National Repository of Grey Literature 30 records found  beginprevious21 - 30  jump to record: Search took 0.01 seconds. 
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
Human Hormonal Drugs and their Residuals in Aquatic Ecosystems
Řehounková, Michaela ; Vytlačilová, Jitka (advisor) ; Kašparová, Marie (referee)
Human hormonal drugs are used to adjust the function of the endocrine system, therapeutics of hormone-dependent tumours, or as part of contraceptive and anti-inflammatory preparations. Those pharmaceuticals contain active substances structurally and chemically similar to endogenous hormones. Above mentioned drugs and their residuals can get into the wastewater after they are metabolised in the human body, or by the illegal disposal of them, and they are removed in the wastewater treatment plant (WWTP). The most efficient technologies for removing hormonal drugs, particular oestrogens, from wastewater are ozonolysis and sonolysis. Concentrations in wastewater are determined by gas and liquid chromatography. The concentration of oestrogens in the waters of the Czech Republic (Vltava River) is ranging from 1.3 to 3.8 ng / l, and their levels in drinking water does not mean an increased health risk for consumers. The effects of oestrogen residuals are demonstrable on aquatic organisms, such as changes in the regulation of endocrine system, reproductive disorders and disorders in embryogenesis.
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)
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.
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.
Capillary isotachophoresis with ESI-MS detection: Ultrahighly sensitve analysis of diclofenac and ibuprofen in waters
Malá, Zdeňka ; Gebauer, Petr ; Boček, Petr
This work shows that CE-MS can reach same sensitivity as HPLC-MS, when it is peformed in the ITP-MS mode. By combination of ITP-ESI-MS with an offline SPE preconcentration step and optimization of MS signal collection, LODs below 2x10-12 M can be reached, corresponding to of 0.6 ng/L of diclofenac (Dic) and 0.4 ng/L of ibuprofen (Ibu), compatible to that of SPE-HPLC-MS.
Studium antioxidačních látek u hroznových semen
Tomášková, Lenka
It is known, that grape seeds are rich in significant antioxidant. The issue of dealing with the analysis and comparison of antioxidant components in the seeds of Vitis vinifera in the individual varieties has not been sufficiently studied, yet. In the first part of the thesis is an extensive literature focused on a summary of the work, which study substances in the vine seeds and their effect on human health. Experimental work is focused on the study of antioxidant components in the seeds of Vitis vinifera. The experiment was used extracts of the three "normal" (Frankova, Ryzlink vlašský and Cabernet Moravia) and three interspecific varieties (Nativa, Marlen and Kofranka). Spectrometric, using three fundamentally different methods - DPPH, ABTS and FRAP was determined antioxidant activity . Spectrophotometry was further investigated the content of total polyphenolic compounds and total content of flavanols . Technique of high- performance liquid chromatography with mass spectroscopy were analyzed nine major flavonoids (apigenin, astragalin, hyperoside, isorhamnetin, kaempferol, myricetin, quercetin, quercitrin and rutin) and two procyanidins (procyanidin A2 and procyanidin B1). The highest values of antioxidant reached interspecific varieties Marlen and Nativa, at the least antioxidant components were recorded in the variety Cabernet Moravia. However, in complex evaluation, between studied of varieties were not significant differences.
Photodegradation of hydrocortisone in homogeneous and heterogeneous photocatalytic reaction
DOUBKOVÁ, Lucie
The aim of this thesis was to measure the kinetics of photochemical degradation of hydrocortisone in heterogeneous photocatalytic reaction on immobilized TiO2 and in homogeneous photocatalytic reaction with Fe(III) using UV-VIS and HPLC for measuring the degradation kinetics.
Anabaena - Phenotypic and genotypic diversity of planktonic strains in fishponds and reservoirs of the Czech Republic
ZAPOMĚLOVÁ, Eliška
Morphological diversity of 61 Anabaena populations of 13 morphospecies was described under the field conditions of Czech fishponds and reservoirs. Polyphasic approach was then applied in classification of 45 clonal strains isolated from those populations. Detailed morphological analyses were performed and partial 16S rRNA gene sequences were obtained for 33 of the strains, and secondary metabolite production was evaluated in 20 strains. Plasticity of morphological characteristics under varied conditions of light, temperature, nitrogen and phosphorus was studied in selected strains, as well as their temperature and light growth requirements. The results were then discussed with respect to the delimitation of single Anabaena morphospecies. A new genus Sphaerospermum was defined for the morphospecies Anabaena kisseleviana, A. reniformis and Aphanizomenon aphanizomenoides, whose phenotypic and genotypic features differed considerably from all other Anabaena morphospecies. Unique information was provided on the occurrence and distribution of A. reniformis and Aph. aphanizomenoides in the Czech Republic.

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