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Analysis of pesticides in the environment using the QuEChERS method
Vašinková, Alena ; Řezáčová, Veronika (referee) ; Mravcová, Ludmila (advisor)
This thesis focuses on pesticides in the environment, more specifically in cereals. Pesticides were monitored in various samples of cereals (barley, rye, oats, and wheat) within the thesis. The monitored substances were isolated in selected samples and concentrated using the QUECHERS method. Gas and liquid chromatography were used to determine pesticides. The theoretical part consists of the common types of pesticides, divided by the ease with which these substances into food and their impact on humans and environment. It also mentions current health protection legislation and environmental legislation.
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Use of various extraction techniques for the analysis of biochar extracts
Jakubčeková, Kristína ; Řezáčová, Veronika (referee) ; Mravcová, Ludmila (advisor)
Biochar is a material whose properties, composition and impact on the environment are often discussed nowadays. The reason is its application as a soil conditioner. This leads to the need for qualitative as well as quantitative knowledge of its composition. This diploma thesis focuses on the qualitative analysis of biochar leachates processed by various extraction techniques. To approximate the real conditions, six aqueous mediums with different pH values is used, which a solid sample of biochar is exposed to. The prepared leachates are after that processed by extraction techniques, which are solid phase microextraction (SPME), single drop microextraction (HS-SDME), solid phase extraction (SPE) and liquid-liquid extraction (LLE). Analysis of the extracts was performed by gas chromatography-mass spectrometry (GC/MS). The measurements showed that the HS-SDME technique did not show a response. SPE was a rapid technique, but compared to other techniques, it acquired a smaller range of substances. Liquid-liquid extraction, a time-consuming technique, did not obtain as much analytes as SPME. By comparing these applied techniques, the SPME technique is the best choice. The most common determined analytes were those from the group of ketones and carboxylic acids and their derivatives.
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Use of capillary electrophoresis to determine a selected group of flavonoids
Tran Xuan, Tiep ; Mravcová, Ludmila (referee) ; Řezáčová, Veronika (advisor)
In recent years, the use of natural medicinal properties of plants has again come to the forefront of interest of the public. Because of their therapeutic properties, these plants are commonly used in alternative treatments for minor ailments. This thesis deals with the determination of polyphenolic acids in extracts from aronia, echinacea, tetradenia and centella. One of the aims of the thesis was to compare the amount of polyphenolic acids in individual plants with their antioxidant properties. The theoretical part includes a general introduction to flavonoids, introduction to polyphenolic acids, introduction to the principles of capillary zone electrophoresis and a summary of selected foreign studies for the determination of flavonoids. An important chapter of the theoretical part is a description of individual plants with an explanation of their possible therapeutic use. The experimental part is devoted to the process of optimization of electrophoretic determination of selected polyphenolic acids and evaluation of their content. It was found that in the extracts six representatives of polyphenolic acids occur in minimal amounts, often below the limit of quantification or detection of the method.
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The use of ion exchanges for preconcentration of platinum group metals
Sýkora, Jiří ; Řezáčová, Veronika (referee) ; Komendová, Renata (advisor)
The aim of this thesis is the elaboration of a detailed literature review on the use of ion exchangers for the preconcentration of platinum group metals. This work contains an actual literature review on this issue. In this work you will find information about the current occurrence of platinum metals in the environment, their impact on health, properties, resources and the use. There are also described ways of decomposition, extraction and use of ion exchangers. In the experimental part this thesis deals with optimization of ion exchangers and following application of real samples from the city of Brno.
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Thermal lens spectrometric detection of MRI contrast agents in the process of their photocatalytic degradation
Petruľák, Michal ; Řezáčová, Veronika (referee) ; Franko, Mladen (advisor)
Diplomová práce je zaměřena na studium degradace kontrastních látek pro magnetickou rezonanci. Tyto látky se dnes ve velké míře používají v oblastech s rozvinutým zdravotnictvím. Můžeme je najít v odtocích z čistíren odpadních vod, což svědčí o tom, že běžné stupně čištění odpadních vod nejsou dostatečně efektivní pro jejich odstranění. O degradaci kontrastních látek na bázi gadolinia je jen málo informací. Fotokatalytický rozklad za pomoci oxidu titaničitého a také ozonace vybrané kontrastní látky gadobutrolu, byl sledován pomocí měření celkového organického uhlíku, mikroskopie termálních čoček a spektrofotometrie.
