chemistry and Biochemistry ASCR, 2009 - (Slaninová, J.), s. 55-58 ISBN 978-80-86241-31-9. - (Collection Symposium Series. 11). [Biologically Active Peptides. Conference /11./. Praha (CZ), 22.04.2009-24.04.2009] R&D Projects: GA ČR(CZ) GA203/08/1428 Grant ostatní: GA ČR(CZ) GA203/09/0675 Institutional research plan: CEZ:AV0Z40550506 Keywords : capillary affinity electrophoresis * valinomycin * peptide complexes Subject RIV: CB - Analytical Chemistry, Separation

  14. Chiral analysis of antimicrobial dipeptide beta-alanyl-tyrosine and its derivatives by capillary zone electrophoresis

    Czech Academy of Sciences Publication Activity Database

    Sázelová, Petra; Šolínová, Veronika; Schimperková, Tereza; Mášová, Alice; Jiráček, Jiří; Kašička, Václav

    Bratislava : Slovenská vákuová spoločnosť, 2013 - (Bodor, R.; Okenicová, L.; Staňová, A.), s. 234-236 ISBN 978-80-971179-1-7. [Analytické metódy a zdravie človeka. Medzinárodná konferencia /19./. Rajecké Teplice (SK), 24.06.2013-27.06.2013] R&D Projects: GA ČR(CZ) GAP206/12/0453; GA ČR GA13-17224S Institutional support: RVO:61388963 Keywords : antimicrobial peptides * chiral separation * capillary electrophoresis Subject RIV: CB - Analytical Chemistry, Separation

  15. Characterization of valinomycin binding with alkali metal ions by capillary affinity electrophoresis and density functional theory

    Czech Academy of Sciences Publication Activity Database

    Ehala, Sille; Dybal, Jiří; Makrlík, E.; Kašička, Václav

    Praha : Institut of organic Chemistry and Biochemistry ASCR, 2009 - (Slaninová, J.), s. 31-33 ISBN 978-80-86241-31-9. - (Collection Symposium Series. 11). [Biologically Active Peptides. Conference /11./. Praha (CZ), 22.04.2009-24.04.2009] R&D Projects: GA ČR(CZ) GA203/08/1428; GA AV ČR 1ET400500402 Institutional research plan: CEZ:AV0Z40550506; CEZ:AV0Z40500505 Keywords : capillary affinity electrophoresis * valinomycin * density funtional theory Subject RIV: CF - Physical ; Theoretical Chemistry

  16. Recent applications of capillary electrophoresis to analysis and physicochemical characterization of peptides

    Czech Academy of Sciences Publication Activity Database

    Kašička, Václav; Koval, Dušan; Ehala, Sille; Sázelová, Petra; Šolínová, Veronika; Hlaváček, Jan

    Praha : Institute of Organic Chemistry and Biochemistry AS CR, v. v. i, 2011 - (Slaninová, J.), s. 61-66 ISBN 978-80-86241-44-9. - (Collection Symposium Series. 13). [Biologically Active Peptides /12./. Praha (CZ), 27.04.2011-29.04.2011] R&D Projects: GA ČR(CZ) GA203/08/1428; GA ČR(CZ) GA203/09/0675 Institutional research plan: CEZ:AV0Z40550506 Keywords : capillary electrophoresis * peptides * proteins Subject RIV: CC - Organic Chemistry

  17. Affinity capillary electrophoresis and its application to investigation of noncovalent interactions of (bio)molecules

    Czech Academy of Sciences Publication Activity Database

    Kašička, Václav; Štěpánová, Sille; Konášová, Renáta; Růžička, Martin

    Rožnov pod Radhoštěm: Česká chromatografická škola, 2015. O9. [Česká chromatografická škola HPLC 2015. 03.05.2015-06.05.2015, Rožnov pod Radhoštěm] R&D Projects: GA ČR(CZ) GA13-17224S Institutional support: RVO:61388963 Keywords : affinity capillary electrophoresis * noncovalent interactions * binding constants Subject RIV: CB - Analytical Chemistry, Separation

  18. Study of deoxyribonucleic acid-ligand interactions by partial filling affinity capillary electrophoresis

    Czech Academy of Sciences Publication Activity Database

    Růžička, Martin; Čížková, Martina; Jirásek, Michael; Teplý, Filip; Koval, Dušan; Kašička, Václav

    2014-01-01

    Roč. 1349, Jul (2014), s. 116-121. ISSN 0021-9673. [ITP 2013. International Symposium on Electro- and Liquid Phase- Separation Techniques /20./. Puerto de la Cruz, 06.10.2013-09.10.2013] R&D Projects: GA ČR(CZ) GAP206/12/0453; GA ČR(CZ) GA13-17224S; GA ČR GA13-32974S; GA ČR GA13-19213S Institutional support: RVO:61388963 Keywords : affinity capillary electrophoresis * stability constant * DNA * ethidium bromide * oligophenylene derivatives * partial filling Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 4.169, year: 2014

  19. Affinity capillary electrophoresis applied to investigation of noncovalent bindings of (bio)molecules

    Czech Academy of Sciences Publication Activity Database

    Kašička, Václav; Norková, Renáta; Růžička, Martin; Koval, Dušan; Čížková, Martina; Teplý, Filip

    Pardubice: Univerzita Pardubice, 2014 - (Horna, A.; Jandera, P.). s. 39 ISBN 978-80-7395-777-3. [ISSS 2014. International Symposium on Separation Sciences /20./. 30.08.2014-02.09.2014, Praha] R&D Projects: GA ČR(CZ) GAP206/12/0453; GA ČR(CZ) GA13-17224S; GA ČR GA13-32974S Institutional support: RVO:61388963 Keywords : affinity capillary electrophoresis * noncovalent interactions * binding constants Subject RIV: CB - Analytical Chemistry, Separation

  20. Partial-filling affinity capillary electrophoresis applied to exploration of DNA oligonucleotides-ethidium bromide interactions

    Czech Academy of Sciences Publication Activity Database

    Růžička, Martin; Koval, Dušan; Kašička, Václav

    Pardubice: Univerzita Pardubice, 2014 - (Horna, A.; Jandera, P.). s. 81 ISBN 978-80-7395-777-3. [ISSS 2014. International Symposium on Separation Sciences /20./. 30.08.2014-02.09.2014, Praha] R&D Projects: GA ČR(CZ) GAP206/12/0453; GA ČR(CZ) GA13-17224S; GA ČR GA13-32974S Institutional support: RVO:61388963 Keywords : affinity capillary electrophoresis * partial filling * DNA complexes Subject RIV: CB - Analytical Chemistry, Separation

  1. Method development and optimization for the determination of rare earth metal ions by capillary zone electrophoresis

    International Nuclear Information System (INIS)

    The separation of rare earth metal ions by capillary zone electrophoresis in the presence of creatinine as UV-absorbing background electrolyte and the complexing agent 2-hydroxyisobutyric acid was investigated. The separation is mainly influenced by the pH of the buffer and the concentration of the complexing agent. Both parameters were used in a central composite design to determine optimal conditions. After modelling of the migration behaviour, the optimal conditions were selected using a multi-criteria approach in which separation coefficient (α), sensitivity and analysis time were considered. Finally, the method was validated regarding its detection limit, linearity and reproducibility

  2. Separation and determination of iron from uranium matrix by capillary zone electrophoresis (CZE)

    International Nuclear Information System (INIS)

    The paper describes about the development of a simple and rapid capillary zone electrophoresis (CZE) method for the separation and determination of iron from uranium compounds without assorting prior matrix separation. The uranium samples are dissolved in nitric acid medium and finally taken in 0.01M HCl to have the sample pH as 2. An electrolyte solution consisted of HCl and KCl having total concentration of 75mM was found to be suitable for achieving the desired separation of iron from uranium. Absorption detection at 214nm with direct detection mode was used. (author)

  3. Study on Rhizoma Chuanxiong based on capillary electrophoresis with amperometric detection

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    A high-performance capillary electrophoresis with amperometric detection(CE-AD) method has been developed for the analysis of seven bioactive ingredients,namely ferulic acid(FA),vanillin,vanillic acid,p-hydroxybenzoic acid,caffeic acid,gallic acid and protocatechuic acid,in Rhizoma Chuanxiong.The effects of several factors such as the acidity and concentration of running buffer,the separation voltage,the applied potential to working electrode and the injection time were investigated.Under the optimum con...

  4. Capillary electrophoresis is a sensitive monitor of the hairpin-random coil transition in DNA oligomers

    OpenAIRE

    Stellwagen, Earle; Renze, Anne; Stellwagen, Nancy C.

    2007-01-01

    Capillary electrophoresis (CE) has been used to characterize the hairpin-random coil transition of four octamers in the GCxxxxGC minihairpin family, where xxxx is GAAA, TTTC, TTTT, or AAAA. The transition can be monitored by CE because differences in the frictional coefficients of the hairpin and coil forms of each octamer lead to a difference of ~9% in the free solution mobilities of the two conformations. The GAAA octamer is unusually stable, with a melting temperature of 65°C. The TTTT oct...

  5. New electrolyte systems for capillary zone electrophoresis of metal cations and non-ionic organic compounds

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Y.

    1995-06-19

    Excellent separations of metal ions can be obtained very quickly by capillary electrophoresis provided a weak complexing reagent is incorporated into the electrolyte to alter the effective mobilities of the sample ions. Indirect photometric detection is possible by also adding a UV-sensitive ion to the electrolyte. Separations are described using phthalate, tartrate, lactate or hydroxyisobutyrate as the complexing reagent. A separation of twenty-seven metal ions was achieved in only 6 min using a lactate system. A mechanism for the separation of lanthanides is proposed for the hydroxyisobutyrate system.

  6. CAPILLARY ELECTROPHORESIS METHOD FOR THE DETERMINATION OF LACTULOSE AND MANNITOL RATIO FOR ESTIMATING INTESTINAL PERMEABILITY

    OpenAIRE

    E. TÜRKÖZ ACAR1, D. ÖZER ÜNAL2,*, M. KOÇ3, E. TÜRKÖZ ACAR1, D. ÖZER ÜNAL2,*, M.

    2014-01-01

    SUMMARYIn this study, a simple, rapid and accurate capillary electrophoresis method has been developed for the determination of lactulose and mannitol in urine for estimating the intestinal permeability. The urine samples were prepared to analyze by using solid phase extraction. For analysis a background electrolyte (BGE) consisted of 6 mmol/L sorbic acid, 1.25mmol/L hexadecyltrimethylammoniumbromide (HDTMA), 50 mmol/L LiOH (pH 12.5) was used. Separation was performed at -5 kV over 20 min wit...

  7. Optimized Separation of Pharmacologically Active Xanthones from Secuidaca inappendiculata by Capillary Electrophoresis

    Institute of Scientific and Technical Information of China (English)

    TaoBO; XueDongYANG; 等

    2002-01-01

    A capillary electrophoresis (CE) method has been firstly used for the separation of the therapeutically important xanthones from Securidaca inappendiculata. The separation of the nine xanthones was systematically optimized with respect to pH, concentration of running buffers,addition of sulfated β-CD,applied voltage and column temperature.Baseline separation was achieved for the nine xanthones in less than 15 minutes using a background electrolyte consisting of 200 mmol/L borate (pH9.5) and 10 mmol/L sulfated β-CD.

  8. Optimized Separation of Pharmacologically Active Xanthones from Securidaca inappendiculata by Capillary Electrophoresis

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A capillary electrophoresis (CE) method has been firstly used for the separation of the therapeutically important xanthones from Securidaca inappendiculata. The separation of the nine xanthones was systematically optimized with respect to pH, concentration of running buffers, addition of sulfated b-CD, applied voltage and column temperature. Baseline separation was achieved for the nine xanthones in less than 15 minutes using a background electrolyte consisting of 200 mmol/L borate (pH 9.5) and 10 mmol/L sulfated b-CD.

  9. Mapping small DNA ligand hydroxyl radical footprinting and affinity cleavage products for capillary electrophoresis.

    Science.gov (United States)

    He, Gaofei; Vasilieva, Elena; Bashkin, James K; Dupureur, Cynthia M

    2013-08-15

    The mapping of DNA footprints and affinity cleavage sites for small DNA ligands is affected by the choice of sequencing chemistry and end label, and the potential for indexing errors can be significant when mapping small ligand-DNA interactions. Described here is a mechanism for avoiding such errors based on a summary of standard labeling, cleavage, and indexing chemistries and a comparison among them for analysis of these interactions by capillary electrophoresis. The length dependence of the difference between Sanger and Maxam-Gilbert indexing is examined for a number of duplexes of mixed sequence. PMID:23608054

  10. Self-assembly of cellulose nanoparticles as electrolyte additive for capillary electrophoresis separation.

    Science.gov (United States)

    Huang, Dihui; Yang, Qin; Jin, Shanxia; Deng, Qianchun; Zhou, Ping

    2014-11-01

    In this work, a new cellulose derivative, octadecyl modified quaternized cellulose (ODMQC), was synthesized and used as additive in the background electrolyte for capillary electrophoresis. The derivative bearing hydrophobic groups and hydrophilic groups can self-assemble into a stable nano-scaled micelle structure in aqueous solution. When ODMQC was added in running buffer, the capillaries were shown to generate applicable anodal EOF over the investigated range of pH 3.0-12.0. Due to the lack of UV active groups, the ODMQC did not disturb the UV detection. It is shown that ODMQC-added capillaries allow the separation of basic proteins by reducing their adsorption onto the capillary wall. Also, the addition of ODMQC provides adequate separation of aromatic acids with low pKa values and improved separation of sulfa drugs. Moreover, it is demonstrated that the addition of ODMQC can incorporate an additional reversed-phase mechanism that improves the separation of neutral analytes. PMID:25262028

  11. A new post-column reactor-laser induced fluorescence detector for capillary electrophoresis

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Liling

    1996-01-02

    Capillary zone electrophoresis (CZE), a powerful separation method based on the differential migration of charged species under the influence of an electric field, has been widely used for separations covering from small ions to big biomolecules. Chapter 1 describes the method, then discusses detection of the separated analytes by laser induced fluorescence and by chemical derivatization, and the use of O-phthaldialdehyde (OPA) as a post-column reagent. Chapter 2 describes a post-column reactor which uses two narrow bore capillaries connected coaxially. This reactor differs from other coaxial reactors in terms of capillary dimensions, reagent flow control, ease of construction and most importantly, better limits of detection. The derivatization reagent is electroosmotically driven into the reaction capillary and the reagent flow rate is independently controlled by a high voltage power supply. Amino acids, amines and proteins, derivatized by OPA/2-mercaptoethanol using this post-column reactor coupled with LIF detection, show low attomole mass limits of detection, and for the first time, the authors demonstrate single cell capability with a post-column derivatization scheme. The single cell capability shows that this reactor could find applications in assaying non-fluorescent or electrochemically inactive components in individual biological cells in the future.

  12. Laser ablation construction of on-column reagent addition devices for capillary electrophoresis.

    Science.gov (United States)

    Rezenom, Yohannes H; Lancaster, Joseph M; Pittman, Jason L; Gilman, S Douglass

    2002-04-01

    A simple and reproducible technique for constructing perfectly aligned gaps in fused-silica capillaries has been developed for postcolumn reagent addition with capillary electrophoresis. This technique uses laser ablation with the second harmonic of a Nd:YAG laser (532 nm) at 13.5 mJ/pulse and a repetition rate of 15 Hz to create these gaps. A capillary is glued to a microscope slide and positioned at the focal point of a cylindrical lens using the focused beam from a laser pointer as a reference. Gaps of 14.0 +/- 2.2 microm (n = 33) at the bore of the capillary are produced with a success rate of 94% by ablation with 400 pulses. This simple method of gap construction requires no micromanipulation under a microscope, hydrofluoric acid etching, or use of column fittings. These structures have been used for reagent addition for postcolumn derivatization with laser-induced fluorescence detection and have been tested for the separation of proteins and amino acids. Detection limits of 6 x 10(-7) and 1 x 10(-8) M have been obtained for glycine and tranferrin, respectively. Separation efficiencies obtained using these gap reactors range from 38,000 to 213,000 theoretical plates. PMID:12043598

  13. Capillary electrophoresis of heparin and other glycosaminoglycans using a polyamine running electrolyte

    International Nuclear Information System (INIS)

    Highlights: ► Ethylenediamine is likely acting as an ion-pairing agent. ► Oversulfated chondroitin sulfate is last peak instead of first peak. ► There is about a factor of five improved detectability with a 12.5 min analysis time. ► Use of a 50 μm ID capillary is possible. - Abstract: This study involves the use of polyamines as potential resolving agents for the capillary electrophoresis (CE) of glycosaminoglycans (GAGs), specifically heparin, dermatan sulfate, chondroitin sulfate, over-sulfated chondroitin sulfate (OSCS), and hyaluronan. All of the compounds can be separated from each other with the exception of chondroitin sulfate and hyaluronan. Using optimization software, the final run conditions are found to be 200 mM ethylenediamine and 45.5 mM phosphate as the electrolyte with −14 V applied across a 50 μm ID × 24.5 cm fused silica capillary at 15 °C. The ion migration order, with OSCS as the last instead of the first peak, is in contrast to previous reports using either a high molarity TRIS or lithium phosphate run buffer with narrower bore capillaries. Total analysis time is 12. 5 min and the relative standard deviation of the heparin migration time is about 2.5% (n = 5). The interaction mechanism between selected polyamines and heparin is explored using conductivity measurements in addition to CE experiments to show that an ion-pairing mechanism is likely.

  14. Sodium dodecyl sulfate-capillary gel electrophoresis of proteins using non-cross-linked polyacrylamide.

    Science.gov (United States)

    Wu, D; Regnier, F E

    1992-09-11

    Proteins with relative molecular masses of 14,000 to 205,000 were separated by sodium dodecyl sulfate-capillary gel electrophoresis (SDS-CGE) using non-cross-linked linear polyacrylamide gels on both coated and uncoated fused-silica capillaries. It was determined that viscosity of the acrylamide solution was a major factor affecting column stability with linear acrylamide gels. When the viscosity of the acrylamide solution reaches 100 cP, electro-osmotically driven displacement of the gels is insignificant. Uncoated capillaries provided better resolution, stability, and reproducibility than surface coated capillaries when the concentration of linear polyacrylamide was greater than 4%. At lower gel concentrations, non-cross-linked polyacrylamide is easily displaced from the columns. A calibration plot of log molecular mass vs. mobility with non-linear polyacrylamide was linear, which indicated that resolution was equivalent to that obtained with cross-linked acrylamide. Separations with model proteins indicated that baseline resolution between protein species that vary 10% in molecular mass can be achieved. PMID:1430034

  15. A fluorescence detection scheme for capillary electrophoresis of N-methylcarbamates with on-column thermal decomposition and derivatization

    Science.gov (United States)

    Wu; Lee; Li

    2000-04-01

    This paper describes a fluorescence detection method for N-methylcarbamate (NMC) pesticides in micellar electrokinetic chromatography (MEKC) separation. Fulfillment of the fluorescence detection hinged on the discovery that quaternary ammonium surfactants (particularly cetyltrimethylammonium bromide, CTAB), besides serving as hydrophobic pseudophases in MEKC, are also capable of catalyzing the thermal decomposition of NMCs to liberate methylamine. Thus, a multifunctional MEKC medium consisting of borate buffer, CTAB, and derivatizing components (o-phthaldialdehyde/2-mercaptoethanol) was formulated, which allowed first normal MEKC separation, subsequent thermal decomposition, and finally in situ derivatization of NMCs. With careful optimization of the operation conditions, fluorescence detection of 10 NMC compounds was achieved, with column efficiencies typically higher than 50,000 and detection limits better than 0.5 ppm. The present work represents an unprecedented effort in capillary electrophoresis (CE), in which an intact capillary was consecutively utilized as chambers for separation, decomposition, derivatization, and detection, without involving any interfacing features. The success in the implementation of such a detection system resulted in strikingly simple instrumentation as compared with the traditional postcolumn fluorescence determination of NMCs by reversed-phase HPLC. Similar protocols should be workable in the determination of a wide range of pesticides and pharmaceuticals in CE formats. PMID:10763238

  16. Determination of artificial sweeteners by capillary electrophoresis with contactless conductivity detection optimized by hydrodynamic pumping.

    Science.gov (United States)

    Stojkovic, Marko; Mai, Thanh Duc; Hauser, Peter C

    2013-07-17

    The common sweeteners aspartame, cyclamate, saccharin and acesulfame K were determined by capillary electrophoresis with contactless conductivity detection. In order to obtain the best compromise between separation efficiency and analysis time hydrodynamic pumping was imposed during the electrophoresis run employing a sequential injection manifold based on a syringe pump. Band broadening was avoided by using capillaries of a narrow 10 μm internal diameter. The analyses were carried out in an aqueous running buffer consisting of 150 mM 2-(cyclohexylamino)ethanesulfonic acid and 400 mM tris(hydroxymethyl)aminomethane at pH 9.1 in order to render all analytes in the fully deprotonated anionic form. The use of surface modification to eliminate or reverse the electroosmotic flow was not necessary due to the superimposed bulk flow. The use of hydrodynamic pumping allowed easy optimization, either for fast separations (80s) or low detection limits (6.5 μmol L(-1), 5.0 μmol L(-1), 4.0 μmol L(-1) and 3.8 μmol L(-1) for aspartame, cyclamate, saccharin and acesulfame K respectively, at a separation time of 190 s). The conditions for fast separations not only led to higher limits of detection but also to a narrower dynamic range. However, the settings can be changed readily between separations if needed. The four compounds were determined successfully in food samples. PMID:23830447

  17. Determination of cobalamins using capillary electrophoresis inductively coupled plasma mass spectrometry

    Science.gov (United States)

    Baker, S. A.; Miller-Ihli, N. J.

    2000-12-01

    The determination of cobalamins using capillary electrophoresis inductively coupled plasma mass spectrometry (CE-ICP-MS) was investigated. Both capillary zone electrophoresis (CZE) and micellar electrokinetic chromatography (MEKC) modes of operation were studied. The optimal separation of four cobalamin species (cyanocobalamin, hydroxocobalamin, methylcobalamin, and 5'-deoxyadenosylcobalamin) and a potentially harmful corrinoid analogue (cobinamide dicyanide) was obtained using CZE at a pH of 2.5. Both 20 mM phosphate and 20 mM formate buffers were used with success, although the formate buffer provided improved resolution. The CZE-ICP-MS method was used to quantify cyanocobalamin in a vitamin supplement and the analytical results were in good agreement (±5%) with values obtained by ICP-MS for total Co levels. The solution detection limits for cobalamins using CZE-ICP-MS were approximately 50 ng/ml. MEKC was found to be useful for the screening of vitamin preparations because it provided a rapid means of distinguishing cyanocobalamin (the form most commonly used in vitamin preparations) from free cobalt. The separation of free cobalt and cyanocobalamin using MEKC was achieved in less than 10 min.

  18. On-line detection of small radioactive ions by capillary electrophoresis

    International Nuclear Information System (INIS)

    Worldwide environmental interests have placed a great demand on developing techniques for rapid characterization of contaminated soil and groundwater. Detection of radioactive contaminants is necessary for monitoring effluents from nuclear processes or to assure proper long term storage of radioactive waste. The authors have been investigating the chemistry required to separate representative radioactive small cations and anions by capillary electrophoresis. In order to evaluate the separation chemistry, detection of stable isotopes of the representative ions was achieved by indirect absorption for cations and direct absorption for anions. Several buffer systems which have been considered in the optimization of the separations will be discussed. The authors have designed and tested two on-line radioactivity detectors for capillary electrophoresis. An on-line solid state CdTe detector was constructed for this study and a scintillation detector has been designed using a high gain photodiode light sensor. Different scintillation materials have been tested. Comparison of the detectors, design considerations, efficiency and limits of detection will be presented

  19. Highly sensitive fluorescence detection with Hg-lamp and photon counter in microchip capillary electrophoresis

    International Nuclear Information System (INIS)

    A microchip capillary electrophoresis system with highly sensitive fluorescence detection is reported. The system was successfully constructed using an inverted fluorescence microscope, a highly sensitive photon counter, a photomultiplier tube (PMT) and a capillary electrophoresis microchip. This system can be applied to the fluorescence detection with various wavelengths (300-600 nm). Different fluorescence reagents require different excitation wavelengths. The wavelengths of UV light (300-385 nm), blue light (450-480 nm) and green light (530-550 nm) are employed to excite Titan yellow, fluorescence-5-isothiocyanate (FITC) and Rhodamine 6G, respectively. The detection limit (S/N = 3) of FITC is 7 x 10-10 M, which is 2-3 orders of magnitude lower than that obtained with the lamp-based fluorescence and PMT detection system and approaches the data gained by the laser-induced fluorescence detection. The linear relationship is excellent within the range of concentration 1.3 x 10-9 to 6.5 x 10-8 M FITC. It offers a new method to widen the application of the lamp-based fluorescence detection

  20. Genomic DNA detection using cycling probe technology and capillary gel electrophoresis with laser-induced fluorescence.

