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Diaphragm discharge in organic dye solutions
Pajurková, Jana ; Možíšková, Petra (referee) ; Kozáková, Zdenka (advisor)
This Diploma thesis was focused on the degradation of dyes Saturn Red L4B (Direct Red 79) and Saturn Blue LB (Direct Blue 106) by DC diaphragm discharge (DC-DD). Supplied power was between 160 and 180 W. Conductivity and pH were changing at each electrode area during the DC diaphragm discharge, therefore the effect of pH and conductivity changes on the dye solution itself were examined. All samples were measured by UV-VIS spectrometer in the wavelength range of 300–800 nm. No significant dependence of dye absorption spectra on conductivity was observed, while pH significantly affected the absorption curves of dyes. Ageing of dye spectra showed significant changes of Saturn Red L4B. Next task was the comparison of dyes destruction efficiency by DC-DD, audiofrequency diaphragm discharge (AF-DD) and electrolysis. Dye decomposition by AF-DD was not observed at set conditions (voltage of 80–120 V, current of 2.2 A and frequency of 2 kHz). In the case of DC diaphragm discharge the electrolysis played an important role. Decomposition efficiency of the dyes by electrolysis was up to 15 %. The pumping effect in the DC diaphragm discharge was also investigated. Although the individual electrode areas were linked only by a small pinhole in a nonconductive barrier (the pinhole diameter of 0.3 mm), solutions of the anode and cathode compartment interacted with each other up to 10 %. Finally, the degradation products of Saturn Red L4B treated by DC-DD in two electrodes parts are also described. Decomposition products were determined by high performance liquid chromatography (HPLC) combined with the mass spectrometer.
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Study of Pharmaceuticals Degradationby Advanced Oxidation Processes
Bílková, Zuzana ; Čáslavský, Josef (referee) ; Beklová, Miroslava (referee) ; Zachariášová,, Milena (referee) ; Vávrová, Milada (advisor)
At present, the issue of occurrence of female sex hormones, estrogens and progestogens, in aquatic ecosystems is often discussed by experts and the general public. These substances of steroid structure can be difficult to remove completely by conventional wastewater and drinking water treatment technologies. In given context advanced oxidation processes based on in situ generation of highly reactive hydroxyl radicals can be a suitable technique. This thesis deals with the study of kinetics and degradation products of photocatalytic decomposition of seven female sex hormones (estrone, -estradiol, estriol, ethinylestradiol, diethylstilbestrol, progesterone and norethindrone). Experiments were conducted in a laboratory glass reactor, which was equipped with an energy efficient UV-A LED light source (365 nm emission wavelength) and an immobilised photocatalyst in a form of TiO2 five-layer film deposited on glass. Model samples of water with the initial hormone concentration of 1 mg·L-1 were used and the degradation process was monitored by an HPLC-MS method. In the given system all compounds of interest except estriol had very significant tendency to be adsorb. In the case of estriol the formal rate constant of photocatalytic decomposition was determined based on the Langmuir-Hinshelwood model for two different initial concentrations, 0.5527 hour-1 (1 mg·L-1) and 0.1929 hour-1 (5 mg·L-1), and by comparison of these values it was found that the higher degraded compound concentration, the slower decomposition (fivefold increase of the initial concentration resulted in the constant decrease to almost one-third). Moreover nine degradation products of estriol photocatalytic decomposition were recorded and their structure was designed based on mass spectra. In the second thematic part of the thesis attention was paid to development of a SPE-HPLC-MS method for simultaneous determination of female sex hormones in water ecosystems, with emphasis on an extraction part optimization. The final samples treatment process included besides extraction with Supel™ Select HLB 200 mg SPE cartridges also mechanical impurities removal, hormones extraction from solids trapped on filtration material, sample acidification and extract purification with Supelclean™ ENVI-Florisil® cartridges. Optimised method was used for determination of female sex hormones in two Brno rivers, Svitava and Svratka. In the most cases the concentration was below the detection or quantification limit.
