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Analysis of perfluorinated alkyl compounds in environmental matrices
Šimáková, Anna Marie ; Řezáčová, Veronika (referee) ; Mravcová, Ludmila (advisor)
The bachelor thesis deals with the still topical issue of perfluorinated and polyfluorinated substances in the aquatic environment. In the theoretical part, the production and use of PFASs, which has led to the spread of these pollutants into the environment, is first addressed. Then, their behaviour in the environment is presented, which, due to their properties, results in their persistence in the environment, their ability to accumulate in living organisms and, in the case of decomposition, the possibility of even worse impacts. Exposure can result in carcinogens, hormonal changes and various types of toxicity in living organisms. The theoretical part concludes with methods for possible extraction from different matrices and detection by a suitable analytical method. The experimental part deals with the optimization of parameters for the method of determination and extraction of perfluorinated and polyfluorinated substances from water. All parameters were optimized to achieve the highest possible recoveries with acceptable repeatability and to achieve the lowest possible limits of detection and quantification.
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Determination of pesticides in solid environmental matrices
Řepková, Michaela ; Komendová, Renata (referee) ; Mravcová, Ludmila (advisor)
The bachelor thesis deals with the still pressing issue of pesticides in the soil environment. The theoretical part deals with the entry of these pesticide substances into the environment, i.e. their application in various forms to agricultural soil, where they are retained in the soil based on certain factors and subsequently transported from the soil to other components of the environment. As pesticide residues are also present in other parts of the environment, they represent a global problem because of the potential environmental and health risks not only for the human population. Furthermore, the theoretical part deals with the appropriate method for the determination of these pesticide substances in the soil matrix, both a suitable extraction method and a suitable analytical technique. The experimental part primarily focused on the actual determination of these persistent organic pollutants. Pesticides from soil were extracted by one of the most popular extraction methods at present, namely the QuEChERS method. This method has been thoroughly optimised to achieve the lowest possible detection/quantification limits, the highest possible recoveries and good repeatability. The LC-MS/MS method was chosen as the appropriate analytical method for the determination of pesticides in soil extracts.
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Optimization of methods for the analysis of pharmaceuticals residues in different crops
Súkeníková, Kamila ; Zlámalová Gargošová, Helena (referee) ; Mravcová, Ludmila (advisor)
Aim of this thesis is to optimize the extraction method for extracting pharmaceuticals from various types of matrices. Presence of pharmaceuticals in the environment represent an increasing problem, even though they are only found in low concentrations. Therefore, great emphasis is placed on their analysis. Since the concentration of pharmaceuticals is often low and their chemical diversity is large, their analysis presents a significant challenge. For this reason, this thesis is focused on optimizing the extraction method from plant matrices. This optimization is carried out in order to obtain the best possible extraction method, and thus ensuring the highest possible yield of pharmaceuticals from radish, carrot, and mustard matrices. The optimization of the extraction method involved finding the parameters for individual steps of the QuEChERS extraction method that showed the best average yield for all pharmaceuticals.
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Detection of aromatic compounds in plants
Tilešová, Kristína ; Zlámalová Gargošová, Helena (referee) ; Krčma, František (advisor)
This bachelor thesis is focused on the detection of aromatic compounds in plants. Selected plant was Celery (Apium graveolens). In the theoretical part, methods for the volatile substances analysis were reviewed. In the experimental part, celery sample was converted from solid to liquid form and then analyzed using proton-transfer-reaction time-of-flight mass spectrometry (PTR-TOF-MS) and gas chromatography-mass spectrometry (GC/MS). Aromatic compounds with a stronger signal were selected using PTR-TOF-MS, which were analyzed and identified using GC/MS. Monoterpenes represented the main group of compounds in celery seed essential oil, the most important is D-Limonene. Celery also contains phthalides, aldehydes, alcohols, esters. Using a combination of PTR-TOF-MS and GC/MS was obtained the quantitative and qualitative composition of celery essential oil.