    Science.gov (United States)

    Dickinson Laing, Terrina; Mah, David C W; Poirier, Robert T; Bekkaoui, Faouzi; Lee, William E; Bader, Douglas E

    2004-10-01

    Cycling probe technology (CPT) is an isothermal DNA analysis method that has been shown to be useful for identifying genetic markers of antibiotic-resistant bacteria in clinical settings. CPT assays have previously employed several assay methods that include polyacrylamide gel electrophoresis and magnetic beads for separations and radioisotopic and colorimetric detection for detection. Capillary gel electrophoresis with laser-induced fluorescence (CGE-LIF) is an alternative separation and detection method that offers attributes such as low sample consumption, short analysis times, no radiation hazards and potential for high throughput. We report on the development of a CGE-LIF CPT assay for genomic DNA from Erwinia herbicola and the comparison of this assay with a conventional 32p radioisotopic PAGE CPT assay. Separation and detection of intact and cleaved fluorescein-labeled CPT probe molecules by CGE-LIF was achieved in under 4 min through a gel-filled capillary (7 cm separation length to detector). Total time, from setup to detection, was about 1 h for the complete assay versus several hours (3-12 h) for the radioisotopic PAGE CPT assay. Similar detection limits of 10(5)-10(6) copies of genomic target DNA were observed with each assay method. This study demonstrated that CGE-LIF CPT is a suitable analysis method for the detection of genomic DNA sequences. PMID:15356906

  1. Protonated diamines as anion-binding agents and their utility in capillary electrophoresis separations.

    Science.gov (United States)

    Noblitt, Scott D; Speights, Rachel M; Henry, Charles S

    2011-11-01

    Capillary zone electrophoresis is a proven method for separating small ions because of the inherent charge and differences in mobility of these analytes. Despite its resolving power, CZE can be insufficient for separating ions with similar mobilities. One remedy is to modify mobilities via the addition of background electrolyte complexation agents. However, this approach is not straightforward for inorganic anions, which lack complexation options. To address this shortfall, the diprotonated diamine moiety was investigated for complexation of dianions. Dicationic diamines significantly complexed dianions, and this interaction was not purely electrostatic in nature because affinities varied with dianion identity. Aqueous association constants were measured with affinity capillary electrophoresis (ACE) and found to be similar in magnitude but different in selectivity to those of dianions with magnesium ion. Binding was also investigated for zwitterionic buffers containing the protonated diamine moiety. Zwitterions exhibited binding constants as high as 18 M(-1) (30-mM ionic strength). This work discusses the observed binding constants and their potential usefulness in CZE separations of inorganic anions. Also covered are improvements to ACE methodology and an evaluation of some of the assumptions employed. PMID:22002837

  2. Capillary electrophoresis based on nucleic acid detection for diagnosing human infectious disease.

    Science.gov (United States)

    Lian, Dong-Sheng; Zhao, Shu-Jin

    2016-04-01

    Rapid transmission, high morbidity, and mortality are the features of human infectious diseases caused by microorganisms, such as bacteria, fungi, and viruses. These diseases may lead within a short period of time to great personal and property losses, especially in regions where sanitation is poor. Thus, rapid diagnoses are vital for the prevention and therapeutic intervention of human infectious diseases. Several conventional methods are often used to diagnose infectious diseases, e.g. methods based on cultures or morphology, or biochemical tests based on metabonomics. Although traditional methods are considered gold standards and are used most frequently, they are laborious, time consuming, and tedious and cannot meet the demand for rapid diagnoses. Disease diagnosis using capillary electrophoresis methods has the advantages of high efficiency, high throughput, and high speed, and coupled with the different nucleic acid detection strategies overcomes the drawbacks of traditional identification methods, precluding many types of false positive and negative results. Therefore, this review focuses on the application of capillary electrophoresis based on nucleic detection to the diagnosis of human infectious diseases, and offers an introduction to the limitations, advantages, and future developments of this approach. PMID:26352354

  3. Qualitative and quantitative analysis of cations and anions using ion selective detectors in capillary electrophoresis

    International Nuclear Information System (INIS)

    The present work reports on the application of ion-selective microelectrodes as potentiometric detectors for the qualitative and quantitative analysis of cations and anions separated by capillary electrophoresis. Due to the high internal resistance of microelectrodes, their potentials are strongly affected by external electrical fields. Therefore, the influence of the electrophoretic field on the electrode response had to be kept at a minimum. With the electrode tip inserted in the capillary aperture (on-column detection), heavy drifts and noise of the signals were observed, mainly because the electrophoretic potential is superimposed on the Nernstian electrode response. As the potential inside the capillary is site-dependent, already minor movements and vibrations not perceptible under the light microscopy cause unacceptable disturbances of the electrode signal. One possibility to solve the problem consists in post- or off-column detection, i.e., with the detector located outside the influence of the electrophoretic field. If quantitative analyses with maximum resolution are to be achieved, only on-column detection is suitable because outside the capillary, the separation efficiency drops drastically. By etching the detector-side capillary end to a conical aperture, the field strength in the last 10 μm fell approximately 1/25 as compared with that in a cylindrical one. Thus, potential drifts and noise were reduced correspondingly so that on-column detection can also be used for potentiometric detection. To obtain quantitative results, the signals of the ion-selective detector were first delogarithmized and then integrated over time. Thus, it was possible to quantify cations and anions with a coefficient of variations ≤5%. (author) figs., tabs., 179 refs

  4. Monitoring antigenic protein integrity during glycoconjugate vaccine synthesis using capillary electrophoresis-mass spectrometry.

    Science.gov (United States)

    Tengattini, Sara; Domínguez-Vega, Elena; Temporini, Caterina; Terreni, Marco; Somsen, Govert W

    2016-09-01

    A capillary electrophoresis-mass spectrometry (CE-MS) method was developed for the characterization and integrity assessment of the Mycobacterium tuberculosis (MTB) antigens TB10.4 and Ag85B and their chemically produced glycoconjugates, which are glycovaccine candidates against tuberculosis (TB). In order to prevent protein adsorption to the inner capillary wall and to achieve efficient separation of the antigen proteoforms, a polyionic multilayer coating of polybrene-dextran sulfate-polybrene (PB-DS-PB) was used in combination with 1.5 M acetic acid as background electrolyte (BGE). Coupling of CE to high-resolution time-of-flight MS was achieved by a coaxial interface employing a sheath liquid of isopropanol-water (50:50, v/v) containing 0.1 % formic acid. The MTB antigens were exposed to experimental conditions used for chemical glycosylation (but no activated saccharide was added) in order to investigate their stability during glycovaccine production. CE-MS analysis revealed the presence of several closely related degradation products, including truncated, oxidized and conformational variants, which were assigned by accurate mass. Analysis of synthesized mannose conjugates of TB10.4 and Ag85B allowed the determination of the glycoform composition of the neo-glycoproteins next to the characterization of degradation products which were shown to be partly glycoconjugated. Moreover, the selectivity of CE-MS allowed specific detection of deamidated species (protein mass change of 1.0 Da only), indicating that chemical glycosylation increased susceptibility to deamidation. Overall, the results show that CE-MS represents a useful analytical tool for the detailed characterization and optimization of neo-glycoconjugate products. Graphical Abstract Flowchart illustrating Mycobacterium tuberculosis (MTB) antigen glycosylation, glycoconjugate variant and degradation product separation by capillary electrophoresis (CE) and their characterization by intact mass

  5. Cyclodextrine Screening for the Chiral Separation of Amlodipine Enantiomers by Capillary Electrophoresis

    Directory of Open Access Journals (Sweden)

    Gabriel Hancu

    2015-03-01

    Full Text Available Purpose: Amlodipine is a long acting, dihydropyridine type calcium channel blocker frequently used in the treatment of hypertension and coronary insufficiency. The calcium channel blocking activity resides primarily in the S-amlodipine enantiomer, while R-amlodipine is a potent inhibitor of smooth muscle cell migration. Methods: In this study capillary electrophoresis was applied for the enantiomeric separation of amlodipine using different native and derivatized; neutral and charged cyclodextrines as chiral selectors. The effects of pH and composition of the background electrolyte, concentration and type of chiral selector, capillary temperature, running voltage and injection parameters have been investigated. Results: Stereoselective interactions were observed when using α-CD, β-CD, HP-β-CD, RAMEB, CM-β-CD and SBE-β-CD. Optimized separation conditions consisted on a 50 mM phosphate buffer, pH – 3.0, 20 mM RAMEB as chiral selector, + 25 kV applied voltage, 15°C temperature and UV detection at 238 nm. Using the optimized electrophoretic conditions we succeeded the chiral separation of amlodipine enantiomers in approximately 6 minute, the order of migration being R-amlodipine followed by S-amlodipine. The method was successfully applied for the determination of amlodipine enantiomers from commercially available pharmaceuticals. The linearity range, limits of detection and quantification, precision and accuracy were determined and the results obtained confirmed that the method was suitable for this purpose. Conclusion: It can be concluded that the proposed capillary electrophoresis methods can be useful for routine pharmaceutical applications with benefits of its effectivity, simplicity, short analysis time and low consumption of analytes, solvents and chiral selectors.

  6. Discrimination between peak spreading in capillary zone electrophoresis of proteins due to interaction with the capillary wall and due to protein microheterogeneity

    Czech Academy of Sciences Publication Activity Database

    Šťastná, Miroslava; Radko, S. P.; Chrambach, A.

    2001-01-01

    Roč. 22, č. 1 (2001), s. 66-70. ISSN 0173-0835 Institutional research plan: CEZ:AV0Z4031919 Keywords : capillary electrophoresis * dispersion mechanism * wall interaction versus microheterogeneity Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 4.282, year: 2001

  7. The multi-concentration and two-dimensional capillary electrophoresis method for the analysis of drugs in urine samples

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    A novel method has been developed by integration of multi-concentration and two-dimensional(2D) capillary electrophoresis(CE) for simultaneous enhancement of detection sensitivity and separation power in complex samples.Capillary zone electrophoresis(CZE) was used as the first dimension separation according to mobilities,from which the effluent fractions were further analyzed by micellar electrokinetic capillary chromatography(MEKC) acting as the second dimension.Cation-selective exhaustive injection(CSEI) preconcentration method was used to introduce more analytes into the capillary.Furthermore,pH junction and sweeping dual concentration strategies were employed to avoid sample zone diffusion at the interface.The resulting electrophoregram was quite different from that of either CZE or MEKC separation.Up to(0.5-1.2) ×104 fold improvements in sensitivity were obtained relative to the conventional electrokinetic injection method.The proposed method was successfully applied to the determination of drugs in human urine.

  8. Determination of the specific activities of methionine sulfoxide reductase A and B by capillary electrophoresis.

    Science.gov (United States)

    Uthus, Eric O

    2010-06-01

    A capillary electrophoresis (CE) method for the determination of methionine sulfoxide reductase A and methionine sulfoxide reductase B activities in mouse liver is described. The method is based on detection of the 4-(dimethylamino)azobenzene-4'-sulfonyl derivative of l-methionine (dabsyl Met), the product of the enzymatic reactions when either dabsyl l-methionine S-sulfoxide or dabsyl l-methionine R-sulfoxide is used as a substrate. The method provides baseline resolution of the substrates and, therefore, can be used to easily determine the purity of the substrates. The method is rapid ( approximately 20min sample to sample), requires no column regeneration, and uses very small amounts of buffers. Separation was performed by using a 75-mum internal diameter polyimide-coated fused silica capillary (no inside coating) with 60cm total length (50cm to the detector window). Samples were separated at 22.5kV, and the separation buffer was 25mM KH(2)PO(4) (pH 8.0) containing 0.9ml of N-lauroylsarcosine (sodium salt, 30% [w/v] solution) per 100ml of buffer. Prior to use, the capillary was conditioned with the same buffer that also contained 25mM sodium dodecyl sulfate. The CE method is compared with high-performance liquid chromatography (HPLC) as determined by comparing results from measurements of hepatic enzyme activities in mice fed either deficient or adequate selenium. PMID:20167203

  9. Quality criterion to optimize separations in capillary electrophoresis: Application to the analysis of harmala alkaloids.

    Science.gov (United States)

    Tascon, Marcos; Benavente, Fernando; Castells, Cecilia B; Gagliardi, Leonardo G

    2016-08-19

    In capillary electrophoresis (CE), resolution (Rs) and selectivity (α) are criteria often used in practice to optimize separations. Nevertheless, when these and other proposed parameters are considered as an elementary criterion for optimization by mathematical maximization, certain issues and inconsistencies appear. In the present work we analyzed the pros and cons of using these parameters as elementary criteria for mathematical optimization of capillary electrophoretic separations. We characterized the requirements of an ideal criterion to qualify separations within the framework of mathematical optimizations and, accordingly, propose: -1- a new elementary criterion (t') and -2- a method to extend this elementary criterion to compose a global function that simultaneously qualifies many different aspects, also called multicriteria optimization function (MCOF). In order to demonstrate this new concept, we employed a group of six alkaloids with closely related structures (harmine, harmaline, harmol, harmalol, harmane and norharmane). On the basis of this system, we present a critical comparison between the new optimization criterion t' and the former elementary criteria. Finally, aimed at validating the proposed methods, we composed an MCOF in which the capillary-electrophoretic separation of the six model compounds is mathematically optimized as a function of pH as the unique variable. Experimental results subsequently confirmed the accuracy of the model. PMID:27443250

  10. Rugged gap reactor device for postcolumn fluorescence detection in capillary electrophoresis.

    Science.gov (United States)

    Wei, H; Li, S F

    1998-12-01

    In this paper, the construction and performance of a rugged device for postcolumn derivatization in capillary electrophoresis (CE) are described. The device was based on a gap design, and a gap with a very small distance (derivatizing reagents into the reaction capillary was attributable to gravity flow. The concentration of derivatizing reagents can be controlled through manipulating the electroosmotic flow in the reaction capillary and the height of the liquid levels from the derivatizing reagents to the buffer reservoirs. The device has been applied in fluorescence detection of amino acids using a mixture of o-phthaldialdehyde/2-mercaptoethanol as derivatizing reagent. Theoretical plate numbers for 11 amino acids separated in a pH 9.5 borate buffer were obtained in the order of 40 000-250 000. The detection limit for glycine (S/N = 2) was found to be 6.7 × 10(-)(7) mol/L using a commercial HPLC fluorescence detector modified for CE. Free amino acids in a wine sample were also determined. Because the device is quite stable, we believe that it can be used routinely in analytical laboratories. PMID:21644687

  11. Determination of biogenic amines in beer and wine by capillary electrophoresis-tandem mass spectrometry.

    Science.gov (United States)

    Daniel, Daniela; Dos Santos, Vagner Bezerra; Vidal, Denis Tadeu Rajh; do Lago, Claudimir Lucio

    2015-10-16

    A capillary electrophoresis-tandem mass spectrometry (CE-MS/MS) method for the simultaneous assessment of nine biogenic amines (spermine, spermidine, putrescine, cadaverine, histamine, phenylethylamine, tryptamine, tyramine, and urocanic acid) in commercial samples of beer and wine is introduced. The samples were submitted to a simple clean-up step with poly(vinylpolypyrrolidone) followed by filtration. Electrophoretic separation in a polyvinyl alcohol (PVA)-coated capillary using 0.5 mol L(-1) acetic acid (pH 2.5) as background electrolyte and detection by electrospray-tandem mass spectrometry was employed. The range of the correlation coefficients of the calibration curves of the analyzed compounds was 0.996-0.999, and the limits of detection and limits of quantification were in the range of 1-2 μg L(-1) and 3-8 μg L(-1), respectively. The recovery values for samples spiked at three concentration levels (0.2, 0.5, and 1.0 mg L(-1)) ranged from 87 to 113% with standard deviation not greater than 5.8%. The use of a PVA-coated silica capillary allows suppressing the electroosmotic flow and, consequently, increasing of the separation efficiency. The method was successfully used to determine biogenic amines in commercial samples of beer and wine. PMID:26362807

  12. Automated sample preparation and analysis using a sequential-injection-capillary electrophoresis (SI-CE) interface.

    Science.gov (United States)

    Kulka, Stephan; Quintás, Guillermo; Lendl, Bernhard

    2006-06-01

    A fully automated sequential-injection-capillary electrophoresis (SI-CE) system was developed using commercially available components as the syringe pump, the selection and injection valves and the high voltage power supply. The interface connecting the SI with the CE unit consisted of two T-pieces, where the capillary was inserted in one T-piece and a Pt electrode in the other (grounded) T-piece. By pressurising the whole system using a syringe pump, hydrodynamic injection was feasible. For characterisation, the system was applied to a mixture of adenosine and adenosine monophosphate at different concentrations. The calibration curve obtained gave a detection limit of 0.5 microg g(-1) (correlation coefficient of 0.997). The reproducibility of the injection was also assessed, resulting in a RSD value (5 injections) of 5.4%. The total time of analysis, from injection, conditioning and separation to cleaning the capillary again was 15 minutes. In another application, employing the full power of the automated SIA-CE system, myoglobin was mixed directly using the flow system with different concentrations of sodium dodecyl sulfate (SDS), a known denaturing agent. The different conformations obtained in this way were analysed with the CE system and a distinct shift in migration time and decreasing of the native peak of myoglobin (Mb) could be observed. The protein samples prepared were also analysed with off-line infrared spectroscopy (IR), confirming these results. PMID:16732362

  13. Determination of Amino Acids in Panax notoginseng by Microwave Hydrolysis and Derivatization Coupled with Capillary Zone Electrophoresis Detection

    Institute of Scientific and Technical Information of China (English)

    LI Xiao-tian; ZHAO Ya-jing; JIANG Cheng-fei; ZHANG Han-qi; YU Ai-min

    2013-01-01

    The microwave hydrolysis and derivatization coupled with capillary electrophoresis detection were developed for the separation and determination of the amino acids in Panax notoginseng.The experimental conditions for the microwave hydrolysis and derivatization were examined and optimized.Several parameters of capillary electrophoresis,such as pH value of background electrolyte,borate concentration and applied voltage were optimized.Under the selected conditions,11 amino acids were completely separated.The real sample was analyzed and the results were satisfactory.Compared with that of conventional heat hydrolysis and derivatization,the analytical time of this method was significantly shortened.

  14. Enantiopurity analysis of anti-AIDS drugs and related acyclic nucleoside phosphonates-based antivirotics by capillary electrophoresis

    Czech Academy of Sciences Publication Activity Database

    Kašička, Václav; Šolínová, Veronika; Sázelová, Petra; Mikysková, Hana; Koval, Dušan; Holý, Antonín

    Alphaville: AlphaGraphics, 2013 - (Guzman, N.; Tavares, M.). s. 32-32 [LACE 2013. Latin-American Symposium on Biotechnology, Biomedical, Biopharmaceutical, and Industrial Applications of Capillary Electrophoresis and Microchip Technology /19./. 29.11.2013-03.12.2013, Lima] R&D Projects: GA ČR(CZ) GAP206/12/0453; GA ČR(CZ) GA13-17224S; GA MŠk(CZ) ME10040; GA MV VG20102015046 Institutional support: RVO:61388963 Keywords : acyclic nucleoside phosphonates * capillary electrophoresis * chiral analysis Subject RIV: CB - Analytical Chemistry, Separation

  15. Purification and analysis of antimicrobial components from flesfly Neobellieria Bullata by free-flow and capillary zone electrophoresis, and HPLC

    Czech Academy of Sciences Publication Activity Database

    Sázelová, Petra; Šolínová, Veronika; Kašička, Václav; Ciencialová, Alice; Jiráček, Jiří

    - : -, 2007, R05. ISBN 978-80-227-2698-6. [International Symposium on Separation Sciences /13./. Štrbské Pleso (SK), 27.06.2007-29.06.2007] R&D Projects: GA ČR GA203/05/2539; GA ČR GA203/06/1044 Institutional research plan: CEZ:AV0Z40550506 Keywords : capillary zone electrophoresis * free-flow zone electrophoresis * antimicrobial peptides * beta-Ala-Tyr Subject RIV: CB - Analytical Chemistry, Separation

  16. Fast separation of DNA sequencing fragments in highly alkaline solutions of linear polyacrylamide using electrophoresis in bare silica capillaries

    Czech Academy of Sciences Publication Activity Database

    Klepárník, Karel; Malá, Zdeňka; Boček, Petr

    2001-01-01

    Roč. 22, č. 4 (2001), s. 783-788. ISSN 0173-0835 R&D Projects: GA ČR GA203/00/0772; GA ČR GA303/00/0928; GA AV ČR IAA4031703 Institutional research plan: CEZ:AV0Z4031919 Keywords : capillary electrophoresis * alkaline environment * bare capillary Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 4.282, year: 2001

  17. Capillary electrophoresis of heparin and other glycosaminoglycans using a polyamine running electrolyte

    Energy Technology Data Exchange (ETDEWEB)

    Loegel, Thomas N.; Trombley, John D.; Taylor, Richard T. [Department of Chemistry and Biochemistry, Miami University, Oxford, OH 45056 (United States); Danielson, Neil D., E-mail: danielnd@muohio.edu [Department of Chemistry and Biochemistry, Miami University, Oxford, OH 45056 (United States)

    2012-11-13

    Highlights: Black-Right-Pointing-Pointer Ethylenediamine is likely acting as an ion-pairing agent. Black-Right-Pointing-Pointer Oversulfated chondroitin sulfate is last peak instead of first peak. Black-Right-Pointing-Pointer There is about a factor of five improved detectability with a 12.5 min analysis time. Black-Right-Pointing-Pointer Use of a 50 {mu}m ID capillary is possible. - Abstract: This study involves the use of polyamines as potential resolving agents for the capillary electrophoresis (CE) of glycosaminoglycans (GAGs), specifically heparin, dermatan sulfate, chondroitin sulfate, over-sulfated chondroitin sulfate (OSCS), and hyaluronan. All of the compounds can be separated from each other with the exception of chondroitin sulfate and hyaluronan. Using optimization software, the final run conditions are found to be 200 mM ethylenediamine and 45.5 mM phosphate as the electrolyte with -14 V applied across a 50 {mu}m ID Multiplication-Sign 24.5 cm fused silica capillary at 15 Degree-Sign C. The ion migration order, with OSCS as the last instead of the first peak, is in contrast to previous reports using either a high molarity TRIS or lithium phosphate run buffer with narrower bore capillaries. Total analysis time is 12. 5 min and the relative standard deviation of the heparin migration time is about 2.5% (n = 5). The interaction mechanism between selected polyamines and heparin is explored using conductivity measurements in addition to CE experiments to show that an ion-pairing mechanism is likely.

  18. High-Throughput Genetic Analysis and Combinatorial Chiral Separations Based on Capillary Electrophoresis

    Energy Technology Data Exchange (ETDEWEB)

    Wenwan Zhong

    2003-08-05

    Capillary electrophoresis (CE) offers many advantages over conventional analytical methods, such as speed, simplicity, high resolution, low cost, and small sample consumption, especially for the separation of enantiomers. However, chiral method developments still can be time consuming and tedious. They designed a comprehensive enantioseparation protocol employing neutral and sulfated cyclodextrins as chiral selectors for common basic, neutral, and acidic compounds with a 96-capillary array system. By using only four judiciously chosen separation buffers, successful enantioseparations were achieved for 49 out of 54 test compounds spanning a large variety of pKs and structures. Therefore, unknown compounds can be screened in this manner to identify optimal enantioselective conditions in just one rn. In addition to superior separation efficiency for small molecules, CE is also the most powerful technique for DNA separations. Using the same multiplexed capillary system with UV absorption detection, the sequence of a short DNA template can be acquired without any dye-labels. Two internal standards were utilized to adjust the migration time variations among capillaries, so that the four electropherograms for the A, T, C, G Sanger reactions can be aligned and base calling can be completed with a high level of confidence. the CE separation of DNA can be applied to study differential gene expression as well. Combined with pattern recognition techniques, small variations among electropherograms obtained by the separation of cDNA fragments produced from the total RNA samples of different human tissues can be revealed. These variations reflect the differences in total RNA expression among tissues. Thus, this Ce-based approach can serve as an alternative to the DNA array techniques in gene expression analysis.

  19. Miniaturized capillary electrophoresis system with ultraviolet photometric detection combined with flow injection sample introduction using a modified falling-drop interface

    International Nuclear Information System (INIS)

    A miniaturized capillary electrophoresis (CE) system with UV-Vis detection was coupled to a flow injection (FI) system for achieving high throughput continuous sample introduction. The cassette of a commercial CE instrument was modified to hold a 6.5 cm long silica capillary and a flow-through waste reservoir. The cassette was inserted into the flow-cell chamber of a commercial UV detector, with the light beam focused on the capillary and collected by two ball lenses on the cassette. The capillary inlet, left outside the cassette and detector, was positioned on the top of a vertical 3.5 mm diameter glass rod, in close contact with an electrode. Samples injected through the FI system dropped freely on top of the pillar, covering the capillary inlet and electrode. Continuous sample introduction was achieved for CE separations under non-interrupted separation voltage, which was isolated from the FI system through the discontinuity of droplets. The newly developed interface and UV detection system was used for fast separation of sulphamethoxazole (SMZ) and trimethoprim (TMP) in sulphatrim tablets, achieving a high throughput of over 48 h-1, and a low carryover of 2%. Separation efficiencies of 8 μm plate height and detection limits of 1.0 mg l-1 for SMZ and 0.5 mg l-1 (3σ) for TMP were obtained

  20. Screening determination of pharmaceutical pollutants in different water matrices using dual-channel capillary electrophoresis coupled with contactless conductivity detection.

    Science.gov (United States)

    Le, Minh Duc; Duong, Hong Anh; Nguyen, Manh Huy; Sáiz, Jorge; Pham, Hung Viet; Mai, Thanh Duc

    2016-11-01

    In this study, the employment of purpose-made dual-channel compact capillary electrophoresis (CE) instrument with capacitively coupled contactless conductivity detection (C(4)D) as a simple and inexpensive solution for screening determination of various pharmaceutical pollutants frequently occurring in surface water and hospital wastewater in Hanoi, Vietnam is reported. Five negatively charged pharmaceutically active compounds, namely ibuprofen, diclofenac, bezafibrate, ketoprofen and mefenamic acid were determined using the first channel whereas three positively charged ones, namely diphenhydramine, metoprolol and atenolol were determined with the second channel of the CE-C(4)D instrument. Two different background electrolytes (BGEs) were used in these two CE channels independently. The best detection limits achieved were in the range of 0.2-0.8mg/L without sample pre-concentration. Enrichment factors up to 200 were obtainable with the inclusion of a solid phase extraction step. Good agreement between results obtained from CE-C(4)D and those with the standard confirmation method (HPLC-DAD) was achieved, with correlation coefficients higher than 0.98. PMID:27591645

  1. Dual-channel capillary electrophoresis for simultaneous determination of cations and anions.

    Science.gov (United States)

    Opekar, František; Tůma, Petr

    2016-05-13

    An original electrophoresis apparatus for simultaneous rapid determination of cations and anions has been designed and tested. The separation part of the apparatus consists of two identical fused-silica capillaries, each with a length of 10.5cm and inner diameter of 25μm. The injection space is formed by the crossing of four channels in a plexiglass cross-piece. The capillaries pass through two opposing channels and their injection ends are located opposite one another at a distance of approx. 0.5mm in the centre of the crossing point. The exit ends of the capillaries are placed in vessels containing the background electrolyte in which are immersed the electrodes of a high-voltage source. Contactless conductivity detectors with semi-cylindrical electrodes are located 2cm from the exit ends of the capillaries. The injection part of the apparatus consists of two piezoelectric micro-pumps bringing the solution through another channel in the cross-piece to the injection ends of the capillary. During the injection, the sample is brought through one of them and is injected electrokinetically for a defined time. Then the sample zone is forced out of the injection space by a stream of background electrolyte from the second micro-pump. The timing of the injection process is computer-controlled. Thus the equipment can be considered to constitute electrophoresis in one capillary with injection into its centre. The use of short capillaries and miniature micro-pumps without other mechanical components enabled the construction of the apparatus on a board with dimensions of 20×25cm. The proposed equipment was used to test simultaneous separation of a mixture of cations and anions, NH4(+), K(+), Ca(2+), Mg(2+), Sr(2+), Ba(2+), Cl(-), NO3(-), SO4(2-), ClO3(-) and F(-), in BGE with composition 500mM HAc+20mM Tris+2mM 18-crown-6 (pH 3.3). Baseline separation of all the components was achieved in time less than 1min. Quantification of the content of nitrate nitrogen (determined as

  2. Capillary Electrophoresis Single-Strand Conformational Polymorphisms as a Method to Differentiate Algal Species

    Directory of Open Access Journals (Sweden)

    Alice Jernigan

    2015-01-01

    Full Text Available Capillary electrophoresis single-strand conformational polymorphism (CE-SSCP was explored as a fast and inexpensive method to differentiate both prokaryotic (blue-green and eukaryotic (green and brown algae. A selection of two blue-green algae (Nostoc muscorum and Anabaena inaequalis, five green algae (Chlorella vulgaris, Oedogonium foveolatum, Mougeotia sp., Scenedesmus quadricauda, and Ulothrix fimbriata, and one brown algae (Ectocarpus sp. were examined and CE-SSCP electropherogram “fingerprints” were compared to each other for two variable regions of either the 16S or 18S rDNA gene. The electropherogram patterns were remarkably stable and consistent for each particular species. The patterns were unique to each species, although some common features were observed between the different types of algae. CE-SSCP could be a useful method for monitoring changes in an algae species over time as potential shifts in species occurred.

