National Repository of Grey Literature 39 records found  1 - 10nextend  jump to record: Search took 0.01 seconds. 
Chemical analysis of organic residues in archaeological ceramic vessels
Bunžová, Aneta ; Mravcová, Ludmila (referee) ; Čáslavský, Josef (advisor)
The presented bachelor thesis deals with the analysis of organic residues in archaeological ceramic vessels. Apart from theoretical characterisation of residues, the thesis focuses on the possibility of the extraction of residues and subsequent analysis, which is executed on real samples from archaeological sites. In the research, two different derivatizational reagents were used for the subsequent determination using the technique of gas chromatography in combination with mass spectrometry (GC/MS). The thesis endeavours to certain extent to sketch the diet of the users of the analyzed ceramic vessels.
Analysis of biochar aqueous extracts by separation methods
Tučková, Dominika ; Čáslavský, Josef (referee) ; Mravcová, Ludmila (advisor)
This master's thesis deals with the analysis of biochar extracts by separation methods. All analyzed biochar was produced from waterworks sludge by microwave pyrolysis. The aim of the thesis is the optimization of the sample preparation method and its analysis in a laboratory environment. With the ever-growing world population, the problem of a sustainable economy in both agriculture and waste management is becoming increasingly urgent. This fact has led most countries to consider promoting the so-called Circular Economy. The use of sewage sludge as a feedstock for biochar production is perfectly in line with this strategy. So far, however, the short term and the long term benefits and risks of using biochar have not been sufficiently described. Potentially hazardous organic substances were extracted from the biochar extracts by three techniques: liquid-liquid extraction, solid-phase extraction, and solid- phase micro-extraction. The obtained samples were analyzed using the GS-MS/TOF method. The individual methods were compared. Several biochar samples from WWTP Brno and WWTP Drahovice were selected and analyzed to verify the suitability of the selected sample analysis method.
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.
Removal efficiency of selected drugs by various sorptive materials from water
Štofko, Jakub ; Mravcová, Ludmila (referee) ; Vávrová, Milada (advisor)
This thesis deals with sorption of selected drugs from model water by various sorption materials. Contamination of water resources by the pharmaceutical industry is a major problem today. Wastewater treatment plants, whose technological processes are unable to completely remove them, have a significant share in the penetration of these substances into the environment. At present, attention is paid to alternative materials that are capable of eliminating these substances. One of the potential sorption materials is biochar as one of the main pyrolysis products. This work focused on the assessment of the sorption properties of the different types of biochar and commercially used active charcoal. The sorption properties of the individual materials were compared with respect to the non-steroidal anti-inflammatory substance ibuprofen and the sulphonamide antibiotic sulfamethoxazole. The results of vial experiments were analysed on a liquid chromatograph with mass detection.
Determination of organic compounds in biochar produced by microwave torrefaction of biomass
Meindl, Jiří ; Vávrová, Milada (referee) ; Mravcová, Ludmila (advisor)
The thesis is focused on a determination of polycyclic aromatic hydrocarbons (PAHs) contained in dried pelletized sewage sludge and pelletized biochar. Biochars were made in mild conditions by microwave torrefaction of prepared sewage sludge. There were analyzed and quantified the 34 of standardized PAHs compounds in two series. The first serie, also called “Sada 1”, has been aimed at comparison of extraction methods for the chosen sample of sewage sludge and the sample of biochar. In serie “Sada 1”, there were compared efficiencies of chosen type of solvent or solvent mixture by comparison of yields for 34 standardized analytes in a sample of biochar and a sample of sewage sludge. There were compared also to total yields of PAHs and to number of quantified compounds in analyzed samples. The most reliable extraction method has been used for the next analyses of samples in the second serie called “Sada 2”. In Sada 2, there were compared different samples of the same type (e.g. biochar, sludge). The origin of sewage sludge (small or big sewage treatment plant expressed as PE) and used additives (cellulose, chaff, hay) as modificators for torrefaction process were variables for different type of sample. The results of analysis were identification of the most suitable sewage sludge and additive to be used as modificator for microwave torrefaction process. The main goal of correctly chosen sludge and additive was to minimize production of PAH’s during torrefaction and in samples of biochar.
