This diploma thesis deals with humic acid gels and their ability to bind metallic ions on their surface. In the thesis, there was studied the adsorption of copper ions on the provided gels. The gels were prepared by dissolving the humic acid in sodium hydroxide or sodium tripolyphosphate and then precipitated with hydrochloric acid or metal chlorides. Adsorption was studied at different concentrations of the copper (II) chloride and measured on UV-VIS spectrophotometer. It was proved from measuring that gels made from sodium tripolyphosphate are adsorbing less copper ions than the ones prepared by sodium hydroxide. Also, the copper ions are bound with smaller force on gels prepared with polyphosphate. Gels precipitated with magnesium chloride adsorb much more than gels precipitated with acid, thus in the case of gels sequestered metal ions extracted higher.

Presented diploma thesis deals with the analysis of juices of selected red and white currant varieties. The theoretical part is dedicated to the characteristics of a currant, biologically active substances of its fruits, its growing proces and the utilization of currants in the food industry. The analyzed parameters of currants - phenolics, anthocyanins and vitamin C are also characterized in the theoretical part with possibůe methods of their determination. The experimental part is devoted to the preparation of samples and the working practices of individual analysis. Six selected varieties of white and eleven varieties of red currant from Research and Breeding Institute of Pomology Holovousy Ltd. and six varieties of white and ten varieties of red currant from private grower were used for the analysis. Total phenolics and anthocyanins were determined spectrophotometrically, the content of vitamin C was determined by HPLC. Higher values of these compounds were measured mainly in the varieties of Research and Breeding Institute of Pomology Holovousy Ltd. Varieties of red currants contained higher amounts of total phenolics and anthocyanins while white currants contained higher amounts of vitamin C.

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.

To decrease the environmental footprint, the textile industry needs to become more circular. One company that is trying to close the textile lifecycle loop is the Swedish company Renewcell. In the Renewcell process, discarded clothes and other textile waste are turned into a dissolving pulp that can be used for production of new textiles. For this to work, it is important to generate a non-colored dissolved pulp. Therefore, it is of great interest to be able to optimize the bleaching process and evaluate different starting materials. Today, there are different methods that have been used for quantification of specific dyes and for identification of raw materials in textiles. However, there is no complete method that can be used for all types of dyes and raw materials. This master thesis will therefore investigate the bleaching step and the raw materials used in Renewcell’s recycling process. The aim with this project is to develop a method, to be able to analyse the presence of dyes qualitatively and quantitatively in the dissolved pulp from the recycled cotton-based textiles. To do so, different chemical analysing methods were used. These include kappa number measurements, UV-VIS and FTIR. Nine different types of jeans, one yarn, three raw materials (cotton, PET and elastane), and two pure dyes (indigo and black sulfur dye) were selected for this project. The result from the kappa number measurements shows that only the blue jeans, blue yarn and black jeans could be bleached and measured by using the original kappa number method at 25 degrees C. But when the same procedure was done manually and the temperature was increased to 70 degrees C, almost all materials could be bleached and measured. Therefore, the conclusion is that this method can be a successful quantification method. However, the temperature correction equation needs to be developed further to be able to quantify the exact amount of dyes. The kappa number was also compared with the absorbance factor, i.e. the k-value from the UV-VIS results. A correlation could be seen for the blue jeans, blue yarn, and black jeans. So, the UV-VIS method could also be a possible method for quantification of dyes in textiles. For the qualitative analyses, FTIR was used. The results showed that the raw materials could be identified by comparing the resulting FTIR spectra with a reference spectrum. For the jeans and yarn materials, indigo dye was identified for the blue jeans, blue yarn, and black jeans. However, for the other materials, the amount of dyes was too low to be able to draw conclusions about the chemical structure. With further development, these methods could be used as successful qualitative and quantitative methods for analysing dyes in textiles. This would generate positive consequences in several ways. The usage of bleaching chemicals could be optimized, and the quality of the final textile material could be improved. This would benefit both the manufacturer of these recycled textiles (economically) and the consumer who will buy the final product (quality). Indirectly, this would help to decrease the environmental footprint from the textile industry.