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Stability of selected mycotoxins in beer
Štáblová, Taťána ; Benešová, Karolína (referee) ; Běláková, Sylvie (advisor)
Mycotoxins are secondary metabolites of moulds, which attack cereals, for example barley, from which mycotoxins then get to beer. This submitted work is focused on ochratoxin A, deoxynivalenol and zearalenone, which can occur in beer. The first part of this master’s thesis consists of literary research, which describes mycotoxins in general, points out their occurrence, prevention of their formation and delivers information about their physical and chemical properties and toxicity. Furthermore, the research contains basis of malt and beer technology, the occurrence of mycotoxins in beer and raw materials for its production. The research describes changes in concentration of mycotoxins across malt and beer production. The next part deals with possibilities of determination of mycotoxins in barley, malt and beer, compares individual methods of their determination and points out many difficulties of some analyses. The experimental part of this work pursues determination of ochratoxin A, deoxynivalenol and zearalenone in different types of beer with the help of UPLC-FLR, HPLC-MS and ELISA. Instrumental techniques are validated and gathered results are compared with the results in literature. The goal of this master’s thesis is to assess the stability of ochratoxin A and deoxynivalenol in beer over time. The gained results show that there are changes in the concentration of ochratoxin A over time, nevertheless those changes show no pattern. Overall, there was a decrease in concentration in 47 % of the samples and an increase in 28 % of them. In the rest of the samples the concentration did not change. The concentration of deoxynivalenol does not change over time. One of the other goals of this thesis is monitoring of selected mycotoxins in beer. The average concentration of ochratoxin A in the samples was 39 ng/l and deoxynivalenol 9,9 g/l. Zearalenone did not occur in any of the samples when determined by liquid chromatography. All results agree with literature. Next, the thesis compares different analytical methods for determination of ochratoxin A, deoxynivalenol and zearalenone. The screening method ELISA is compared to UPLC-FLR and HPLC-MS. The determination of ochratoxin A by ELISA has shown to be time consuming, nevertheless the results responded to instrumental technique. ELISA overestimated the results of determination of deoxynivalenol in beer by 363–697 % and with zearalenone there were found false positive results.
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Stanovení flavonoidních látek ve vybraných druzích léčivých rostlin používaných v potravinářství
Bačová, Romana
In plant and food research the functional significance of herbs, spices and other plants, including their components is very popular topic. Plant material contains many components that are beneficial to human health by reducing the risk of chronic degenerative diseases. It is necessary to define the individual substances to understand and explain their biological effects. The first part of thesis describes the selected plants (elderberry, nettle, marigold, milk thistle, sea buckthorn, sage, purple coneflower and thyme) and also describes their medicinal properties and uses. The second part of thesis deals with phenolic and flavonoid substances. In the third (experimental) part, of thesis there were qualitatively and quantitatively determined flavonoid compounds in selected plant species. For identification the technique combining liquid chromatography and mass spectrometry - HPLC/MS was used. Extraction was carried out by vortexing and Soxhlet method, using two different concentrations of metanol. These metods were then statistically compared.
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Electrochemical oxidation of ibuprofen
Bolíková, Markéta ; Křížek, Tomáš (advisor) ; Kozlík, Petr (referee)
- 4 - Abstract This diploma thesis deals with the electrochemical oxidation of the active pharmaceutical ingredient ibuprofen as one of the parts of the stability studies of pharmaceutical products. The task is to ensure optimal conditions for the course of electrochemical oxidation, which produces the largest percentage of degradation products, to compare the flow and static experimental setup and its effect on the result of electrochemical oxidation and to identify the resulting degradation products. The examined conditions include the pH of the buffer used to dissolve ibuprofen, the potential applied to the working electrode and the duration of oxidation. Ultra-high performance liquid chromatography coupled with mass detection was used to separate and determine degradation products. Acquity UPLC BEH C18 (2.1 × 100 mm; 1.7 µm) was chosen as the separation column. The mobile phase consisted of an aqueous component (10mM ammonium formate with pH 3.0) and an organic component (acetonitrile). Detection was performed using a photodiode array detector at a wavelength of 222 nm and a quadrupole mass detector in the scan range m/z 50-400. The electrochemical oxidation was performed in a radial electrochemical flow cell and the conditions under which the largest percentage of degradation products formed were as...
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Analysis of historical pharmaceutical preparation containing chicory from the 18th century
Lener, Tomáš ; Nesměrák, Karel (advisor) ; Kubíčková, Anna (referee)
A historical pharmaceutical preparation - chicory extract - from the 18th century whose authenticity was investigated was qualitatively analyzed using HPLC with UV/VIS and MS2 detection. A current dry chicory root was used as a source of selected chicory chemotaxonomic markers and an indicator of the success of extraction with different solvents. The authenticity of the historical extract was proved by a water solubility test. A VIS spectrometric determination of inulin was used and the inuline content was determined to be 52.4% in the current dry chicory root and 7.45% in the historical extract. The detection wavelength 254 and 320 nm was selected from measured UV/VIS spectra of selected standards and the literature. The authenticity of the historical chicory extract was proven by tandem mass spectrometry, and, moreover, arteincultone - a new chicory chemotaxonomic marker - was identified. Key words: HPLC-MS, HPLC-UV/VIS, UV/VIS Spectrometry, Chicory, Historical extract, Chicory root, Arteincultone
