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Basic chemical characteristics of juices of selected honeysuckle varieties
Cibulcová, Pavla ; Vránová, Dana (referee) ; Vespalcová, Milena (advisor)
This thesis includes a theoretical part, which speaks about the classification and incidence of honeysuckle plant description, the conditions for growth, recovery, species and varieties. It also includes methods for the determination of selected chemical parameters such as yield, total solids, soluble solids, pH, titratable acidity, formol number and gravimetric determination of reducing sugars.
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Influence of metal ions on microorganization of humic substances
Odehnalová, Nikola ; Krouská, Jitka (referee) ; Klučáková, Martina (advisor)
This bachelor thesis is focused on the study of influence of metal ions on microorganization of humic substances. This issue was studied on a sample od fulvic acid. Solution of cocentration 1 g/l was prepared from this sample. This solution was ten titrate with solutions of copper, calcium and magnesium ions. For this purpose, methods of dinamic and electrophoretic light scattering were used. The results obtained by these methods show that the solution of fulvic acid is the most made by associated molecules of fulvic acid. The size of molecules became larger and larger during titrations. Copper was sorpted the most.
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Preparation of a laboratory assignment for the Ecology of production subject
Dovčík, František ; Vaněk, Jiří (referee) ; Bača, Petr (advisor)
The thesis deals with the quality of water in general as well as from the perspective of water pollution, wastewater and its treatment within the context of electrotechnical production. The thesis is based on the laboratory task in the practical part, which has been included in the Ecology of Production class. The laboratory task tests the selected indicators of water quality using titration and rapid tests. The thesis is based on the wastewater operation of a company producing PCB.
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Quantification of the Influence of Biochar on Soil Respiration
Losová, Anežka ; Mravcová, Ludmila (referee) ; Kalina, Michal (advisor)
This master‘s thesis is focused on the investigation of methods for evaluating the effect of biochar and NPK fertilizer on the activity of soil microorganisms by measuring soil respiration. The theoretical part describes the characteristics of soil, the properties of biochar and its production process. Furthermore, the literature research was focused on the definition and optimization of the various methodologies that can be used to measure soil respiration. The experimental part describes selected physicochemical characteristics of soil and biochar (pH, conductivity, water retention capacity). Thermogravimetric analysis and elemental analysis were used for measuring of the amount of organic and inorganic content and the composition of organic elements (C, H, O and N) in the soil and biochar samples. From the literature research, a dynamic incubation system was chosen for monitoring of the influence of biochar application on the microbial activity of soil microorganisms through the measurement of soil respiration. The produced carbon dioxide was sorbed into sodium hydroxide solution during the incubation and the released amount was determined by titration and conductometric method. The measured results of both methods correlated with each other, and both of these methods are suitable for determining the rate of soil respiration. Experimental data showed that biochar had positive effects on the rate of carbon dioxide production by soil respiration. The combined application of biochar and NPK fertilizer did not significantly increase the efficiency of biochar. In summary, biochar as a soil conditioner in agriculture has great potential to act and to support the level of soil respiration.
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Trivalent and tetravalent metal complexes for radiodiagnostics
Hacaperková, Eliška ; Kubíček, Vojtěch (advisor) ; Drahoš, Bohuslav (referee) ; Polášek, Miloslav (referee)
Fluorine-18 is the most utilized nucleus for positron emission tomography (PET). In 2009, incorporation of fluorine-18 to the coordination sphere of Al(III) was introduced as a new alternative for commonly employed compounds with F-C bond. Such a radiotracer consists of two parts: a metal complex with a fluoride and a peptide or a small/part of biomolecule. Shortly after that, first clinical studies showed a promising potential of such com- pounds for clinical use. Despite a great number of papers dealing with this issue, the research is mostly application-driven and focused on the peptide part of the molecule responsible for specific accumulation within the organism. Studies oriented on a sta- bility of metal-ligand-fluorine ternary system are rather rare and only very little is known about such a three-component system from a chemical point of view in gen- eral. However, stability of F-Al bond strongly dependents on the chemical structure of other ligands in the coordination sphere. Pendant arms of a hexadentate ligand (usually used for Al(III) complexation, e.g., H3NOTA) can compete with fluoride and cause its release which leads to unspecific radioactivity accumulation. Lower ligand denticity should increase the F-Al bond stability, but can decrease the stability of the whole complex at the...
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The comparison of methods for determination of ascorbic acid in medical formulations
Kohoutová, Petra ; Nesměrák, Karel (advisor) ; Červený, Václav (referee)
The aim of this thesis is to compare and assess chosen analytical methods for ascorbic acid determination in pharmaceuticals with respect to their correctness, accuracy, time and finance exigencies. Four methods were chosen alkalimetric titration with visual and instrumental indication, iodometry and spectrophotometry. Pills, capsules and injection solution were chosen as samples of pharmaceuticals. The obtained results as to accuracy of the declared value (or range permitted under Pharmacopoeia) agreed by all titration methods, spectrophotometric determination showed overestimated results. All used methods were approximately equally accurate. As time seems to be most optimal acidobasic titration with visual indication, while demanding in terms of time was spectrophotometry. If we consider methods on financial intensity all titration methods were quite equal.
