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Study of the electrochemical oxidation of meta substituted phenol derivatives on boron-doped diamond electrode activated by anodic oxidation
Sládková, Šárka ; Dejmková, Hana (advisor) ; Fischer, Jan (referee)
This thesis is focused on the study of electrochemical oxidation of meta-substituted phenol derivatives on boron doped diamond electrode. Four different doped electrodes prepared at a gas phase B/C ratio of 500 ppm, 1000 ppm, 2000 ppm and 8000 ppm were used for the measurement. At first, five redox markers were measured, i.e. potassium hexacyanoferrate, hexaamintuthenium chloride, methyl viologene dichloride hydrate, N,N,N′,N′-tetramethyl-p-phenylenediamine, and quinizarin. Then, phenol and its derivatives were observed by DCV ,,direct current'' voltametry; among the studied substituents were −CH3, −OCH3, − (CH2)2COOH, −COOH, −NO2, −CF3 and −Cl. The measurement was performed on anodic activated O-BDD surface. Two media for the measurement were selected, with pH 2 and pH 11. In the alkaline medium, the potential values of electrochemical oxidation were lower than in the acidic one. Phenolic acids did not provide any anodic signal in a basic solution and could not be detected. This is most likely due to electrostatic repulsion between the partially negative electrode surface and the acid anion. Finally a Hammett correlation was created for the studied phenol derivatives to assess the electronic effects of functional groups on the oxidation potential of individual phenols. Better correlation was...
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Determination of pesticide chlortoluron on carbon felt electrode
Sládková, Šárka ; Dejmková, Hana (advisor) ; Vyskočil, Vlastimil (referee)
This bachelor thesis deals with the optimization of the determination method for pesticide chlortoluron by HPLC coupled with coulometric detection on the carbon felt electrode. As the stationary phase Purospher® RP-18 column (125 x 4 mm, 5 μm) (LiChroCART) was used. The mobile phase was phosphate-acetate buffer pH 4 and methanol 40:60 and the potential applied to the working electrode was 1400 mV. The dependence of the signal on the concentration was monitored in the concentration range from 1·10-4 to 7,5·10-9 mol·dm- 3 . Firstly, this dependence was observed in deionized water. Detection limits obtained by HPLC-UV and HPLC-ED were determined to be 4,42·10-9 mol·dm-3 and 1,26·10-7 mol·dm-3 , respectively. Applicability of the method on the environmental samples was verified on model samples of river water and soil. The limits of detection of river water were determined by HPLC-UV method at 7,76·10-9 mol·dm-3 and by HPLC-ED method at 1,71·10-7 mol·dm-3 . For the soil, the limit of detection was measured by HPLC-UV at 0,198 µg·g-1 . and by method HPLC-ED it was determined as 0,135 µg·g-1 . Assays in model samples giving very similar results as in the pure solvents and this means that the matrix influence on the determination is low.
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Cooperation of the public administration and the self administration with non-profit organizations working with children and youth in their free time in the Tábor region
SLÁDKOVÁ, Šárka
My thesis is aimed at ``Cooperation of the public and local administration with non-profit organizations involved in free-time activities of children and young people in Tábor region``. The theoretical part clarifies the terms public administration, local administration, non-profit organizations and provides further related information. The practical part describes the aims of the thesis, research methods and the results themselves. The aim of the research was to summarize cooperation of the public and local administration with non-profit organizations involved in free-time activities of children and young people in Tábor region, to find out mutual expectation of the public and local administration with non-profit organizations involved in free-time activities of children and young people in Tábor region and to propose further possible ways of cooperation of public and local administration with non-profit organizations involved in free-time activities of children and young people in Tábor region. I chose qualitative type of research, questioning method and semi controlled dialogue for implementation of the research. The research results have shown that the ways of cooperation of the public administration and local administration with non-profit organizations involved in free-time activities of children and young people in Tábor region differ, however they have mostly financial character.
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