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The utitilization of boron-doped diamond thin film electrode for the voltammetric and amperometric determination of amino derivatives of biphenyl
Maixnerová, Lucie ; Schwarzová, Karolina (advisor) ; Zima, Jiří (referee)
The aim to this work was to develop methods for the determination of 2 aminobiphenyl (2-AB), 3 aminobiphenyl (3-AB), and 4-aminobiphenyl (4-AB) in model mixtures. Concretely, the direct determination of the mixture of studied analytes has been tested using spectrophotometry and differential pulse voltammetry (DPV). Furthermore, separation and detection of 2-AB, 3-AB, and 4-AB have been performed using high performance liquid chromatography with electrochemical detection (HPLC-ED) with boron-doped diamond film thin electrode (BDDFE) in ,,wall-jet" configuration and using high performance liquid chromatography with UV detection (HPLC-UVD). It was found out that the spectrophotometric determination of 2-AB, 3-AB, and 4-AB is impossible in their mixture because of nearby values of local absorption maxima wavelengths of all three analytes studied. Upon the determination of 2-AB, 3-AB, and 4-AB in their mixture using DPV in BR buffer pH 2.0, the difference in peak potentials of 2-AB and 3-AB is too low for their determination in mixture. Upon the determination of mixture containing 2-AB and 4-AB in BR buffer pH 12.0, the limits of determination (LDs) were obtained in the concentration order of 10-6 mol.l-1 for 2-AB and 10-7 mol.l-1 for 4-AB. LDs for the mixture containing 3-AB and 4-AB were obtained in the...
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The utitilization of boron-doped diamond thin film electrode for the voltammetric and amperometric determination of amino derivatives of biphenyl
Maixnerová, Lucie ; Zima, Jiří (referee) ; Schwarzová, Karolina (advisor)
The aim to this work was to develop methods for the determination of 2 aminobiphenyl (2-AB), 3 aminobiphenyl (3-AB), and 4-aminobiphenyl (4-AB) in model mixtures. Concretely, the direct determination of the mixture of studied analytes has been tested using spectrophotometry and differential pulse voltammetry (DPV). Furthermore, separation and detection of 2-AB, 3-AB, and 4-AB have been performed using high performance liquid chromatography with electrochemical detection (HPLC-ED) with boron-doped diamond film thin electrode (BDDFE) in ,,wall-jet" configuration and using high performance liquid chromatography with UV detection (HPLC-UVD). It was found out that the spectrophotometric determination of 2-AB, 3-AB, and 4-AB is impossible in their mixture because of nearby values of local absorption maxima wavelengths of all three analytes studied. Upon the determination of 2-AB, 3-AB, and 4-AB in their mixture using DPV in BR buffer pH 2.0, the difference in peak potentials of 2-AB and 3-AB is too low for their determination in mixture. Upon the determination of mixture containing 2-AB and 4-AB in BR buffer pH 12.0, the limits of determination (LDs) were obtained in the concentration order of 10-6 mol.l-1 for 2-AB and 10-7 mol.l-1 for 4-AB. LDs for the mixture containing 3-AB and 4-AB were obtained in the...
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Analytical Features of the Optical Biosensor for Glucose Detection
Maixnerová, Lucie
The first aim of my work was to determine boundaries of the above-mentioned parameters as maxima and minima of the weight (thickness) of the layer and the quantity of the immobilized enzyme. Glucose oxidase from Aspergilus niger (37.7 KU⋅g−1 solid) immobilized on Sepabeads® (SPB) coated together with the ruthenium oxygen sensitive complex in the organic-inorganic polymer ORMOCER® were used in all experiments. From process parameters maxima and minima concentrations of oxygen and glucose were detected. The second aim was to prepare biosensors with substantially diverse analytical characteristics via combinations of these parameters. The obtained experimental data will be a base for a detailed mathematical model of MATINOES biosensors (outlined in our previous paper1), which we are going to develop in the collaboration with ICT Prague. This model should enable a preparation of MATINOES biosensors with tailor-made analytical features.
Fulltext: content.csg -  PDF
Plný tet: SKMBT_C22015061709372 - PDF
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Enzymatic Sensor of Biogenic Amines with Optical Oxygen Transducer
Maixnerová, Lucie ; Horvitz, Alexandar ; Kuncová, Gabriela ; Přibyl, M. ; Šebela, M. ; Koštejn, Martin
The biogenic amines (BA) are formed by the decarboxylation of amino acids. Because of their impact on human health, they have been used as markers for assessing the freshness and quality of a wide variety of protein-containing products. We studied biosensor for BA with an optical oxygen transducer that contained a diamine oxidase from pea and ruthenium complex. Both active components were incorporated in chemically stable polymer to form sensitive films thickness of 100 - 200 μm. With aim to optimize a composition and manufacturing of the biosensor we developer a mathematical model of processes inside the sensing film. The developed mathematical model revealed qualitative dependencies of the biosensor behavior (sensitivity, response time and dynamic range) on the (i) thickness of the sensitive layer, (ii) concentrations of substrates in the solution, (iii) enzyme activity in the layer and (iv) layer permeability for the substrates.
Fulltext: content.csg - PDF
Plný tet: SKMBT_C22015011213553 - PDF
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12M-IMMEDIATE Research Report: Preparation of Pt on Carbon Black Supported Catalysts
Kaluža, Luděk ; Zdražil, Miroslav ; Gulková, Daniela ; Vít, Zdeněk ; Šolcová, Olga ; Soukup, Karel ; Maixnerová, Lucie
The aim of this work was to elucidate on advanced preparation of Pt/C catalysts from TimCal carbon black and H2PtCl6. The attention was directed to residual content of chloride in the prepared catalysts and scale-up to the amount about 1 gram of final product. The textrual properties of the supports and selected catalyst were studied by nitrogen physisorption. The analytical methods such as instrumental neutron activation analysis (INAA), liquid ion chromatography (LC), and titration with silver nitrates were applied for Cl analysis. Electron probe micro analysis (SEM-EDX), hydrogen chemisorption, temperature programed desorption of hydrogen (TPD) and a simplified determination of ignition temperature in air flow were used for Pt/C catalysts characterization.
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Highly Loaded Carbon Black Supported Pt Catalysts for Fuel Cells
Kaluža, Luděk ; Zdražil, Miroslav ; Gulková, Daniela ; Vít, Zdeněk ; Šolcová, Olga ; Soukup, Karel ; Maixnerová, Lucie
The aim of this work was to elucidate on the methods of Pt deposition on carbon black to achieve high loadings of Pt of about 60 wt.% in highly dispersed form. The carbon black supports were characterized by nitrogen physisorption. Platinum was deposited on the supports: from true solutions of H2PtCl6, Pt(C5H7O2)2, Pt(NH3)4(NO3)2, or Pt(NH3)2(NO2)2, and from fine dispersions of Pt(C5H7O2)2, PtO2, Pt(NH3)4(OH)2. Atomic adsorption spectroscopy, AAS, and scanning electron microscopy, SEM, were used for elemental analysis and determination of Pt content. The deposited Pt species were dried, calcined or reduced and were subjected to temperature programmed reduction, TPR. After degassing at increased temperature, the Pt dispersion was determined by hydrogen chemisorption at -60 C.
Fulltext: content.csg - PDF
Plný tet: SKMBT_C22014082908313 - PDF
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