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Utilization of pulse labelling techniques for studying the dynamics of proteins and protein complexes
Polák, Marek ; Novák, Petr (advisor) ; Obšil, Tomáš (referee) ; Vrbacký, Marek (referee)
(In English) Mass spectrometry (MS) techniques are routinely used to probe the structure and dynamics of proteins and protein complexes. Although MS techniques lack the high resolution of data provided by X-ray crystallography, NMR, or cryo-EM, they excel in providing insights into analyte dynamics, structure, and interactions with other components, such as ligands. This doctoral thesis presents a contribution to the field of structural biology employing and extending covalent labelling approaches, namely Fast Photochemical oxidation of Proteins (FPOP) and oxidation by singlet oxygen (1 O2). These approaches were followed to study the structure, dynamics, and interaction of proteins, nucleic acids, and protein-DNA complexes in solution. Initially, FPOP was used to investigate the interaction interface of FOXO4 and DAF16-DNA response element and to show the possibilities of analyzing such a complex using both 'bottom- up' and 'top-down' approaches. Furthermore, an isotope depletion strategy combined with multiCASI-ECD proved effective in delivering structural information with the highest possible resolution for mapping protein-DNA interfaces. This research showcases how information derived from structural proteomic methods can guide the construction of in-silico models for protein-DNA complexes with...
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Development of mass spectrometric methods for structural analysis of fatty acids and estolides
Cudlman, Lukáš
(EN) This doctoral thesis summarizes the use of modern mass spectrometric methods for the structural identification of fatty acids and triacylglycerol estolides (TG-EST) and their subsequent characterization in the lipidome of vernix caseosa, i.e., the biofilm covering the skin of the human fetus during the last trimester of in-utero development. Vernix caseosa has mainly antimicrobial properties and the ability to heal wounds and burns. The first part of the doctoral thesis focuses on the diversity of fatty acids in the lipidome of vernix caseosa. These acids form the structural subunits of complex lipids, such as the abundant triacylglycerols and wax esters. By studying fatty acids and their structural features, this thesis has provided valuable insights into the structural variability of the vernix caseosa lipidome. Without a full understanding of the structure of these key subunits, it would be impossible to complete the analysis of this lipidome in the future. In this thesis, fatty acids using high-performance liquid chromatography (HPLC) and modern mass spectrometry methods, namely ultraviolet photodissociation (UVPD) and ozone-induced dissociation (OzID), were characterized. The coupling of HPLC and mass spectrometry (HPLC-MS) provided unambiguous information on the positions and geometry of...
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Monitoring process contaminants in coffee roasting using LC-MS
Ilyushchenkova, Alexandra ; Juglová, Zuzana (referee) ; Diviš, Pavel (advisor)
The bachelor thesis focuses on monitoring changes in the concentration of process contaminants during coffee roasting using liquid chromatography with mass detection. Green coffee was roasted at 220 °C for 14 minutes with two-minute intervals. Samples for analysis were taken from 10. by 24. minutes of roasting. Practical monitoring of the acrylamide’s formation during coffee roasting was not carried out, since it was not possible to detect acrylamide in coffee using a mass detector, even after its derivatization with thiosalicylic acid. The relevant data were taken from other scientific articles, which reported a linear increase in concentration with the roasting time up to the maximum value and a subsequent exponential decrease at the end of roasting. By monitoring 5-hydroxymethylfurfural, it was found that during roasting, this substance is gradually formed in coffee due to the decomposition of carbohydrates, however, with increasing roasting time, the degradation of this substance occurs quite quickly. The concentration of 5-hydroxymethylfurfural was also determined in coffee samples purchased in the trade network. Concentrations of 5-hydroxymethylfurfural in these samples ranged from 0,3 to 0,38 mg/kg, which are corresponded to those reported in other expert studies.
