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Physicochemical characterization of soil humic substances isolated from Fluvisol
Šátková, Eliška ; Kalina, Michal (referee) ; Enev, Vojtěch (advisor)
This bachelor thesis is focused on the physicochemical characterization of humic substances that are isolated from fluvisol. Humic substances were isolated by a standard procedure according to the International Humic Substances Society (IHSS). Extracted humic substances were further characterized by thermal and spectrometric methods, which include elemental (EA) and thermogravimetric analysis (TGA), UV/Vis, and FTIR spectrometry. Potentiometric titration was an important contribution to characterization. Based on the obtained data obtained from the EA and TGA, the content of biogenic elements and the thermal stability of HL were determined. Absorption coefficients were calculated from the measured UV/Vis spectra to determine the aromaticity and average molecular weight of HL. The HL functional groups were determined by FTIR spectra, and the acidity was determined by potentiometric titrations. The obtained results very well characterized the individual humic substances isolated from fluvisol.
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Physicochemical characterization of soil humic substances isolated from Fluvisol
Šátková, Eliška ; Kalina, Michal (referee) ; Enev, Vojtěch (advisor)
This bachelor thesis is focused on the physicochemical characterization of humic substances that are isolated from fluvisol. Humic substances were isolated by a standard procedure according to the International Humic Substances Society (IHSS). Extracted humic substances were further characterized by thermal and spectrometric methods, which include elemental (EA) and thermogravimetric analysis (TGA), UV/Vis, and FTIR spectrometry. Potentiometric titration was an important contribution to characterization. Based on the obtained data obtained from the EA and TGA, the content of biogenic elements and the thermal stability of HL were determined. Absorption coefficients were calculated from the measured UV/Vis spectra to determine the aromaticity and average molecular weight of HL. The HL functional groups were determined by FTIR spectra, and the acidity was determined by potentiometric titrations. The obtained results very well characterized the individual humic substances isolated from fluvisol.
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Determination of dissociation exponents of selected polyaza derivatives
Hajduová, Jana ; Nesměrák, Karel (advisor) ; Rychlovský, Petr (referee)
Title: Determination of dissociation exponents of selected polyaza derivatives Annotation: The aim of this thesis is extimation of dissociation exponets of seclected polyaza derivatives by acid-base titration with potentiometric registration of titration curve. The titration curve was processed using Hyperquad 2006 software. The satisfactory agreement of determined values of dissociation exponents with literature data was found. Key words: dissociation exponent, potentiometric titration, polyaza compounds
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Hyaluronan-amino acids interactions
Jugl, Adam ; Maršálek, Roman (referee) ; Mráček, Aleš (referee) ; Pekař, Miloslav (advisor)
The presented dissertation focuses on non-covalent interactions of hyaluronan of different molecular weights (9–1540 kDa) with basic (oligo)-amino acids (especially arginine) and the antimicrobial peptide cecropin B. High-resolution ultrasonic spectroscopy (HR-US), isothermal titration calorimetry (ITC) and potentiometric titration techniques were chosen to investigate the interactions. The thesis focuses on the characterization of interactions, especially with respect to the used molecular weight of interacting polymers and the ionic strength of the environment. Whether interactions occur or not was determined primarily by the length of the arginine oligomer chain. For monomeric amino acids, the interactions were investigated mainly by potentiometric titrations. Interactions were observable from arginine oligomers with eight monomer units. The molecular weight of hyaluronan mainly affected the intensity of the interactions. The transition between the individual conformations of hyaluronan (rod and random coil) was especially significant. Investigation of interactions was performed in water, in solutions with different concentrations of sodium chloride and in PBS. The sufficiently high ionic strength of the solution was able to suppress the interactions in water between the oligomers of arginine and hyaluronan. The basic antimicrobial peptide cecropin B has been shown to interact with hyaluronan in water but not in PBS. Based on these results, it was possible to conclude that the hyaluronan-cecropin B system would be particularly suitable for topical applications.
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Determination of dissociation exponents of selected polyaza derivatives
Hajduová, Jana ; Rychlovský, Petr (referee) ; Nesměrák, Karel (advisor)
Title: Determination of dissociation exponents of selected polyaza derivatives Annotation: The aim of this thesis is extimation of dissociation exponets of seclected polyaza derivatives by acid-base titration with potentiometric registration of titration curve. The titration curve was processed using Hyperquad 2006 software. The satisfactory agreement of determined values of dissociation exponents with literature data was found. Key words: dissociation exponent, potentiometric titration, polyaza compounds
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