  3. Application of 2,3-Naphthalenediamine in Labeling Natural Carbohydrates for Capillary Electrophoresis

    Directory of Open Access Journals (Sweden)

    Jim-Min Fang

    2012-06-01

    Full Text Available Neutral and acidic monosaccharide components in Ganoderma lucidum polysaccharide are readily labeled with 2,3-naphthalenediamine, and the resulting saccharide-naphthimidazole (NAIM derivatives are quantified by capillary electrophoresis (CE in borate buffer. Using sulfated-α-cyclodextrin as the chiral selector, enantiomers of monosaccharide-NAIMs are resolved on CE in phosphate buffer, allowing a simultaneous determination of the absolute configuration and sugar composition in the mucilage polysaccharide of a medicinal herb Dendrobium huoshanense. Together with the specific enzymatic reactions of various glycoside hydrolases on the NAIM derivatives of glycans, the structures of natural glycans can be deduced from the digestion products identified by CE analysis. Though heparin dissachrides could be successfully derived with the NAIM-labeling method, the heparin derivatives with the same degree of sulfation could not be separated by CE.

  4. Micro-solid phase extraction of ochratoxin A, and its determination in urine using capillary electrophoresis

    International Nuclear Information System (INIS)

    We describe a simple, environmentally friendly and selective technique for the determination of ochratoxin A (OTA) in urine. It involves (a) the use of a molecularly imprinted polymer as a sorbent in micro-solid-phase extraction in which the sorbent is contained in a propylene membrane envelope, and (b) separation and detection by capillary electrophoresis (CE). Under optimized conditions, response is linear in the range between 50 and 300 ng mL−1 (with a correlation coefficient of 0.9989), relative standard deviations range from 4 to 8 %, the detection limit for OTA in urine is 11.2 ng mL−1 (with a quantification limits of 32.5 ng mL−1) which is lower than those of previously reported methods for solid-phase extraction combined with CE. The recoveries of OTA from urine spiked at levels of 50, 150 and 300 ng mL−1 ranged from 93 to 97 %. (author)

  5. Protein A Detection Based on Quantum Dots-Antibody Bioprobe Using Fluorescence Coupled Capillary Electrophoresis

    Directory of Open Access Journals (Sweden)

    Lin Qiu

    2014-01-01

    Full Text Available In this report, fluorescence detection coupled capillary electrophoresis (CE-FL was used to detect Protein A. Antibody was first labeled with Cy5 and then mixed with quantum dots (QDs to form QDs-antibody bioprobe. Further, we observed fluorescence resonance energy transfer (FRET from QDs donor to Cy5 acceptor. The bioprobe was formed and brought QDs and Cy5 close enough to allow FRET to occur. After adding protein A, the FRET system was broken and caused the FRET signal to decrease. Thus, a new method for the determination of protein A was proposed based on the FRET signal changes. This study provides a new trail of thought for the detection of protein.

  6. A multiscale products technique for denoising of DNA capillary electrophoresis signals

    Science.gov (United States)

    Gao, Qingwei; Lu, Yixiang; Sun, Dong; Zhang, Dexiang

    2013-06-01

    Since noise degrades the accuracy and precision of DNA capillary electrophoresis (CE) analysis, signal denoising is thus important to facilitate the postprocessing of CE data. In this paper, a new denoising algorithm based on dyadic wavelet transform using multiscale products is applied for the removal of the noise in the DNA CE signal. The adjacent scale wavelet coefficients are first multiplied to amplify the significant features of the CE signal while diluting noise. Then, noise is suppressed by applying a multiscale threshold to the multiscale products instead of directly to the wavelet coefficients. Finally, the noise-free CE signal is recovered from the thresholded coefficients by using inverse dyadic wavelet transform. We compare the performance of the proposed algorithm with other denoising methods applied to the synthetic CE and real CE signals. Experimental results show that the new scheme achieves better removal of noise while preserving the shape of peaks corresponding to the analytes in the sample.

  7. Signal Detection of Multi-Channel Capillary Electrophoresis Chip Based on CCD

    Science.gov (United States)

    Lv, Hongfeng; Yan, Weiping; Yang, Xiaobo; Li, Jiechao; Zhu, Jieying

    2012-12-01

    A kind of multi-channel capillary electrophoresis (CE) chip signal detection system based on CCD was developed. The output signal of the CCD sensor was processed by a series of pre-processing circuits and ADC, and then it was collected by the Field Programmable Gate Array (FPGA) chip which communicated with a host computer. The core in FPGA was designed to control the signal flow of the CCD and transfer the data to PC based on a Nios II embedded soft-processor. The application of PC was used to store the data and demonstrate the curve. The measurement of the fluorescent signals for different concentration Rhodamine B dyes is presented and the comparison with other detection systems is also discussed.

  8. Automatic Combination of Microfluidic Nanoliter-Scale Droplet Array with High-Speed Capillary Electrophoresis

    Science.gov (United States)

    Li, Q.; Zhu, Y.; Zhang, N.-Q.; Fang, Q.

    2016-05-01

    In this paper, we developed a novel approach for interfacing a microfluidic two-dimensional droplet array to a high-speed capillary electrophoresis (HSCE) system. Picoliter-scale sample injection (ca. 200 pL) from a nanoliter-scale droplet array covered by nonvolatile oil was automatically achieved using the spontaneous injection mode, without the interference from the cover oil and the need of special droplet extraction interface as in previously reported systems. The system was applied in consecutive separations of 25 different samples of amino acids with a whole separation time less than 15 min, as well as on-line monitoring of in-droplet derivatizing reaction of amino acids by fluorescein isothiocyanate (FITC) over 3 hours. High separation speed (up to 100 samples per hour) and high separation efficiency (up to 9.22 × 105 N/m) were achieved.

  9. Recent Advances in the Determination of Pesticides in Environmental Samples by Capillary Electrophoresis

    Directory of Open Access Journals (Sweden)

    Po-Ling Chang

    2016-04-01

    Full Text Available Nowadays, owing to the increasing population and the attempts to satisfy its needs, pesticides are widely applied to control the quantity and quality of agricultural products. However, the presence of pesticide residues and their metabolites in environmental samples is hazardous to the health of humans and all other living organisms. Thus, monitoring these compounds is extremely important to ensure that only permitted levels of pesticide are consumed. To this end, fast, reliable, and environmentally friendly methods that can accurately analyze dilute, complex samples containing both parent substances and their metabolites are required. Focusing primarily on research published since 2010, this review summarizes the use of various sample pretreatment techniques to extract pesticides from various matrices, combined with on-line preconcentration strategies for sensitivity improvement, and subsequent capillary electrophoresis analysis.

  10. Hydrogel plug for independent sample and buffer handling in continuous microchip capillary electrophoresis

    Science.gov (United States)

    Puchberger-Enengl, Dietmar; Bipoun, Mireille; Smolka, Martin; Krutzler, Christian; Keplinger, Franz; Vellekoop, Michael J.

    2013-05-01

    In microchip capillary electrophoresis most frequently electrokinetic sample injection is utilized, which does not allow pressure driven sample handling and is sensitive for pressure drops due to different reservoir levels. For efficient field tests a multitude of samples have to be processed with the least amount of external equipment. We present the use of a hydrogel plug to separate the sample from clean buffer to enable independent sample change and buffer refreshment. In-situ polymerization of the gel does away with complex membrane fabrication techniques. The sample is electrokinetically injected through the gel and subsequently separated by a voltage between the second gel inlet and the buffer outlet. By blocking of disturbing flows by the gel barrier a well-defined ion plug is obtained. After each experiment, the sample and the separation channel can be flushed independently, allowing for a continuous operation mode in order to process multiple samples.

  11. Capillary electrophoresis-electrochemistry microfluidic system for the determination of organic peroxides

    Science.gov (United States)

    Wang, Joseph; Escarpa, Alberto; Pumera, Martin; Feldman, Jason; Svehla, D. (Principal Investigator)

    2002-01-01

    A microfluidic analytical system for the separation and detection of organic peroxides, based on a microchip capillary electrophoresis device with an integrated amperometric detector, was developed. The new microsystem relies on the reductive detection of both organic acid peroxides and hydroperoxides at -700 mV (vs. Ag wire/AgCl). Factors influencing the separation and detection processes were examined and optimized. The integrated microsystem offers rapid measurements (within 130 s) of these organic-peroxide compounds, down to micromolar levels. A highly stable response for repetitive injections (RSD 0.35-3.12%; n = 12) reflects the negligible electrode passivation. Such a "lab-on-a-chip" device should be attractive for on-site analysis of organic peroxides, as desired for environmental screening and industrial monitoring.

  12. Detection of Elevated Signaling Amino Acids in Human Diabetic Vitreous by Rapid Capillary Electrophoresis

    Directory of Open Access Journals (Sweden)

    Miao-Jen Lu

    2007-01-01

    Full Text Available Elevated glutamate is implicated in the pathology of PDR. The ability to rapidly assess the glutamate and amino acid content of vitreous provides a more complete picture of the chemical changes occurring at the diabetic retina and may lead to a better understanding of the pathology of PDR. Vitreous humor was collected following vitrectomies of patients with PDR and control conditions of macular hole or epiretinal membrane. A capillary electrophoresis method was developed to quantify glutamate and arginine. The analysis is relatively fast (<6 minutes and utilizes a poly(ethyleneoxide and sodium dodecylsulfate run buffer. Both amino acid levels show significant increases in PDR patients versus controls and are comparable to other reports. The levels of vitreal glutamate vary inversely with the degree of observed hemorrhage. The results demonstrate a rapid method for assessment of a number of amino acids to characterize the chemical changes at the diabetic retina to better understand tissue changes and potentially identify new treatments.

  13. Typing of 49 autosomal SNPs by single base extension and capillary electrophoresis for forensic genetic testing

    DEFF Research Database (Denmark)

    Børsting, Claus; Tomas Mas, Carmen; Morling, Niels

    2012-01-01

    We describe a method for simultaneous amplification of 49 autosomal single nucleotide polymorphisms (SNPs) by multiplex PCR and detection of the SNP alleles by single base extension (SBE) and capillary electrophoresis. All the SNPs may be amplified from only 100 pg of genomic DNA and the length of...... the amplicons range from 65 to 115 bp. The high sensitivity and the short amplicon sizes make the assay very suitable for typing of degraded DNA samples, and the low mutation rate of SNPs makes the assay very useful for relationship testing. Combined, these advantages make the assay well suited for...... disaster victim identifications, where the DNA from the victims may be highly degraded and the victims are identified via investigation of their relatives. The assay was validated according to the ISO 17025 standard and used for routine case work in our laboratory....

  14. Recent Advances in the Determination of Pesticides in Environmental Samples by Capillary Electrophoresis

    Science.gov (United States)

    Chang, Po-Ling; Hsieh, Ming-Mu; Chiu, Tai-Chia

    2016-01-01

    Nowadays, owing to the increasing population and the attempts to satisfy its needs, pesticides are widely applied to control the quantity and quality of agricultural products. However, the presence of pesticide residues and their metabolites in environmental samples is hazardous to the health of humans and all other living organisms. Thus, monitoring these compounds is extremely important to ensure that only permitted levels of pesticide are consumed. To this end, fast, reliable, and environmentally friendly methods that can accurately analyze dilute, complex samples containing both parent substances and their metabolites are required. Focusing primarily on research published since 2010, this review summarizes the use of various sample pretreatment techniques to extract pesticides from various matrices, combined with on-line preconcentration strategies for sensitivity improvement, and subsequent capillary electrophoresis analysis. PMID:27070634

  15. Low-temperature microchip nonaqueous capillary electrophoresis of aliphatic primary amines: applications to Titan chemistry.

    Science.gov (United States)

    Cable, Morgan L; Stockton, Amanda M; Mora, Maria F; Willis, Peter A

    2013-01-15

    We demonstrate microchip nonaqueous capillary electrophoresis (μNACE) analysis of primary aliphatic amines (C1-C18) in ethanol down to -20 °C as a first step in adapting microfluidic protocols for in situ analysis on Titan. To our knowledge, this is the first report of a nonaqueous separation at -20 °C on-chip. Limits of detection (LODs) ranged from 1.0 nM to 2.6 nM, and we identified several primary amines ranging in length from C2 to C16 in Titan aerosol analogue (tholin) samples; new amines were also detected in a tholin sample exposed to oxygen and liquid water. This preliminary work validates the sensitivity and efficacy of microfluidic chemical analysis of complex organics with relevance to Titan aerosols and surface deposits. PMID:23214444

  16. Detection of biogenic amines in C57BL/6 mice brain by capillary electrophoresis electrokinetic supercharging.

    Science.gov (United States)

    Wang, Wei-feng; Ju, Fu-rong; Ran, Yan-li; Zhang, Hui-ge; Chen, Xing-guo

    2016-02-01

    Ischemic stroke is caused when blood flow to the brain is stopped and is a major cause of death and long term disability across the globe. Excessive release of neurotransmitters is triggered in the brain by ischemia that mediates neuronal damage and causes ischemic injury. In this study, a simple, sensitive, and on-line preconcentration capillary electrophoresis method based on electrokinetic supercharging (EKS) was developed for the determination of the biogenic amines including dopamine (DA), epinephrine (E), and norepinephrine (NE) in C57BL/6 mice brain. Under the optimized conditions, the analytes were concentrated and detected within 10 min. The detection limits for the analytes ranged from 0.42 to 0.57 ng mL(-1) for a mice brain matrix. With the proposed method, the analyses of three neurochemical amines in C57BL/6 mice brain tissue during cerebral ischemic/reperfusion had been performed successfully. PMID:26658278

  17. Investigation of interaction between the drug and cell membrane by capillary electrophoresis

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    By introducing cell membrane into electrophoretic buffer as pseudo-stationary phase,a novel capillary electrophoresis method was established to explore the interaction between drugs and cell membrane,where the interaction between citalopram and rabbit red blood cell membrane was used as an example. A series of concentrations of cell membrane were suspended into the running buffer by peak-shift method. The binding constant of citalopram to rabbit red blood cell membrane of 0.977 g-1·L was obtained after treatment of Scatchard plot. This method could provide not only a new way for the investigation on the interactions between drugs and cell membrane,but also a new approach for high throughput screening of the drug membrane permeability,biological activity,and evaluating drugs in vivo.

  18. Capillary electrophoresis. A potentially powerful technique for long-lived radionuclide speciation?

    International Nuclear Information System (INIS)

    Capillary electrophoresis (CE) is a relatively new technique in the field of metal ion analysis. CE has been utilised for metal speciation studies, but mostly it has been used as a fast and convenient metal ion separation technique. With CE it is possible to investigate chemical characteristics like charge-to-mass ratios, structural properties and reactivity. The speciation of some environmentally relevant metal ions (Al, Cu, Fe, Hg, Pb and Sr) is discussed in the presence of degraded natural organic material, humic substances (humic and fulvic acid). The results from this work on stable elements could serve as a basis for speciation studies of long-lived radionuclides. Two detection modes were applied: UV and LIF detection. With the direct UV detection and the LIF detection, Na2B4O7 - at different concentrations and with different organic solvents - was used as the electrolyte. The influence of metal ions on chemical characteristics of humic substances is also presented. (author)

  19. Automatic Combination of Microfluidic Nanoliter-Scale Droplet Array with High-Speed Capillary Electrophoresis.

    Science.gov (United States)

    Li, Q; Zhu, Y; Zhang, N-Q; Fang, Q

    2016-01-01

    In this paper, we developed a novel approach for interfacing a microfluidic two-dimensional droplet array to a high-speed capillary electrophoresis (HSCE) system. Picoliter-scale sample injection (ca. 200 pL) from a nanoliter-scale droplet array covered by nonvolatile oil was automatically achieved using the spontaneous injection mode, without the interference from the cover oil and the need of special droplet extraction interface as in previously reported systems. The system was applied in consecutive separations of 25 different samples of amino acids with a whole separation time less than 15 min, as well as on-line monitoring of in-droplet derivatizing reaction of amino acids by fluorescein isothiocyanate (FITC) over 3 hours. High separation speed (up to 100 samples per hour) and high separation efficiency (up to 9.22 × 10(5) N/m) were achieved. PMID:27230468

  20. Determination of small carboxylic acids by capillary electrophoresis with electrospray-mass spectrometry

    International Nuclear Information System (INIS)

    Capillary electrophoresis (CE) is used with electrospray-mass spectrometry (ES-MS) to analyze a mixture of succinic, maleic, malonic, and glutaric acids as the negative parent ions ([M-H]-). The CE is coupled with the ES-MS via a make-up sheath flow. The CE mobile phase consists of an aqueous solution of naphthalene disulfonate (NDS), pyromellitic acid, and methanol, with diethylene triamine (DETA) as an electroosmotic flow modifier. Compromise experimental parameters for the CE separation and ES-MS detection are evaluated. Detection limits for CE-ES-MS determination of the sample are 1-10 ppm or 60-600 pg. The carboxylic acid sample is injected directly into the CE column with little or no preparation. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

  1. Evaluation of capillary electrophoresis for in-flight ionic contaminant monitoring of SSF potable water

    Science.gov (United States)

    Mudgett, Paul D.; Schultz, John R.; Sauer, Richard L.

    1992-01-01

    Until 1989, ion chromatography (IC) was the baseline technology selected for the Specific Ion Analyzer, an in-flight inorganic water quality monitor being designed for Space Station Freedom. Recent developments in capillary electrophoresis (CE) may offer significant savings of consumables, power consumption, and weight/volume allocation, relative to IC technology. A thorough evaluation of CE's analytical capability, however, is necessary before one of the two techniques is chosen. Unfortunately, analytical methods currently available for inorganic CE are unproven for NASA's target list of anions and cations. Thus, CE electrolyte chemistry and methods to measure the target contaminants must be first identified and optimized. This paper reports the status of a study to evaluate CE's capability with regard to inorganic and carboxylate anions, alkali and alkaline earth cations, and transition metal cations. Preliminary results indicate that CE has an impressive selectivity and trace sensitivity, although considerable methods development remains to be performed.

  2. A multiscale products technique for denoising of DNA capillary electrophoresis signals

    International Nuclear Information System (INIS)

    Since noise degrades the accuracy and precision of DNA capillary electrophoresis (CE) analysis, signal denoising is thus important to facilitate the postprocessing of CE data. In this paper, a new denoising algorithm based on dyadic wavelet transform using multiscale products is applied for the removal of the noise in the DNA CE signal. The adjacent scale wavelet coefficients are first multiplied to amplify the significant features of the CE signal while diluting noise. Then, noise is suppressed by applying a multiscale threshold to the multiscale products instead of directly to the wavelet coefficients. Finally, the noise-free CE signal is recovered from the thresholded coefficients by using inverse dyadic wavelet transform. We compare the performance of the proposed algorithm with other denoising methods applied to the synthetic CE and real CE signals. Experimental results show that the new scheme achieves better removal of noise while preserving the shape of peaks corresponding to the analytes in the sample. (paper)

  3. Functional integration of PCR amplification and capillary electrophoresis in a microfabricated DNA analysis device.

    Science.gov (United States)

    Woolley, A T; Hadley, D; Landre, P; deMello, A J; Mathies, R A; Northrup, M A

    1996-12-01

    Microfabricated silicon PCR reactors and glass capillary electrophoresis (CE) chips have been successfully coupled to form an integrated DNA analysis system. This construct combines the rapid thermal cycling capabilities of microfabricated PCR devices (10 degrees C/s heating, 2.5 degrees C/s cooling) with the high-speed (Real-time monitoring of PCR target amplification in these integrated PCR-CE devices is also feasible. Amplification of the beta-globin target as a function of cycle number was directly monitored for two different reactions starting with 4 x 10(7) and 4 x 10(5) copies of DNA template. This work establishes the feasibility of performing high-speed DNA analyses in microfabricated integrated fluidic systems. PMID:8946790

  4. Development of a capillary electrophoresis method for the simultaneous determination of cephalosporins

    Directory of Open Access Journals (Sweden)

    Hancu Gabriel

    2013-01-01

    Full Text Available A rapid and simple capillary electrophoresis method has been developed for the simultaneous determination of six extensively used cephalosporin antibiotics (cefaclor, cefadroxil, cefalexin, cefuroxim, ceftazidim, ceftriaxon. The determination of cephalosporins was performed at a pH 6.8, using a 25 mM phospate - 25 mM borate mixed buffer, + 25 kV voltage at a temperature of 25 °C. We achieved a baseline separation in approximately 10 minutes. The separation resolution was increased by addition of an anionic surfactant, 50 mM sodium dodecyl sulfate, to the buffer solution. The proposed separation was evaluated on the basis of detection and quantification limits, effective electrophoretic mobility and relative standard deviation for migration times and peak areas.

  5. Capillary electrophoresis with electrochemiluminescence detection for the analysis of quinolone drugs and pharmacokinetics study

    Institute of Scientific and Technical Information of China (English)

    Yan Ming Liu; Jun Tao Cao; Hui Wang

    2008-01-01

    A novel method for the determination of two quinolone drugs norfloxacin (NOR) and levofloxacin (LVX) was described by capillary electrophoresis with electrochemiluminescence detection. The good relationship (r ≥ 0.9991) between peak area and concentration of analytes was established over two orders of magnitude. The limits of detection (LOD, S/N = 3) in standard solution are 4.8 × 10-7 mol/L for NOR and 6.4 × 10-7 mol/L for LVX, respectively. The limits of quantitation (LOQ, S/N = 10) in real human urine samples are 1.2 × 10-6 mol/L for NOR and 1.4 × 10-6 mol/L for LVX, respectively. The present method was successfully applied to the determination of NOR and LVX in human urine and the study of pharmacokinetics of NOR.

  6. Chiral analysis and characterization of acyclic nucleoside phosphonates-based antiviral drugs by capillary electrophoresis

    Czech Academy of Sciences Publication Activity Database

    Kašička, Václav; Šolínová, Veronika; Sázelová, Petra; Mikysková, Hana; Koval, Dušan; Břehová, Petra; Krečmerová, Marcela; Janeba, Zlatko; Holý, Antonín

    Bratislava: Slovenská vákuová spoločnosť, 2013 - (Bodor, R.; Okenicová, L.; Staňová, A.), s. 14-17 ISBN 978-80-971179-1-7. [Analytické metódy a zdravie človeka. Medzinárodná konferencia /19./. Rajecké Teplice (SK), 24.06.2013-27.06.2013] R&D Projects: GA ČR(CZ) GAP206/12/0453; GA ČR GA13-17224S; GA MŠk(CZ) ME10040; GA MV VG20102015046 Institutional support: RVO:61388963 Keywords : acyclic nucleoside phosphonates * chiral analysis * capillary electrophoresis Subject RIV: CB - Analytical Chemistry, Separation

  7. Analysis of Phenolic Compounds in Coke Plant Wastewater by Capillary Zone Electrophoresis with Inhibited Chemiluminescence Detection

    Institute of Scientific and Technical Information of China (English)

    Xiang Dong XU; Yong Gang HU; Ze Yu YANG

    2006-01-01

    A capillary electrophoresis(CE) with on-line inhibited chemiluminescence (CL) detection was firstly used for the simultaneous analysis of benzenediol isomers and phenol. It is based on the quenching effect of benzenediol isomers and phenol on the chemiluminescence reaction of luminol with potassium ferricyanide in sodium hydroxide medium. Under the optimum conditions, the four phenols were baseline separated and detected in less than 10 min.The detection limits (S/N=3) for hydroquinone, resorcinol, catechol and phenol were 2.9×10-8mol/L, 3.7×10-7 mol/L, 8.4×10-8 mol/L and 4.4×10-6 mol/L, respectively. Finally, the presented method has been successfully applied to real sample.

  8. Electrostatic interaction mechanism on the separation of phenols by non-aqueous capillary electrophoresis

    Institute of Scientific and Technical Information of China (English)

    WEI WeiLi; YIN YongGuang; XIA ZhiNing; CHEN ZhiTao; LIU WeiQi

    2007-01-01

    The electrostatic interaction between additive and analyte is of great importance to non-aqueous capillary electrophoresis (NACE) separation. Three tetraalkylammonium bromides and acetonitrile were applied as additives and running solvent respectively. The effect of alkyl chain length and concentration of additive on electrostatic interactions was investigated by the separation of phenols. The separation ability was found to increase with decreasing alkyl chain length of the additive, and the resolution values were increased with increasing additive concentration. The separation was seriously deteriorated after a little amount of water was added in the running solution. Furthermore, the electrostatic interaction is strong under the conditions of low electron cloud density, weak steric hindrance and multi-interaction sites. Thus, the separation result can be predicted by theoretical analysis, which is helpful for the separation of other substances in NACE based on electrostatic interaction.

  9. Determination of dissociation constants of pharmacologically active xanthones by capillary zone electrophoresis with diode array detection.

    Science.gov (United States)

    Wu, Xiaomu; Gong, Suxuan; Bo, Tao; Liao, Yiping; Liu, Huwei

    2004-12-24

    In this article, the dissociation constants (pKa) of 10 pharmacologically active xanthones isolated from herbal medicine Securidaca inappendiculata were determined by capillary zone electrophoresis with diode array detection. The pKa values determined by the method based on the electrophoretic mobilities (calculated from migration times) have been proved by the method based on UV absorbance calculated from the online spectra corresponding peaks. No conspicuous difference was observed between the two methods with acceptable reproducibility. Two pKa values (pKa1 and pKa2) were found for four xanthones while generally the 10 compounds possess the pKa values ranging from 6.4 to 9.2. PMID:15641365

  10. Fluorescence- and capillary electrophoresis (CE)-based SSR DNA fingerprinting and a molecular identity database for the Louisiana sugarcane industry

    Science.gov (United States)

    A database of Louisiana sugarcane molecular identity has been constructed and is being updated annually using FAM or HEX or NED fluorescence- and capillary electrophoresis (CE)-based microsatellite (SSR) fingerprinting information. The fingerprints are PCR-amplified from leaf DNA samples of current ...

