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Spray &Trap Method for Analysis of Residual Toxic Agents in Water
Vlčková, Lenka ; Podborský, Vladimír (referee) ; Brno), (VTÚO (advisor)
This work deals with verification of the analysis of precursors or degradation products of toxic compounds in the air and water through GC/MS by method of the thermal desorption or combination of methods "spray & trap" followed by the thermal desorption transfer the sample into the analyzer. Toxic compounds triethyl phosphate (TEP) and diisopropylmethyl phosphonate (DIMP) were choosen for the analysis. For choosen compounds has been optimized desorption time, for TEP 240 seconds and DIMP 210 seconds. Then the calibration curve was made for different concentrations of compounds DIMP and TEP. On the basis of these measurements was tested the possibility of determining the concentration of the compound in water sample using of method "spray & trap“. Thanks to the high solubility of compounds TEP and DIMP in water, higher boiling temperatures in comparison with boiling temperature of water, and extraction at room temperature, it was not possible to detect used compounds. Therefore, the analysis of compounds DIMP and TEP in the water by method "spray & trap“ seems inappropriate.
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Study of chemical processes in the gliding arc discharge by optical emission spectroscopy
Maďarová, Štefánia ; Töröková, Lucie (referee) ; Mazánková, Věra (advisor)
The aim of the bachelor thesis is to study the chemical processes of the glow discharge and the sliding arc under the post discharge conditions. The post discharge or afterglow plasma means that the external source of energy is removed from the system and the relaxation process can start. The experiments in bachelor work were performed under the different experimental conditions, for various pressures and gas mixtures. The theoretical part briefly describes term plasma and kinetic processes occurring in plasma generated by electrical discharges. Also there is described the problem of Titan’s atmosphere and possibility of mimic it by the gliding arc discharge. In the experiments, pure nitrogen and a gaseous mixture of nitrogen and methane were used at the same flow rate and different pressures. Optical Emission Spectroscopy (OES) and Gas Chromatography-Mass Spectrometry (GC-MS) were used to analyze chemical reaction products. The glow discharge was generated by a DC voltage source and the measurement was in flow mode. The total gas pressure ranged from 1 000-4 000 Pa at a nitrogen flow rate of 400 ml / min and methane of 0.025 ml / min. The current was in the range of 85-150 mA. In all experimental conditions, a well-known phenomenon called “pink afterglow” was observed. This phenomenon corresponds to the maximum intensity of radiation in a stagnant discharge, exhibiting a significant increase in characteristic pink radiation. The optical emission spectra of the discharging discharge were scanned in the wavelength range 540-640 nm. Three spectral nitrogen systems (the first and the second positive and the first negative ones) have been identified in the measured spectra, they have maximum values in the so-called " "Pink-afterglow". These maxims dropped with increasing pressure and shifted to a later decay time.
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Contamination of environment of musk compounds
Tobková, Lenka ; Mravcová, Ludmila (referee) ; Vávrová, Milada (advisor)
Synthetic musk compounds are artificial organic substances commonly used as fragrant constituents of personal care products as parfums, cosmetics, detergents, in-house cleaning and washing agents. Given their large area of applications and their ability to be persistent, they leaked into all parts of ecosystem, especially aquatic one. There have been a big focus on studiyng these compounds, their properties and fate in the different parts of ecosystems in the last years. The aim of master's thesis was carry out the determination of five representatives (habanolide, exaltolide, ambrettolide, musk MC4 and ethylene brassylate) of macrocyclic musk compounds in waste water samples from influent and effluent of three water treatment plants (WWTP Brno-Modřice, WWTP Lednice and WWTP Mikulov). One of the main tasks was to perform a method optimisation for the determination of selected musk compounds in waste water and evaluation and interpretation of the results. Solid phase microextraction (SPME) technique was used for the extraction of analytes, consequently gas chromatography-mass spectrometry was used for analysis of selected analytes. Following evaluation the removal efficiency of musk compounds in the waste water treatment plant was assessed.
