National Repository of Grey Literature 18 records found  1 - 10next  jump to record: Search took 0.01 seconds. 
Mathematical analysis in mass spectrometry
Vlachová Hutová, Eliška ; Adam, Vojtěch (referee) ; Valla, Martin (advisor)
In this bachelor work, there is theoretically described the principle of mass spectometry and tandem mass spectometry, usage the method in practices and description of functionality of separate analysers. Next, there is also mentioned the description of mass spectrum and the algorithm to its analysis. Practical part of the work describes the creation of analytic tool to evaluate spectrum and following usage of this programming tool for the practical analysis of flavonoid compounds, concretely isoflavonoid.
Study of the occurrence of colistin in soil
Veldamonová, Aneta ; Zlámalová Gargošová, Helena (referee) ; Mravcová, Ludmila (advisor)
Colistin is a polypeptide antibiotic used as a "last resort" effective against Gram-negative bacteria. However, increase in its consumption in veterinary medicine in the last 30 years has led to the development of bacterial resistance even to colistin. The application of slurry to soil containing unmetabolized colistin and resistant bacteria poses a risk, because the resistance of bacteria to colistin can be further developed and spread to other components of the environment. Therefore, this work was focused on the creation and optimization of extraction and analytical methods for soil samples containing colistin. Colistin was detected by liquid chromatography in connection with mass spectrometry (HPLC/MS and UPLC/MS/MS). Many extraction solutions have been tested in connection with ultrasonic extraction and purification on various SPE columns, yet colistin has not been successfully extracted from the soil. Colistin was successfully detected only in the slurry extract. The reason why colistin was not detected in soil extracts could be the sorption of colistin on soil organic matter or the formation of complexes of colistin with humic substances.
Study of selected antibiotics sorption on polyhydroxybutyrate
Amrichová, Anna ; Doležalová Weissmannová, Helena (referee) ; Řezáčová, Veronika (advisor)
The bachelor thesis deals with the issue of sorption of antibiotics on microplastics. Antibiotics and microplastics are now a highly studied topic, due to the positive and negative properties. Antibiotics with groups of sulfonamides and quinolones were selected for the experiment. From sulfonamides, sulfamethoxazole and trimethoprim were selected, and from the quinolones, enrofloxacin and ciprofloxacin, which have already been the impetus for some microplastic studies. Biodegradable polyhydroxybutyrate was used as the microplastic. Two experiments were performed in the laboratory. The first aimed to monitor the time dependence of antibiotic sorption on polyhydroxybutyrate, the second the concentration. The concentration dependence was subsequently evaluated using the Freundlich and Langmuir isotherms. The method of liquid chromatography with mass spectrometry was used for analyzes.
Analysis of flavonoids in beer by LC-MS
Měřínská, Radana ; Kočí, Radka (referee) ; Márová, Ivana (advisor)
Presented diploma thesis is focused on analysis of phenolic compounds in various types of beers. The aim of this work was to find possible differences among several types of beers and also between Czech beers and beers of foreign production. Theoretical part contains detailed description of beer technology, review of important analytical methods for determination of phenolic compounds and total antioxidant activity. The main attention is focused on instrumental technique LC/MS. In the experimental part values of total phenolics and total flavonoids and results of antioxidant status in analyzed beers were determined spectrophotometrically. Basic brewing characteristics were determined by pycnometry. On-line liquid chromatography with photo diode array detection and mass spectrometry detection was used for identification and quantification of individual phenolic compounds. Spectrophotometric analysis of phenolic and flavonoid levels seems to be less specific, that is consistent with findings in accessible literature. It was proved, that iso- bitter compounds exhibit about 65.44 – 90.93 % of the total bitter substances. These components are responsible for the main part of beer bitterness. The HPLC/PDA/ESI-MS was necessary to use for determination of characteristic phenolic compounds in individual types of beer. Within our measurement three columns were tested, the most favourable results were obtained using the column Restek C18. When compared with foreing beers, in Czech beers higher level of majority of phenolic compounds was detected and specific distribution of individual derivatives was found as well.
Analytical methods for verifying the authenticity of the wine
Flegr, Šimon ; Štursa, Václav (referee) ; Diviš, Pavel (advisor)
This bachelor’s thesis deals with the authenticity of wine, focusing on the authenticity of geographic origin. The theoretical part of this work summarises the main components of wine and their changes during the production proces. Control techniques are introduced, including the ones used by the goverment’s control bureau (SZPI) and other documented methods. Areas recognised for growing wine are described, including the Morava area in Czechia and its imminent adjacent areas in Austria and Slovakia. Experimental part deals with the trace amount analysis of selected elements and phenolic compounds. The element analysis was conducted using mass spectrometry and optical emission spectrometry, whilst the phenolic compounds were separated using high-pressure liquid chromatography with spectrophotometric detection. The results were analysed using discrimination analysis to separate groups with different areas of origin, with the aid of data from former research.