  11. Determination of Roxithromycin Tablets by Capillary Electrophoresis Employing Non-aqueous Media with Square-wave Amperometric Detection

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A new method of determination for roxithromycin tablets by non-aqueous capillary electrophoresis (NACE) with square-wave amperometric detection was carried out. Several parameters affecting the NACE-AD determination were studied. The data was modified by spline wavelet least square (SWLS). The method is simple, rapid and highly reliable for routine analysis.

  12. A chip-type thin-layer electrochemical cell coupled with capillary electrophoresis for online separation of electrode reaction products

    Energy Technology Data Exchange (ETDEWEB)

    He, Jian-Bo, E-mail: jbhe@hfut.edu.cn; Cui, Ting; Zhang, Wen-Wen; Deng, Ning

    2013-07-05

    Graphical abstract: -- Highlights: •A new coupling of thin-layer electrolysis with capillary electrophoresis (CE). •Rapid electrolysis, direct sampling followed by online CE separation. •At least 13 products of quercetin oxidation were separated. •Thermodynamic and kinetic parameters were determined from CE peak areas. -- Abstract: A coupling technique of thin-layer electrolysis with high-performance capillary electrophoresis/UV–vis technique(EC/HPCE/UV–vis) is developed for online separation and determination of electrode reaction products. A chip-type thin-layer electrolytic (CTE) cell was designed and fabricated, which contains a capillary channel and a background electrolyte reservoir, allowing rapid electrolysis, direct sampling and online electrophoretic separation. This chip-type setup was characterized based on an electrophoresis expression of Nernst equation that was applied to the redox equilibrium of o-tolidine at different potentials. The utility of the method was demonstrated by separating and determining the electro-oxidation products of quercetin in different pH media. Two main products were always found in the studied time, potential and pH ranges. The variety of products increased not only with increasing potential but also with increasing pH value, and in total, at least 13 products were observed in the electropherograms. This work illustrates a novel example of capillary electrophoresis used online with thin-layer electrolysis to separate and detect electrode reaction products.

  13. Electrochemical Detection of Alkaline Phosphatase in BALB/c Mouse Fetal Liver Stromal Cells with Capillary Electrophoresis

    Institute of Scientific and Technical Information of China (English)

    Xue Mei SUN; Dong LI; Zeng Liang BAI; Wen Rui JIN

    2004-01-01

    A method for determination of alkaline phosphatase (ALP) in BALB/c mouse fetal liver stromal cells has been described based on the catalytic reaction. After the cell extract is incubated with the substrate disodium phenyl phosphate, the reaction product phenol generated by ALP is determined by capillary electrophoresis with electrochemical detection.

  14. Determination of simple carbohydrates in citrus juices by using capillary electrophoresis with indirect detection and high performance liquid chromatography

    Czech Academy of Sciences Publication Activity Database

    Cabálková, J.; Chmelík, Josef

    96(S), - (2002), s. S150-S152. ISSN 0009-2770. [Meeting of Chemistry & Life /2./. Brno, 10.09.2002-11.09.2002] Institutional research plan: CEZ:AV0Z4031919 Keywords : carbohydrates * citrus juice * capillary electrophoresis Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 0.336, year: 2002

  15. DNA Sequencing by Capillary Electrophoresis Using Quasi-inter penetrating Network Formed by Polyacrylamide and Poly(N-hydroxymethylacrylamide)

    Institute of Scientific and Technical Information of China (English)

    Wen Long ZHANG; Yan Mei WANG

    2006-01-01

    Quasi-interpenetrating network formed by polyacrylamide and poly (N-hydroxymethylacrylamide) was designed, synthesized, and tested for DNA sequencing by capillary electrophoresis. The performance of quasi-IPN on DNA sequencing was determined by the acrylamide to N-hydroxymethylacrylamide molar ratio and sequencing temperature.

  16. Optimisation of solid phase extraction of selected non-steroidal anti-inflammatory drugs by capillary zone electrophoresis

    Czech Academy of Sciences Publication Activity Database

    Čapka, Lukáš; Lacina, P.; Vávrová, M.

    Greece, 2014. [International Symposium on Environmental Pollution and its Impact on Life in the Mediterranean Region /16./. 24.09.2014-27.09.2014, Ioannina] Institutional support: RVO:68081715 Keywords : solid phase extraction * capillary electrophoresis * non-steroidal anti-inflammatory drugs Subject RIV: CB - Analytical Chemistry, Separation

  17. A chip-type thin-layer electrochemical cell coupled with capillary electrophoresis for online separation of electrode reaction products

    International Nuclear Information System (INIS)

    Graphical abstract: -- Highlights: •A new coupling of thin-layer electrolysis with capillary electrophoresis (CE). •Rapid electrolysis, direct sampling followed by online CE separation. •At least 13 products of quercetin oxidation were separated. •Thermodynamic and kinetic parameters were determined from CE peak areas. -- Abstract: A coupling technique of thin-layer electrolysis with high-performance capillary electrophoresis/UV–vis technique(EC/HPCE/UV–vis) is developed for online separation and determination of electrode reaction products. A chip-type thin-layer electrolytic (CTE) cell was designed and fabricated, which contains a capillary channel and a background electrolyte reservoir, allowing rapid electrolysis, direct sampling and online electrophoretic separation. This chip-type setup was characterized based on an electrophoresis expression of Nernst equation that was applied to the redox equilibrium of o-tolidine at different potentials. The utility of the method was demonstrated by separating and determining the electro-oxidation products of quercetin in different pH media. Two main products were always found in the studied time, potential and pH ranges. The variety of products increased not only with increasing potential but also with increasing pH value, and in total, at least 13 products were observed in the electropherograms. This work illustrates a novel example of capillary electrophoresis used online with thin-layer electrolysis to separate and detect electrode reaction products

  18. Hair analysis for illicit drugs by using capillary zone electrophoresis-electrospray ionization-ion trap mass spektrometry

    Czech Academy of Sciences Publication Activity Database

    Gottardo, R.; Bortolotti, F.; De Paoli, G.; Pascali, J. P.; Mikšík, Ivan; Tagliaro, F.

    2007-01-01

    Roč. 1159, 1-2 (2007), s. 185-189. ISSN 0021-9673 Institutional research plan: CEZ:AV0Z50110509 Keywords : capillary electrophoresis * hair analysis Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 3.641, year: 2007

  19. Analysis of ethyl glucuronide in human serum by capillary electrophoresis with sample self-stacking and indirect detection

    Czech Academy of Sciences Publication Activity Database

    Křivánková, Ludmila; Caslavska, J.; Malášková, Hana; Gebauer, Petr; Thormann, W.

    2005-01-01

    Roč. 1081, č. 1 (2005), s. 2-8. ISSN 0021-9673 R&D Projects: GA AV ČR IAA4031401 Institutional research plan: CEZ:AV0Z40310501 Keywords : ethyl glucuronide * capillary electrophoresis * serum Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 3.096, year: 2005

  20. Characterisation of Crevice and Pit Solution Chemistries Using Capillary Electrophoresis with Contactless Conductivity Detector

    Directory of Open Access Journals (Sweden)

    Robert J.K. Wood

    2013-09-01

    Full Text Available The ability to predict structural degradation in-service is often limited by a lack of understanding of the evolving chemical species occurring within a range of different microenvironments associated with corrosion sites. Capillary electrophoresis (CE is capable of analysing nanolitre solution volumes with widely disparate concentrations of ionic species, thereby producing accurate and reliable results for the analysis of the chemical compositions found within microenvironment corrosion solutions, such as those found at crevice and pit corrosion sites. In this study, CE with contactless conductivity detection (CCD has been used to characterize pitting and crevice corrosion solution chemistries for the first time. By using the capillary electrophoresis with contactless conductivity detection (CE-CCD system, direct and simultaneous detection of seven metal cations (Cu2+, Ni2+, Fe3+, Fe2+, Cr3+, Mn2+, and Al3+ and chloride anions was achieved with a buffer solution of 10 mM 2,6-pyridinedicarboxylic acid and 0.5 mM cetyltrimethylammonium hydroxide at pH 4 using a pre-column complexation method. The detection limits obtained for the metal cations and chloride anions were 100 and 10 ppb, respectively. The CE-CCD methodology has been demonstrated to be a versatile technique capable of speciation and quantifying the ionic species generated within artificial pit (a pencil electrode and crevice corrosion geometries for carbon steels and nickel-aluminium bronze, thus allowing the evolution of the solution chemistry to be assessed with time and the identification of the key corrosion analyte targets for structural health monitoring.

  1. Analyses of Phytohormones in Coconut (Cocos Nucifera L. Water Using Capillary Electrophoresis-Tandem Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Swee Ngin Tan

    2014-12-01

    Full Text Available Capillary electrophoresis (CE coupled with mass spectrometry (MS or tandem mass spectrometry (MS/MS is reported as an alternative and potentially useful method for the simultaneous analysis of various classes of phytohormones with diversified structures, including indole-3-acetic acid (IAA, indole-3-butyric acid (IBA, abscisic acid (ABA, gibberellic acid (GA, zeatin (Z, N6-benzyladenine (BA, α-naphthaleneacetic acid (NAA and 2,4-dichlorophenoxyacetic acid (2,4-D. The key to the CE-MS/MS analysis was based on electroosmotic flow reversal using a cationic polymer-coated capillary. Under optimum conditions, a baseline separation of eight phytohormones was accomplished within 30 min using 60 mM ammonium formate/formic acid buffer of pH 3.8 with −20 kV as the separation voltage. The accessibility of MS/MS together with the characterization by migration properties obtained by CE allows for the development of CE-MS/MS as an emerging potential method for the analysis of different classes of phytohormones in a single run. The utility of the CE-MS/MS method was demonstrated by the comprehensive screening of phytohormones in coconut (Cocos nucifera L. water after pre-concentration and purification through solid-phase extraction (SPE cartridge. IAA, ABA, GA and Z were detected and quantified in the purified coconut water extract sample.

  2. Characterization of cationic copolymers by capillary electrophoresis using indirect UV detection and contactless conductivity detection.

    Science.gov (United States)

    Anik, Nadia; Airiau, Marc; Labeau, Marie-Pierre; Vuong, Chi-Thanh; Cottet, Hervé

    2012-01-01

    For many industrial applications, the combination of two different monomers in statistical or diblock copolymers enhances the properties of the corresponding polymer. However, during the polymerization reaction, homopolymers might be formed and can influence the properties for the applications. Consequently, the separation and the quantification of the homopolymers contained in copolymer samples are crucial. In addition, the charge density distribution of the statistical copolymer is an important characteristic for the applications. The purpose of this work was to study the characterization of a statistical copolymer of acrylic acid (AA) and diallyldimethyl ammonium chloride (DADMAC) by capillary electrophoresis (CE) in acidic conditions (cationic copolymers). For that purpose, a free solution electrophoretic separation was carried out according to the charge rate (chemical composition) independently of the molar mass. The second objective was to compare contactless conductivity detection and indirect UV absorbance modes for the quantification of DADMAC homopolymers present in copolymer samples. Different coated capillaries based on neutral or positively charged modification were also compared. The comparison of indirect absorbance UV and contactless conductimetric detection demonstrated that both detection modes can be used for a complete CE characterization of non-UV absorbing PAA-DADMAC copolymers. PMID:22169192

  3. Influence of Analyte Concentration on Stability Constant Values Determined by Capillary Electrophoresis.

    Science.gov (United States)

    Sursyakova, Viktoria V; Burmakina, Galina V; Rubaylo, Anatoly I

    2016-08-01

    The influence of analyte concentration when compared with the concentration of a charged ligand in background electrolyte (BGE) on the measured values of electrophoretic mobilities and stability constants (association, binding or formation constants) is studied using capillary electrophoresis (CE) and a dynamic mathematical simulator of CE. The study is performed using labile complexes (with fast kinetics) of iron (III) and 5-sulfosalicylate ions (ISC) as an example. It is shown that because the ligand concentration in the analyte zone is not equal to that in BGE, considerable changes in the migration times and electrophoretic mobilities are observed, resulting in systematic errors in the stability constant values. Of crucial significance is the slope of the dependence of the electrophoretic mobility decrease on the ligand equilibrium concentration. Without prior information on this dependence to accurately evaluate the stability constants for similar systems, the total ligand concentration must be at least >50-100 times higher than the total concentration of analyte. Experimental ISC peak fronting and the difference between the direction of the experimental pH dependence of the electrophoretic mobility decrease and the mathematical simulation allow assuming the presence of capillary wall interaction. PMID:27090731

  4. Development of a fast capillary electrophoresis method to determine inorganic cations in biodiesel samples.

    Science.gov (United States)

    Piovezan, Marcel; Costa, Ana Carolina O; Jager, Alessandra Vincenzi; de Oliveira, Marcone Augusto Leal; Micke, Gustavo Amadeu

    2010-07-19

    The aim of this study was to develop a fast capillary electrophoresis method for the determination of inorganic cations (Na(+), K(+), Ca(2+), Mg(2+)) in biodiesel samples, using barium (Ba(2+)) as the internal standard. The running electrolyte was optimized through effective mobility curves in order to select the co-ion and Peakmaster software was used to determine electromigration dispersion and buffer capacity. The optimum background electrolyte was composed of 10 mmol L(-1) imidazole and 40 mmol L(-1) of acetic acid. Separation was conducted in a fused-silica capillary (32 cm total length and 23.5 cm effective length, 50 microm I.D.), with indirect UV detection at 214 nm. The migration time was only 36 s. In order to obtain the optimized conditions for extraction, a fractional factorial experimental design was used. The variables investigated were biodiesel mass, pH, extractant volume, agitation and sonication time. The optimum conditions were: biodiesel mass of 200 mg, extractant volume of 200 microL and agitation of 20 min. The method is characterized by good linearity in the concentration range of 0.5-20 mg kg(-1) (r>0.999), limit of detection was equal to 0.3 mg kg(-1), inter-day precision was equal to 1.88% and recovery in the range of 88.0-120%. The developed method was successfully applied to the determination of cations in biodiesel samples. PMID:20599036

  5. Determination of sinomenine in Sinomenium acutum by capillary electrophoresis with electrochemiluminescence detection

    International Nuclear Information System (INIS)

    A Ru(bpy)32+-based electrochemiluminescence (ECL) detection coupled with capillary electrophoresis (CE) has been established for the determination of sinomenine for the first time. Optimum separation was achieved with a fused-silica capillary column (50 cm x 25 μm i.d.) and a background electrolyte of 50 mM sodium phosphate (pH 5.0) at a separation voltage of 15 kV. The content of sinomenine was detected by ECL at the detection voltage of 1.15 V (versus Ag/AgCl) with 5 mM Ru(bpy)32+ in 75 mM phosphate solution (pH 8.0) when a chemically modified platinum electrode by europium(III)-doped prussian blue analogue (Eu-PB) was used as a working electrode. Under the optimized conditions, the ECL intensity was in proportion to sinomenine concentration in the range from 0.01 to 1.0 μg mL-1 with a detection limit of 2.0 ng mL-1 (3σ). The relative standard derivations of migration time and ECL intensity were 0.93 and 1.11%, respectively. The level of sinomenine in Sinomenium acutum Rehd. et Wils was easily determined with recoveries between 98.6 and 102.7%

  6. Capillary electrophoresis separation of neutral organic compounds, pharmaceutical drugs, proteins and peptides, enantiomers, and anions

    Energy Technology Data Exchange (ETDEWEB)

    Ding, W.L.

    1999-02-12

    Addition of a novel anionic surfactant, namely lauryl polyoxyethylene sulfate, to an aqueous-acetonitrile electrolyte makes it possible to separate nonionic organic compounds by capillary electrophoresis. Separation is based on differences in the association between analytes and the surfactant. Highly hydrophobic compounds such as polyaromatic hydrocarbons are well separated by this new surfactant. Migration times of analytes can be readily changed over an unusually large range by varying the additive concentration and the proportion of acetonitrile in the electrolyte. Several examples are given, including the separation of four methylbenz[a]anthracene isomers and the separation of normal and deuterated acetophenone. The effect of adding this new surfactant to the acidic electrolyte was also investigated. Incorporation of cetyltrimethylammonium bromide in the electrolyte is shown to dynamically coat the capillary and reverse electroosmotic flow. Chiral recognition mechanism is studied using novel synthetic surfactants as chiral selectors, which are made from amino acids reacting with alkyl chloroformates. A satisfactory separation of both inorganic and organic anions is obtained using electrolyte solutions as high as 5 M sodium chloride using direct photometric detection. The effect of various salts on electrophoretic and electroosmotic mobility is further discussed. Several examples are given under high-salt conditions.

  7. Separation of tramadol enantiomers by capillary electrophoresis using highly sulfated cyclodextrins

    Directory of Open Access Journals (Sweden)

    Majid Zandkarimi

    2005-07-01

    Full Text Available In the pharmaceutical industry a continuing need for chiral resolution of drugs for various purposes and in diverse matrices exist. For these reasons, analysts may require a number of different separation systems capable of resolving a given pair of enantiomers. Highly sulfated cyclodextrins (HS-CDs represent a relatively new class of chiral selectors in capillary electrophoresis (CE. In this investigation the use of HS-CDs as chiral selectors in CE for enantioseparation of tramadol, a highly potent analgesic, as the model drug and the influence of the type of selector and its concentration on enantiomeric resolution were studied. All of the available HSCDs ( , and  could resolve tramadol enantiomers, but HS--CD showed better resolution and a baseline resolution was achieved with this selector even at a concentration as low as 0.5% w/v. Additionally, effect of the buffer pH on the enantioresolution was studied. At low pH buffers, in which electroosmotic flow is low in CE, the negatively charged selector prevented the cationic tramadol to migrate out of the capillary even after a long analysis time of 60 minutes. However, at higher pH values (pH=7 or more, the electroosmotic flow is high enough to drag drug-selector complex toward the detector and a reasonable of the enantiomers of the drug was achieved.

  8. Capillary electrophoresis methods for the determination of covalent polyphenol-protein complexes.

    Science.gov (United States)

    Trombley, John D; Loegel, Thomas N; Danielson, Neil D; Hagerman, Ann E

    2011-09-01

    The bioactivities and bioavailability of plant polyphenols including proanthocyanidins and other catechin derivatives may be affected by covalent reaction between polyphenol and proteins. Both processing conditions and gastrointestinal conditions may promote formation of covalent complexes for polyphenol-rich foods and beverages such as wine. Little is known about covalent reactions between proteins and tannin, because suitable methods for quantitating covalent complexes have not been developed. We established capillary electrophoresis methods that can be used to distinguish free protein from covalently bound protein-polyphenol complexes and to monitor polyphenol oxidation products. The methods are developed using the model protein bovine serum albumin and the representative polyphenol (-)epigallocatechin gallate. By pairing capillaries with different diameters with appropriate alkaline borate buffers, we are able to optimize resolution of either the protein-polyphenol complexes or the polyphenol oxidation products. This analytical method, coupled with purification of the covalent complexes by diethylaminoethyl cellulose chromatography, should facilitate characterization of covalent complexes in polyphenol-rich foods and beverages such as wine. PMID:21400190

  9. Simultaneous determination of melamine and 5-hydroxymethylfurfural in milk by capillary electrophoresis with diode array detection.

    Science.gov (United States)

    Chen, Zhijun; Yan, Xiaomei

    2009-10-14

    This article describes the development of a simple analytical approach for the simultaneous determination of melamine and 5-hydroxymethylfurfural (HMF) in milk samples using capillary electrophoresis (CE) with diode array detection (DAD) for the first time. Ultraviolet absorption at wavelengths of 214 and 280 nm was applied for the detection of melamine and HMF, respectively. Milk samples were extracted with 1% trichloroacetic acid using a high-speed blender and ultrasonication. After centrifugation and filtration, the extract was analyzed by CE-DAD directly. Micellar electrokinetic capillary chromatography was employed as the separation mode by adding sodium dodecyl sulfate (SDS) to the electrolyte. Under optimal separation conditions, melamine, HMF, and interferents were well resolved. The linear dynamic ranges were 0.05-100 microg/mL for melamine (R(2) = 0.9996) and 0.1-100 microg/mL for HMF (R(2) = 0.9997). The assay detection limits were 0.047 microg/mL and 0.067 microg/mL for melamine and HMF, respectively. Satisfactory results were obtained for the assay recovery rate and repeatability. The proposed method was successfully applied for the analysis of melamine and HMF in real milk samples, and the results of melamine were comparable to those obtained using HPLC-UV reference method. PMID:19761188

  10. A capillary zone electrophoresis method to detect conformers and dimers of antithrombin in therapeutic preparations.

    Science.gov (United States)

    Marie, Anne-Lise; Tran, Nguyet Thuy; Saller, François; Abdou, Youmna Mohamed; Zeau, Pascal; Plantier, Jean-Luc; Urbain, Rémi; Borgel, Delphine; Taverna, Myriam

    2016-07-01

    Antithrombin (AT) is a human plasma glycoprotein that possesses anticoagulant and anti-inflammatory properties. However, the native (active) form of AT is unstable and undergoes conformational changes, leading to latent, cleaved, and heterodimeric forms. The presence of these alternative forms mostly inactive can highly impact the quality and therapeutic activity of pharmaceutical AT preparations. We developed a capillary zone electrophoresis method, based on a neutral polyethylene oxide-coated capillary and a buffer close to physiological conditions, enabling the separation of more than eight forms of AT. Several peaks were identified as native, latent, and heterodimeric forms. The CZE method was reproducible with intraday relative standard deviations less than 0.5 and 2% for migration times and peak areas, respectively. The method was applied to the comparison of AT preparations produced by five competitive pharmaceutical companies, and statistical tests were performed. Important differences in the proportion of each form were highlighted. In particular, one AT preparation was shown to contain a high quantity of heterodimer, and two preparations contained high quantities of latent form. In addition, one AT preparation exhibited additional forms, not yet identified. PMID:26989842

  11. Multi-Site N-glycan mapping study 1: Capillary electrophoresis - laser induced fluorescence.

    Science.gov (United States)

    Szekrényes, Ákos; Park, SungAe Suhr; Santos, Marcia; Lew, Clarence; Jones, Aled; Haxo, Ted; Kimzey, Michael; Pourkaveh, Shiva; Szabó, Zoltán; Sosic, Zoran; Feng, Peng; Váradi, Csaba; de l'Escaille, François; Falmagne, Jean-Bernard; Sejwal, Preeti; Niedringhaus, Thomas; Michels, David; Freckleton, Gordon; Hamm, Melissa; Manuilov, Anastasiya; Schwartz, Melissa; Luo, Jiann-Kae; van Dyck, Jonathan; Leung, Pui-King; Olajos, Marcell; Gu, Yingmei; Gao, Kai; Wang, Wenbo; Wegstein, Jo; Tep, Samnang; Guttman, András

    2016-01-01

    An international team that included 20 independent laboratories from biopharmaceutical companies, universities, analytical contract laboratories and national authorities in the United States, Europe and Asia was formed to evaluate the reproducibility of sample preparation and analysis of N-glycans using capillary electrophoresis of 8-aminopyrene-1,3,6-trisulfonic acid (APTS)-labeled glycans with laser induced fluorescence (CE-LIF) detection (16 sites) and ultra high-performance liquid chromatography (UHPLC, 12 sites; results to be reported in a subsequent publication). All participants used the same lot of chemicals, samples, reagents, and columns/capillaries to run their assays. Migration time, peak area and peak area percent values were determined for all peaks with >0.1% peak area. Our results demonstrated low variability and high reproducibility, both, within any given site as well across all sites, which indicates that a standard N-glycan analysis platform appropriate for general use (clone selection, process development, lot release, etc.) within the industry can be established. PMID:26466659

  12. Rapid enantioseparation of amlodipine by highly sulfated cyclodextrins using short-end injection capillary electrophoresis

    Directory of Open Access Journals (Sweden)

    M Zandkarimi

    2009-12-01

    Full Text Available "n  "n Background and the purpose of the study:The use of highly sulfated cyclodextrins (HS-CDs as chiral selectors in capillary electrophoresis (CE has been examined for rapid and reproducible enantioseparation of the model drug amlodipine, a calcium channel blocker. "nMaterials and Methods: Fused silica capillaries with an inner diameter of 50 μm, and a total length of 45.5 cm (8.5 cm to the detector were used. Capillaries were rinsed with polyethylene oxide (PEO once daily. A systematic method development approach was conducted by modifying selected parameters such as the type and concentration of the chiral selector, the buffer pH and concentration of the background electrolyte. "nResults: Baseline separation was achieved at low (i.e. 0.05%w/v concentrations of HS-αCD, but migration time and peak area repeatability were more than 4% and 25% of the relative standard deviation (RSD, respectively. At higher concentrations (>0.3% of HS-αCD, amlodipine was transported to the anode by the carrier ability of HS-αCD. In carrier mode, the migration order of enantiomers was reversed, the migration time was reduced and the peak area repeatability of analysis was improved. The optimum electrophoretic conditions for the stereoselective analysis of amlodipine were obtained in carrier mode with 25 mM sodium phosphate buffer containing 1.25% w/v of HS-αCD at pH 2.5 with an applied voltage of +15 kV. Under these conditions migration time was less than 3 min and within-day migration time and peak area repeatability, were less than 0.4% and 2.1% RSD, respectively. Conclusions: Rapid enantioseparation was achieved with minimum variation in quantitative analysis. These optimized conditions are appropriate for the enantioselective analysis of amlodipine.

  13. Self-assembled and covalently linked capillary coating of diazoresin and cyclodextrin-derived dendrimer for analysis of proteins by capillary electrophoresis.

    Science.gov (United States)

    Yu, Bing; Chi, Ming; Han, Yuxing; Cong, Hailin; Tang, Jianbin; Peng, Qiaohong

    2016-05-15

    Self-assembled and covalently linked capillary coatings of cyclodextrin-derived (CD) dendrimer were prepared using photosensitive diazoresin (DR) as a coupling agent. Layer by layer (LBL) self-assembled DR/CD-dendrimer coatings based on ionic bonding was fabricated first on the inner surface of capillary, and subsequently converted into covalent bonding after treatment with UV light through a unique photochemistry reaction of DR. Protein adsorption on the inner surface of capillary was suppressed by the DR/CD-dendrimer coating, and thus a baseline separation of lysozyme (Lys), myoglobin (Mb), bovine serum albumin (BSA) and ribonuclease A (RNase A) was achieved using capillary electrophoresis (CE). Compared with the bare capillary, the DR/CD-dendrimer covalently linked capillary coatings showed excellent protein separation performance with good stability and repeatability. Because of the replacement of highly toxic and moisture sensitive silane coupling agent by DR in the covalent coating preparation, this method may provide an environmentally friendly and simple way to prepare the covalently coated capillaries for CE. PMID:26992496

  14. Exploring bitterness of traditional Chinese medicine samples by potentiometric electronic tongue and by capillary electrophoresis and liquid chromatography coupled to UV detection.