La propolis est un produit de la ruche à base de résine de plantes et d’arbres mélangée à de la cire d’abeille. Elle est utilisée pour polir les murs de la ruche et la protéger contre les intrus provenant de l’extérieur. Elle contient un grand nombre de composés incluant les métabolites des plantes, alors elle est un ingrédient des médicaments naturels, des additifs alimentaires et des produits cosmétiques en raison de sa richesse en polyphénols qui lui confèrent ses propriétés anti-oxydantes, anti-inflammatoires et antibiotiques. La composition de la propolis est cependant complexe et très variable en raison de la région de provenance qui est étroitement liée aux résines utilisées par les abeilles. De plus, la présence de contaminants dans l’environnement, comme les pesticides et les éléments traces d’origine anthropique, incluant des métaux lourds, donne un risque d’exposition à ces substances en consommant la propolis ou les extraits de propolis. Plusieurs échantillons de propolis brute ainsi que des teintures commerciales et artisanales provenant du Canada, de la Roumanie et du Brésil ont été analysés. L’extraction des polyphénols totaux des échantillons bruts a été faite 3 fois dans l’éthanol (EtOH) 70 % (v/v) à 70 ̊C, et les teintures ont quant à elles été diluées dans l’EtOH 70 %. Les polyphénols totaux ont ensuite été analysés par spectroscopie moléculaire UV-Vis en utilisant la méthode de Folin- Ciocalteu. Des analyses chromatographiques préliminaires par la chromatographie liquide couplée à la spectrométrie de masse (LC-MS) ont permis de comparer des polyphénols et des pesticides dans deux sources de propolis du Québec, avec une grande similarité entre les deux extraits. Des échantillons bruts ainsi que des extraits éthanoliques et des teintures ont été analysés suite à l’ionisation par plasma à couplage inductif (ICP-MS) et la spectroscopie de fluorescence atomique à vapeur froide (CVAFS) pour déterminer des concentrations de certains éléments traces présents à l’état de trace incluant l’As, le Cd, le Pb et le Hg total. / Propolis is a honeybee product made of plant and tree resins mixed with beeswax. It is used to build and repair the walls of the hive and to protect it from outside invaders. It contains a large number of compounds including plant metabolites, and is thus used in natural medications, cosmetic products and as food additives due to its richness in polyphenols, which confer its antioxidant, anti-inflammatory and antibiotic properties. However, the composition of propolis is complex and highly variable because of the geographical location of the resins used by the bees. Furthermore, the presence of contaminants in the environment, such as pesticides and trace elements of anthropogenic origin, brings a risk of exposure to these substances when consuming the propolis. Various raw propolis samples as well as commercial and homemade tinctures from Canada, Romania and Brazil were analysed. The raw samples were extracted 3 times in 70 % EtOH (v/v) at 70 ̊C, whereas the tinctures were diluted in 70 % EtOH. The total polyphenol content was determined by UV-Vis spectroscopy using the Folin-Ciocalteu method. Preliminary chromatography analyses by LC-MS on two propolis samples from Québec showed that the detected polyphenols and pesticides in their extracts were very similar, with only a few compounds found exclusively in either one or the other sample. Several raw propolis samples, their extracts and some tinctures were analyzed by ICP-MS and CVAFS to determine trace concentrations of heavy metals including As, Cd, Pb and total Hg.

