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Use of Hofmeister series of ions for fractionation of soil humic acids
Kebabová, Mona ; Doskočil, Leoš (referee) ; Enev, Vojtěch (advisor)
The bachelor thesis deals with the study of the structure and behaviour of humic acids (HA) in the presence of salts of the Hofmeister series of ions. Haplic Luvisol and sodium humate extracted from it were characterized by elemental analysis (EA) and thermogravimetric analysis (TGA) to determine the percentage of elements and ash. Fourier Transform Infrared Spectroscopy (FT-IR) was used to determine the functional groups in the sample. UV-VIS was used to investigate the effect of the Hofmeister salts. From its results were calculated the absorption coefficients EET/EBZ, E2/E3, E2/E4 and E2/E6, and the specific absorbance values SUVA254 and SUVA280. Other methods like Dynamic Light Scattering (DLS) and fluorescence spectroscopy were used to better understand HA's structure. The main goal of this bachelor thesis was to find a simple experimental method based on which we would be able to study supramolecular associations of HK, which are preferentially linked to the formation of weak intra- and intermolecular interactions in aqueous solutions.
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Use of Hofmeister series of ions for fractionation of soil humic acids
Kebabová, Mona ; Doskočil, Leoš (referee) ; Enev, Vojtěch (advisor)
The bachelor thesis deals with the study of the structure and behaviour of humic acids (HA) in the presence of salts of the Hofmeister series of ions. Haplic Luvisol and sodium humate extracted from it were characterized by elemental analysis (EA) and thermogravimetric analysis (TGA) to determine the percentage of elements and ash. Fourier Transform Infrared Spectroscopy (FT-IR) was used to determine the functional groups in the sample. UV-VIS was used to investigate the effect of the Hofmeister salts. From its results were calculated the absorption coefficients EET/EBZ, E2/E3, E2/E4 and E2/E6, and the specific absorbance values SUVA254 and SUVA280. Other methods like Dynamic Light Scattering (DLS) and fluorescence spectroscopy were used to better understand HA's structure. The main goal of this bachelor thesis was to find a simple experimental method based on which we would be able to study supramolecular associations of HK, which are preferentially linked to the formation of weak intra- and intermolecular interactions in aqueous solutions.
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Characterization of new czech hop varieties
Faruzel, Vojtěch ; Diviš, Pavel (referee) ; Pořízka, Jaromír (advisor)
In this thesis the problem of characterization of new Czech hop varieties was investigated. The selected new varieties were Mimosa, Jazz and Blues. Their composition was compared with the widely used varieties Žatecký poloraný červeňák and Kazbek. The content of -bitter acids and -bitter acids, total phenolic content, flavonoid content and antioxidant activity were determined by UV-VIS spectroscopy for all hop varieties. The composition of hop essential oils was estimated by SPME-GC-MS. The diversity of the hop varieties was confirmed from the measured data by statistical analysis. The new varieties showed statistically significant differences in all monitored parameters, especially in comparison with the varieties Žatecký poloraný červeňák and Kazbek. The quantitatively different representation of -bitter acids and -bitter acids has an influence on the character and intensity of bitterness of these hop varieties. The composition of the hop essential oils, the content of phenolic substances, flavonoids and antioxidant activity are reflected in the different organoleptic properties of the hops analysed and of the beer.
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Solubility of lipophilic model carcinogens in water environment and effect of biomolecules
Řeboun, Martin ; Martínek, Václav (advisor) ; Hudeček, Jiří (referee)
2-Nitrobenzanthron (2-NBA) and 3-nitrobenzanthron (3-NBA) are pollutants widely occurring in the environment. The main sources of benzanthrones are combustion products (i.e. diesel exhausts, wood and cigarette smoke ...). 3-NBA is proven strong mutagen and carcinogen for bacteria and mammals and it is probably mutagenic also to humans, while 2- NBA shows genotoxic properties lower by 3-4 orders of magnitude. Here we consider the possibility that large difference in the solubility, and consequently also the difference in bioavailability of these isomers could be the factor partially explaining this phenomenon. One goal was to determine solubility of 2-NBA in water and compare it with 3-NBA and also with other carcinogens studied in our laboratory (Sudan I, ellipticin). Another objective was to evaluate the effect of model proteins (bovine serum albumin, lysozyme) on solubility of Sudan I and ellipticine. The last aim was to determine extinction coefficients of these compounds in water and in methanol. Two different methods were employed to determine the solubility of the model compounds. The first method was based on spectrophotometric verification of the Lambert- Beer law. The results were than compared with other method measuring concentration of a compound in saturated solution (In Czech) Key...