    Science.gov (United States)

    Yaroshenko, Irina; Kirsanov, Dmitry; Kartsova, Lyudmila; Sidorova, Alla; Sun, Qiyong; Wan, Haitong; He, Yu; Wang, Ping; Legin, Andrey

    2016-05-15

    Instrumental bitterness assessment of traditional Chinese herbal medicine (TCM) preparations was addressed in this study. Three different approaches were evaluated, high-performance liquid chromatography coupled to UV detector (HPLC), capillary electrophoresis coupled to UV detector (CE) and a potentiometric multisensor system - electronic tongue (ET). Most studies involving HPLC and CE separations use these as selective instruments for quantification of individual substances. However we employed these techniques to provide chromatographic or electrophoretic sample profiles. These profiles are somewhat analogous to the profiles produced by the ET. Profiles from all instruments were then related to professional sensory panel evaluations using projections on latent structures (PLS) regression. It was found that all three methods allow for bitterness assessment in TCM samples in terms of human sensory panel with root mean squared errors of prediction ca. 0.9 within bitterness scale from 0 (no bitterness) to 6 (maximal bitterness). PMID:26992500

  15. Evaluation of capillary zone electrophoresis for charge heterogeneity testing of monoclonal antibodies.

    Science.gov (United States)

    Moritz, Bernd; Schnaible, Volker; Kiessig, Steffen; Heyne, Andrea; Wild, Markus; Finkler, Christof; Christians, Stefan; Mueller, Kerstin; Zhang, Li; Furuya, Kenji; Hassel, Marc; Hamm, Melissa; Rustandi, Richard; He, Yan; Solano, Oscar Salas; Whitmore, Colin; Park, Sung Ae; Hansen, Dietmar; Santos, Marcia; Lies, Mark

    2015-03-01

    Within pharmaceutical industry charge heterogeneity testing of biopharmaceuticals has to be reproducible and fast. It should pass method validation according to ICH Q2. Classical approaches for the analysis of the charge heterogeneity of biopharmaceuticals are ion exchange chromatography (IEC) and isoelectric focusing (IEF). As an alternative approach, also capillary zone electrophoresis (CZE) was expected to allow reliable charge heterogeneity profiling by separation according to the analyte's net charge and hydrodynamic radius. Aim of this study was to assess if CZE possesses all of the required features. Therefore, beside lab internal validation of this method also an international cross company study was organized. It was shown that CZE is applicable across a broad pI range between 7.4 and 9.5. The coefficient of correlation was above 0.99 which demonstrated linearity. Precision by repeatability was around 1% (maximum relative standard deviation per level) and accuracy by recovery was around 100% (mean recovery per level). Accuracy was further verified by direct comparison of IEC, IEF and CZE, which in this case showed comparable %CPA results for all three methods. However, best resolution for the investigated MAb was obtained with CZE. In dependence on sample concentration the detection limit was between 1 and 3%. Within the intercompany study for CZE the same stressed and non-stressed samples were analyzed in each of the 11 participating labs. The finally obtained dataset contained more than 1000 separations which provided an extended dataset for further statistical evaluation. Among the different labs no significant differences between the peak profiles were observed. Mean driver for dropouts in quantitative evaluation was linked to the performance of some participating labs while the impact of the method performance was negligible. In comparison to a 50cm capillary there was a slightly better separation of impurities and drug substance related compounds

  16. Self-assembled covalent capillary coating of diazoresin/carboxyl fullerene for analysis of proteins by capillary electrophoresis and a comparison with diazoresin/graphene oxide coating.

    Science.gov (United States)

    Yu, Bing; Shu, Xi; Cong, Hailin; Chen, Xin; Liu, Huwei; Yuan, Hua; Chi, Ming

    2016-03-11

    Self-assembled and covalently linked capillary coatings of carboxyl fullerenes (C60-COOH) were prepared using photosensitive diazoresin (DR) as a coupling agent. Layer by layer (LBL) self-assembled DR/C60-COOH coatings based on ionic bonding was fabricated first on the inner surface of silica capillary, and subsequently converted into covalent bonding after treatment with UV light through a unique photochemistry reaction of DR. The covalently bonded coatings had the ability of suppressing protein adsorption on the inner surface of silica capillary, and thus the baseline separation of lysozyme (Lys), cytochrome c (Cyt-c), bovine serum albumin (BSA) and myoglobin (Mb) was achieved within 13min by using capillary electrophoresis (CE). The covalently linked DR/C60-COOH capillary coatings presented good chemical stability and repeatability. The reproducibility of the separation of proteins was less than 1%, 2.5%, and 3.5%, respectively, for run-to-run, day-to-day, capillary-to-capillary, respectively; and the RSD of migration time for the proteins are all less than 2.5% after a continuous 100 times running in a coating column. Compared with DR/graphene oxide (GO) coatings prepared by the same method, the DR/C60-COOH capillary coatings showed excellent protein separation performance due to a self-lubrication based anti-fouling mechanism. Because of the replacement of highly toxic and moisture sensitive silane coupling agent by DR in the covalent coating preparation, this method may provide an environmentally friendly and simple way to prepare the covalently coated capillaries for CE. PMID:26875118

  17. Determination of arsenic species in Solanum Lyratum Thunb using capillary electrophoresis with inductively coupled plasma mass spectrometry.

    Science.gov (United States)

    Shuai, Pei-Yu; Yang, Xiao-Jun; Qiu, Zong-Qing; Wu, Xiao-Hui; Zhu, Xi; Pokhrel, Ganga Raj; Fu, Yu-Ying; Ye, Hui-Min; Lin, Wen-Xiong; Yang, Gui-Di

    2016-08-01

    A simple and highly efficient interface to couple capillary electrophoresis with inductively coupled plasma mass spectrometry by a microflow polyfluoroalkoxy nebulizer and a quadruple ion deflector was developed in this study. By using this interface, six arsenic species, including arsenite, arsenate, monomethylarsonic acid, dimethylarsinic acid, arsenobetaine, and arsenocholine, were baseline-separated and determined in a single run within 11 min under the optimized separation conditions. The instrumental detection limit was in the range of 0.02-0.06 ng/mL for the six arsenic compounds. Repeatability expressed as the relative standard deviation (n = 5) of both migration time and peak area were better than 2.5 and 4.3% for six arsenic compounds. The proposed method, combined with a closed-vessel microwave-assisted extraction procedure, was successfully applied for the determination of arsenic species in the Solanum Lyratum Thunb samples from Anhui province in China with the relative standard deviations (n = 5) ≤4%, method detection limits of 0.2-0.6 ng As/g and a recovery of 98-104%. The experimental results showed that arsenobetaine was the main speciation of arsenic in the Solanum Lyratum Thunb samples from different provinces in China, with a concentration of 0.42-1.30 μg/g. PMID:27378629

  18. Dereplication of Known Nucleobase and Nucleoside Compounds in Natural Product Extracts by Capillary Electrophoresis-High Resolution Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Junhui Chen

    2015-03-01

    Full Text Available Nucleobase and nucleoside compounds exist widely in various organisms. An often occurring problem in the discovery of new bioactive compounds from natural products is reisolation of known nucleobase and nucleoside compounds. To resolve this problem, a capillary electrophoresis-high resolution mass spectrometry (CE-HR-MS method providing both rapid separation and accurate mass full-scan MS data was developed for the first time to screen and dereplicate known nucleobase and nucleoside compounds in crude extracts of natural products. Instrumental parameters were optimized to obtain optimum conditions for CE separation and electrospray ionization-time-of-flight mass spectrometry (ESI-TOF/MS detection. The proposed method was verified to be precise, reproducible, and sensitive. Using this method, known nucleobase and nucleoside compounds in different marine medicinal organisms including Syngnathus acus Linnaeus; Hippocampus japonicus Kaup and Anthopleura lanthogrammica Berkly were successfully observed and identified. This work demonstrates that CE-HR-MS combined with an accurate mass database may be used as a powerful tool for dereplicating known nucleobase and nucleoside compounds in different types of natural products. Rapid dereplication of known nucleobase and nucleoside compounds allows researchers to focus on other leads with greater potential to yield new substances.

  19. Improvement on Simultaneous Determination of Cr(III) and Cr(VI) by Capillary Electrophoresis and Chemiluminescence Detection

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    A sensitive method for the simultaneous determination of Cr(III) and Cr(VI) using in-capillary reaction capillary electrophoresis separation and chemiluminescence detection was developed. The procedures were designed as follows: The sample, hydrochloric acid and sodium hydrogen sulfite solution segments were injected sequentially into the capillary. The reaction of Cr(VI) reduced to Cr(III) by HSO3- occurred inside the capillary after applying the running voltage. According to the migration time difference of both Cr(III) ions moving towards to the cathode (detection end), they could be separated and determined. The limits of detection for chromium(III) and chromium(VI) (S/N = 3) were 6.0(10-13 mol/L (12 zmol) and 1.9(10-11 mol/L (380 zmol), respectively.

  20. Automation and integration of polymerase chain reaction with capillary electrophoresis for high throughput genotyping and disease diagnosis

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, N.

    1999-02-12

    Genotyping is to detect specific loci in the human genome. These loci provide important information for forensic testing, construction of genetic linkage maps, gene related disease diagnosis and pharmacogenetic research. Genotyping is becoming more and more popular after these loci can be easily amplified by polymerase chain reaction (PCR). Capillary electrophoresis has its unique advantages for DNA analysis due to its fast heat dissipation and ease of automation. Four projects are described in which genotyping is performed by capillary electrophoresis emphasizing different aspects. First, the author demonstrates a principle to determine the genotype based on capillary electrophoresis system. VNTR polymorphism in the human D1S80 locus was studied. Second, the separation of four short tandem repeat (STR) loci vWF, THO1, TPOX and CSF1PO (CTTv) by using poly(ethylene oxide) (PEO) was studied in achieving high resolution and preventing rehybridization of the DNA fragments. Separation under denaturing, non-denaturing conditions and at elevated temperature was discussed. Third, a 250 {micro}m i.d., 365 {micro}m o.d. fused silica capillary was used as the microreactor for PCR. Fourth, direct PCR from blood was studied to simplify the sample preparation for genotyping to minimum.

  1. Capillary ion electrophoresis-capacitively coupled contactless conductivity detection of inorganic cations in human saliva on a polyvinyl alcohol-coated capillary.

    Science.gov (United States)

    Mori, Masanobu; Kaseda, Maki; Yamamoto, Tsukasa; Yamada, Sachiko; Itabashi, Hideyuki

    2012-03-01

    Capillary ion electrophoresis-capacitively coupled contactless conductivity detection (CIE-C4D) with a polyvinyl alcohol chemically coated capillary (PVA capillary) was used to analyze inorganic cations (Na(+), K(+), NH(4)(+), Mg(2+), and Ca(2+)) commonly found in human saliva. The PVA capillary, which was made by our laboratory, minimized electro-osmotic flow in the wide pH range of the background electrolyte (BGE), and the PVA layer adsorbed to capillary wall did not affect the conductimetric background level. In this study, we determined an optimized BGE of 30 mM lactic acid/histidine plus 3 mM 18-crown-6 for the CIE-C4D system using the PVA capillary, which could simultaneously improve the separation of Mg(2+) and Ca(2+) from Na(+) and that of K(+) from NH(4)(+). This system obtained highly reproducible separation of cations in human saliva samples within 8 min at 20 kV without deprotonation. The quantifiability of cations in human saliva samples on the CIE-C4D system was demonstrated through identification by ion chromatography with satisfactory results. PMID:22252656

  2. CEval: All-in-one software for data processing and statistical evaluations in affinity capillary electrophoresis.

    Science.gov (United States)

    Dubský, Pavel; Ördögová, Magda; Malý, Michal; Riesová, Martina

    2016-05-01

    We introduce CEval software (downloadable for free at echmet.natur.cuni.cz) that was developed for quicker and easier electrophoregram evaluation and further data processing in (affinity) capillary electrophoresis. This software allows for automatic peak detection and evaluation of common peak parameters, such as its migration time, area, width etc. Additionally, the software includes a nonlinear regression engine that performs peak fitting with the Haarhoff-van der Linde (HVL) function, including automated initial guess of the HVL function parameters. HVL is a fundamental peak-shape function in electrophoresis, based on which the correct effective mobility of the analyte represented by the peak is evaluated. Effective mobilities of an analyte at various concentrations of a selector can be further stored and plotted in an affinity CE mode. Consequently, the mobility of the free analyte, μA, mobility of the analyte-selector complex, μAS, and the apparent complexation constant, K('), are first guessed automatically from the linearized data plots and subsequently estimated by the means of nonlinear regression. An option that allows two complexation dependencies to be fitted at once is especially convenient for enantioseparations. Statistical processing of these data is also included, which allowed us to: i) express the 95% confidence intervals for the μA, μAS and K(') least-squares estimates, ii) do hypothesis testing on the estimated parameters for the first time. We demonstrate the benefits of the CEval software by inspecting complexation of tryptophan methyl ester with two cyclodextrins, neutral heptakis(2,6-di-O-methyl)-β-CD and charged heptakis(6-O-sulfo)-β-CD. PMID:27062723

  3. Analysis of multiple herbicides in soybeans using pressurized liquid extraction and capillary electrophoresis

    International Nuclear Information System (INIS)

    Several herbicides commonly used on soybeans are often difficult to extract, isolate, and quantify from the complex soybean matrix at low concentrations. Typical analytical methods for herbicide residues in soybeans are single analyte procedures using HPLC or GC after chemical derivatization. In this study, method development for the analysis of six polar herbicides in soybeans was performed using pressurized liquid extraction (PLE), which is also known by the trade name, Accelerated Solvent Extraction, and capillary electrophoresis (CE). In CE, a 50 mM ammonium acetate running buffer, pH 4.75, was able to separate imazaquin (Scepter), chlorimuron-ethyl (Classic), thifensulfuronmethyl (Harmony), acifluorfen (Blazer), bentazon (Basagran), and 2,4-dichlorophenoxyacetic acid in a 75 mum i.d., 83 cm capillary (65 cm to detector) within 30 min at 17 kV applied voltage. Chlorsulfuron (Glean) was used as an internal standard in the analysis, and detection was by UV absorbance at 240 nm in a high-sensitivity optical cell. PLE extracts required extensive cleanup prior to CE/UV analysis. Several cleanup techniques were investigated and compared, including liquid-liquid partitioning, gel-permeation chromatography, semipreparative HPLC, and solid-phase extraction with a variety of stationary and mobile phase combinations. A combination of techniques that provided the most efficient cleanup was selected in the final method. Four of the six herbicides could be determined by the method in samples fortified at tolerance levels with average recoveries of 71% and relative standard deviation (RSD) of 11%. At a higher spiking level, all of the herbicide recoveries were 70% with %RSDs 10%, except for acifluorfen which gave more variable recoveries

  4. Highly sensitive wavelength-dependent nonaqueous capillary electrophoresis for simultaneous screening of various synthetic organic dyes.

    Science.gov (United States)

    Park, Moonhee; Bahng, Seung-Hoon; Woo, Nain; Kang, Seong Ho

    2016-05-15

    A novel multi-wavelength nonaqueous capillary electrophoresis (MW-NACE) technique based on wavelength-dependent laser-induced fluorescence (LIF) detection was investigated for the simultaneous screening of various synthetic organic dyes. Multi-wavelength excitation light sources were utilized to excite different organic dyes [e.g., 543nm for crystal violet (CV), methyl violet B (MVB), methyl violet B base (MBB), rhodamine 6G (R6G), and rhodamine B base (RBB); 635nm for nile blue A (NBA) and methylene blue (MB)] simultaneously. Using a nonaqueous buffer system composed of 15mM sodium borate and 835mM acetic acid in 100% ethanol (pH=5.4), all dyes were analyzed within 15min with excellent resolution (R≥4.0) under an electric field of 500V/cm. Calibration curves showed excellent linearity with square of correlation coefficients (r(2)) greater than 0.9908 over wide dynamic ranges of 0.4-50μM for CV, 0.8-50μM for MVB, 1.5-50μM for MBB, 0.08-5nM for R6G, 0.06-10μM for MB, 0.02-10μM for NBA, and 0.13-10 pM for RBB. The detection limits (S/N=3) of 40fM to 0.5μM were 10-200,000 times lower than those of previous detection methods. While adjacent peaks were not well distinguished with baseline separation in a single capillary, the devised technique was faster and more sensitive than conventional aqueous and nonaqueous CE approaches, thereby enabling the quantitative analysis of various dyes based on wavelength-dependent fluorescence detection with different excitation wavelengths. PMID:26992516

  5. Analysis of Trinitrophenylated Adenosine and Inosine by Capillary Electrophoresis and γ-Cyclodextrin-Enhanced Fluorescence Detection.

    Science.gov (United States)

    Stephen, Terilyn K L; Guillemette, Katherine L; Green, Thomas K

    2016-08-01

    Monitoring molecules such as adenosine (Ado) and inosine (Ino) in the central nervous system has enabled the field of neuroscience to correlate molecular concentrations dynamics to neurological function, behavior, and disease. In vivo sampling techniques are commonly used to monitor these dynamics; however, many techniques are limited by the sensitivity and sample volume requirements of currently available detection methods. Here, we present a novel capillary electrophoresis-laser-induced fluorescence detection (CE-LIF) method that analyzes Ado and Ino by derivatization with 2,4,6-trinitrobenzenesulfonic acid to form fluorescent trinitrophenylated complexes of Ado (TNP-Ado) and Ino (TNP-Ino). These complexes exhibit ∼25-fold fluorescence enhancement upon the formation of inclusion complexes with γ-cyclodextrin (γ-CD). Association constants were determined as 4600 M(-1) for Ado and 1000 M(-1) for Ino by CE-LIF. The structure of the TNP-Ado:γ-CD complex was determined by 2D nuclear magnetic resonance (NMR) spectroscopy. Optimal trinitrophenylation reaction conditions and CE-LIF parameters were determined and resulted in the limit of detection of 1.6 μM for Ado and 4 μM for Ino. Ado and Ino were simultaneously quantified in homogenized rat forebrain samples to illustrate application of the technique. Simulated biological samples, desalted by ultrafiltration in the presence γ-CD, were concentrated on-capillary by large-volume sample stacking (LVSS) to achieve detection limits of 32 and 38 nM for TNP-Ado and TNP-Ino, respectively. PMID:27314490

  6. Portable, Battery Operated Capillary Electrophoresis with Optical Isomer Resolution Integrated with Ionization Source for Mass Spectrometry

    Science.gov (United States)

    Moini, Mehdi; Rollman, Christopher M.

    2016-03-01

    We introduce a battery operated capillary electrophoresis electrospray ionization (CE/ESI) source for mass spectrometry with optical isomer separation capability. The source fits in front of low or high resolution mass spectrometers similar to a nanospray source with about the same weight and size. The source has two high voltage power supplies (±25 kV HVPS) capable of operating in forward or reverse polarity modes and powered by a 12 V rechargeable lithium ion battery with operation time of ~10 h. In ultrafast CE mode, in which short narrow capillaries (≤15 μm i.d., 15-25 cm long) and field gradients ≥1000 V/cm are used, peak widths at the base are <1 s wide. Under these conditions, the source provides high resolution separation, including optical isomer resolution in ~1 min. Using a low resolution mass spectrometer (LTQ Velos) with a scan time of 0.07 s/scan, baseline separation of amino acids and their optical isomers were achieved in ~1 min. Moreover, bovine serum albumin (BSA) was analyzed in ~1 min with 56% coverage using the data-dependent MS/MS. Using a high resolution mass spectrometer (Thermo Orbitrap Elite) with 15,000 resolution, the fastest scan time achieved was 0.15 s, which was adequate for CE-MS analysis when optical isomer separation is not required or when the optical isomers were well separated. Figures of merit including a detection limit of 2 fmol and linear dynamic range of two orders of magnitude were achieved for amino acids.

  7. Determination of 2-methylimidazole and 4-methylimidazole in caramel colors by capillary electrophoresis.

    Science.gov (United States)

    Petruci, João Flávio da Silveira; Pereira, Elisabete Alves; Cardoso, Arnaldo Alves

    2013-03-01

    The use of chemical preservative compounds is common in the food products industry. Caramel color is the most usual additive used in beverages, desserts, and breads worldwide. During its fabrication process, 2- and 4-methylimidazole (MeI), highly carcinogenic compounds, are generated. In these cases, the development of reliable analytical methods for the monitoring of undesirable compounds is necessary. The primary procedure for the analysis of 2- and 4-MeI is using LC- or GC-MS techniques. These procedures are time-consuming and require large amounts of organic solvents and several pretreatment steps. This prevents the routine use of this procedure. This paper describes a rapid, efficient, and simple method using capillary electrophoresis (CE) for the separation and determination of 2- and 4-MeI in caramel colors. The analyses were performed using a 75 μm i.d. uncoated fused-silica capillary with an effective length of 40 cm and a running electrolyte consisting of 160 mmol L(-1) phosphate plus 30% acetonitrile. The pH was adjusted to 2.5 with triethylamine. The analytes were separated within 6 min at a voltage of 20 kV. Method validation revealed good repeatability of both migration time (<0.8% RSD) and peak area (<2% RSD). Analytical curves for 2- and 4-MeI were linear in the 0.4-40 mg L(-1) concentration interval. Detection limits were 0.16 mg L(-1) for 4-MeI and 0.22 mg L(-1) for 2-MeI. The extraction recoveries were satisfactory. The developed method showed many advantages when compared to the previously used method. PMID:23379790

  8. Analytical potential of mid-infrared detection in capillary electrophoresis and liquid chromatography: A review

    International Nuclear Information System (INIS)

    Literature published in the last decade concerning the use of mid-infrared spectrometry as a detection system in separation techniques employing a liquid mobile phase is reviewed. In addition to the continued use of isocratic liquid chromatographic (LC) techniques, advances in chemometric data evaluation techniques now allow the use of gradient techniques on a routine basis, thus significantly broadening the range of possible applications of LC-IR. The general trend towards miniaturized separation systems was also followed for mid-IR detection where two key developments are of special importance. Firstly, concerning on-line detection the advent of micro-fabricated flow-cells with inner volumes of only a few nL for transmission as well as attenuated total reflection measurements enabled on-line mid-IR detection in capillary LC and opened the path for the first successful realization of on-line mid-IR detection in capillary zone electrophoresis as well as micellar electrokinetic chromatography. Secondly, concerning off-line detection the use of micro-flow through dispensers now enables to concentrate eluting analytes on dried spots sized a few tens of micrometers, thus matching the dimensions for sensitive detection by mid-IR microscopy. Finally in an attempt to increase detection sensitivity of on-line mid-IR detection, mid-IR quantum cascade lasers have been used. Applications cover the field of food analysis, environmental analysis and the characterization of explosives among others. Best detection sensitivities for on-line and off-line detection have been achieved in miniaturized systems and are in the order of 50 ng and 2 ng on column, respectively.

  9. Structural and conformational variants of human beta2-microglobulin characterized by capillary electrophoresis and complementary separation methods

    DEFF Research Database (Denmark)

    Heegaard, Niels H H; Rovatti, Luca; Nissen, Mogens H;

    2003-01-01

    The small (Mr = 11729) serum protein beta2-microglobulin is prone to precipitate as amyloid in a protein conformational disorder (PCD) that occurs in a significant number of patients on chronic hemodialysis. Analyses by capillary electrophoresis (CE) were undertaken to study beta2-microglobulin...... capillary temperature, organic solvent concentration, and analysis time. The results suggest that the apparent beta2-microglobulin heterogeneity observed by CE is caused by two distinct protein conformations that are present in beta2-microglobulin under partly denaturing conditions and that Met99-oxidized...

  10. Human neutrophil elastase inhibition studied by capillary electrophoresis with laser induced fluorescence detection and microscale thermophoresis.

    Science.gov (United States)

    Syntia, Fayad; Nehmé, Reine; Claude, Bérengère; Morin, Philippe

    2016-01-29

    Capillary electrophoresis-laser induced fluorescence (CZE-LIF) and microscale thermophoresis (MST) were used for the first time to study the inhibition of human neutrophil elastase (HNE). We recently studied HNE kinetics (Km and Vmax) by developing an in-capillary CZE-LIF assay based on transverse diffusion of laminar flow profiles (TDLFP) for reactant mixing. In this work, the former assay was adapted to monitor HNE inhibition. Two natural well known HNE inhibitors from the triterpene family, ursolic acid and oleanolic acid, were tested to validate the developed assay. Since the solubility of pentacyclic triterpenes in aqueous media where the enzymatic reaction will take place is limited, the effect of DMSO and ethanol on HNE was studied using microscale thermophoresis (MST). An agglomeration of the enzyme was revealed when preparing the inhibitor in 5% (v/v) DMSO. This phenomenon did not occur in the presence of ethanol. Therefore, ethanol was used as inhibitor solvent, at a limited percentage of 20% (v/v). In these conditions and after optimization of the TDLFP approach, the repeatability (RSD on migration times and peak-areas inferior to 2.2%) of the CZE-LIF assay and the sensitivity (LOQ of few nM) were found to be satisfactory for conducting inhibition assays. IC50 values for ursolic and oleanolic acid were successfully determined. They were respectively equal to 5.62±0.10μM (r(2)=0.9807; n=3) and to 8.21±0.23μM (r(2)=0.9887; n=3). Excellent agreement was found between the results obtained by CE and those reported in literature which validates the developed method. Particularly, the CE-based assay is able to rank HNE inhibitors relative to each other. Furthermore, MST technique was used for evaluating HNE interaction with the ursolic acid. Up to 16 capillaries were automatically processed to obtain in one titration experiment the dissociation constant for the HNE-ursolic acid complex. Ki was found to be 2.72±0.66μM (n=3) which is in excellent agreement

  11. Uranium speciation studies in biological medium by capillary electrophoresis and time-resolved laser-induced fluorescence

    International Nuclear Information System (INIS)

    Uranium speciation studies in biological medium by capillary electrophoresis and time-resolved laser-induced fluorescence. The knowledge of the chemical state of uranium in biological medium requires more detailed investigations to understand the behaviour of uranium in the organism. The characterization of the different complexes of uranium can be improved by combining two techniques: time-resolved laser-induced fluorescence (TRLIF) and capillary electrophoresis (CE). CE, indeed, using the isoelectric focusing mode (CIEF), allows for the separation of the different complexes as a function of their isoelectric points (pI) and TRLIF as a speciation method leads to the identification at very low level of different uranyl complexes by temporal resolution and spectral unfolding. Results obtained on various inorganic chemical systems (phosphate, bicarbonate) together with biological systems (citrate, transferrin) will be presented and discussed. The complexation between uranium and human transferrin has been pointed out through CIEF. (authors)

  12. Real-time monitoring of peptide grafting onto chitosan films using capillary electrophoresis.

    Science.gov (United States)

    Taylor, Danielle L; Thevarajah, Joel J; Narayan, Diksha K; Murphy, Patricia; Mangala, Melissa M; Lim, Seakcheng; Wuhrer, Richard; Lefay, Catherine; O'Connor, Michael D; Gaborieau, Marianne; Castignolles, Patrice

    2015-03-01

    Chitosan, being antimicrobial and biocompatible, is attractive as a cell growth substrate. To improve cell attachment, arginine-glycine-aspartic acid-serine (RGDS) peptides were covalently grafted to chitosan films, through the widely used coupling agents 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC-HCl) and N-hydroxysuccinimide (NHS), via the carboxylic acid function of the RGDS molecule. The grafting reaction was monitored, for the first time, in real time using free-solution capillary electrophoresis (CE). This enabled fast separation and determination of the peptide and all other reactants in one separation with no sample preparation. Covalent RGDS peptide grafting onto the chitosan film surface was demonstrated using solid-state NMR of swollen films. CE indicated that oligomers of RGDS, not simply RGDS, were grafted on the film, with a likely hyperbranched structure. To assess the functional properties of the grafted films, cell growth was compared on control and peptide-grafted chitosan films. Light microscopy and polymerase chain reaction (PCR) analysis demonstrated greatly improved cell attachment to RGDS-grafted chitosan films. PMID:25680633

  13. Determination of Active Ingredients of Hawthorn by Capillary Electrophoresis with Electrochemical Detection

    Institute of Scientific and Technical Information of China (English)

    TANG Zhu-Xing; ZENG Yi-Kun; ZHOU Yun; ZANG Shu-Liang; HE Pin-Gang; FANG Yu-Zhi

    2006-01-01

    A method based on capillary electrophoresis with electrochemical detection has been developed for the separation and determination of epicatechin, kaempferol, chlorogenic acid, 4-hydroxybenzoic acid, quercetin and protocatechuic acid in hawthorn for the first time. The effects of working electrode potential, pH and concentration of running buffer, separation voltage and injection time on CE-ED were investigated. Under the optimum conditions,the analytes could be separated in a 60 mmol·L-1 borate buffer (pH 8.7) within 21 min. A 300 μm diameter carbon disk electrode has a good response at +0.95 V (vs. SCE) for all analytes. The response was linear over three orders of magnitude with detection limits (S/N=3) ranging from 3×10-8 to2×10-7 g·mL-1 for the analytes. The method has been successfully applied to the analysis of real sample, with satisfactory results.

