|
Detailed characterization of pyrolysis oil by separation techniques and mass spectrometry
Žvaková, Veronika ; Mravcová, Ludmila (referee) ; Čáslavský, Josef (advisor)
The aim of this work is detailed characterization of pyrolysis oil by advanced analytical separation methods and mass spectrometry. During the pyrolysis process decomposition of complex organic material take place in the presence of high temperatures and the absence of oxygen. Condensable part of vapours and aerosols forms viscous liquid called pyrolysis oil which is a complex mixture of large amount of compounds. In this work samples from microwave pyrolysis of woodchips and sewage sludge from wastewater treatment plant Brno-Modřice were analysed. Samples were provided by Bionic Laboratories company. Samples were separated by column chromatography on activated silica. For detailed characterization of each fraction gas chromatography with mass spectrometry detection and comprehensive two-dimensional gas chromatography with mass spectrometric detection with time of flight analyser were used. Substances that have been identified can be divided into several groups: alkanes, alkenes, aromatic hydrocarbons, polycyclic aromatic hydrocarbons, alcohols, aldehydes, esters, carboxylic acid and heterocycles.
|
|
Analysis of tar formed by combustion of biomass
Chytil, Václav ; Čáslavský, Josef (referee) ; Vávrová, Milada (advisor)
This bachelor's thesis is focused on the analysis of the tar formed during combustion of biomass. Samples of the tar were provided by Energy Institute, Faculty of Mechanical Engineering, Brno University of Technology. BTEX, polycyclic aromatic hydrocarbons (PAHs) and n-alkanes were chosen as groups of target compounds. Samples (tar solutions in acetone) were refined before the final analysis. In the case of BTEX and n-alkanes, only filtration and dilution were used. In the case of polycyclic aromatic hydrocarbons, samples were filtered and then cleaned-up by column chromatography using silica gel. Gas chromatography with flame ionization detector (GC-FID) was chosen as an appropriate analytical method for the determination of target compounds from selected groups of BTEX and n-alkanes. Target compounds from the group of polycyclic aromatic hydrocarbons were determined by gas chromatography with mass spectrometric detection (GC-MS).
|
|
Characterization of organic substances in biochar and their release in the soil ecosystem
Bočán, David ; Doležalová Weissmannová, Helena (referee) ; Mravcová, Ludmila (advisor)
The aim of this master’s thesis was to optimize the extraction of 38 PAH and 7 PCB compounds from samples of commercially available biochar and then apply the most suitable extraction method to real samples of biochar and soil. The concentrations of mentioned compounds were determined by using gas chromatography with mass spectrometry detection. Finally, from these concentrations in individual samples, a rate of release of these compounds from biochar to soil was determined. The theoretical part was focused on summarizing the process of biochar production and its properties. The next part deals with compounds that can be present in biochar, their physicochemical properties and effects on organisms and the environment. Also, a most common ways of extracting and determinating these compounds are mentioned. The final part focuses on soil and its characteristics and the changes it undergoes when biochar is applied to it. In the practical part an extensive optimization of extractions using a PSE extractor and thermal desorption extraction was conducted. After determining optimal conditions for both types of extraction methods, these methods were applied to real samples of biochar and soil. Qualitative analysis was carried out using GCxGC-TOF mass spectrometer and quantitative analysis by MRM method on GC-MS2 mass spectrometer.
|
|
Spatio-temporal distribution of atmospheric aerosol in urban and rural environment
Bendl, Jan ; Hovorka, Jan (advisor) ; Mikuška, Pavel (referee) ; Vojtíšek, Michal (referee)
Air quality in Europe remains a significant environmental concern, affecting the health and quality of life of its population. While stationary network ambient air quality monitoring allows for the observation of main trends, it is not fully representative of personal exposure of citizens due to high spatio-temporal variability of atmospheric aerosol. Therefore, highly time-and- space resolved measurements with state-of-the-art instruments and methods are needed to observe the aerosol variability, dynamics, identify hot-spots, and pollution sources, which are necessary for successful targeted mitigation measures. This thesis addresses this gap focusing on the characterization of spatio-temporal distribution of atmospheric aerosol in inhabited environments. Novel mobile measurement systems were developed and employed to investigate diverse environments, including rural, urban and suburban area. Aerosol source-apportionment were conducted, and the toxicological effects associated with these environments were also investigated. A novel mobile measurement system was developed for personal exposure measurements and pollution mapping in urban and rural environments. The system was used to measure air quality in the Munich subway, revealing high aerosol dynamics with significantly higher concentrations of...
|
|
Analysis of organic compounds in the soil-biochar-salad system
Hlaváčová, Josefína ; Řezáčová, Veronika (referee) ; Mravcová, Ludmila (advisor)
The bachelor’s thesis presented focuses on the analysis of polycyclic aromatic hydrocarbons extracted from lettuce, soil, biochar and soil mixed with biochar. Polycyclic aromatic hydrocarbons are introduced into the biochar during the production process, i.e., pyrolysis. After applying the biochar to the soil, the polycyclic aromatic hydrocarbons can be released into the soil and contaminate it. The theoretical part of the thesis focuses on the production and characterisation of biochar, its applications to the soil and subsequent changes it induces within the soil. The experimental part focuses on the optimization of the microwave-assisted extraction process. Furthermore, experiments were carried out, assessing the influence of the added biochar on the concentration of polycyclic aromatic hydrocarbons within soil and lettuce. The sample analysis included microwave-assisted extraction and quantitative and qualitative determination using GC/MS/MS. The samples analysed were assessed for the presence and concentration of 16 different polycyclic aromatic hydrocarbons, prioritised by the U.S. Environmental Protection Agency. The analysis of the samples of lettuce grown in the soil containing biochar display a higher concentration of polycyclic aromatic hydrocarbons compared to samples without biochar. The analysis of the lettuce roots showed identical results.