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Posttranslational modification of proteins - their analysis and physiological aspects
Mikulíková, Kateřina ; Mikšík, Ivan (advisor) ; Bílková, Zuzana (referee) ; Glatz, Zdeněk (referee)
This thesi s is eoneerned with the deteetion of posttranslational modifieation of proteins. These proteins are identified using liquid ehromatography and eapillary eleetrophoresis, their eoupling and eoupling to mass speetrometry. The first part of the theoretieal ehapter is devoted to the strueture, classifieation and metabolits ehanges of proteins in the human body. Major attention is foeused on eollagen, its strueture and individual eollagen types. The seeond part eonsiders the problems of nonenzymatie glyeation and its influenee on the body and engage in produets of posttranslational modifieation. The third part summarizes the individual separation proeedures and analysis of posttranslationaly modified proteins. The seeond ehapter deseribes experimental parameters, including ehemieals, instrumentation, materials and methods. The preparation of individual samples is also deseribed. All results and findings are summarized and diseussed in the last ehapter. This ehapter is divided in two parts. The first part foeuses on problems of in vivo experiments. The seeond part foeuses on problems of in vitro experiments. Powered by TCPDF (www.tcpdf.org)
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Determination of niacin and its metabolites by HPLC-MS
Pultarová, Kamila ; Čabala, Radomír (advisor) ; Staňková, Barbora (referee)
Nicotinic acid (NA) is a hypolipidemic agent with pleiotropic effects on plasma lipoproteins. Its medicamentous form with delayed secretion leads to pyrimidine metabolites, which make increased risk of hepatotoxicity and should be monitored. The aim of the presented study was to introduce HPLC-MS method for the determination of NA, nicotinamide (NAM), nicotinuric acid (NUA), 1-methyl-nicotiamide (MNA), nicotinamid-N-oxide (NNO), 1-methyl-2-pyridon-5-carboxamide (2-Pyr) and 1-methyl- 4-pyridon-5-carboxamide (4-Pyr) in blood plasma useful for the monitoring of hypolipidemic therapy. We have compared calibration dependences of individual metabolites using two columns - Hypercarb (grapfite carbon) and Hypersil Silica (silicagel). Both columns revealed linear calibration dependences for all mentioned analytes except MNA in the concentration range 10-2000 ng/ml for chemical standards; calibration dependence in human blood plasma measured with the column Hypersil Silica was linear in the range 20-4000 ng/ml for all tested analytes. Correlation coefficient varied between the value 0,9400 and 0,9997. Analysis time was 15 min with the column Hypercarb and 27 min with Hypersil Silica. Biological samples were extracted using solid phase with sulphonyl group. Reproducibility of the results of biological samples...
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The Preparation and the Characterization of the Cationic Liposomes Carrying New Immunoadjuvant.
Houšť, Jiří ; Nesměrák, Karel (advisor) ; Kozlík, Petr (referee)
The aim of this diploma thesis was preparation, characterization and determination of encapsulation efficiency of the cationic liposomes composed of dimethyldioctadecylammonium bromide (DDAB) and cholesterol carrying new drug MT05 with an immunoadjuvant effect. The influence of the temperature of sonication bath and the influence of the volume of liposomal suspension on the average size of liposomes and their polydispersity index was monitored. The most effective liposome preparation by sonication bath was at temperature of 60 řC. The volume of liposomes undergoing sonication did not influence the resulting values of the average size of liposomes and their polydispersity index. The time of sonication time was 6 hours and could be shortened by using sonication bath with higher output. The determination of encapsulation efficiency was carried out in three separated experiments by HPLC-MS/MS. The encapsulation efficiency of the cationic liposomes was 30.1 ± 8.5 % in the first experiment, 43 ± 25 % in the second, and 32 ± 25 % in the third. The amount of DDAB was determined only in the liposomes prepared in the third experiment. The amount of DDAB in the purified liposomes was 78.9 ± 3.7 % in the first replicate, 65.4 ± 1.8 % in the second and 53.8 ± 1.4 % in the third. The actual molar ratio of MT05...
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Analysis of products of cardanol metathesis by HPLC-MS/MS method
Flenerová, Zuzana ; Čabala, Radomír (advisor) ; Vrkoslav, Vladimír (referee)
Cardanols are more and more used in the industry of polymers, resins, coatings, friction materials, etc. At right conditions, these lipid-like chemicals can undergo metathesis reaction. The main aim of the diploma thesis is an analysis of products of cardanol metathesis by HPLC-MS/MS. Standard 3,3'-hexadec-8-en-1,16-diyldiphenol, one of the main products of cardanol metathesis, was prepared for quantitative HPLC analysis. The standard was prepared in two steps. The first step was cardanol ethenolysis to give 3-(non-8-enyl)phenol. The second step was self-metathesis of 3-(non-8- enyl)phenol to give 3,3'-hexadec-8-en-1,16-diyldiphenol. The standard was characterised by HPLC/MS, MS/MS, EI-MS, UV/VIS, IR, Raman a NMR spectroscopy. The second part of the thesis is dedicated to the study of a mechanism of double-bond localization method in long chain hydrocarbons by acetonitrile APCI-MS. The formation of adducts [M + 55]+ , which are the key substances of this method, was studied using simple alkene models by MS and MS/MS. At the end, the structure and the mechanism of the formation of adducts [M + 55]+ were suggested. Key words: Cardanol, olefin metathesis, HPLC-MS, double-bond localization, APCI, acetonitrile
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