Study of glyphosate degradation in water plasma application
Sehnalíková, Alena ; Vávrová, Milada (referee) ; Mravcová, Ludmila (advisor)
This work deals with the current problem of increasing concentrations of glyphosate in groundwater and wastewater due to insufficient efficiency of methods used in wastewater treatment. From this point of view effective removing of glyphosate from water have to be developed by new methods and technological processes. The methods used so far in wastewater treatment plants should be replaced or supplemented by advanced oxidation processes. The practical part of this work is devoted to glyphosate and its degradation in water by plasma. Samples were taken sequentially during plasma application and further evaluated by LC/MS selected as suitable analytical methods. The aim of this work was to determine the efficiency of plasma in water with admixture of glyphosate.
Use of derivatization methods in gas chromatography
Brédová, Boglárka ; Řezáčová, Veronika (referee) ; Mravcová, Ludmila (advisor)
This study is focused on verifying the possibility of derivatization in gas chromatography for the determination of fatty acids in oil samples and on the use of derivatization for the determination of organic substances in a sample of vine seed extract. The theoretical part deals with the characteristics of individual analytes. In the next section derivatization methods and transesterifications for fatty acid determination are described. The last chapter deals with the basic knowledge of gas chromatography and its instrumentation. The experimental part was divided into three chapters: analysis of fatty acids by transesterification, determination of mono- , di-, and triglycerides by derivatization and analysis of grape seed extracts. Three types of oils were analyzed in the experimental part: poppy, linseed and nut oil. The most common fatty acids in plant oils are palmitic, stearic, oleic, linoleic and linolenic acids. The optimization method was carried out using the derivatizing agent MSTFA. The determination of fatty acid methyl esters was measured on a gas chromatograph with a flame ionization detector. To confirm the presence of fatty acids, additional analysis was used on gas chromatograph with a mass spectrometer. Analysis of the grape extract was also performed on GC/MS. The method was most convenient using MSTFA, BSTFA and BSA+ TMCS derivatizing agents.
Use of plasma for degradation of ibuprofen in water
Bača, Ondřej ; Landová, Pavlína (referee) ; Mravcová, Ludmila (advisor)
This Bachelor’s thesis deals with the current problem of increasing concentrations of nonsteroidal anti-inflammatory drugs in water. The concentration increase of these drugs is due to rised anti-inflammatory drugs intake in modern era. Wastewater treatment plants are not capable of sufficient elimination of these drugs in wastewater. That leads to contamination of groundwater and surface water. The long-term impacts of these drugs on human health is not fully understood, so it is necessary to develop new methods, which will lead to complete degradation of nonsteroidal anti-inflammatory drugs and other pollutants. Theoretical part of the Bachelor’s thesis focuses on description and properties of nonsteroidal anti-inflammatory drugs and their consumption in the Czech Republic. Furthermore, the paper deals with advanced oxidation processes especially with plasma. This part of the paper also deals with determination of nonsteroidal anti-inflammatory drugs in water. For degradation of ibuprofen was used plasma. During the plasma treatment, samples were taken in regular time intervals, which were afterwards determined by an appropriate analytical method LC-ESI-MS. The results were compared with scientific studies dealing with this topic.
Optimization of the coagulation procedure for wastewater treatment
Švábová, Martina ; Mravcová, Ludmila (referee) ; Repková, Martina (advisor)
This bachelor thesis deals with the optimization of the determination of the chemical oxygen demand in the test tubes and the optimization of the coagulation process for the external company. COD is one of the basic analysis for all types of water, although there are numerous environmentally-unfriendly agents in case of using a standard version produced. Therefore, an alternative method of using the test tubes was used, the procedure of which has been modified from ČSN ISO 15705 and is now available to the public. The aim was also to optimize the coagulation process in the treatment of wastewater from an industrial paintshop. The minimum dose of coagulating agent occurring in the instructions for usage was disproved and the pH value at which aluminium sulfate as a coagulating agent was proposed.
Determination of organic acids in wine
Michálková, Kateřina ; Mravcová, Ludmila (referee) ; Řezáčová, Veronika (advisor)
This bachelor thesis deals with determination of organic acids in wine by capillary zone isotachophoresis method. The theoretical part is devoted to the properties of wine, its composition, its benefit to human health and capillary zone isotachophoresis and its practical use. The practical part deals with determination of organic acids in wine by capillary zone isotachophoresis. Organic acids are determined in three phases of white and red wine production.

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