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Multidimensional characterization of polyelectrolytes and interpolyelectrolyte complexes in aqueous solutions
Murmiliuk, Anastasiia ; Štěpánek, Miroslav (advisor) ; Šachl, Radek (referee) ; Hoffmann, Ingo (referee)
Multidimensional characterization of polyelectrolytes and interpolyelectrolyte complexes in aqueous solutions Abstract: This PhD thesis is dedicated to the study of polyelectrolytes and their self-assembly in aqueous solutions. The morphology and ionization state of individual polymer chains were investigated as well as their co-assembly with oppositely charged species. First, the charge regulation of short and long weak polyelectrolytes in aqueous solution was investigated to deeper understand their pH-responsive properties. The changes of ionization degree and charge of oligopeptides composed of 5 amino acids with acid side-chains and 5 with basic side chains were followed upon varying the pH in order to reveal the effect of interactions between the like-charged and oppositely charged groups. It was shown that intra-molecular electrostatic interactions and conformational flexibility caused the suppression of the total charge and enhancement of ionization of the peptides. To get an insight into the distribution of local H+ concentration in the proximity of a polyelectrolyte chain, a modified polyelectrolyte structure was used with a fluorescent pH- indicator, covalently attached at the end of the chain. Ionization of the pH-responsive fluorophore revealed its effective pK which was compared with the local...
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Multidimensional characterization of polyelectrolytes and interpolyelectrolyte complexes in aqueous solutions
Murmiliuk, Anastasiia ; Štěpánek, Miroslav (advisor) ; Šachl, Radek (referee) ; Hoffmann, Ingo (referee)
Multidimensional characterization of polyelectrolytes and interpolyelectrolyte complexes in aqueous solutions Abstract: This PhD thesis is dedicated to the study of polyelectrolytes and their self-assembly in aqueous solutions. The morphology and ionization state of individual polymer chains were investigated as well as their co-assembly with oppositely charged species. First, the charge regulation of short and long weak polyelectrolytes in aqueous solution was investigated to deeper understand their pH-responsive properties. The changes of ionization degree and charge of oligopeptides composed of 5 amino acids with acid side-chains and 5 with basic side chains were followed upon varying the pH in order to reveal the effect of interactions between the like-charged and oppositely charged groups. It was shown that intra-molecular electrostatic interactions and conformational flexibility caused the suppression of the total charge and enhancement of ionization of the peptides. To get an insight into the distribution of local H+ concentration in the proximity of a polyelectrolyte chain, a modified polyelectrolyte structure was used with a fluorescent pH- indicator, covalently attached at the end of the chain. Ionization of the pH-responsive fluorophore revealed its effective pK which was compared with the local...
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Interaction of weak polyelectrolytes with multivaltent ions
Staňo, Roman ; Košovan, Peter (advisor) ; Heyda, Jan (referee)
By means of molecular simulations, we study dissociative behavior of weak polyacids with added mutlivalent salt. Weak polyacids are macromolecules that bear weak acid groups, therefore, their ionization varies with pH. The titration curve of such an acid deviates from the ideal one - its ionization is suppressed because of the strong repulsion between charged groups on the polyacid contour. The presence of salt in solution of a polyacid enhances the ionzation due to the effects of electrostatic screening and counterion condensation. Up to now, the influence of the salt valency on the weak polyacid ionization has not been explored, although it plays an important role in biological processes. In this thesis, we examine weak polyacid solutions with added salt of various cation valencies (+1,+2,+3) at fixed charge ratio of salt cations to po- lymer segments. We show that increasing the salt valency promotes the polyelectrolyte ionization in a manner which is different from the effect of increasing ionic strength. A higher counterion valency leads to a lower value of the critical Manning parameter, initiating strong counterion condensation which results in additional ionization due to ion-ion correlations between the condensed counterions and charged groups of the polyelectrolytes.
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Influence of metal ions on microorganization of humic substances
Odehnalová, Nikola ; Krouská, Jitka (referee) ; Klučáková, Martina (advisor)
This bachelor thesis is focused on the study of influence of metal ions on microorganization of humic substances. This issue was studied on a sample od fulvic acid. Solution of cocentration 1 g/l was prepared from this sample. This solution was ten titrate with solutions of copper, calcium and magnesium ions. For this purpose, methods of dinamic and electrophoretic light scattering were used. The results obtained by these methods show that the solution of fulvic acid is the most made by associated molecules of fulvic acid. The size of molecules became larger and larger during titrations. Copper was sorpted the most.
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