Study of selected antibiotics sorption on polyhydroxybutyrate
Amrichová, Anna ; Doležalová Weissmannová, Helena (referee) ; Řezáčová, Veronika (advisor)
The bachelor thesis deals with the issue of sorption of antibiotics on microplastics. Antibiotics and microplastics are now a highly studied topic, due to the positive and negative properties. Antibiotics with groups of sulfonamides and quinolones were selected for the experiment. From sulfonamides, sulfamethoxazole and trimethoprim were selected, and from the quinolones, enrofloxacin and ciprofloxacin, which have already been the impetus for some microplastic studies. Biodegradable polyhydroxybutyrate was used as the microplastic. Two experiments were performed in the laboratory. The first aimed to monitor the time dependence of antibiotic sorption on polyhydroxybutyrate, the second the concentration. The concentration dependence was subsequently evaluated using the Freundlich and Langmuir isotherms. The method of liquid chromatography with mass spectrometry was used for analyzes.
Study of the occurrence of colistin in soil
Veldamonová, Aneta ; Zlámalová Gargošová, Helena (referee) ; Mravcová, Ludmila (advisor)
Colistin is a polypeptide antibiotic used as a "last resort" effective against Gram-negative bacteria. However, increase in its consumption in veterinary medicine in the last 30 years has led to the development of bacterial resistance even to colistin. The application of slurry to soil containing unmetabolized colistin and resistant bacteria poses a risk, because the resistance of bacteria to colistin can be further developed and spread to other components of the environment. Therefore, this work was focused on the creation and optimization of extraction and analytical methods for soil samples containing colistin. Colistin was detected by liquid chromatography in connection with mass spectrometry (HPLC/MS and UPLC/MS/MS). Many extraction solutions have been tested in connection with ultrasonic extraction and purification on various SPE columns, yet colistin has not been successfully extracted from the soil. Colistin was successfully detected only in the slurry extract. The reason why colistin was not detected in soil extracts could be the sorption of colistin on soil organic matter or the formation of complexes of colistin with humic substances.
Utilization of mass spectrometry for analysis of biologically active compounds
Kaliba, David
This PhD thesis provides a commented set of four publications. These publications are focused on capillary electrophoresis, liquid chromatography, and UV/Vis spectrometry used to study complexes of rhenium with aromatic ligands. The methods of mass spectrometry with soft ionization techniques, 1 H and 13 C nuclear magnetic resonance, and infrared spectrometry were used for structural characterization of the individual complexes. The complexes were synthetized in reactions of the rhenium precursor tetrabutylammonium tetrachlorooxorhenate with the corresponding ligand under both aerobic and anaerobic conditions. In the course of the research, it was revealed that the prepared complexes (with Re in the oxidation number +V and +VI) are unstable and their oxidation numbers change to another more stable form (Re+VII ). Sub-projects which were successfully implemented during the research were as follows:  Design and successful realization of the process of synthesis of selected rhenium complexes with aromatic ligands 1,2-dihydroxybenzene, 1,2,3-trihydroxybenzene, and 2,3-dihydroxynaphthalene in reactions with and without air access, and their structural characterization by ESI-MS, APPI- MS, LDI-MS, ESI-MS/MS, NMR, and IR.  ESI-MS SRM and UV/Vis time studies of the behaviour of primary rhenium complexes...
Proteomic analysis of soluble and transmembrane proteins in human lymphoma cells
Vít, Ondřej
In the works presented here, we studied molecular changes associated with drug resistance in human mantle cell lymphoma (MCL) cells using proteomics. Our analyses allowed us to identify causal and/or secondary changes in protein expression associated with the development of resistance to the experimental drug TRAIL and the clinically used antimetabolites cytarabine and fludarabine. Resistance of MCL cells to the recombinant proapoptotic cytokine TRAIL was associated with downregulation of key enzymes of purine metabolism. This pathway potentially represents a molecular weakness , which could be used as a therapeutic target for selective elimination of such resistant cells. Resistance to the pyrimidine analog drug cytarabine was associated with cross-resistance to other antinucleosides. Proteomic and transcriptomic analyses showed pronounced downregulation of deoxycytidine kinase (dCK), which activates both purine and pyrimidine antinucleosides. This change explains the cross-resistance and is the causal mechanism of resistance to cytarabine. Our observations suggest that MCL patients, who do not respond to cytarabine-based therapy, should be treated with non-nucleoside drugs. MCL cells resistant to purine-derived antinucleoside fludarabine were cross-resistant to all tested antinucleosides and also...
Utilization of mass spectrometry for analysis of biologically active compounds
Kaliba, David
This PhD thesis provides a commented set of four publications. These publications are focused on capillary electrophoresis, liquid chromatography, and UV/Vis spectrometry used to study complexes of rhenium with aromatic ligands. The methods of mass spectrometry with soft ionization techniques, 1 H and 13 C nuclear magnetic resonance, and infrared spectrometry were used for structural characterization of the individual complexes. The complexes were synthetized in reactions of the rhenium precursor tetrabutylammonium tetrachlorooxorhenate with the corresponding ligand under both aerobic and anaerobic conditions. In the course of the research, it was revealed that the prepared complexes (with Re in the oxidation number +V and +VI) are unstable and their oxidation numbers change to another more stable form (Re+VII ). Sub-projects which were successfully implemented during the research were as follows:  Design and successful realization of the process of synthesis of selected rhenium complexes with aromatic ligands 1,2-dihydroxybenzene, 1,2,3-trihydroxybenzene, and 2,3-dihydroxynaphthalene in reactions with and without air access, and their structural characterization by ESI-MS, APPI- MS, LDI-MS, ESI-MS/MS, NMR, and IR.  ESI-MS SRM and UV/Vis time studies of the behaviour of primary rhenium complexes...

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