  14. Capillary zone electrophoresis to study humic fraction in forest soils and its relationship with radionuclide mobility

    International Nuclear Information System (INIS)

    In order to determine the humic acid content in soil samples, a methodology has been developed using capillary zone electrophoresis (CZE), which is a technique with high separation efficiency and resolution. Working conditions of CZE separation were optimized and procedure was established. This methodology was applied to study the influence of organic matter matter (mainly humic acids) on the retention of radionuclides. The design mentioned above provided us with a great number of samples. For each sampling, samples were taken from the different horizons in several points. The fraction of radionuclide incorporated to each horizon was measured. The percentage of radionuclide associated with humic acids was estimated by means of single extractions using suitable reagents. The dark-coloured supernatant was separated from the residue by centrifugation and radionuclide content was quantified by gamma spectrometry. Humic content in these extracts was determined by acidifying with HCl to pH = 1 and allowing it to stand at room temperature for 16 hours. In this way, humic acid was obtained in a coagulated form, dissolved in NaOH solution and subsequently estimated using the CZE technique. After these measurements it is possible to test whether there is any correlation between humic acid and radionuclide contents in each sample and to obtain conclusions about the role of organic matter in radionuclide retention. 1 fig

  15. Capillary electrophoresis fingerprinting and spectrophotometric determination of antioxidant potential for classification of Mentha products.

    Science.gov (United States)

    Roblová, Vendula; Bittová, Miroslava; Kubáň, Petr; Kubáň, Vlastimil

    2016-07-01

    In this work aqueous infusions from ten Mentha herbal samples (four different Mentha species and six hybrids of Mentha x piperita) and 20 different peppermint teas were screened by capillary electrophoresis with UV detection. The fingerprint separation was accomplished in a 25 mM borate background electrolyte with 10% methanol at pH 9.3. The total polyphenolic content in the extracts was determined spectrophotometrically at 765 nm by a Folin-Ciocalteu phenol assay. Total antioxidant activity was determined by scavenging of 2,2-diphenyl-1-picrylhydrazyl radical at 515 nm. The peak areas of 12 dominant peaks from CE analysis, present in all samples, and the value of total polyphenolic content and total antioxidant activity obtained by spectrophotometry was combined into a single data matrix and principal component analysis was applied. The obtained principal component analysis model resulted in distinct clusters of Mentha and peppermint tea samples distinguishing the samples according to their potential protective antioxidant effect. Principal component analysis, using a non-targeted approach with no need for compound identification, was found as a new promising tool for the screening of herbal tea products. PMID:27306863

  16. Inhibitor screening of pharmacological chaperones for lysosomal β-glucocerebrosidase by capillary electrophoresis.

    Science.gov (United States)

    Shanmuganathan, Meera; Britz-McKibbin, Philip

    2011-03-01

    Pharmacological chaperones (PCs) represent a promising therapeutic strategy for treatment of lysosomal storage disorders based on enhanced stabilization and trafficking of mutant protein upon orthosteric and/or allosteric binding. Herein, we introduce a simple yet reliable enzyme assay using capillary electrophoresis (CE) for inhibitor screening of PCs that target the lysosomal enzyme, β-glucocerebrosidase (GCase). The rate of GCase-catalyzed hydrolysis of the synthetic substrate, 4-methylumbelliferyl-β-D: -glucopyranoside was performed using different classes of PCs by CE with UV detection under standardized conditions. The pH and surfactant dependence of inhibitor binding on recombinant GCase activity was also examined. Enzyme inhibition studies were investigated for five putative PCs including isofagomine (IFG), ambroxol, bromhexine, diltiazem, and fluphenazine. IFG was confirmed as a potent competitive inhibitor of recombinant GCase with half-maximal inhibitory concentration (IC(50)) of 47.5 ± 0.1 and 4.6 ± 1.4 nM at pH 5.2 and pH 7.2, respectively. In contrast, the four other non-carbohydrate amines were demonstrated to function as mixed-type inhibitors with high micromolar activity at neutral pH relative to acidic pH conditions reflective of the lysosome. CE offers a convenient platform for characterization of PCs as a way to accelerate the clinical translation of previously approved drugs for oral treatment of rare genetic disorders, such as Gaucher disease. PMID:21286689

  17. Metabolomics, peptidomics and proteomics applications of capillary electrophoresis-mass spectrometry in Foodomics: A review

    International Nuclear Information System (INIS)

    Graphical abstract: -- Highlights: •Foodomics allows studying food and nutrition through the application of advanced omics approaches. •CE-MS plays a crucial role as analytical platform to carry out omics studies. •CE-MS applications for food metabolomics, proteomics and peptidomics are presented. -- Abstract: In the current post-genomic era, Foodomics has been defined as a discipline that studies food and nutrition through the application of advanced omics approaches. Foodomics involves the use of genomics, transcriptomics, epigenetics, proteomics, peptidomics, and/or metabolomics to investigate food quality, safety, traceability and bioactivity. In this context, capillary electrophoresis-mass spectrometry (CE-MS) has been applied mainly in food proteomics, peptidomics and metabolomics. The aim of this review work is to present an overview of the most recent developments and applications of CE-MS as analytical platform for Foodomics, covering the relevant works published from 2008 to 2012. The review provides also information about the integration of several omics approaches in the new Foodomics field

  18. [Recent advances in the application of high performance capillary electrophoresis for food safety].

    Science.gov (United States)

    Dong, Yalei; Chen, Xiaojiao; Hu, Jing; Chen, Xingguo

    2012-11-01

    In recent years, food safety incidents become a serious social problem. Foods are usually complex mixtures consisting of a large diversity of molecules. Analysis of foods is a topic that demands the development of rapid, robust, efficient, sensitive and cost-effective analytical methodologies. Therefore, new techniques for food safety purpose are required by analytical chemists. Capillary electrophoresis (CE) is a popular separation technique that possesses fast and efficient performances in an automated way with minimum consumption of sample and reagents. Nowadays, CE represents a desired strategy for the determination of many compounds or molecules in various kinds of food. In this paper, the review intends to provide the recent innovative developments reported in food safety analysis using CE methods for a full overview. As a fundamental review, it focuses on the introduction and detection of several common hazardous materials existing in food such as non-food additives, pesticide residues, veterinary drug residues, heavy metal ion contaminants, toxins, biphenol A and phthalates in packaging materials and so on. Furthermore, this review prospects the main development direction of CE in this field for the future. A total of 63 papers published during the period of Jan 2009 - Jun 2012 are included in the present review. PMID:23451513

  19. Determination of active ingredients of Rhododendron dauricum L. by capillary electrophoresis with electrochemical detection.

    Science.gov (United States)

    Cao, Yuhua; Lou, Changgang; Fang, Yuzhi; Ye, Jiannong

    2002-01-11

    High-performance capillary electrophoresis with electrochemical detection was employed to analyse active ingredients of Rhododendron dauricum L., an important crude herb frequently used in Chinese medicines. Farrerol, quercetin, syringic acid, vanillic acid, 4-hydroxybenzoic acid, protocatechuic acid are major important active ingredients. Operated in a wall-jet configuration, a 300-microm diameter carbon-disk electrode was used as the working electrode, which exhibits a good response at +950 mV (vs. saturated calomel electrodes) for six analytes. Under the optimum conditions, the analytes were baseline separated within 16 min in a borax buffer (pH 8.7). Notably, excellent linearity was obtained over two orders of magnitude with detection limits (S/N=3) ranged from 9 x 10(-7) to 3.0 x 10(-6) M for all analytes. This method was successfully used in the analysis of Rhododendron dauricum L. with relatively simple extraction procedures, and the assay results were satisfactory. PMID:11820277

  20. Metabolomics, peptidomics and proteomics applications of capillary electrophoresis-mass spectrometry in Foodomics: A review

    Energy Technology Data Exchange (ETDEWEB)

    Ibáñez, Clara; Simó, Carolina; García-Cañas, Virginia; Cifuentes, Alejandro, E-mail: a.cifuentes@csic.es; Castro-Puyana, María

    2013-11-13

    Graphical abstract: -- Highlights: •Foodomics allows studying food and nutrition through the application of advanced omics approaches. •CE-MS plays a crucial role as analytical platform to carry out omics studies. •CE-MS applications for food metabolomics, proteomics and peptidomics are presented. -- Abstract: In the current post-genomic era, Foodomics has been defined as a discipline that studies food and nutrition through the application of advanced omics approaches. Foodomics involves the use of genomics, transcriptomics, epigenetics, proteomics, peptidomics, and/or metabolomics to investigate food quality, safety, traceability and bioactivity. In this context, capillary electrophoresis-mass spectrometry (CE-MS) has been applied mainly in food proteomics, peptidomics and metabolomics. The aim of this review work is to present an overview of the most recent developments and applications of CE-MS as analytical platform for Foodomics, covering the relevant works published from 2008 to 2012. The review provides also information about the integration of several omics approaches in the new Foodomics field.

  1. Effects of organic solvent and cationic additive on capillary electrophoresis of peptides

    International Nuclear Information System (INIS)

    Capillary electrophoresis (CE) of nine peptides namely, bradykinin, bradykinin fragment 1-5, substance P, Arg8-vasopressin, luteinizing hormone-releasing hormone (LHRH), bombesin, leucine-enkephalin, methionine-enkephalin and oxytocin were carried out using 0.5 % and 1.0 % formic acid (FA) as the separation buffers, added with acetonitrile (ACN) and triethylamine (TEA) as an additive at low pH. The electrophoretic behavior of these peptides was examined at different concentration of TEA (0, 10, 20, 30, 40 and 50 mM), and ACN (30, 40, 50, 60, 70 %) at their respective measured final pH. The results showed that all nine peptides were fully resolved with addition of 10-20 mM TEA. Peak efficiency was improved significantly by increasing TEA concentration up to 40 mM where 800 000 m-1 was obtained. Without TEA, the closely related enkephalins were co-migrating. Interestingly, by addition of as little as 5 mM TEA has sufficient to separate them almost at baseline. Increasing ACN to 40 % has shortened the analysis time by ca. 1 min. However, further increase of ACN can cause peak broadening and current instability. (author)

  2. Fabrication of microfluidic devices using dry film photoresist for microchip capillary electrophoresis.

    Science.gov (United States)

    Tsai, Yuan-Chien; Jen, Hsiu-Ping; Lin, Kuan-Wen; Hsieh, You-Zung

    2006-04-14

    An inexpensive, disposable microfluidic device was fabricated from a dry film photoresist using a combination of photolithographic and hot roll lamination techniques. A microfluidic flow pattern was prefabricated in a dry film photoresist tape using traditional photolithographic methods. This tape became bonded to a poly(methyl methacrylate) (PMMA) sheet with prepouched holes when passed through a hot roll laminator. A copper working electrode and platinum decoupler was readily incorporated within this microchip. The integrated microchip device was then fixed in a laboratory-built Plexiglas holder prior to its use in microchip capillary electrophoresis. The performance of this device with amperometric detection for the separation of dopamine and catechol was examined. The separation was complete within 50 s at an applied potential of 200 V/cm. The relative standard deviations (RSD) of analyte migration times were less than 0.71%, and the theoretical plate numbers for dopamine and catechol were 3.2 x 10(4) and 4.1 x 10(4), respectively, based on a 65 mm separation channel. PMID:16384565

  3. Comparative study between capillary electrophoresis and high performance liquid chromatography in 'guarana' based phytopharmaceuticals.

    Science.gov (United States)

    Sombra, Lorena L; Gómez, María R; Olsina, Roberto; Martínez, Luis D; Silva, María F

    2005-01-01

    The last years have seen a significant increase in the use of herbal medicines and their preparations all over the world. Adulterations with synthetic drugs are common problems with phytopharmaceutical products and this can potentially cause adverse effects. In consequence, it is important to determine the presence of synthetic drugs in herbal medicines to ensure their efficacy and safety. In this study, guarana derivatives were analyzed by capillary electrophoresis (CE), and the results were compared with those obtained by the HPLC technique. In order to obtain adequate fingerprints, and search for adulterants, caffeine was used as the marker compound. This separation method was applied to analyze the seed powder and commercial tablets of Paulinia cupana Mart. The methodology performance was evaluated in terms of specificity, sensitivity and precision. The results are in agreement with those obtained by the HPLC method. Furthermore, the analysis time of the CE method is up to two times shorter than the respective parameter in HPLC and solvent consumption is more than 100-fold less. PMID:15620524

  4. Development of a simplified microfluidic injector for analysis of droplet content via capillary electrophoresis.

    Science.gov (United States)

    DeLaMarre, Michael F; Shippy, Scott A

    2014-10-21

    Droplet-based microfluidic platforms sequester nanoliter to picoliter samples in an immiscible carrier phase and have gained notoriety for their ability to be used in laboratory procedures on a miniaturized scale. Recently, droplet microfluidics has been used to prevent zone diffusion in time-resolved sample collection methods and in separation techniques. The assay of droplets remains challenging, however, because the carrier phase is often incompatible with separation techniques. In this work, we report the development of a droplet injector for capillary electrophoresis (CE) which delivers 750 pL droplets to a channel for separation while excluding the fluorous carrier phase. This design is simple compared to previous reports, consisting of only two straight channels and no additional working parts such as membranes or valves. To demonstrate a proof-of-concept and characterize performance, riboflavin was used as a biologically relevant model molecule. Droplets containing a step change in riboflavin concentration were injected and mobilized by CE. The current method is capable of riboflavin peak % relative standard deviations (RSDs) down to 4.4% and temporal resolutions down to 15 s. Human urine samples containing riboflavin and its photolysis products were successfully separated and found to be chemically compatible with the injector. Our simplified design could improve robustness and ruggedness and may allow device construction via nontraditional fabrication techniques. PMID:25226066

  5. Reverse polarity capillary zone electrophoresis analysis of nitrate and nitrite in natural water samples

    International Nuclear Information System (INIS)

    This paper describes the application of reverse polarity capillary zone electrophoresis (RPCE) for rapid and accurate determination of nitrate and nitrite in natural water samples. Using hexamethonium bromide (HMB) as an electroosmotic flow modifier in a borate buffer at pH 9.2, the resolution of nitrate and nitrite was accomplished in less than 3 minutes. RPCE was compared with ion chromatographic (IC) and cadmium reduction flow injection analysis (Cd-FIA) methods which are the two most commonly used standard methods for the analysis of natural water samples for nitrate and nitrite. When compared with the ion chromatographic method for the determination of nitrate and nitrite, RPCE reduced analysis time, decreased detection limits by a factor of 10, cut laboratory wastes by more than two orders of magnitude, and eliminated interferences commonly associated with IC. When compared with the cadmium reduction method, RPCE had the advantage of simultaneous determination of nitrate and nitrite, could be used in the presence of various metallic ions that normally interfere in cadmium reduction, and decreased detection limits by a factor of 10

  6. Methoxypropylamino β-cyclodextrin clicked AC regioisomer for enantioseparations in capillary electrophoresis

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Jie; Wang, Yiying; Liu, Yun; Tang, Jian; Tang, Weihua, E-mail: whtang@mail.njust.edu.cn

    2015-04-08

    Highlights: In this paper, we demonstrate: • The click synthesis of a AC regioisomer cationic cyclodextrin (CD) as chiral selector. • The good enantioselectivities (chiral resolution over 5) for acidic racemates. • The strong chiral recognition of new CD by NMR study. • Baseline enantioseparation of some acidic racemates at CD of 0.5 mM. - Abstract: In this work, a novel methoxypropylamino β-cyclodextrin (β-CD) clicked AC regioisomer, 6{sup A}-4-hydroxyethyl-1,2,3-triazolyl-6{sup C}-3-methoxypropylamino β-cyclodextrin (HETz-MPrAMCD), was synthesized via nucleophilic addition and click chemistry. The chiral separation ability of this AC regioisomer cationic CD was evaluated toward 7 ampholytic and 13 acidic racemates by capillary electrophoresis. Dependence of enantioselectivity and resolution on buffer pH (5.5–8.0) and chiral selector concentration (0.5–7.5 mM) was investigated. Enantioselectivities (α ≥ 1.05) could be achieved for most analytes under optimal conditions except dansyl-DL-noreleucine and dansyl-DL-serine. The highest resolutions for 2-chloromandelic acid p-hydroxymandelic acid were 15.6 and 9.7 respectively. The inclusion complexation between HETz-MPrAMCD and each 3-phenyllactic acid enantiomer was also revealed with nuclear magnetic resonance study.

  7. Enantiodifferentiation of chiral baclofen by β-cyclodextrin using capillary electrophoresis: A molecular modeling approach

    Science.gov (United States)

    Suliman, FakhrEldin O.; Elbashir, Abdalla A.

    2012-07-01

    Using capillary electrophoresis baclofen (BF) enantiomers were separated only in the presence of β-cyclodextrin (βCD) as a chiral selector when added to the background electrolyte. Proton nuclear magnetic resonance and electrospray ionization mass spectrometry (ESI-MS) techniques were used to determine the structure of the BF-βCD inclusion complexes. From the MS data BF was found to form a 1:1 complex with α- and βCD, while the NMR data suggest location of the aromatic ring of BF into the cyclodextrin cavity. A molecular modeling study, using the semiempirical PM6 calculations was used to investigate the mechanism of enantiodifferentiation of BF with cyclodextrins. Optimization of the structures of the complexes by PM6 method indicated that separation is obtained in the presence of β-CD due to a large binding energy difference (ΔΔE) of 46.8 kJ mol-1 between S-BF-βCD and R-BF-βCD complexes. In the case of αCD complexes ΔΔE was 1.3 kJ mol-1 indicating poor resolution between the two enantiomers. Furthermore, molecular dynamic simulations show that the formation of more stable S-BF-βCD complex compared to R-BF-β-CD complex is primarily due to differences in intermolecular hydrogen bonding.

  8. Identification of primary amines in Titan tholins using microchip nonaqueous capillary electrophoresis

    Science.gov (United States)

    Cable, M. L.; Hörst, S. M.; He, C.; Stockton, A. M.; Mora, M. F.; Tolbert, M. A.; Smith, M. A.; Willis, P. A.

    2014-10-01

    Titan, the moon of Saturn with a thick atmosphere and an active hydrocarbon-based weather cycle, is considered the best target in the solar system for the study of organic chemistry on a planetary scale. Microfluidic devices that employ liquid phase techniques such as capillary electrophoresis with ultrasensitive laser-induced fluorescence detection offer a unique solution for in situ analysis of complex organics on Titan. We previously reported a protocol for nonaqueous microfluidic analysis of primary aliphatic amines in ethanol, and demonstrated separations of short- and long-chain amines down to -20 °C. We have optimized this protocol further, and used it to analyze Titan aerosol analogues (tholins) generated in two separate laboratories under a variety of different conditions. Ethylamine was a major product in all samples, though significant differences in amine content were observed, in particular for long-chain amines (C12-C27). This work validates microfluidic chemical analysis of complex organics with relevance to Titan, and represents a significant first step in understanding tholin composition via targeted functional group analysis.

  9. Simultaneous analysis of saturated and unsaturated fatty acids present in pequi fruits by capillary electrophoresis

    Directory of Open Access Journals (Sweden)

    Patrícia M. de Castro Barra

    2013-01-01

    Full Text Available In the current study, an alternative method has been proposed for simultaneous analysis of palmitic, stearic, oleic, linoleic, and linolenic acids by capillary zone electrophoresis (CZE using indirect detection. The background electrolyte (BGE used for the analysis of these fatty acids (FAs consisted of 15.0 mmol L−1 NaH2PO4/Na2HPO4 at pH 6.86, 4.0 mmol L−1 SDBS, 8.3 mmol L−1 Brij 35, 45% v/v acetonitrile (can, and 2.1% n-octanol. The FAs quantification of FAs was performed using a response factor approach, which provided a high analytical throughput for the real sample. The CZE method, which was applied successfully for the analysis of pequi pulp, has advantages such as short analysis time, absence of lipid fraction extraction and derivatization steps, and no significant difference in the 95% confidence intervals for FA quantification results, compared to the gas chromatography official method (AOCS Ce 1h-05.

  10. Review on the development of truly portable and in-situ capillary electrophoresis systems

    Science.gov (United States)

    Lewis, A. P.; Cranny, A.; Harris, N. R.; Green, N. G.; Wharton, J. A.; Wood, R. J. K.; Stokes, K. R.

    2013-04-01

    Capillary electrophoresis (CE) is a technique which uses an electric field to separate a mixed sample into its constituents. Portable CE systems enable this powerful analysis technique to be used in the field. Many of the challenges for portable systems are similar to those of autonomous in-situ analysis and therefore portable systems may be considered a stepping stone towards autonomous in-situ analysis. CE is widely used for biological and chemical analysis and example applications include: water quality analysis; drug development and quality control; proteomics and DNA analysis; counter-terrorism (explosive material identification) and corrosion monitoring. The technique is often limited to laboratory use, since it requires large electric fields, sensitive detection systems and fluidic control systems. All of these place restrictions in terms of: size, weight, cost, choice of operating solutions, choice of fabrication materials, electrical power and lifetime. In this review we bring together and critique the work by researchers addressing these issues. We emphasize the importance of a holistic approach for portable and in-situ CE systems and discuss all the aspects of the design. We identify gaps in the literature which require attention for the realization of both truly portable and in-situ CE systems.

  11. Centimeter-scale characterization of biogeochemical gradients at a wetland-aquifer interface using capillary electrophoresis

    Science.gov (United States)

    Baez-Cazull, S.; McGuire, J.T.; Cozzarelli, I.M.; Raymond, A.; Welsh, L.

    2007-01-01

    Steep biogeochemical gradients were measured at mixing interfaces in a wetland-aquifer system impacted by landfill leachate in Norman, Oklahoma. The system lies within a reworked alluvial plain and is characterized by layered low hydraulic conductivity wetland sediments interbedded with sandy aquifer material. Using cm-scale passive diffusion samplers, "peepers", water samples were collected in a depth profile to span interfaces between surface water and a sequence of deeper sedimentary layers. Geochemical indicators including electron acceptors, low-molecular-weight organic acids, base cations, and NH4+ were analyzed by capillary electrophoresis (CE) and field techniques to maximize the small sample volumes available from the centimeter-scale peepers. Steep concentration gradients of biogeochemical indicators were observed at various interfaces including those created at sedimentary boundaries and boundaries created by heterogeneities in organic C and available electron acceptors. At the sediment-water interface, chemical profiles with depth suggest that SO42 - and Fe reduction dominate driven by inputs of organic C from the wetland and availability of electron acceptors. Deeper in the sediments (not associated with a lithologic boundary), a steep gradient of organic acids (acetate maximum 8.8 mM) and NH4+ (maximum 36 mM) is observed due to a localized source of organic matter coupled with the lack of electron acceptor inputs. These findings highlight the importance of quantifying the redox reactions occurring in small interface zones and assessing their role on biogeochemical cycling at the system scale. ?? 2007 Elsevier Ltd. All rights reserved.

  12. Microfluidic-based metal enhanced fluorescence for capillary electrophoresis by Ag nanorod arrays

    Science.gov (United States)

    Xiao, Chenyu; Cao, Zhen; Deng, Junhong; Huang, Zhifeng; Xu, Zheng; Fu, Junxue; Yobas, Levent

    2014-06-01

    As metal nanorods show much higher metal enhanced fluorescence (MEF) than metal nanospheres, microfluidic-based MEF is first explored with Ag nanorod (ND) arrays made by oblique angle deposition. By measuring the fluorescein isothiocyanate (FITC) solution sandwiched between the Ag NDs and a piece of cover slip, the enhancement factors (EFs) are found as 3.7 ± 0.64 and 6.74 ± 2.04, for a solution thickness at 20.8 μm and 10 μm, respectively. Because of the strong plasmonic coupling between the adjacent Ag NDs, only the emission of the fluorophores present in the three-dimensional NDs array gets enhanced. Thus, the corresponding effective enhancement factors (EEFs) are revealed to be relatively close, 259 ± 92 and 340 ± 102, respectively. To demonstrate the application of MEF in microfluidic systems, a multilayer of SiO2 NDs/Ag NDs is integrated with a capillary electrophoresis device. At a microchannel depth of 10 μm, an enhancement of 6.5 fold is obtained for amino acids separation detection. These results are very encouraging and open the possibility of MEF applications for the Ag ND arrays decorated microchannels. With the miniaturization of microfluidic devices, microfluidic-based MEF by Ag ND arrays will likely find more applications with further enhancement.