|
|
Použití kapalinové chromatografie v analýze vzorků životního prostředí
KŘÍŽOVÁ, Monika
This work deals with the use of HPLC method in the analysis of environmental samples. Cigarette butts are one of the most common garbage in nature. These cigarette butts may contain high amounts of polycyclic aromatic hydrocarbons (PAHs) and many other toxic and chemical compounds, which may contaminate the environment. One of the aims of this work was to optimize extraction process of 16 priority PAHs from freshly smoked cigarette butts and the HPLC/FLD analytical method and consequently to determine their contents in collected samples. The second part of the work is devoted to the introduction of a method suitable for the quantitative evaluation of metformin loss in 100% aqueous samples. The method will be further used for the analysis of standard solutions in the monitoring and evaluation of possible photochemical reactions of metformin.
|
|
Characterization of organic substances in biochar and their release in the soil ecosystem
Bočán, David ; Doležalová Weissmannová, Helena (referee) ; Mravcová, Ludmila (advisor)
The aim of this master’s thesis was to optimize the extraction of 38 PAH and 7 PCB compounds from samples of commercially available biochar and then apply the most suitable extraction method to real samples of biochar and soil. The concentrations of mentioned compounds were determined by using gas chromatography with mass spectrometry detection. Finally, from these concentrations in individual samples, a rate of release of these compounds from biochar to soil was determined. The theoretical part was focused on summarizing the process of biochar production and its properties. The next part deals with compounds that can be present in biochar, their physicochemical properties and effects on organisms and the environment. Also, a most common ways of extracting and determinating these compounds are mentioned. The final part focuses on soil and its characteristics and the changes it undergoes when biochar is applied to it. In the practical part an extensive optimization of extractions using a PSE extractor and thermal desorption extraction was conducted. After determining optimal conditions for both types of extraction methods, these methods were applied to real samples of biochar and soil. Qualitative analysis was carried out using GCxGC-TOF mass spectrometer and quantitative analysis by MRM method on GC-MS2 mass spectrometer.
|
|
Role of benzo[a]pyrene in cancer development
Vaňátková, Petra ; Moserová, Michaela (advisor) ; Kubíčková, Božena (referee)
4 ABSTRACT Cancer is nowadays one of the most serious diseases. Tumor development is a multistage process in which the effect of internal and external factors lead to failure of regulatory and defense mechanisms of the organism and to the accumulation of mutations which are generated by these organisms. Chemical carcinogens and also biological and physical factors can be regarded as the main external factors. Polycyclic aromatic hydrocarbons are large group of chemical carcinogens. One of them, benzo[a]pyren is the most studied polycyclic aromatic hydrocarbon. Carcinogenic, mutagenic and teratogenic effects of benzo[a]pyrene had been shown on laboratory animals. Benzo[a]pyrene is considered as the main carcinogen in tobacco smoke and is connected with lung cancer development among smokers. Benzo[a]pyrene is metabolized in activation or detoxication pathways by enzymes of mixed function monooxygenase systeme of cytochromes P450. The most important enzymes involved in the activation of these compounds are CYP1A1 and CYP1B1 with cooperation of epoxide hydrolase. The reactive species generated in its activation pathway are able to form covalent adducts with DNA. The most important carcinogenic product of benzo[a]pyrene is benzo[a]pyrene-7,8-dihydrodiol-9,10-epoxide, which can caused irreversible ganges in...
|
|
PAH bond to nanoparticles of atmospheric aerosol: substrate specifity.
Bendl, Jan ; Hovorka, Jan (advisor) ; Cajthaml, Tomáš (referee)
Polycyclic aromatic hydrocarbons (PAHs) are reviewed including their chemical and chemical- physical features, their impact on health and the environment. Different behaviour of PAHs is mentioned. The detailed instruction for the measurement using high-volume cascade impactor BGI 900 (Hi-Vol) is described. Cleaning, equilibration, weighting, protection against contamination of the substrates and technique of the measurement were introduced. The experiment was done: under the last teflon back-up filter the extra PUF substrate was placed, where after the air exposition the significant amounts of gaseous phase of phenanthrene, anthracene, fluoranthene, pyrene and benzo(a)anthracene were captured. The extent of the volatile PAHs capture correlated positively with the vapour pressure (ranging from 10-4 to 10-1 Pa.). The other measured PAHs (coronene, benzo(ghi)perylene, chrysene, benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(a)pyrene, dibenzo(a,h)anthracene and indeno(1,2,3-cd)pyrene) with vapour pressure from 10-5 to 10-10 Pa were not captured. The experiment found out that polyurethane (PUF) substrates captured in noticeable amount the volatile phase of PAHs and therefore the correction for the capture of gaseous phase in the particle size fractions of PAHs was calculated. The deduction for the...
|
|
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.
|