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Preparation of humic hydrogels with incorporated metal ions
Palková, Michaela ; Kislinger, Jiří (referee) ; Sedláček, Petr (advisor)
This bachelor’s thesis deals with the study of interaction of cupric ions as a model heavy metal with humic-substances in a hydrogel form. Main objective of the work was to suggest and optimize methods of preparing hydrogel forms of humic acids with the cupric ions and to study the influence of the ions on the properties of the prepared hydrogels while using analytical and physic-chemical methods. The investigated parameters for the characterization of prepared hydrogels were inner pH of the hydrogels and the pH of the solution at different stages of preparation, the quantity of copper ions in the hydrogels, the possibility of extraction and characterization of the structure of resulting hydrogel forms. The experimental results have conformed the expected influence of metal contact in the hydrogel forms of humic substances
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Spectrometric Methods for Research of Humic Substances
Enev, Vojtěch ; Maršálek, Roman (referee) ; Sýkorová, Ivana (referee) ; Klučáková, Martina (advisor)
The main aim of doctoral thesis is the study on physicochemical properties of humic substances (HS) by modern instrumental techniques. The subject of the study were HS isolated from South Moravian lignite, South Bohemian peat, forest soil Humic Podzol and finally extract from brown sea algae Ascophyllum nodosum. With respect on determination of structure and reactivity of these unique “biocolloids”, standard samples (Leonardite HA, Elliott Soil HS and Pahokee Peat HS) were also studied. These samples were obtained from International Humic Substances Society (IHSS). All mentioned substances were characterized by elemental analysis (EA), molecular absorption spectroscopy in ultraviolet and visible region (UV/Vis), infrared spectroscopy with Fourier transformation (FTIR), nuclear magnetic resonance spectroscopy of carbon isotope 13C (LS 13C NMR), steady-state and time resolved fluorescence spectroscopy. Obtained fluorescence, UV/Vis and 13C NMR spectra were used for calculation of fluorescence and absorption indexes, values of specific absorbance and structural parameters respectively, which were used for fundamental characterization of these “biocolloidal” compounds. Infrared spectroscopy with Fourier transformation was utilized for the identification of functional groups and structural units of HS. Evaluation of infrared spectra is quiet complicated by overlapping of absorption bands especially in fingerprint region. This problem was overcome by Fourier self-deconvolution (FSD). Steady-state fluorescence spectroscopy was used for deeper characterization of HS with respect to origin, structural units, amount of substituents with electron-donor and electron-acceptor effects, content of reactive functional groups, “molecular” heterogeneity, the degree of humification, etc. Parameters of complexation of samples Elliott Soil with heavy metal ions (Cu2+, Pb2+ and Hg2+) were obtained by using modified Stern-Volmer equation. These ions were chosen purposefully, because the interaction of HS with these ions is one of the fundamental criteria for the assessment of the reactivity of HS. Key part of the whole doctoral thesis is time-resolved fluorescence spectroscopy. It is able to determine the origin of emission of HS by method Time-Resolved Area Normalized Emission Spectra (TRANES). The viscosity of micro medium about excited fluorophores of HS was determined by Time-Resolved Emission Spectra (TRES).
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Models for complexation of humic compounds
Věžníková, Kateřina ; Jaroslav,, Záhora (referee) ; Klučáková, Martina (advisor)
This bachelors thesis deals with interactions of copper ions with humic acids. The bond between metal ions and humic acids is formed mainly trough carboxylic and phenolic groups. Mechanism of these interactions is not so far enlighted. Essential part in this, is reality that humic acids are not chemical individuals, but polydisperse mixtures of substances. This work contains interactions of metal ions with model compounds like citric acid, salicylic acid, pthalic acid, hydroquinone, catechol and EDTA, which simulates possible binding sites in the structure of humic acids. Several analytical methods have been used to study this problems: potentiometry (pH), conductometry and UV/VIS spectroscopy. As a model metal ion has been chosen copper cation because of its high afinity to humic acids.
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Utilization of flow-through coulometry for study of reactivity of humic acids
Pavlíková, Marcela ; Sýkorová,, Ivana (referee) ; Klučáková, Martina (advisor)
Humic acids are part of humus material abounded in nature. Humic acids are generally aromatic stuffs with sidechains and there can be linked various functional groups as carboxylic and fenolic mainly. This functional groups are able to form transitions elements ions and complexes of different stability. This property can be used in the environment, because certain polutants should be imobilized in nature. Diploma thesis studies adsorption of metal ions Cu2+, Cd2+, Zn2+ and Pb2+ on humic acids by electroanalytical method called flow – through coulometry.