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Analysis of organic substances present in biochar
Bača, Ondřej ; Řezáčová, Veronika (referee) ; Mravcová, Ludmila (advisor)
This master's thesis deals with the analysis of organic substances, which are present in biochar. Biochar contains a number of organic compounds, that can be toxic and also carcinogenic to living organisms. In order for biochar to be used to improve soil quality or to be used for other applications, its safety must be declared by European or international certifications. Relevant European and international standards have been created for the determination of organic substances, that could be present in biochar. The theoretical part of the thesis was focused on selected organic substances, the process of pyrolysis and thermochemolysis, biochar characterisation and the used analytical methods. The experimental part of the thesis consisted of extraction with toluene and after that the determination of concentration of the 38 polycyclic aromatic hydrocarbons was performed. Qualitative analysis was performed by two-dimensional gas chromatography. Biochar samples were also subjected to thermochemolysis method and then they were analysed on GC-MS again. In both analytical methods, a large number of substances from groups such as PAHs, carboxylic acids, amines, substituted naphthalenes etc. was found, as well as smaller number of eg. polychlorinated biphenyls.
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Newe methods used for the finding of fire causes
Přichystal, Lukáš ; Vávrová, Milada (referee) ; Osvald, Josef (advisor)
Master’s thesis deals with a determination problem of ignitable liquids from fire debris. The aim of this work is to introduce the properties of used fire accelerants and to give an overview and evaluation of the various techniques which can be conducive to the fire investigator. Determination of fire accelerants from fire debris was made by the technique of solid phase microextraction (SPME) with subsequent chemical analysis by GC/MS. Based on the chromatographic results were established the target compounds and reconstructed ion chromatograms which are typical for some kinds of flammable liquids. There were used gasoline, diesel, kerosene and technical gasoline (white spirit) as the fire accelerants. This work also deals with the influence of interfering products in fire debris analysis, including their identification and characterization. Different kinds of substrates were burned, extracted and analyzed in order to identify all the interfering products that they may release.
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Analysis of organic substances present in biochar
Bača, Ondřej ; Řezáčová, Veronika (referee) ; Mravcová, Ludmila (advisor)
This master's thesis deals with the analysis of organic substances, which are present in biochar. Biochar contains a number of organic compounds, that can be toxic and also carcinogenic to living organisms. In order for biochar to be used to improve soil quality or to be used for other applications, its safety must be declared by European or international certifications. Relevant European and international standards have been created for the determination of organic substances, that could be present in biochar. The theoretical part of the thesis was focused on selected organic substances, the process of pyrolysis and thermochemolysis, biochar characterisation and the used analytical methods. The experimental part of the thesis consisted of extraction with toluene and after that the determination of concentration of the 38 polycyclic aromatic hydrocarbons was performed. Qualitative analysis was performed by two-dimensional gas chromatography. Biochar samples were also subjected to thermochemolysis method and then they were analysed on GC-MS again. In both analytical methods, a large number of substances from groups such as PAHs, carboxylic acids, amines, substituted naphthalenes etc. was found, as well as smaller number of eg. polychlorinated biphenyls.
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Study of chemical processes in the gliding arc discharge by optical emission spectroscopy
Maďarová, Štefánia ; Töröková, Lucie (referee) ; Mazánková, Věra (advisor)
The aim of the bachelor thesis is to study the chemical processes of the glow discharge and the sliding arc under the post discharge conditions. The post discharge or afterglow plasma means that the external source of energy is removed from the system and the relaxation process can start. The experiments in bachelor work were performed under the different experimental conditions, for various pressures and gas mixtures. The theoretical part briefly describes term plasma and kinetic processes occurring in plasma generated by electrical discharges. Also there is described the problem of Titan’s atmosphere and possibility of mimic it by the gliding arc discharge. In the experiments, pure nitrogen and a gaseous mixture of nitrogen and methane were used at the same flow rate and different pressures. Optical Emission Spectroscopy (OES) and Gas Chromatography-Mass Spectrometry (GC-MS) were used to analyze chemical reaction products. The glow discharge was generated by a DC voltage source and the measurement was in flow mode. The total gas pressure ranged from 1 000-4 000 Pa at a nitrogen flow rate of 400 ml / min and methane of 0.025 ml / min. The current was in the range of 85-150 mA. In all experimental conditions, a well-known phenomenon called “pink afterglow” was observed. This phenomenon corresponds to the maximum intensity of radiation in a stagnant discharge, exhibiting a significant increase in characteristic pink radiation. The optical emission spectra of the discharging discharge were scanned in the wavelength range 540-640 nm. Three spectral nitrogen systems (the first and the second positive and the first negative ones) have been identified in the measured spectra, they have maximum values in the so-called " "Pink-afterglow". These maxims dropped with increasing pressure and shifted to a later decay time.