  13. Using capillary electrophoresis to study the chemical conditions within cracks in aluminum alloys.

    Science.gov (United States)

    Cooper, K R; Kelly, R G

    1999-07-30

    The environment-assisted cracking (EAC) susceptibility of some aluminum alloys used for airplane structural components currently limits their use in the peak strength condition. Understanding the mechanism of EAC will facilitate the development of crack-resistant alloys with optimum mechanical properties. One component towards understanding the fundamental processes responsible for EAC is a comprehensive knowledge of the chemical conditions within cracks. The present work uses capillary electrophoresis (CE) to quantify the crack chemistry in order to provide insight into the nature of the mechanism controlling cracking. The highly restricted geometry of cracks in metals means that a crack typically contains less than 10 microliters of solution. The high mass sensitivity combined with the inherently robust nature of CE makes it an ideal analytical technique for this application. Complicating factors in the accurate determination of the crack environment include high levels of sodium present from the test solution. Low sample volume and analyte matrix complexity necessitated the development of specific sampling, extraction and analysis methods. Analysis of the crack solutions in EAC-susceptible material revealed high levels of Al3+, Mg2+, Zn2+, and Cl- near the crack tip. Cations arise from the anodic dissolution of the alloy, whereas chloride ingress from the external environment occurs to maintain solution electroneutrality within the crack. In contrast, EAC-resistant material exhibited significantly lower concentrations of dissolution products. PMID:10457501

  14. Synthesis of ino Acid Derived β-Cyclodextrins Used in Chiral Separation by Capillary Electrophoresis

    Institute of Scientific and Technical Information of China (English)

    戴荣继; 佟斌; 魏征; 顾峻岭; 邓玉林; 李明愉; 傅若农

    2004-01-01

    Six new kinds of ino acid derived β-cyclodextrins were synthesized to improve their water solubility and chiral separation properties. They are heptakis{2,6-di-O-[3-L-(1-isopropyl carboxyl methyl ino)-2-hydroxy propyl]}-β-cyclodextrin (i.e. L-Val-β-CD), heptakis{2,6-di-O-[3-L-(1-benzyl carboxyl methyl ino)-2-hydroxy propyl]}-β-cyclodextrin (i.e. L-Phe-β-CD), heptakis{2,6-di-O-[3-(D, L-1-benzyl carboxyl methyl ino)-2-hydroxy propyl]}-β-cyclodextrin (i.e. D,L-Phe-β-CD), heptakis{2,6-di-O-[3-(L-1-hydroxymethyl carboxyl methyl ino)-2-hydroxy propyl]}-β-cyclodextrin (i.e. L-Ser-β-CD), heptakis{2,6-di-O-[3-(L-1-carboxylmethyl carboxyl methyl ino)- 2-hydroxy propyl]}-β-cyclodextrin (i.e. L-Asp-β-CD), heptakis{2,6-di-O-[3-(L-2-carboxyl tetrethylene ino)-2-hydroxy propyl]}-β-cyclodextrin (i.e. L-Pro-β-CD). Their chemical structures were certified using FTIR and 1H NMR. Except for L-Phe-β-CD and D,L-Phe-β-CD, that are in soluble in water, the other ino acid derived β-CDs all have good water solubility. D,L-tyrosine and promethazine were baselinely separated by L-Val-β-CD in capillary electrophoresis.

  15. Postcolumn derivatization of proteins in capillary sieving electrophoresis/laser-induced fluorescence detection.

    Science.gov (United States)

    Kaneta, Takashi; Yamamoto, Daisuke; Imasaka, Totaro

    2009-11-01

    The separation methods for proteins with high resolution and sensitivity are absolutely important in the field of biological sciences. Capillary sieving electrophoresis (CSE) is an excellent separation technique for DNA and proteins with high resolution, while LIF permits the most sensitive detection in CSE. Therefore, proteins have to be labeled with fluorescent or fluorogenic reagent to produce fluorescent derivatives. Both precolumn and oncolumn derivatization have been employed for the labeling of proteins in CSE. However, there is no report on the postcolumn derivatization due to the limitation in the use of a standard migration buffer, despite it being a promising method for sensitive detection of proteins. Here, we show a novel postcolumn derivatization method for protein separation by CSE, using a tertiary amine as a buffer component in the running buffer. Tris, which is commonly used as a base in CSE separation buffers, was substituted by tertiary amines, 2-(diethylamino)ethanol and triethanolamine. A buffer solution containing 2-(diethylamino)ethanol or triethanolamine can be used for the CSE separation followed by the postcolumn derivatization of proteins, since both reagents are unreactive toward a fluorogenic labeling reagent, naphthalene-2,3-dicarbaldehyde. Thus, LIF detection using the postcolumn derivatization permits significant reduction in the LOD (by a factor of 2.4-28) of proteins, compared with conventional absorbance detection. PMID:19862753

  16. Stereoselective analysis of herbicides by capillary electrophoresis using sulfobutyl ether beta-cyclodextrin as chiral selector.

    Science.gov (United States)

    Desiderio, C; Polcaro, C M; Fanali, S

    1997-02-01

    Capillary zone electrophoresis has been used for the enantiomeric separation of several herbicides. Different beta-cyclodextrin (CD) derivatives have been investigated for chiral separations and among them the negatively charged sulfobutyl ether beta-cyclodextrin (SBE-beta-CD) proved to be effective for the stereo-selective resolutions of the investigated herbicides. The effect of CD concentration, buffer pH and organic modifier on effective mobilities, resolution and selectivity of the analytes have been studied. Addition of SBE-beta-CD (5-50 mg/mL) to the buffer at pH 9 resulted in a general increase of migration times as well as resolution. A CD concentration as low as 5 mg/mL was effective to completely resolve napropamide and ethofumesate enantiomers. Buffer solutions containing 40 mg/mL of SBE-beta-CD were chosen to study the effect of buffer pH (7, 8, and 9) on chiral separation of the herbicides. No great differences in resolution and effective mobilities have been found in the pH 7-9 range. The addition of different organic modifiers to the background electrolyte at pH 9, containing 20 mg/mL of SBE-beta-CD, showed different effects. Methanol was the most effective in improving resolution but in some cases total loss in enantiomeric separation was observed. The qualitative analysis of an enantiomerically pure herbicide (flamprop isopropyl) commercial preparation is also shown. PMID:9080130

  17. Simultaneous determination of phenylurea herbicides in yam by capillary electrophoresis with electrochemiluminescence detection.

    Science.gov (United States)

    Hu, Yuefang

    2015-04-01

    A method of capillary electrophoresis (CE) coupled with electrochemiluminescence (ECL) detection has been applied to detect three major phenylurea herbicides (monuron, monolinuron and diuron) simultaneously. The effects of yam sample preparation, injection voltage and time, detection potential, detection buffer concentration and pH, Ru(bpy)₃(2+) concentration, separation buffer type, separation buffer pH and concentration, separation voltage were investigated in detail. Under optimum conditions, a good baseline separation and highly sensitive detection for monuron, monolinuron and diuron were achieved. The ECL intensity (I) was in proportion to three analytes concentration (ρ) in the range of 0.1-10,000 μg/L for monuron (r≥0.9993), 0.1-18,000 μg/L for monolinuron (r≥0.9995) and 0.1-20,000 μg/L for diuron (r≥0.9997). The detection limits for monuron, monolinuron and diuron were 0.05, 0.04 and 0.01 μg/L (S/N=3), respectively. The developed method was successfully applied for the analysis of monuron, monolinuron and diuron residues in yam simultaneously. The average recoveries are in the ranges of 90.0-99.2% with relative standard deviations less than 3.2%. The limits of detection of the proposed method were 0.010 μg/kg for monuron, 0.008 μg/kg for monolinuron and diuron in yam. PMID:25732033

  18. Determination of Four Active Ingredients in Vc Yinqiao Tablets by Capillary Zone Electrophoresis with Amperometric Detection

    Institute of Scientific and Technical Information of China (English)

    L(U),Jin; WANG,Qing-Jiang; CHENG,Xi; LIU,Hai-Yan; HE,Pin-Gang; FANG,Yu-Zhi

    2006-01-01

    A simple, reliable and reproducible method, based on capillary zone electrophoresis with amperometric detection (CZE-AD), has been developed for simultaneous determination of four active ingredients in Vc Yinqiao tablets including paracetamol, vitamin C, caffeic acid and chlorogenic acid. A carbon-disk electrode was used as working electrode and 0.95 V (versus SCE) was selected as detection potential. The optimal conditions of CZE experiment were 30 mmol·L-1 borate solution (pH 9.5) as running buffer, 14 kV as separation voltage and 8 s (14 kV) as electro-kinetic sampling time. Under the selected optimum conditions, paracetamol, vitamin C, caffeic acid and chlorogenic acid could be perfectly separated within 22 min, and their detection limits (S/N=3) ranged from 5 × 10-7 to 1×10-6 mol·L-1. This proposed method demonstrated good reproducibility with relative standard deviations of less than 3% for both migration time and peak current (n=7). The utility of this method was demonstrated by monitoring a kind of compound medicine named Vc Yinqiao tablets and the assay results were satisfactory.

  19. Screening of the binding properties of molecularly imprinted nanoparticles via capillary electrophoresis.

    Science.gov (United States)

    Musile, Giacomo; Cenci, Lucia; Andreetto, Erika; Ambrosi, Emmanuele; Tagliaro, Franco; Bossi, Alessandra Maria

    2016-05-01

    In response to the need for straightforward analytical methods to assess the affinity of molecularly imprinted nanoparticles (MIP NPs) for ligands, capillary electrophoresis (CE) was exploited using MIP NPs targeting the iron-regulating hormone hepcidin. In this work, MIP NPs were challenged with their template peptide, i.e., the N-terminal 5-mer of hepcidin, in comparison to unrelated ligand peptides. A CE separation method was developed ex novo achieving, after optimization of the background electrolyte (150 mM sodium phosphate pH 7.4) and of the running temperature (35 °C), the full separation of the free ligand from the complexed MIP NPs. The CE binding isotherm allowed the estimation of a micromolar dissociation constant for the 5-mer template-MIP NPs complex, in agreement with independent measurements. The CE offered the advantages of a direct injection of the MIP NPs/ligand incubation mix, without preliminary fractionation steps, requiring only minimal sample volumes and short analysis times. In conclusion CE proved to be a valid technique for characterizing the interactions of MIP NP libraries for selected target compounds. Graphical Abstract Five different nanodiamond samples were exhaustively characterized using a suite of analytical techniques. PMID:26960903

  20. Fluorescent silver nanocluster DNA probes for multiplexed detection using microfluidic capillary electrophoresis.

    Science.gov (United States)

    Del Bonis-O'Donnell, Jackson Travis; Fygenson, Deborah K; Pennathur, Sumita

    2015-03-01

    DNA-stabilized fluorescent silver nanoclusters (AgNC DNA) are a new class of fluorophore that are formed by sequence specific interactions between silver and single-stranded DNA. By incorporating both target-binding and fluorescent-reporting sequences into a single synthetic DNA oligomer, AgNC DNA probes eliminate the need to conjugate dye or quencher molecules. In this study, we modify a AgNC DNA probe to demonstrate single-color multiplexed detection of DNA targets. We show that appending different lengths of poly-dT to the probe sequences tunes the electrophoretic mobility of AgNC DNA probes without affecting their fluorescence spectra. We use this to introduce a set of AgNC DNA probes selective for Hepatitis A, B and C target sequences that can be processed together in a simple, single-step protocol and distinguished with a resolution of 3.47 and signal to noise ratio of 17.23 in under 10 seconds by microfluidic capillary electrophoresis. PMID:25601044

  1. End-to-end differential contactless conductivity sensor for microchip capillary electrophoresis.

    Science.gov (United States)

    Fercher, Georg; Haller, Anna; Smetana, Walter; Vellekoop, Michael J

    2010-04-15

    In this contribution, a novel measurement approach for miniaturized capillary electrophoresis (CE) devices is presented: End-to-end differential capacitively coupled contactless conductivity measurement. This measurement technique is applied to a miniaturized CE device fabricated in low-temperature cofired ceramics (LTCC) multilayer technology. The working principle is based on the placement of two distinct detector areas near both ends of the fluid inlet and outlet of the separation channel. Both output signals are subtracted from each other, and the resulting differential signal is amplified and measured. This measurement approach has several advantages over established, single-end detectors: The high baseline level resulting from parasitic stray capacitance and buffer conductivity is reduced, leading to better signal-to-noise ratio and hence higher measurement sensitivity. Furthermore, temperature and, thus, baseline drift effects are diminished owing to the differentiating nature of the system. By comparing the peak widths measured with both detectors, valuable information about zone dispersion effects arising during the separation is obtained. Additionally, the novel measurement scheme allows the determination of dispersion effects that occur at the time of sample injection. Optical means of dispersion evaluation are ineffective because of the opaque LTCC substrate. Electrophoretic separation experiments of inorganic ions show sensitivity enhancements by about a factor of 30-60 compared to the single-end measurement scheme. PMID:20337422

  2. Evaluation of Fluorescent Capillary Electrophoresis for Rapid Identification of Candida Fungal Infections.

    Science.gov (United States)

    Obručová, Hana; Tihelková, Radka; Kotásková, Iva; Růžička, Filip; Holá, Veronika; Němcová, Eva; Freiberger, Tomáš

    2016-05-01

    Early diagnosis of fungal infection is critical for initiating antifungal therapy and reducing the high mortality rate in immunocompromised patients. In this study, we focused on rapid and sensitive identification of clinically important Candida species, utilizing the variability in the length of the ITS2 rRNA gene and fluorescent capillary electrophoresis (f-ITS2-PCR-CE). The method was developed and optimized on 29 various Candida reference strains from which 26 Candida species were clearly identified, while Candida guilliermondii, C. fermentati, and C. carpophila, which are closely related, could not be distinguished. The method was subsequently validated on 143 blinded monofungal clinical isolates (comprising 26 species) and was able to identify 88% of species unambiguously. This indicated a higher resolution power than the classical phenotypic approach which correctly identified 73%. Finally, the culture-independent potential of this technique was addressed by the analysis of 55 retrospective DNA samples extracted directly from clinical material. The method showed 100% sensitivity and specificity compared to those of the combined results of cultivation and panfungal PCR followed by sequencing used as a gold standard. In conclusion, this newly developed f-ITS2-PCR-CE analytical approach was shown to be a fast, sensitive, and highly reproducible tool for both culture-dependent and culture-independent identification of clinically important Candida strains, including species of the "psilosis" complex. PMID:26935732

  3. Analysis of silica nanoparticles by capillary electrophoresis coupled to an evaporative light scattering detector.

    Science.gov (United States)

    Adelantado, Carlos; Rodríguez-Fariñas, Nuria; Rodríguez Martín-Doimeadios, Rosa C; Zougagh, Mohammed; Ríos, Ángel

    2016-06-01

    A simple and rapid methodology has been developed to identify and separate silica nanoparticles (SiO2NPs) of different sizes in aqueous solution by capillary zone electrophoresis coupled to an evaporative light scattering detector (CE-ELSD). SiO2NPs were separated using 3 mM ammonium acetate buffer, containing 1% methanol at pH 6.9. SiO2NPs of 20, 50 and 100 nm were successfully separated under the optimum experimental conditions. CE coupled to ELSD has been proven to be an effective separation technique to determine particles with such small sizes, although the peaks are very close to each other, and it is a promising technique that may allow the separation of other types of nanoparticles. Confirmation by TEM and quantification of the SiO2 content was also carried out by inductively coupled plasma-mass spectrometry (ICP-MS). The new method was applied to the analysis of real samples, in order to assess its ability to avoid matrix effects in the determination of SiO2NPs in these kinds of samples. PMID:27155305

  4. Review on the development of truly portable and in-situ capillary electrophoresis systems

    International Nuclear Information System (INIS)

    Capillary electrophoresis (CE) is a technique which uses an electric field to separate a mixed sample into its constituents. Portable CE systems enable this powerful analysis technique to be used in the field. Many of the challenges for portable systems are similar to those of autonomous in-situ analysis and therefore portable systems may be considered a stepping stone towards autonomous in-situ analysis. CE is widely used for biological and chemical analysis and example applications include: water quality analysis; drug development and quality control; proteomics and DNA analysis; counter-terrorism (explosive material identification) and corrosion monitoring. The technique is often limited to laboratory use, since it requires large electric fields, sensitive detection systems and fluidic control systems. All of these place restrictions in terms of: size, weight, cost, choice of operating solutions, choice of fabrication materials, electrical power and lifetime. In this review we bring together and critique the work by researchers addressing these issues. We emphasize the importance of a holistic approach for portable and in-situ CE systems and discuss all the aspects of the design. We identify gaps in the literature which require attention for the realization of both truly portable and in-situ CE systems. (topical review)

  5. Applicability of capillary electrophoresis to the analysis of trace rare earth elements in geological samples

    International Nuclear Information System (INIS)

    This study developed a methodology to analyze trace rare earth elements (REEs) in geological materials by capillary electrophoresis (CE). Changed from dilute HNO3 into a water medium by heating, REE ions are detectable at ∼2 ng mL-1. In the presence of coexisting elements from geological samples, REE separations were carried out. After sample fusion with Na2O2 and interference separation with ammonium pyrrolidinedithiocarbamate chelate, REE analytes were coprecipitated with Mg(OH)2 at pH 8.5, and then prepared into a water medium for CE determination. Using the standard addition method, this protocol was validated by analyses with better than 5% precision. This method was applied to geological materials; the REE results are in consistence with their certified values. With electrokinetic injection, internal standard (IS) selected among lanthanides is a prerequisite of high-quality REE data. An approach was proposed to derive the IS content for further correcting its contribution from unknown samples. (author)

  6. Application of capillary electrophoresis to the uranyl/citrate system in moderately acidic solutions

    International Nuclear Information System (INIS)

    The capillary electrophoresis method has been applied to the speciation study of uranium(VI) at room temperature, in 0.02M citrate buffer solutions, at pH values between 2.5 and 5.5 and at citrate/U ratios between 20 and 40. No negatively charged species have been pointed out at pH values lower than 3. For a pH value higher than 5, the electropherograms are ill-defined and the signals cannot be analyzed simply (owing to a high and rough baseline). In the pH range 3-5, up to 4 peaks can be attributed to U(VI) species. Two of them are likely due to the expected monomer [(UO2)(Cit)]- and dimer [(UO2)2(Cit)2]2- complex species and these species are shown to be in quasi-equilibrium with two other species possessing slightly lower migration velocities, [(UO2)H(Cit)(OH)]- and [(UO2)2H2(Cit)2(OH)2]2-, respectively. Speciation diagrams calculated by an exact analytical approach are proposed in order to explain the experimental results. A complete agreement between theoretical and experimental results needs to take into account kinetic and hydrolysis effects. (author)

  7. Quantitative analysis of rutin and quercetin in flos sophorae from different areas by capillary zone electrophoresis

    International Nuclear Information System (INIS)

    A new method using capillary zone electrophoresis was developed for the rapid quantification of two active components, rutin and quercetin in Flos Sophorae. The effects of various parameters, such as buffer concentration, pH value, applied voltage and beta-CD concentrations, were investigated. After a series of optimization, the separation of rutin and quercetin was achieved successfully within 7 min in the 20 mmol/L borax buffer (pH 9.2), 25kV and 1 mmol/L beta-CD. The linearity, the detection limits, reproducibility, and recovery were satisfactory. The newly developed method was successfully applied to analyze contents of rutin and quercetin in Flos Sophorae samples, which were collected from eleven areas of Dezhou. The analytical result of samples showed that contents of rutin and quercetin were different in different areas, so the analytical result of samples provides basic data for selection of picking location, picking time and development of traditional Chinese medicine. (author)

  8. Routine quality control of recycled target [18O]water by capillary electrophoresis and gas chromatography

    International Nuclear Information System (INIS)

    Recycling of [18O]water for [18F]fluoride production can be accomplished with reliable results. We have developed sensitive, robust, and rapid analyses of impurities in [18O]water. Anions were quantitated by capillary electrophoresis and organic residuals were quantitated by gas chromatography using methods with excellent reproducibility and linearity. Kryptofix 222 (K-222) was quantitated by a sensitive LC-MS-MS technique. Isotopic composition was determined by GC-MS with satisfactory accuracy and precision. These methods were employed to evaluate recovered [18O]water purified by a novel electrolysis method. 2-[18F]FDG yields using purified [18O]water with very low levels of impurities are indistinguishable from newly purchased [18O]water. High (> 300 ppm) carbonate concentration reduces the fluoride trapping efficiency of QMA. The analyses of anions, organics, and isotopic enrichment were applied routinely for quality control of [18O]water to predict a satisfactory outcome of 2-[18F]FDG production

  9. Effects of organic solvent and cationic additive on capillary electrophoresis of peptides

    International Nuclear Information System (INIS)

    Capillary electrophoresis (CE) of nine peptides namely, bradykinin, bradykinin fragment 1-5, substance P, Arg8-vasopressin, luteinizing hormone-releasing hormone (LHRH), bombesin, leucine-enkephalin, methionine-enkephalin and oxytocin were carried out using 0.5 % and 1.0 % formic acid (FA) as the separation buffers, added with acetonitrile (ACN) and triethylamine (TEA) as an additive at low pH. The electrophoretic behaviour of these peptides was examined at different concentration of TEA (0, 10, 20, 30, 40 and 50 mM), and ACN (30, 40, 50, 60, 70 %) at their respective measured final pH. The results showed that all nine peptides were fully resolved with addition of 10 - 20 mM TEA. Peak efficiency was improved significantly by increasing TEA concentration up to 40 mM where 800 000 m-1 was obtained. Without TEA, the closely related enkephalins were co-migrating. Interestingly, by addition of as little as 5 mM TEA has sufficient to separate them almost at baseline. Increasing ACN to 40 % has shortened the analysis time by ca. 1 min. However, further increase of ACN can cause peak broadening and current instability. (author)

  10. Contribution of capillary electrophoresis to an integrated vision of humic substances size and charge characterizations

    International Nuclear Information System (INIS)

    The physicochemical properties of three different humic substances (HS) are probed using capillary zone electrophoresis in alkaline carbonate buffers, pH 10. Special attention is drawn to the impact of the electrolyte ionic strength and counter-ion nature, chosen within the alkali-metal series, on HS electrophoretic mobility. Taylor-Aris dispersion analysis provides insights into the hydrodynamic radius (R-H) distributions of HS. The smallest characterized entities are of nano-metric dimensions, showing neither ionic strength- nor alkali-metal-induced aggregation. These results are compared with the entities evidenced in dynamic light scattering measurements, the size of which is two order of magnitude higher, ca. 100 nm. The extended Onsager model provides a reasonable description of measured electrophoretic mobilities in the ionic strength range 1-50 mM, thus allowing the estimation of limiting mobilities and ionic charge numbers for the different HS samples. An unexpected HS electrophoretic mobility increase (in absolute value) is observed in the order Li+ ≤ Na+ ≤ K+ ≤ Cs+ and discussed either in terms of retarding forces or in terms of ion-ion interactions. (authors)

  11. Capillary zone electrophoresis of lanthanoid elements after complexation with aminopolycarboxylic acids

    International Nuclear Information System (INIS)

    Capillary zone electrophoresis was applied to the separation of the lanthanoid elements chelated with aminopolycarboxylic acids. Several aminopolycarboxylic reagents (ethylenediaminetetraacetic acid and chemically similar analogues) were varied in an effort to optimize the separation resolution. By varying the pH and concentration of the electrophoretic buffer, it was also possible to manipulate the migration times, efficiency and detectability. Optimum resolution and analysis time (within 12 min) for lanthanoids(III), and also scandium(III) and yttrium(III), was achieved with cyclohexane-1,2-diaminetetraacetic acid (CDTA) and simple electrolytes such as a borate buffer (20 mmol 1-1, pH 11.0) containing 1 mmol 1-1 CDTA. Determination of the lanthanoid complexes was performed by direct UV detection at 214 nm. The calibration graphs were linear (r > 0.99) over at least two orders of magnitude of concentration. The detection limits were at the mid-ppb level and the relative standard deviation was about 2.8% at the mid-calibration range. The method appeared to be feasible to determining the lanthanoid elements in nuclear fuel waste, and may also be recommended for assessing lanthanoid impurities in nuclear field. (author)

  12. Methoxypropylamino β-cyclodextrin clicked AC regioisomer for enantioseparations in capillary electrophoresis

    International Nuclear Information System (INIS)

    Highlights: In this paper, we demonstrate: • The click synthesis of a AC regioisomer cationic cyclodextrin (CD) as chiral selector. • The good enantioselectivities (chiral resolution over 5) for acidic racemates. • The strong chiral recognition of new CD by NMR study. • Baseline enantioseparation of some acidic racemates at CD of 0.5 mM. - Abstract: In this work, a novel methoxypropylamino β-cyclodextrin (β-CD) clicked AC regioisomer, 6A-4-hydroxyethyl-1,2,3-triazolyl-6C-3-methoxypropylamino β-cyclodextrin (HETz-MPrAMCD), was synthesized via nucleophilic addition and click chemistry. The chiral separation ability of this AC regioisomer cationic CD was evaluated toward 7 ampholytic and 13 acidic racemates by capillary electrophoresis. Dependence of enantioselectivity and resolution on buffer pH (5.5–8.0) and chiral selector concentration (0.5–7.5 mM) was investigated. Enantioselectivities (α ≥ 1.05) could be achieved for most analytes under optimal conditions except dansyl-DL-noreleucine and dansyl-DL-serine. The highest resolutions for 2-chloromandelic acid p-hydroxymandelic acid were 15.6 and 9.7 respectively. The inclusion complexation between HETz-MPrAMCD and each 3-phenyllactic acid enantiomer was also revealed with nuclear magnetic resonance study

  13. Tris(2,2'-bipyridyl) ruthenium(II)-bisoprolol-based electrochemiluminescence coupled with capillary zone electrophoresis

    International Nuclear Information System (INIS)

    Capillary zone electrophoresis (CZE) coupled with tris(2,2'-bipyridyl) ruthenium(II)-based end-column electrogenerated chemiluminescence (ECL) has been utilized to detect bisoprolol in drugs and tablets after its separation from metoprolol. Tetrahydrofuran was used as an additive in the running buffer to obtain the absolute ECL peak of bisoprolol. Bisoprolol reacts as a co-reactant in tris(2,2'-bipyridyl) ruthenium(II) ECL system. Under the optimized experimental conditions, bisoprolol was separated successfully and efficiently from metoprolol and other co-existed materials in tablets and urine samples. The ECL intensity of tris(2,2'-bipyridyl) ruthenium(II)-bisoprolol-based system is linear with the concentration of bisoprolol from 1.5 μM to 0.3 mM with a detection limit of 0.3 μM. Relative standard derivations of the ECL intensity are 2.58% for the detection of 15 μM bisoprolol. This method is a simple, rapid, selective, and sensitive. It was applied successfully for the monitoring of bisoprolol in market available tablets and human urine samples

  14. Simultaneous determination of flavonoids and anthraquinones in chrysanthemum by capillary electrophoresis with amperometry detection

    Institute of Scientific and Technical Information of China (English)

    Yin Yan Zhang; Zi Cheng Li; Jin Kun Zhu; Zhi Yong Yang; Qing Jiang Wang; Pin Gang He; Yu Zhi Fang

    2010-01-01

    A high-performance capillary electrophoresis with amperometry detection method(CE-AD)has been developed for the analysis of flavonoids and anthraquinones(emodin,kaempferol,apigenin,luteolin and rhein)in chrysanthemum.Under optimum conditions,these five analytes were base-line separated within 17 min using a borate-phosphate running buffer(1.5 × 10-2mol/L borate-3 × 10-2 mol/L phosphate running buffer,pH 9.0)at a working potential of+0.90 V(vs.SCE)and a separation voltage of 19 kV.The linear relationship between concentration and current response was obtained with detection limits(S/N = 3)ranging from 1.0 × 10-7 to 2.1 × 10-7 g/mL for all analytes.This proposed method was successfully used in the analysis of four kinds of chrysanthemum with relatively simple extraction procedures,the assay results were satisfactory.