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Analysis of volatile organic compounds produced by monocytes during sepsis
Bártová, Adéla ; Řezáčová, Veronika (referee) ; Mravcová, Ludmila (advisor)
This thesis is focused on the possibility of analysis of volatile organic compounds produced by monocytes during sepsis. Method of comprehensive two-dimensional gas chromatography with mass spectrometric detection was chosen for this purpose. Content of the first part was the optimization of the method of two-dimensional gas chromatography for the determination of volatile organic compounds. In this part were gradually adjusted parameters of the gas chromatography method to achieve the maximum efficiency. Further were adjusted conditions of samples preparation. Content of the second part was the usage of already optimized method for the analysis of the samples set of monocytes. Samples were subjected to the action of different inhibitors of the immune system and stimulators simulating bacterial or yeast infection. Based on this analysis were identified some compounds, which are produced by monocytes under condition simulating the infection.
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Ecotoxicological evaluation of selected psychotropic drugs
Hricová, Nikoleta ; Řezáčová, Veronika (referee) ; Zlámalová Gargošová, Helena (advisor)
This bachelor thesis done by literary research is about the issue of the occurence of psychopharmacs in the enviroment. Psychopharmacs such as antidepressants, anxiolytics, hypnotics, sedatives etc. belong to one of the most sold drugs around the world. The consumption of psychopharmacs is concerning and growing. Therofore their occurence in nature is also growing, which can negatively affect the ecosystems. Many studies confirmed the persistency of psychopharmacs in nature, their following bioaccumulation and ecotoxicity for the representatives of each ecosystem. This bachelor thesis describes possible ways of the drug’s intersection (penetration) in nature, the metabolism of psychopharmacs in the human body and the effectivity of their elimination in sewage tanks. This work also focuses on the occurence, stability, degradability and persistency of psychopharmacs in aquatic and in terrestrial enviroment. The consideration of risks in the occurence of psychopharmacs for the representatives of each ecosystems was processed by many ecotoxicological studies, which point out the danger of these substances. Based on this acquired knowledge, in the conclusion of this work, there was drafted a battery of ecotoxicological tests for the estimated effects of psychopharmacs.
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Determination of surfactants by capillary zone electrophoresis.
Tůmová, Klára ; Zemanová, Jana (referee) ; Řezáčová, Veronika (advisor)
Surfactans are synthetically made surface-active ingredients contained in washing and cleaning products. They decrease the surface tension and remove dirt. Surfactans can be divided into four basic classes: anionic, cationic, non-inonic and ampholitic. The most commonly used are the anionic ones. Thanks to the massive use they penetrate into waste water and can disturb the environment. This thesis is focused on the optimization methods and the determination of three anionic surfactants by capillary zone electrophoresis.
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Application of a novel continuous sampler for the determination of compounds in ultrafine aerosol
Hlaváčková, Hana ; Řezáčová, Veronika (referee) ; Alexa,, Lukáš (advisor)
The diploma thesis is focused on the use of new type of continuous sampler for the determination of compounds in ultra-fine aerosol. The aim of the study was to optimize parameters of the aerosol sampler CGU-ACTJU (Condensation-Growth Unit – Aerosol Counterflow Two-Jets Unit) and its application for the real aerosol samples. The ACTJU sampler connected to upstreamed CGU enables sampling of ultra-fine fraction of particulate matter to the diameter about few nanometers. The measured results from CGU-ACTJU were compared with commercial sampler (cascade impactor) with subsequent offline analysis. The atmospheric aerosol was sampled in two campaigns (July–August 2021 and February 2022) on the terrace of Institute of Analytical Chemistry of CAS in Brno. Theoretical part of the study contains information about analytical methods for the characterization of aerosol, the experimental part describes used methods in detail and the results of experiments are discussed.
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