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Determination of residual substances from the preparation of colloidal systems based on biopolymers
Borůvková, Tereza ; Vávrová, Milada (referee) ; Mravec, Filip (advisor)
Volatile organic compounds could be isolated and concentrated from liquid solution using methods, which are based on analysis of equilibrium gas phase, because of their volatility. The aim of this bachelor´s thesis is determination the amount of residual tert-butanol, belonging to volatile organic compounds, in the samples after lyophilisation. Samples were prepared by mixing hydrofobic sonde and hydrofilic hyaluronan. For mixing these components it is necessary to add organic solvent tert-butanol, which ensures stable environment. Thanks to its presence mixing of probe and hyaluronan occurs. Consecutive lyopfilisation of the sample leads to the disruption of a water cover of hyaluronan and nonpolar hydrogen atoms, which are hidden in it, can interact with hydrofobic probe. Bonding the probe is important in oncology, where this fact could be used in targeted distribution of pharmaceuticals. However presence of tert-butanol is unacceptable in the final product, mainly in medical applications. The object this study is the minimization of residual tert-butanol amount in final lyophilised cake. The method of equilibrium gas phase analysis (static Head-Space) by gas chromatography with flame ionization detection (GC/FID) was used for the determination of its content.
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Spectroscopy of VOC degradation by surface discharge catalyzed by TiO2
Veverková, Radka ; Slavíček, Pavel (referee) ; Kozáková, Zdenka (advisor)
Bachelor thesis is focused on the study of degradation of volatile organic compounds in surface discharge catalysed by TiO2. Volatile organic compounds are dangerous both for human beings and the environment. Therefore it is necessary to eliminate volatile organic compounds. Plasma technology is one of the options how to reach their efficient removal. The experiment was carried out in the plasma reactor with electrodes for surface discharge. One or two layers of TiO2 catalyst were deposited on one of the electrodes. Nitrogen was used as a carrier gas and it was mixed with air before entering the reactor. The radiation emitted by the discharge during the degradation of VOC was transmitted via optical fibre to the optical emission spectrometer Jobin Yvon TRIAX 550. Toluene, hexane, cyklohexane and xylene were used as model VOCs. During the experiment the impact of input power on catalysed or non-catalysed degradation of VOC by the discharge has been monitored. Using optical emission spectrometry it is possible to determine some important parameters of surface discharge, such as rotation and vibration temperature. The values were determined for each measurement in the range from 650 to 1050 K for rotation temperature and from 1600 to 1950 K for vibration temperature. The average error of determination was 100 K for rotation temperature and 120 K for vibration temperature. It was found, that the catalyst is without effect on the rotation and vibration temperature. In contrast, change of discharge input power significantly influenced both rotation and vibration temperature. Significantly different values of rotation and vibration temperature were obtained in the presence of particular compound for lower input power, while these values were similar for higher input power. Further, the spectral bands of nitrogen, oxygen and NO were identified from emission spectra. The obtained results may be used as a fundament for further study of volatile organic compounds decomposition in surface discharge.
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Analysis of breath by mass spectrometry
Hoffmann, Pavel ; Vašinová Galiová, Michaela (referee) ; Mravcová, Ludmila (advisor)
This thesis is focused on analysis of volatile organic compounds in breath by mass spectrometry. For on-line analysis of breath, proton-transfer reaction mass spectrometry (PTR MS) was used. For off-line analysis, gas chromatography-mass spectrometry (GC-MS) and PTR-MS were used. For off line analysis breath sampling, Tedlar bags were used. For extraction and preconcentration of breath sample, solid-phase microextraction (SPME) was used. PTR-MS analysis was performed both qualitative and quantitative. GC-MS was performed only qualitative. Using PTR-MS, 7 different volatile organic compounds were found. Their concentrations were compared between sapmles. Namely, formaldehyde, methanol, acetaldehyde, ethanol, acetone, dimethyl sulfide and isoprene were found in ppb concentrations. Using GC-MS, 142 unique volatile organic compounds were found. Selected compounds were compared between selected samples.
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Decomposition of Volatile Organic Compounds in Gliding Arc Discharge
Grossmannová, Hana ; Kapička, Vratislav (referee) ; Pekárek,, Stanislav (referee) ; Krčma, František (advisor)
The aim of this thesis was to elaborate the issue of the decomposition of volatile organic compounds in the Gliding Arc plasma discharge at atmospheric pressure. Technologies based on nonthermal plasma could offer a good alternative to conventional techniques for the decomposition of volatile organic compounds, such as thermal and catalytic oxidation. Gliding Arc discharge (GidArc) is a widely exploited nonthermal plasma source used for many industrial applications, such as air-pollution control. The energy efficiency, reaction selectivity or production of specific species may be achieved in this kind of plasma, and thus for various chemical processes it can be much more effective then in conventional techniques. Presented experiments are linked to the previous results published in diploma thesis, which gave us the basics for construction of new reactor and optical emission spectroscopy measurements have been done to characterize the plasma. Toluene (aromatic, unsaturated), cyclohexane (aromatic, saturated) and hexane (aliphatic, saturated) were used as the model compounds for these experiments in the concentration range from hundreds to thousands ppm. Results focused on the electrical parameters of the reactor were carried out, with the aim to operate the system at a lower energy cost. In order to get the time-resolved diagnostics of the moving plasma channel, the evolution of the plasma channel was recorded continuously by using a high-speed video camera. In next part of the work, some results concerning generation of low molecular products like nitric oxide, nitrogen dioxide, hydrogen and carbon monoxide on the discharge conditions are presented. In combustion process, undesirable mixture of toxic highmolecular by-products can be formed. Samples were therefore analysed in gas chromatograph linked to mass spectrometer, to characterize the chemical transformation pathway of VOC in plasma.
