National Repository of Grey Literature 19 records found  previous11 - 19  jump to record: Search took 0.00 seconds. 
Silica-based monolithic capillary columns modified to zwitterionic stationary phase for hydrophilic interaction liquid chromatography
Moravcová, Dana ; Planeta, Josef ; Kahle, Vladislav ; Horká, Marie ; Roth, Michal
Zwitterionic monolithic capillary columns intended for isocratic gradient hydrophilic interaction chromatography (HILIC) separations are introduced. Silica-based capillary columns (150 mm x 0.1 mm) were prepared by acidic hydrolysis of tetramethoxysilane in the presence of polyethylene glycol and urea. The modification by a 3-(trimethoxysilyl)propyl methacrylate and then by a zwitterionic [2-(methacryloyloxy)ethyl]-dimethyl-(3-sulfopropyl)-ammonium hydroxide to HILIC stationary phase bearing sulfoalkylbetaine groups on its surface followed. Prepared columns were characterized in HILIC separation mode employing mobile phase containing 10% (v/v) of 5 mM ammonium acetate pH = 4.5 in acetonitrile. Comparison with the commercially available ZIC-HILIC® column (Merck SeQuant®) under the same separation conditions using a mixture of aromatic carboxylic acids as a sample was done on the basis of separation efficiency of tested columns as well as retention factors and peak asymmetry of individual solutes.
Differences in fingerprints of biofilm-positive and biofilm-negative Candida strains exploitable for clinical practice
Vykydalová, Marie ; Horká, Marie ; Šalplachta, Jiří ; Růžička, E. ; Kahle, Vladislav
In this study, we have presented differences in fingerprints of Candida parapsilosis and Candida metapsilosis as well as their biofilm-positive and biofilm-negative forms. Fingerprints of yeasts were obtained by sodium dodecyl sulfate polyacrylamide gel electrophoresis, capillary isoelectric focusing, and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Samples for analyses were prepared by treatment of yeasts by boiling water or ethanol. Fingerprints of tested yeasts cells have differed in all cases. This knowledge can be used for obtaining rapid and simple method which distinguishes above mentioned yeasts in standard biochemical laboratories.
Nano column gradient separations: Implementation of simple splitless gradient generator with integrated sample delivery
Šesták, Jozef ; Duša, Filip ; Moravcová, Dana ; Kahle, Vladislav
Automated liquid chromatographic system based on simple splitless gradient generation principle and with integrated sample delivery has been assembled and tested.
A novel portable device for fast analysis of energetic materials in the environment
Šesták, Jozef ; Večeřa, Zbyněk ; Kahle, Vladislav ; Moravcová, Dana ; Mikuška, Pavel ; Kellner, J. ; Navrátil, J.
Construction of portable device for fast analysis of energetic materials is described in this paper. The device is able to determine selectively most of nitramine- and nitroester-based explosives as well as inorganic nitrates at trace concentrations in water or soil extracts in less than 8 minutes.
Using of divergent flow isoelectric focusing and capillary liquid
Duša, Filip ; Moravcová, Dana ; Kahle, Vladislav ; Šlais, Karel
Separation of analytes from complex matrices play important role in their further identification. In this article we propose two-dimensional separation method of bovine serum albumin tryptic peptides. At the first dimension peptides are separated by divergent flow isoelectric focusing followed by reverse-phase liquid chromatography as the second dimension. Due to composition of input mixture it is possible to use autofocusing mode in first dimension. In this mode peptides are focused without addition of carrier ampholytes. Chromatograms from the second dimension were processed into contour map. Acquired data showed good separation efficiency of isoelectric focusing. Autofocusing mode enabled better resolution of peptides with close isoelectric points.
Differentiation of Candida strains by capillary HPLC
Vykydalová, Marie ; Moravcová, Dana ; Horká, Marie ; Růžička, F. ; Kahle, Vladislav
The aim of this study was to compare chromatographic profiles of lysate of Candida parapsilosis positive and Candida parapsilosis negative using capilary high performance liquid chromatography.
Stará řeka, Tipeček and Žegrovský waterfall in the Rudické propadání cave: new data from tracer tests and sump effect of the Tipeček
Bruthans, J. ; Kamas, J. ; Balák, I. ; Dostál, I. ; Vilhelm, Z. ; Kahle, Vladislav ; Šebela, R.
Five new quantitative tracer tests by using fluorescein and natrium chloride were carried out on underground tributaries of Jedovnický Creek in Rudické propadání Cave in Moravian Karst.
Optimization of sample injection in capillary electrochromatography
Kahle, Vladislav ; Košťál, Vratislav ; Zeisbergerová, Marta
The sample injection is an important part of the electrochromatographic (CEC) analysis.. This work focuses on injection optimization with use of the splitter working in the heart-cut regime. Mechanisms of spontaneous and electrokinetic injection were studied. Good repeateability of peak heights, peak areas and retention times was reached for standard, gradient and preconcentration CEC separations.
Determination of biologically active compounds in medical plants by capillary electrochromatography
Kvasničková, L. ; Štěrbová, H. ; Glatz, O. ; Kahle, Vladislav ; Slanina, J.
Capillary electrochromatography in macroporous polyacrylamide columns was successfully used to analyse and quantify lignans in extract of the seeds of Schisandra chinensis. Good separations were achieved in less than 35 min. The levels of schizandrin, gomisin A, gomisin N and wuweizisu C determined by CEC were in good agreement with those obtained by reverse-phase HPLC.

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