|
|
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Contamination of environment of musk compounds
Tobková, Lenka ; Mravcová, Ludmila (referee) ; Vávrová, Milada (advisor)
Synthetic musk compounds are artificial organic substances commonly used as fragrant constituents of personal care products as parfums, cosmetics, detergents, in-house cleaning and washing agents. Given their large area of applications and their ability to be persistent, they leaked into all parts of ecosystem, especially aquatic one. There have been a big focus on studiyng these compounds, their properties and fate in the different parts of ecosystems in the last years. The aim of master's thesis was carry out the determination of five representatives (habanolide, exaltolide, ambrettolide, musk MC4 and ethylene brassylate) of macrocyclic musk compounds in waste water samples from influent and effluent of three water treatment plants (WWTP Brno-Modřice, WWTP Lednice and WWTP Mikulov). One of the main tasks was to perform a method optimisation for the determination of selected musk compounds in waste water and evaluation and interpretation of the results. Solid phase microextraction (SPME) technique was used for the extraction of analytes, consequently gas chromatography-mass spectrometry was used for analysis of selected analytes. Following evaluation the removal efficiency of musk compounds in the waste water treatment plant was assessed.
|
|
|
Newe methods used for the finding of fire causes
Přichystal, Lukáš ; Vávrová, Milada (referee) ; Osvald, Josef (advisor)
Master’s thesis deals with a determination problem of ignitable liquids from fire debris. The aim of this work is to introduce the properties of used fire accelerants and to give an overview and evaluation of the various techniques which can be conducive to the fire investigator. Determination of fire accelerants from fire debris was made by the technique of solid phase microextraction (SPME) with subsequent chemical analysis by GC/MS. Based on the chromatographic results were established the target compounds and reconstructed ion chromatograms which are typical for some kinds of flammable liquids. There were used gasoline, diesel, kerosene and technical gasoline (white spirit) as the fire accelerants. This work also deals with the influence of interfering products in fire debris analysis, including their identification and characterization. Different kinds of substrates were burned, extracted and analyzed in order to identify all the interfering products that they may release.
|
|
|
Spray &Trap Method for Analysis of Residual Toxic Agents in Water
Vlčková, Lenka ; Podborský, Vladimír (referee) ; Brno), (VTÚO (advisor)
This work deals with verification of the analysis of precursors or degradation products of toxic compounds in the air and water through GC/MS by method of the thermal desorption or combination of methods "spray & trap" followed by the thermal desorption transfer the sample into the analyzer. Toxic compounds triethyl phosphate (TEP) and diisopropylmethyl phosphonate (DIMP) were choosen for the analysis. For choosen compounds has been optimized desorption time, for TEP 240 seconds and DIMP 210 seconds. Then the calibration curve was made for different concentrations of compounds DIMP and TEP. On the basis of these measurements was tested the possibility of determining the concentration of the compound in water sample using of method "spray & trap“. Thanks to the high solubility of compounds TEP and DIMP in water, higher boiling temperatures in comparison with boiling temperature of water, and extraction at room temperature, it was not possible to detect used compounds. Therefore, the analysis of compounds DIMP and TEP in the water by method "spray & trap“ seems inappropriate.
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