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Evaluation of the contamination of working environment in the Gumotex Breclav joint stock company
Petrušová, Pavlína ; Vávrová, Milada (referee) ; Čáslavský, Josef (advisor)
Diploma thesis deals with the assessment of volatile organic compounds contamination of selected working environment in Gumotex, joint stock company using passive sampling. The theoretical part contains description of these compounds and their reactions in the atmosphere, practical use of these substances and their effect on human health. The possibilities of passive sampling and determination of these substances are described as well. The experimental part contains analysis of volatile organic compounds at two selected workplaces in Gumotex, joint stock company using passive samplers Radiello. Final determination by gas chromatography with flame ionization detector was preceded by adsorption surface extraction of sampler with carbon disulfide. In conclusion, obtained data are compared with the permissible exposure limits and maximum allowable concentrations, which are defined by the National Health Institute.
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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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Faktory ovlivňující kvalitu vnitřního pobytového prostředí z hlediska zatížení interiéru těkavými organickými látkami (VOCs)
Málková, Andrea
This thesis is divided into two parts, a theoretical and a practical. The theoretical part contains six chapters and it is written in the form of a literature review. In these chapters, there are gradually characterized the features of indoor environmental quality and indoor air quality, which are associated with volatile organic compounds (VOCs) and their sources. Then following chapter deals with the effects of VOCs on human health and the possibilities of how to avoid these influences in the apartment interior. Among other things, the literary review deals with outdoor air quality in the area of the examined objects as one of the factors that influence the indoor air quality. The last chapter is devoted to legislation that relates to the researched topic. Main, practical part of the thesis id divided into five chapters. It deals with the measurement of VOCs in four different apartments in a period of three seasons (fall, winter, spring). These chapters describe the assessed objects and the corresponding measurement methodology used together with the devices, by which the measuring and subsequent analysis of the interior load VOCSs were carried out. The last chapter of the practical section discusses the results of measurements and their interpretation of the word.
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Analysis of breath by mass spectrometry
Hoffmann, Pavel ; Vašinová Galiová, Michaela (referee) ; Mravcová, Ludmila (advisor)
This thesis is focused on analysis of volatile organic compounds in breath by mass spectrometry. For on-line analysis of breath, proton-transfer reaction mass spectrometry (PTR MS) was used. For off-line analysis, gas chromatography-mass spectrometry (GC-MS) and PTR-MS were used. For off line analysis breath sampling, Tedlar bags were used. For extraction and preconcentration of breath sample, solid-phase microextraction (SPME) was used. PTR-MS analysis was performed both qualitative and quantitative. GC-MS was performed only qualitative. Using PTR-MS, 7 different volatile organic compounds were found. Their concentrations were compared between sapmles. Namely, formaldehyde, methanol, acetaldehyde, ethanol, acetone, dimethyl sulfide and isoprene were found in ppb concentrations. Using GC-MS, 142 unique volatile organic compounds were found. Selected compounds were compared between selected samples.
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Study of links between biogenic VOC emissions and concentration of tropospheric ozone
Zemánková, Kateřina ; Brechler, Josef (advisor) ; Bednář, Jan (referee) ; Braniš, Martin (referee)
Title of dissertation: Study of links between biogenic VOC emissions and concentration of tropospheric ozone Kateřina Zemánková, 2010 Dissertation directed by: doc. RNDr. Josef Brechler, CSc. Dept. of Meteorology and Environment Protection, Faculty of Mathematics and Physics, Charles University in Prague Presented work focuses on influence of volatile organic compounds from biogenic sources on concentration of tropospheric ozone. Volatile organic compounds (VOC) play an important role in the tropospheric chemical system. Together with oxides of nitrogen they form two major components of reactions leading to low-level ozone formation. Volatile organic compounds are emitted into the atmosphere from an- thropogenic as well as from biogenic sources. In global, VOCs from natural sources are approximately ten times higher in magnitude than those of anthropogenic origin. Biogenic VOCs are emitted from various sources among which the forest ecosystems predominate. Group of VOCs of natural origin comprises wide range of chemical com- pounds. Those emitted in highest concentrations are isoprene and group of monoter- penes. Emissions of biogenic VOCs from the area of the Czech Republic have been es- timated based on the high resolution land cover data giving detailed information of sigle tree species...
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