[pt] O tiomersal é um composto organomercurial usado como conservante em vacinas. Sua degradação sob exposição luz visível ou ao UV produz ácido tiosalicílico, ácido ditiobenzóico e etilmercúrio. A inclusão do tiomersal em composições vacinais é controversa, pois alguns estudos apontam sua correlação com neurotoxicidade, porém, outras investigações ressaltam a sua segurança. O objetivo desse estudo foi avaliar o grau de degradação do tiomersal sob influência de luz, pH, temperatura e material da embalagem, mediante a comparação de três técnicas analíticas. Adicionalmente, foi avaliado o efeito de excipientes vacinais. Conduziu-se uma investigação, inicialmente por espectrofotometria de absorção molecular no UV-vis, em relação à foto-exposição e presença dos excipientes. Para apoiar a confiabilidade dos resultados, testes estatísticos foram realizados. Para a análise da formação de quantidades ultra-traço de espécies mercuriais (etilmercúrio e mercúrio inorgânico), técnicas de maior sensibilidade como a espectrometria de absorção atômica e de fluorescência atômica acoplada à cromatografia gasosa foram utilizadas. Os resultados revelaram degradação do tiomersal sob exposição ao UV. A presença de excipientes durante a foto-irradiação demonstrou efeitos variados na estabilidade do tiomersal, com alguns excipientes favorecendo a degradação. Além disso, o material do recipiente foi relevante e as variações de temperatura e pH não afetaram significativamente a estabilidade. O tiomersal manteve-se estável na maioria dos testes que envolvia condições reais de armazenamento de vacinas. Essas descobertas contribuem para a compreensão do comportamento do conservante frente a fatores potenciais que influenciam sua estabilidade, subsidiando o desenvolvimento e armazenamento de vacinas, garantindo sua eficácia e segurança. / [en] Thiomersal is an organomercury compound used as a preservative in vaccines. Its degradation under exposure to visible light or UV produces thiosalicylic acid, dithiobenzoic acid and ethylmercury. The inclusion of thiomersal in vaccine compositions is controversial, as some studies indicate its correlation with neurotoxicity, , however, other investigations emphasize its safety. The objective of this study was to evaluate the degree of degradation of thiomersal under the influence of light, pH, temperature and packaging material, by comparing three analytical techniques. Additionally, the effect of vaccine excipients was evaluated. An investigation was conducted, initially by UV-vis molecular absorption spectrophotometry, regarding photo-exposure and the presence of excipients. To support the reliability of the results, statistical tests were performed. To analyze the formation of ultra-trace amounts of mercury species (ethylmercury and inorganic mercury), highly sensitive techniques such as atomic absorption and atomic fluorescence spectrometry coupled to gas chromatography were used. The results revealed degradation of thiomersal under UV exposure. The presence of excipients during photoirradiation demonstrated varying effects on the stability of thiomersal, with some excipients favoring degradation. Furthermore, the container material was relevant and variations in temperature and pH did not significantly affect stability. Therefore, thiomersal remained stable in most tests involving real vaccine storage conditions. These findings contribute to the understanding of preservative behavior in the face of potential factors that influence its stability, supporting the development and storage of vaccines, ensuring their efficacy and safety.

A series of para-substituted acetophenones bearing a furanyl or a thiophenyl moiety show a large Stokes-shift, which is a function of various solvent properties. Photophysical properties such as emission lifetime of the compounds have been determined using time-correlated-single photon counting to secure the intrinsic fluorescence behaviour. The solvent dependent position of the UV/Vis emission band [small nu, Greek, tilde]max,em of the compounds has been measured in 26 various solvents. The influence of the solvent on [small nu, Greek, tilde]max,em is of very complex nature and mathematically analysed by multiple square linear solvation energy (LSE)-correlation analysis using Catalán's four-solvent parameter set. Solvent acidity has a strong influence on the bathochromic shift of 2,5-disubstituted furan derivatives compared to the non-5-substituted furan and thiophene derivatives, which show a contrary behaviour. Therefore, the 5-cyanofuranyl-substituted acetophenone derivative is useful as a probe for measuring environmental properties by fluorescence spectroscopy. / Dieser Beitrag ist aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.

Pour notre travail de thèse, nous avons établi une méthodologie, basée sur la DFT et sa variante dépendante du temps, qui permet l'évaluation efficace et la prédiction rapide des couleurs de différentes familles de colorants carbonylés dans différents environnements. Ainsi, nous sommes capables de fournir des valeurs théoriques très précises pour les énergies de transition des dérivés de l'anthraquinone, de la coumarine et de l'indigo ainsi que du thioindigo. Notre stratégie prend en compte aussi bien les effets de solvatation, dans le cadre d'une modélisation en continuum, que les effets du pH, sur la position de la bande d'absorption maximale du spectre UV/VIS. / The project of the Ph. D. work consists in the elaboration of a theoretical methodology able to evaluate and predict the color of organic dyes (see the List of recent publications for more details). Our methodology takes into account the solvent effects as well as the pH impact on the color of the dyes. The theoretical tools used are the Density Functional Theory (DFT, for ground-state optimization) and the Time Dependent TDDFT for excitation spectra calculations. The solvent effects are taken into account via the PCM (Polarizable continuum Model).