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Synthesis of sulphanylaminoderivatives of cyclodextrines and computational simulations of their complexes formation
Provazníková, Adéla ; Jindřich, Jindřich (advisor) ; Míšek, Jiří (referee)
This master thesis deals with synthesis of 6I -N-monosubstituted β-CD bearing a linear spacer of various lenghts containing disulfidic bond and terminated by amine. Whole series was succesfully prepared by nucleophilic substitution of toluenesulfonyl group on tosyl β-CD by a spacer's amine group. In case of the shortest spacer (cystamine) 35 % yield was achieved. Synthesis of β-CD derivatives using longer and more lipophilic spacer derived from di-, tri- and tetraethylenglycol yielded 66 to 85 %. The oligoethylene spacers were prepared by standard chemical modifications. A separation method using n-butanol elution mixtures was optimized for isolation of β-CD derivatives. To better understand the β-CD derivative behavior in solution, molecular dynamics (MD) computations were used. The synthetized species were intended to be used for fluorescent sensor construction. For the same reason the inclusion of small organic molecules in β-CD cavity was studied with molecular dynamic simulations. MD method for computation of relative binding energy was optimized and gave values of right sign and order of magnitude.
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Determination of complexation constants of weak electrolyte analytes by Affinity capillary electrophroesis
Ansorge, Martin ; Šteflová, Jana (advisor) ; Ušelová, Kateřina (referee)
Capillary electrophoresis is not only excellent separation technique but it is often advantageously used for determination of physical-chemical parameters of compounds such as complexation constants of analyte and appropriate complexation agent. The most frequently used electrophoretic method for determination of complexation constants is affinity capillary electrophoresis. In the frame of this work the affinity capillary electrophoresis is used for determination of complexation constants of R and S enantiomers of flurbiprofen, particularly both its neutral and fully dissociated form with neutral β- cyclodextrin. For this purpose we utilized classical method introduced in literature, where complexation constants are determined at two pHs, where analyte is fully and partially dissociated, respectively. Simultaneously, the complexation constants were observed by the new method based on multidimensional nonlinear regression, where all data measured at different pHs and β-cyclodextrin concentrations were utilized for evaluation. Results show that classical method can be highly confusing, especially if unsuitable pH is chosen for determination of stability constants of neutral form of analyte. Multidimensional regression method provides substantially more reliable data but with higher error of estimate....
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Synthesis of fluorophores with permanent positive charges for construction of chemosensors on solid phase
Smolka, Ondřej ; Jindřich, Jindřich (advisor) ; Matoušová, Eliška (referee)
This bachelor work is focused on the synthesis of fluorophores with two positive charges based on 1,2,3-triazole motive. The work deals with optimalization of their synthetic processes and characterization of the compounds. Optical properties of the double charged fluorophores and their complexation ability with -cyclodextrin were studied. Key words: 1,2,3-triazoles, charged fluorophores, positive charges, cyclodextrines, complexation
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Synthesis of fluorophores with permanent positive charges for construction of chemosensors on solid phase
Smolka, Ondřej ; Jindřich, Jindřich (advisor) ; Matoušová, Eliška (referee)
This bachelor work is focused on the synthesis of fluorophores with two positive charges based on 1,2,3-triazole motive. The work deals with optimalization of their synthetic processes and characterization of the compounds. Optical properties of the double charged fluorophores and their complexation ability with -cyclodextrin were studied. Key words: 1,2,3-triazoles, charged fluorophores, positive charges, cyclodextrines, complexation
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Synthesis of sulphanylaminoderivatives of cyclodextrines and computational simulations of their complexes formation
Provazníková, Adéla ; Jindřich, Jindřich (advisor) ; Míšek, Jiří (referee)
This master thesis deals with synthesis of 6I -N-monosubstituted β-CD bearing a linear spacer of various lenghts containing disulfidic bond and terminated by amine. Whole series was succesfully prepared by nucleophilic substitution of toluenesulfonyl group on tosyl β-CD by a spacer's amine group. In case of the shortest spacer (cystamine) 35 % yield was achieved. Synthesis of β-CD derivatives using longer and more lipophilic spacer derived from di-, tri- and tetraethylenglycol yielded 66 to 85 %. The oligoethylene spacers were prepared by standard chemical modifications. A separation method using n-butanol elution mixtures was optimized for isolation of β-CD derivatives. To better understand the β-CD derivative behavior in solution, molecular dynamics (MD) computations were used. The synthetized species were intended to be used for fluorescent sensor construction. For the same reason the inclusion of small organic molecules in β-CD cavity was studied with molecular dynamic simulations. MD method for computation of relative binding energy was optimized and gave values of right sign and order of magnitude.
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Organophosphorus derivatives for "click-chemistry"
Zemek, Ondřej ; Kotek, Jan (advisor) ; Veselý, Jan (referee)
Ondřej Zemek Organophosphorus derivatives for "click-chemistry" In this diploma thesis two new macrocyclic ligands were synthesized. They have DO3A moiety where metal (lanthanide) ion can be coordinated and terminal acetylenic or azide group connected through the phosphinic acid. Both terminal acetylenic and azide group should serve for connecting to another molecules or partitions by mean of "click chemistry" i.e. [1,3] copperI catalyzed dipolar cycloaddition between azide and acetylene. In this thesis two ligands, its complexes with some lanthanides as well as its precursors were prepared and characterized. Gd3+ complexes will be further used and studied for potential MRI contrast agents applications.
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