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Study of the use of crops for phytoremediation of contaminated soil by pharmaceuticals
Hamplová, Marie ; Zlámalová Gargošová, Helena (referee) ; Mravcová, Ludmila (advisor)
Pharmaceuticals leaking into the environment from wastewater and livestock farms raise concerns about the impact on the ecosystem and human health. Residues of pharmaceuticals present in soil are subject to a number of biotic and abiotic processes, including uptake, translocation and accumulation by plants. The ability of plants to accumulate or degrade pharmaceuticals could have potential applications in the process of 'phytoremediation', where plants and their associated micro-organisms are used to stabilise, degrade or remove contaminants from the environment. In the framework of this thesis, experiments on phytoremediation of drug-contaminated soil by the cover crop oilseed radish (Raphanus sativus L. var. Oleiformis) under controlled conditions were conducted. Soil samples were extracted by ultrasonic extraction, plant samples by QuEChERS method and the final analysis of drugs was performed by UPLC-MS/MS. Oilseed radish produced a large amount of aboveground biomass compared to the other two crops and the presence of drugs had no negative effect on its growth. However, the determined levels of each drug in the soil and in the crop showed insufficient effectiveness of phytoremediation. The accumulation of drugs by the crop was low except for residues of the antidepressant venlafaxine. Therefore, according to these results, oilseed radish is not a suitable crop for phytoremediation of drug-contaminated soil. Experiments were also carried out with the root vegetable radish (Raphanus sativus L. var. Sativus) and carrot (Daucus carota L.) to assess the risk to human health associated with the accumulation of drugs in vegetable roots. The risk has not been demonstrated in terms of the amount of established drugs in the roots. Only the metabolite clofibric acid accumulated to a higher extent and the antibiotic trimethoprim was the most translocated to the aerial parts of the crop. The rate of uptake and translocation of drugs by the plant depended on many factors, as their content varied considerably between drug groups and between parts and types of crops.
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Studz of direct and indirect plasma application on onion seeding bulbs
Krejsová, Lenka ; Enev, Vojtěch (referee) ; Krčma, František (advisor)
Nowadays, agriculture is based on conventional methods that involve the application of pesticides, agricultural chemicals and fertilizers. These substances have a negative impact on nature and human health, so more environmentally friendly methods are being sought. This thesis deals with the analysis of fragrances in onions treated with plasma before planting. The treatment was carried out to see if it would improve onion growth while maintaining or increasing the fragrance content. The theoretical part deals with the soil and it is characterization methods, plasma, quantitative and qualitative methods for the determination of volatile substances. It contains the principles of UV-VIS spectrometry, atomic absorption spectrometry (AAS), mass spectrometry (MS) as well as tandem connection of gas chromatography with mass spectrometry (GC–MS). The experimental part was carried out over a period of three years at 22 sites. The preparation and analysis of soil samples are described, which was also evaluated. Furthermore, the procedures for treating the bulbs with corona discharge and plasma-activated water before planting were described. In total, four treatment variants were carried out and bulbs from the fifth variant were not additionally treated. Each treatment variant was planted in four replications of ten bulbs each. Twenty selected grown onions from one site were individually converted to liquid samples and the saturated vapor was analysed by proton transfer reaction time of flight mass spectrometry (PTR–TOF–MS). Thanks to this analysis, the concentrations of volatile substances were determined. Some samples were analyzed by gas chromatography with mass spectrometer as detector to identify the compounds. Subsequently, the data were processed and evaluated. From the results obtained, it is evident that plasma treatment can be useful for the treatment of onions in agriculture, because it confirmed harvest increase without decrease of fragrances concentrations. Thus, it is necessary to carry out experiments on a larger scale in the future.
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Development of mass spectrometric methods for structural analysis of fatty acids and estolides
Cudlman, Lukáš ; Cvačka, Josef (advisor) ; Kozlík, Petr (referee) ; Lísa, Miroslav (referee)
(EN) This doctoral thesis summarizes the use of modern mass spectrometric methods for the structural identification of fatty acids and triacylglycerol estolides (TG-EST) and their subsequent characterization in the lipidome of vernix caseosa, i.e., the biofilm covering the skin of the human fetus during the last trimester of in-utero development. Vernix caseosa has mainly antimicrobial properties and the ability to heal wounds and burns. The first part of the doctoral thesis focuses on the diversity of fatty acids in the lipidome of vernix caseosa. These acids form the structural subunits of complex lipids, such as the abundant triacylglycerols and wax esters. By studying fatty acids and their structural features, this thesis has provided valuable insights into the structural variability of the vernix caseosa lipidome. Without a full understanding of the structure of these key subunits, it would be impossible to complete the analysis of this lipidome in the future. In this thesis, fatty acids using high-performance liquid chromatography (HPLC) and modern mass spectrometry methods, namely ultraviolet photodissociation (UVPD) and ozone-induced dissociation (OzID), were characterized. The coupling of HPLC and mass spectrometry (HPLC-MS) provided unambiguous information on the positions and geometry of...
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