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Ligands for Multifunctional Dinuclear Complexes
Králová, Marie ; Vojtíšek, Pavel (advisor) ; Lukeš, Ivan (referee)
Title: Ligands for Multifunctional Dinuclear Complexes Author: Marie Králová Site: Charles University in Prague, Faculty of Science Supervisor: doc. RNDr. Pavel Vojtíšek, CSc. Abstract The aim of this work was to prepare substitued phenols as ligands for binuclear complexes of copper(II), which could be used as anion receptors. Two main sythethic strategies are summarised in the introduction: First is single step Mannich-type reaction of 4-substitued phenol, paraformaldehyde and secondary amine, other includes preparation of substitued bis(halomethy)phenol and it's following reaction with secondary anime. A single step Mannich-type reaction was used for preparations of following known ligands: 2,6-bis[(N-methyl piperazine-1-yl)methyl]-4-formyl phenol (L1), 2,6-bis[(N- methyl piperazine-1-yl)methyl]-4-nitro phenol (L3) and 2,6-bis[(N-phenyl piperazine-1- yl)methyl]-4-nitro phenol (L4). The new ligand, 2,6-bis[(N-phenyl piperazine-1-yl)methyl]- 4-formyl phenol (L2), was prepared in the same way. A structure of this ligand was determined using X-ray. One Pd(II) complex [PdL2Cl2]·1.5MeCN (K3) was prepared and it's structure was determined. UV-VIS spectroscopy was used to study interactions in ligand - metal and ligand - metal - anion systems in order to determine the anion - binding capabilities of the...
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Native hyaluronan as a delivery system for hydrophobic drugs
Černá, Eva ; Mravec, Filip (referee) ; Pekař, Miloslav (advisor)
The aim of this paper is to discover whether it is possible to use the native form of hyaluronic acid as a hydrophobic drug carrier for a targeted distribution in the body. In its structure, hyaluronic acid is a linear high molecular weight biopolysaccharide which is found in most living organisms. Hyaluronan is involved in many physiological processes and therefore is essential for the functionality of the human body. It is in most tissues of the human body, high concentration is in the skin, the vitreous body and is also observed in cancer cells that contain several receptors for hyaluronan. These receptors include CD44 and RHAMM. The interaction of the hyaluronic acid delivery system and the hydrophobic medicinal with these receptors could ensure a free passage for drugs to the affected tissue, where the release of the drug would destroy the affected cells. The drug would directly target the damaged tissue and did not burden the rest of the body like the cytotoxic agents do. In this paper the native form of hyaluronic acid, which we normally find in the human organism, was chosen as the carrier. Its properties do not stand above other carrier systems, but its biocompatibility and biodegradability in the body greatly exceed them. High molecular weight hyaluronic acid was used as a carrier and the hydrophobic dye sudan red G, a substance of similar properties, was used instead of a hydrophobic drug.