  15. Immunochromatographic removal of albumin in erythropoietin biopharmaceutical formulations for its analysis by capillary electrophoresis.

    Science.gov (United States)

    Lara-Quintanar, Pilar; Lacunza, Izaskun; Sanz, Jesus; Diez-Masa, Jose Carlos; de Frutos, Mercedes

    2007-06-15

    Human serum albumin (HSA) is added to some pharmaceutical preparations as an excipient. This is the case for some of the commercial preparations of recombinant erythropoietin (rEPO). Differences in the number of the sialic acid moieties in the different rEPO glycoforms confer to these forms different net charges and different bioactivity. Knowledge of the isoforms present in each pharmaceutical product is then of interest. Differences in net charge of the rEPO forms make possible their separation by electrophoretical methods. However it has been observed in our laboratory that the amount of HSA usually present in these drug formulations interferes or even precludes separation of rEPO bands by capillary zone electrophoresis (CZE). In this work, an immunochromatographic method to remove HSA from rEPO biopharmaceutical formulations and a procedure to concentrate the sample that is needed to be performed prior to the analysis by CZE are developed. A home-made computer program to compare the percentage of correct assignments of electrophoretical bands provided by different migration parameters is used to study the effect of HSA remaining in samples on the accuracy of assignment of rEPO bands. When there exists a residual concentration of HSA in the sample (studies and for the quality control laboratories of the manufacturers. PMID:16919660

  16. Determination of low molecular weight organic acids in soil, plants, and water by capillary zone electrophoresis.

    Science.gov (United States)

    Li, Ying-Hui; Huang, Bi-Xia; Shan, Xiao-Quan

    2003-03-01

    Determination of low molecular weight organic acids in soils and plants by capillary zone electrophoresis was accomplished using a phthalate buffer and indirect UV detection mode. The influence of some crucial parameters, such as pH, buffer concentration and surfactant were investigated. A good separation of seven organic acids was achieved within 5 min using an electrolyte containing 15 mmol L(-1) potassium hydrogen phthalate, 0.5 mmol L(-1) myristyltrimethylammonium bromide (MTAB), and 5% methanol (MeOH) (v/v) at pH 5.60, separation voltage -20 kV, and temperature 25 degrees C. The relative standard deviation (n=5) of the method was found to be in range 0.18-0.56% for migration time and 3.2-4.8% for peak area. The limit of detection ranged between 0.5 micro mol L(-1) to 6 micro mol L(-1) at a signal-to-noise ratio of 3. The recovery of standard organic acids added to real samples ranged from 87 to 119%. This method was simple, rapid and reproducible, and could be applied to the simultaneous determination of organic acids in environmental samples. PMID:12664177

  17. Uranyl complexation with acetate studied by means of affinity capillary electrophoresis.

    Science.gov (United States)

    Sladkov, Vladimir

    2013-05-10

    The interaction of uranyl with acetate is studied by affinity capillary electrophoresis in aqueous acid solutions at the pH values 2.0 and 2.5. The use of data on metal ion mobilities at different pHs allows to establish the ligand species interacting with metal ion and complex species formed. The formation of two complex species UO2CH3COO(+) and UO2(CH3COO)2 is observed (acetic acid concentration is up to 0.8M). In the case of uranyl-acetic acid system, the viscosity of solution is significantly changed with an increase of acid concentration. For calculation of ion mobilities the viscosity changes are taken into account. The stability constants are calculated at the ionic strengths 0.02 and 0.05 mol L(-1). The logarithms of the thermodynamic stability constants (β°) calculated with Davies equation for the activity coefficients of the ions are log β1(°)=2.94±0.08 and log β2(°)=5.50±0.15 at 25 °C. Obtained values are compared with literature data. PMID:23570853

  18. Analysis of Trace Ingredients in Green Tea by Capillary Electrophoresis with Amperometric Detection

    Institute of Scientific and Technical Information of China (English)

    LI Ping; DONG Shu-Qing; WANG Qing-Jiang; FANG Yu-Zhi

    2008-01-01

    In this paper, four trace ingredients (rutin, gallic acid, quercetin, chlorogenic acid) in green tea were simultaneously determined by capillary electrophoresis coupled with amperometric detection (CE-AD). Effects of several important factors such as the pH and concentration of running buffer, separation voltage, injection time and detection potential were investigated to acquire the optimum conditions. Under the optimum conditions, the analytes could be separated within 20 min at a separation voltage of 18 kV in a 60 mmol/L borate buffer (pH 8.7). A 300 μmdiameter carbon disk electrode generated good responses at 950 mV (vs. SCE) for all analytes. The relationship between the peak currents and concentrations of the analytes was linear over about three orders of magnitude with demonstrated long-term stability and reproducibility with relative standard deviations less than 3% for both migration time and peak current (n=7), which could be successfully used for the determination of the analytes in green tea with satisfactory assay results.

  19. Capillary electrophoresis method with UV-detection for analysis of free amino acids concentrations in food.

    Science.gov (United States)

    Omar, Mei Musa Ali; Elbashir, Abdalla Ahmed; Schmitz, Oliver J

    2017-01-01

    Simple and inexpensive capillary electrophoresis with UV-detection method (CE-UV) was optimized and validated for determination of six amino acids namely (alanine, asparagine, glutamine, proline, serine and valine) for Sudanese food. Amino acids in the samples were derivatized with 4-chloro-7-nitro-2,1,3-benzoxadiazole (NBD-Cl) prior to CE-UV analysis. Labeling reaction conditions (100mM borate buffer at pH 8.5, labeling reaction time 60min, temperature 70°C and NBD-Cl concentration 40mM) were systematically investigated. The optimal conditions for the separation were 100mM borate buffer at pH 9.7 and detected at 475nm. The method was validated in terms of linearity, limit of detection (LOD), limit of quantification (LOQ), precision (repeatability) (RSD%) and accuracy (recovery). Good linearity was achieved for all amino acids (r(2)>0.9981) in the concentration range of 2.5-40mg/L. The LODs in the range of 0.32-0.56mg/L were obtained. Recoveries of amino acids ranging from 85% to 108%, (n=3) were obtained. The validated method was successfully applied for the determination of amino acids for Sudanese food samples. PMID:27507479

  20. Precision improvement for the analysis of flavonoids in selected Thai plants by capillary zone electrophoresis.

    Science.gov (United States)

    Suntornsuk, Leena; Anurukvorakun, Oraphan

    2005-02-01

    A capillary zone electrophoresis (CZE) method for the analyses of kaempferol in Centella asiatica and Rosa hybrids and rutin in Chromolaena odorata was developed. The optimization was performed on analyses of flavonoids (e.g., rutin, kaempferol, quercetin, myricetin, and apigenin) and organic carboxylic acids (e.g., ethacrynic acid and xanthene-9-carboxylic acid) by investigation of the effects of types and amounts of organic modifiers, background electrolyte concentrations, temperature, and voltage. Baseline separation (R(s) = 2.83) of the compounds was achieved within 10 min in 20 mM NaH2PO4 - Na2HPO4 (pH 8.0) containing 10% v/v ACN and 6% v/v MeOH using a voltage of 25 kV, a temperature of 30 degrees C, and a detection wavelength set at 220 nm. The application of the corrected migration time (t(c)), using ethacrynic acid as the single marker, was efficient to improve the precision of flavonoid identification (% relative standard deviation (RSD) = 0.65%). The method linearity was excellent (r2 > 0.999) over 50-150 microg/mL. Precision (%RSD 96% and %RSDs odorata was 0.088 g/100 g (%RSD = 0.06%). PMID:15690438

  1. High-sensitivity quantum dot-based fluorescence resonance energy transfer bioanalysis by capillary electrophoresis.

    Science.gov (United States)

    Li, Yong-Qiang; Wang, Jian-Hao; Zhang, Hai-Li; Yang, Jie; Guan, Li-Yun; Chen, Hong; Luo, Qing-Ming; Zhao, Yuan-Di

    2010-02-15

    Here a new method for high-sensitivity quantum dot (QD)-based fluorescence resonance energy transfer (FRET) bioanalysis was developed. In this method, capillary electrophoresis (CE) with fluorescence detection was applied. The FRET system consisted of water-soluble 532-nm emitting CdTe QDs donor and 632-nm emitting CdSe/ZnS QDs acceptor which were covalently conjugated with mouse IgG and goat anti-mouse IgG, respectively. The bio-affinity between antigen and antibody brought two kinds of QDs close enough to make the FRET happen between them. In the CE experiments, highly efficient separation of donor-acceptor immunocomplexes was obtained, and the process of FRET was monitored. Results showed that FRET efficiency obtained by CE (38.56-69.58%) improved substantially in comparison with that obtained by ensemble measurement (12.77-52.37%). The high efficient separation of donor-acceptor immunocomplexes and the possible conformation change of antigen and antibody, contributes to the lower analysis uncertainty (variance) and higher FRET efficiency obtained in CE and consequentially, this makes the analysis of FRET more sensitive. This novel CE-based technique can be easily extended to other FRET system based on QDs and may have potential application in the study of biomolecule conformation change. PMID:19914053

  2. Synthesis and applications of sulfopropyl ether γ-cyclodextrin polymer as chiral selector in capillary electrophoresis.

    Science.gov (United States)

    Bao, James J; Jia, Feifei; Li, Youxin; Liang, Qinggang; Wang, Yan

    2016-05-01

    A novel sulfopropyl ether γ-cyclodextrin polymer (SPE-γ-CDP) through polycondensating sulfated cyclodextrins (SCDs) was synthesized. This synthesis approach also has the potential of preparing other derived cyclodextrins (CDs) polymers. The polymerized SCDs took on both the properties of SCDs and certain characteristics of polymers, such as chiral selectivity and high viscosity. Synthesis parameters, including reactions sequence, sulfation, and polycondensation conditions were investigated systematically. The product was characterized by elemental analysis, infrared spectroscopy (IR), and indirect UV detections prior to use as background electrolytes additive. The separation conditions, including the concentration of SPE-γ-CDP, the concentration and pH of running buffer, separation voltage, as well as the additional organic solution were optimized during chiral separation of neutral, acidic, and basic enantiomers in capillary electrophoresis (CE). SPE-γ-CDP was proven to be an effective chiral resolving agent in CE with the advantages of simple synthesis process, low cost, similar ratio of charge-to-mass, low current, great reproducibility, and reusability. Graphical Abstract Synthesis and applications of sulfopropyl ether γ-cyclodextrin polymer. PMID:26993309

  3. Detection of Chlorogenic Acid in Honeysuckle Using Infrared-Assisted Extraction Followed by Capillary Electrophoresis with UV Detector

    OpenAIRE

    Tang, Zhuxing; Zang, Shuliang; Zhang, Xiangmin

    2012-01-01

    In this study, a novel infrared-assisted extraction method coupled capillary electrophoresis (CE) is employed to determine chlorogenic acid from a traditional Chinese medicine (TCM), honeysuckle. The effects of pH and the concentration of the running buffer, separation voltage, injection time, IR irradiation time, and anhydrous ethanol in the extraction concentration were investigated. The optimal conditions were as follows: extraction time, 30 min; extraction solvent, 80% (v/v) ethanol in wa...

  4. Estimation of apparent binding constant of complexes of selected acyclic nucleoside phosphonates with -cyclodextrin by affinity capillary electrophoresis

    Czech Academy of Sciences Publication Activity Database

    Šolínová, Veronika; Mikysková, Hana; Kaiser, Martin Maxmilian; Janeba, Zlatko; Holý, Antonín; Kašička, Václav

    2016-01-01

    Roč. 37, č. 2 (2016), s. 239-247. ISSN 0173-0835 R&D Projects: GA ČR(CZ) GA13-17224S; GA ČR(CZ) GA15-01948S Institutional support: RVO:61388963 Keywords : acyclic nucleoside phosphonates * affinity capillary electrophoresis * binding constant * nucleotide analogs * beta-cyclodextrin Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 3.028, year: 2014

  5. Separation of etodolac enantiomers by capillary electrophoresis. Validation and application of the chiral method to the analysis of commercial formulations

    OpenAIRE

    Rodríguez de Pablos, Raquel; García Ruiz, Carmen; Crego Navazo, Antonio Luis; Marina Alegre, María Luisa

    2005-01-01

    Separation of etodolac enantiomers, which exhibit different biological activity and pharmacokinetic profiles, has been achieved using the randomly substituted (2-hydroxy)propyl-β-cyclodextrin (HP-β-CD) as chiral selector in capillary electrophoresis. The selection of this CD was made after screening of different CD derivatives of neutral and anionic nature. The effect on the enantioresolution of the buffer concentration and of the degree of substitution (DS) and concentration of the CD as wel...

  6. Further development and applications of capillary electrophoresis with capacitively coupled contactless conductivity detection and sequential injection analysis in analytical chemistry

    OpenAIRE

    Stojkovic, Marko

    2013-01-01

    This dissertation is based on the further development and applications of capillary electrophoresis (CE) with capacitively coupled contactless conductivity detection (C4D), i. e. sequential injection analysis (SIA) applications when coupled with CE-C4D, or determination and quantification of various ions that are not or barely UV absorbed. A purpose made CE-C4D system was used for determination of the DNA fragments of different length, using additives to modify the medium and to sieve ch...

  7. A Capillary Electrophoresis Detection Scheme for Water-soluble Vitamins Based on Luminol - BrO- Chemiluminescence System

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    A novel chemiluminescence detection scheme has been developed for detecting water-soluble vitamins following capillary electrophoresis (CE) separation. This detection was based on the inhibitory effect of vitamins on the CL reaction between luminol and BrO- in basic aqueous solution. Detection of vitamins was accomplished with a borate-based background electrolyte at pH 9.2. The luminol was used as a component of the separation carrier electrolyte.

  8. In-line coupling of microextraction techniques to capillary electrophoresis for direct analyses of biological, clinical and toxicological samples

    Czech Academy of Sciences Publication Activity Database

    Kubáň, Pavel; Pantůčková, Pavla; Boček, Petr

    2015. L-27. ISBN N. [International Symposium on Electro- and Liquid Phase-Separation Techniques (ITP2015) /22./ and the Nordic Separation Science (NoSSS) symposium /8./. 30.08.2015-03.09.2015, Helsinki] R&D Projects: GA ČR(CZ) GA13-05762S Institutional support: RVO:68081715 Keywords : in-line coupling * microextractions * capillary electrophoresis Subject RIV: CB - Analytical Chemistry, Separation

  9. Determination of methicillin-resistant and methicillin-susceptible Staphylococcus aureus bacteria in blood by capillary zone electrophoresis

    Czech Academy of Sciences Publication Activity Database

    Horká, Marie; Tesařová, Marie; Karásek, Pavel; Růžička, F.; Holá, V.; Sittová, M.; Roth, Michal

    2015-01-01

    Roč. 868, APR (2015), s. 67-72. ISSN 0003-2670 R&D Projects: GA ČR(CZ) GAP106/12/0522; GA MV VG20102015023 Institutional support: RVO:68081715 Keywords : capillary zone electrophoresis * Staphylococcus aureus * human whole blood Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 4.513, year: 2014 http://hdl.handle.net/11104/0245801

  10. Study of solvent effects on formation of dibenzo-18crown-6 complex with alkali metal ions by affinity capillary electrophoresis

    Czech Academy of Sciences Publication Activity Database

    Konášová, Renáta; Jaklová Dytrtová, Jana; Kašička, Václav

    Helsinki: -, 2015. YS2. [International Symposium on Electro- and Liquid Phase-Separation Techniques (ITP2015) /22./ and Nordic Separation Science Symposium (NoSSS2015) /8./. 30.08.2015-03.09.2015, Helsinki] R&D Projects: GA ČR(CZ) GA15-01948S Institutional support: RVO:61388963 Keywords : solvent effect * stability constant * affinity capillary electrophoresis Subject RIV: CB - Analytical Chemistry, Separation

  11. Using capillary electrophoresis to separate trivalent f-elements based on their speciation when complexed with simple organic ligands

    International Nuclear Information System (INIS)

    Capillary electrophoresis (CE) is a useful method for rapid separations of metal cations. Under ideal conditions, CE can provide complete separation of the trivalent lanthanides in less than 10 min. Simple organic ligands must be included in the electrolyte matrix to achieve good resolution between the cations. In this paper, we demonstrate how to use complexation constants from the literature to design separation protocols for the trivalent f-elements. (author)

  12. Chiral separations of drugs and catalysts by partial-filling affinity capillary electrophoresis using helquats as chiral selectors

    Czech Academy of Sciences Publication Activity Database

    Růžička, Martin; Jirásek, Michael; Reyes Gutierrez, Paul Eduardo; Teplý, Filip; Koval, Dušan; Kašička, Václav

    Helsinki: -, 2015. YS3. [International Symposium on Electro- and Liquid Phase-Separation Techniques (ITP2015) /22./ and Nordic Separation Science Symposium (NoSSS2015) /8./. 30.08.2015-03.09.2015, Helsinki] R&D Projects: GA ČR(CZ) GA15-01948S; GA ČR GA13-32974S Institutional support: RVO:61388963 Keywords : chiral selectors * helquats * affinity capillary electrophoresis Subject RIV: CB - Analytical Chemistry, Separation

  13. Analysis of quantum dots and their conjugates by capillary electrophoresis with detection of laser-induced luminescence

    Czech Academy of Sciences Publication Activity Database

    Klepárník, Karel; Datinská, Vladimíra; Voráčová, Ivona; Lišková, Marcela

    2nd Edition. Totowa: Humana Press Inc, 2014 - (Fontes, A.), s. 33-54. (Methods in Molecular Biology. Volume 1199). ISBN 978-1-4939-1279-7 R&D Projects: GA ČR GAP206/11/2377; GA ČR(CZ) GA14-28254S Institutional support: RVO:68081715 Keywords : capillary electrophoresis * quantum dots * laser-induced fluorescence * immuno assay Subject RIV: CB - Analytical Chemistry, Separation

  14. Elemental speciation by capillary electrophoresis with inductively coupled plasma spectrometry: A new approach by flow focusing® nebulization

    OpenAIRE

    Kovachev, Nikolay; Aguirre Pastor, Miguel Ángel; Hidalgo Núñez, Montserrat; Simitchiev, Kiril; Stefanova, Violeta M.; Kmetov, Veselin Y.; Canals Hernández, Antonio

    2014-01-01

    A novel system for Capillary Electrophoresis (CE) and Inductively Coupled Plasma (ICP) sample introduction that incorporates a dedicated Flow-Focusing® based nebulizer as aerosol generation unit is presented, aiming to provide high signal sensitivity and low detection limits for element speciation at short analysis times. To prove its viability, the system prototype constructed has been coupled to an inductively coupled plasma - optical emission spectrometer (ICP-OES) and an inductively coupl...

  15. Fast and simple method for determination of iodide in human serum, sea water and cooking salt by capillary zone electrophoresis

    Czech Academy of Sciences Publication Activity Database

    Pantůčková, Pavla; Křivánková, Ludmila

    2003, s. 172. [HPLC 2003. Symposium on High Performance Liquid Phase Separations and Related Techniques /27./. Nice (CZ), 15.06.2003-19.06.2003] R&D Projects: GA ČR GA203/02/0023; GA ČR GA203/01/0401; GA AV ČR IAA4031103 Institutional research plan: CEZ:AV0Z4031919 Keywords : capillary zone electrophoresis * determination of iodide * body fluids Subject RIV: CB - Analytical Chemistry, Separation

  16. Enantiomeric Separation of Antidepressant Trimipramine by Capillary Electrophoresis Combined with Electrochemiluminescence Detection in Aqueous-organic Media

    Institute of Scientific and Technical Information of China (English)

    YU Cai-xia; YUAN Bai-qing; YOU Tian-yan

    2011-01-01

    The antidepressant trimipramine(Tri) enantiomers were successfully separated by capillary electrophoresis(CE) coupled with electrochemiluminescence(ECL) detection in aqueous-organic media. A dual cyclodextrin(CD)system combining β-CD and hydroxypropyl-β-cyclodextrin(HP-β-CD) was used as chiral selector. Acetonitrile(ACN)was added to the running buffer to improve the separation efficiency, detection sensitivity and repeatability. The method was also successfully applied to the chiral separation of Tri in spiked human urine sample.

  17. Assessment of chiral purity of acyclic nucleoside phosphonates-based anti-AIDS drugs by capillary electrophoresis

    Czech Academy of Sciences Publication Activity Database

    Sázelová, Petra; Šolínová, Veronika; Kašička, Václav; Holý, Antonín

    Baltimore Inner Harbor, MD, 2010. s. 74-75. [International Symposium on Electro- and Liquid Phase-separation Techniques /17./. 29.08.2010-01.09.2010, Baltimore Inner Harbor, MD] R&D Projects: GA ČR(CZ) GA203/08/1428; GA ČR(CZ) GA203/09/0675 Institutional research plan: CEZ:AV0Z40550506 Keywords : chiral analysis * acyclic nucleoside phosphonates * capillary electrophoresis Subject RIV: CB - Analytical Chemistry, Separation

  18. Magnetic bead purification of labeled DNA fragments forhigh-throughput capillary electrophoresis sequencing

    Energy Technology Data Exchange (ETDEWEB)

    Elkin, Christopher; Kapur, Hitesh; Smith, Troy; Humphries, David; Pollard, Martin; Hammon, Nancy; Hawkins, Trevor

    2001-09-15

    We have developed an automated purification method for terminator sequencing products based on a magnetic bead technology. This 384-well protocol generates labeled DNA fragments that are essentially free of contaminates for less than $0.005 per reaction. In comparison to laborious ethanol precipitation protocols, this method increases the phred20 read length by forty bases with various DNA templates such as PCR fragments, Plasmids, Cosmids and RCA products. Our method eliminates centrifugation and is compatible with both the MegaBACE 1000 and ABIPrism 3700 capillary instruments. As of September 2001, this method has produced over 1.6 million samples with 93 percent averaging 620 phred20 bases as part of Joint Genome Institutes Production Process.

  19. Interfacing capillary electrophoresis and surface-enhanced resonance Raman spectroscopy for the determination of dye compounds.

    Science.gov (United States)

    Arráez Román, D; Efremov, E; Ariese, F; Segura Carretero, A; Gooijer, C

    2005-05-01

    The at-line coupling of capillary electrophoresis (CE) and surface-enhanced resonance Raman spectroscopy (SERRS) was optimized for the separation and subsequent spectroscopic identification of charged analytes (dye compounds). Raman spectra were recorded following deposition of the electropherogram onto a moving substrate. To this end a new interface was developed using a stainless steel needle as a (grounded) cathode. The outlet end of the CE capillary was inserted into this metal needle; CE buffer touching the needle tip served as the electrical connection for the CE separation. A translation table was used to move the TLC plate at a constant speed during the deposition. The distance between the tip of the fused silica column and the TLC plate was kept as small as possible in order to establish a constant bridge-flow, while avoiding direct contact. The dyes Basic Red 9 (BR9), Acid Orange 7 (AO7) and Food Yellow 3 (FY3) were used as test compounds. After CE separation in a 20 mM borate buffer at pH 10, after deposition, concentrated silver colloid was added to each analyte spot, followed by irradiation with 514.5 nm light from an argon ion laser to record the SERRS signal using a Raman microscope. Different types of silver colloids were tested: Lee-Meisel type (citrate), borate, and gold-coated silver. BR9 (positively charged) gave much more intense SERRS spectra than the two negatively charged dyes. For BR9 and AO7 the citrate-coated Lee-Meisel colloid yielded the most intense SERRS spectra. The CE-SERRS system was used to separate and detect the negatively charged dyes. Silver colloid and nitric acid (to improve adsorption) were added post-deposition. Even though their chemical structures are very similar, AO7 and FY3 could be readily distinguished based on their SERRS spectra. The limits of detection (S/N = 3) of the CE-SERRS system ranged from 6.7 x 10(-5) M (2.6 x 10(-12) mol injected) for FY3 down to 1.8 x 10(-6) M (7.0 x 10(-14) mol injected) for BR9. PMID

  20. Boron-doped diamond microelectrodes for use in capillary electrophoresis with electrochemical detection.

    Science.gov (United States)

    Cvacka, Josef; Quaiserová, Veronika; Park, JinWoo; Show, Yoshiyuki; Muck, Alexander; Swain, Greg M

    2003-06-01

    The fabrication and characterization of boron-doped diamond microelectrodes for use in electrochemical detection coupled with capillary electrophoresis (CE-EC) is discussed. The microelectrodes were prepared by coating thin films of polycrystalline diamond on electrochemically sharpened platinum wires (76-, 25-, and 10-microm diameter), using microwave-assisted chemical vapor deposition (CVD). The diamond-coated wires were attached to copper wires (current collectors), and several methods were explored to insulate the cylindrical portion of the electrode: nail polish, epoxy, polyimide, and polypropylene coatings. The microelectrodes were characterized by scanning electron microscopy, Raman spectroscopy, and cyclic voltammetry. They exhibited low and stable background currents and sigmoidally shaped voltammetric curves for Ru(NH3)6(3+/2+) and Fe(CN)6(3-/4-) at low scan rates. The microelectrodes formed with the large diameter Pt and sealed in polypropylene pipet tips were employed for end-column detection in CE. Evaluation of the CE-EC system and the electrode performance were accomplished using a 10 mM phosphate buffer, pH 6.0, run buffer, and a 30-cm-long fused-silica capillary (75-microm i.d.) with dopamine, catechol, and ascorbic acid serving as test analytes. The background current (approximately 100 pA) and noise (approximately 3 pA) were measured at different detection potentials and found to be very stable with time. Reproducible separation (elution time) and detection (peak current or area) of dopamine, catechol, and ascorbic acid were observed with response precisions of 4.1% or less. Calibration curves constructed from the peak area were linear over 4 orders of magnitude, up to a concentration between 0.1 and 1 mM. Mass limits of detection for dopamine and catechol were 1.7 and 2.6 fmol, respectively (S/N = 3). The separation efficiency was approximately 33,000, 56,000, and 98,000 plates/m for dopamine, catechol, and ascorbic acid, respectively. In