Die Suche nach neuen Materialien von technischem Interesse hat in den letzten Jahren neue Antriebe zu der Untersuchung organischer Verbindungen gegeben. Organische Substanzen haben viele Vorteile wie z.B. die Möglichkeit, ihre Eigenschaften durch verschiedene chemische und physikalische Techniken im Herstellung-Prozess für ein bestimmtes Ziel zu modifizieren. Oxadiazolverbindungen sind interessant aufgrund ihrer Nutzung als Material für Licht emittierende Dioden und Scintillatoren. <br /> <br /> Die physikalischen Eigenschaften eines Festkörpers hängen von seiner Struktur ab. Unterschiedliche Strukturen entwickeln unterschiedliche intra- und intermolekülare Wechselwirkungen. Eine ausgezeichnete Weise, um sowohl die intra- als auch die intermolekularen Wechselwirkungen eines bestimmtes Stoffes zu beeinflussen, ohne seine chemischen Charakteristiken zu ändern, ist die Verwendung von hohem Druck. <br /> <br /> Wir haben den Einfluss von hohem Druck und hoher Temperatur auf die super-molekulare Struktur einiger Oxadiazolverbindungen im kristallinem Zustand untersucht. Aus diesen Untersuchungsergebnissen wurde eine Zustandsgleichung für diese Kristalle bestimmt. Überdies wurden die spektroskopischen Eigenschaften dieser Materialien unter hohem Druck charakterisiert. / In recent years the search for new materials of technological interest has given new impulses to the study of organic compounds. Organic substances possess a great number of advantages such as the possibility to adjust their properties for a given purpose by different chemical and physical techniques in the preparation process. Oxadiazole derivatives are interesting due to their use as material for light emitting diodes (LED) as well as scintillators. <br /> <br /> The physical properties of a solid depend on its structure. Different structures induce different intra- and intermolecular interactions. An advantageous method to modify the intra- as well as the intermolecular interactions of a given substance is the application of high pressure. Furthermore, using this method the chemical features of the compound are not influenced.<br /> <br /> We have investigated the influence of high pressure and high temperature on the super-molecular structure of several oxadiazole derivatives in crystalline state. From the results of this investigation an equation of state for these crystals was determined. Furthermore, the spectroscopical features of these materials under high pressure were characterized.

Im Rahmen dieser Arbeit wurden Siliciumkomplexe mit dianionischen Pyrrol-2-carbaldimin-funktionalisierten N,N,O- und N,N,N,N-Chelatliganden synthetisiert und kristallografisch, NMR- und UV/Vis-spektroskopisch und mittels quantenchemischer Berechnungen charakterisiert. Die pentakoordinierten Si-Komplexe mit N,N,O-Ligandrückgraten wiesen in Abhängigkeit von den weiteren Si-gebundenen Substituenten unterschiedlich konfigurierte verzerrt trigonal-bipyramidale Si-Koordinationssphären auf. Die Ursache der Farbigkeit dieser Verbindungen konnte mittels quantenchemischer Berechnungen detailliert erklärt werden. – Die Si-Komplexe mit N,N,N,N-Ligandrückgraten liegen in Abhängigkeit von den weiteren Si-gebundenen Substituenten als 5-fach koordinierte kationische oder neutrale 6-fach koordinierte Si-Komplexe vor. Deren Farbigkeit wurde mittels UV/VIS-Spektroskopie untersucht. Von ausgewählten Komplexen wurden die Tensoren der 29Si-NMR-Verschiebung rechnerisch und CP/MAS-NMR-spektroskopisch bestimmt.