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Solubility of lipophilic model carcinogens in water environment and effect of biomolecules
Řeboun, Martin ; Martínek, Václav (advisor) ; Hudeček, Jiří (referee)
2-Nitrobenzanthron (2-NBA) and 3-nitrobenzanthron (3-NBA) are pollutants widely occurring in the environment. The main sources of benzanthrones are combustion products (i.e. diesel exhausts, wood and cigarette smoke ...). 3-NBA is proven strong mutagen and carcinogen for bacteria and mammals and it is probably mutagenic also to humans, while 2- NBA shows genotoxic properties lower by 3-4 orders of magnitude. Here we consider the possibility that large difference in the solubility, and consequently also the difference in bioavailability of these isomers could be the factor partially explaining this phenomenon. One of our goals was to determine the solubility of 2-NBA in water and compare it with 3-NBA and also with other carcinogens studied in our laboratory (Sudan I, ellipticin). The second aim was to determine extinction coefficients of these compounds in water and in methanol. Two different methods were employed to determine the solubility of the model compounds. The first method was based on spectrophotometric verification of the Lambert- Beer law. The results were than compared with other method utilizing determination of concentration of a compound in equilibrium with solid phase. (In Czech) Key words: solubility, UV-VIS spectroscopy, 3-nitrobenzanthrone, 2-nitrobenzanthrone, ellipticine, Sudan I
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Solubility of lipophilic model carcinogens in water environment and effect of biomolecules
Řeboun, Martin ; Martínek, Václav (advisor) ; Hudeček, Jiří (referee)
2-Nitrobenzanthron (2-NBA) and 3-nitrobenzanthron (3-NBA) are pollutants widely occurring in the environment. The main sources of benzanthrones are combustion products (i.e. diesel exhausts, wood and cigarette smoke ...). 3-NBA is proven strong mutagen and carcinogen for bacteria and mammals and it is probably mutagenic also to humans, while 2- NBA shows genotoxic properties lower by 3-4 orders of magnitude. Here we consider the possibility that large difference in the solubility, and consequently also the difference in bioavailability of these isomers could be the factor partially explaining this phenomenon. One goal was to determine solubility of 2-NBA in water and compare it with 3-NBA and also with other carcinogens studied in our laboratory (Sudan I, ellipticin). Another objective was to evaluate the effect of model proteins (bovine serum albumin, lysozyme) on solubility of Sudan I and ellipticine. The last aim was to determine extinction coefficients of these compounds in water and in methanol. Two different methods were employed to determine the solubility of the model compounds. The first method was based on spectrophotometric verification of the Lambert- Beer law. The results were than compared with other method measuring concentration of a compound in saturated solution (In Czech) Key...
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Study of optical properties of thin films of organic photovoltaic cells
Čuboň, Tomáš ; Schmiedová, Veronika (referee) ; Zmeškal, Oldřich (advisor)
This master´s thesis is focused on measurement of optical properties of thin layer of materials used in organic solar cells (OSC). The usage of graphene oxides and its reduced forms as parts of hole transport layer (HLT) in OSC were studied. At the beginning of the thesis, there is described basic theory necessary to understand the optical properties of thin layers. The thin layer deposition and reduction of GO are discussed too. The experimental part is aimed to the optical characterization of prepared thin films. The results from optical microscopy, UV-VIS spectroscopy, FT-IR spectroscopy and spectroscopic ellipsometry were obtained. At the end of the thesis, the results are concluded and compared with already published literature.
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Influence of photochromic additives on the optical and electrical properties of polymer matrices
Tumová, Šárka ; Toman, Petr (referee) ; Weiter, Martin (advisor)
This thesis is focused on the photochromic molecule of spiropyran, which changes its structure as well as physical and chemical properties after UV irradiation. These changes are reversible, the molecule thermally restore its initial structure. For the study, the molecule SP1 with the systematic name 1',3'-dihydro-1',3',3'-trimethyl-6-nitrospiro[2H-1-benzopyran-2,2'-(2H)-indole] was used. This molecule was incorporated within polymers PVK, Tg PPV, PCBTDPP and PCDTBT and the method of UV-VIS spectroscopy was used to observe the photochromic activity within these matrices. The influence of matrices to the ability to undergo UV induced photochromic conversion as well as to the reverse conversion to the initial structure induced by heat was monitored. Furthermore, the influence of spiropyran to the electrical properties of individual matrices was studied. The effect of photochromic conversion to both, the mobility of charge carriers and to the photogeneration was observed. For this purpose, the method of current-voltage measurement was used.
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