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Determination of content of organic compounds in biochar
Novotná, Martina ; Řezáčová, Veronika (referee) ; Mravcová, Ludmila (advisor)
Biochar is created during the pyrolysis of organic biomass. Once added into the soil, it can improve its features. Biochars made from sewage sludge have various compositions. It is because of the vast difference between entrance materials. Organic pollutants can be absorbed into its surface during the cooling proces sof pyrolysis. If released into the enviroment, these compounds can cause inhibition of plant growth, get into food chains and adversely affect living organisms. Organic pollutans are determined most often by GC/MS after organic solvent extraction.
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Determination of benzo(a)pyrene content in smoked meat products using modern isolation techniques
Suranová, Mária ; Šimon, Peter (referee) ; Šimko, Peter (advisor)
In this work a new simplified procedure for isolation and determination of PAH in smoked meat products was developed. This procedure is using ASE as selective extraction technique. Its principle is addition of silicagel activated during 18 hours at 140 °C directly to the extraction cell in ratio 10 g to 1 g of homogenized sample. In the next step the sample is extracted by n-hexane at 100 °C and 10 MPa for three 10 minutes static extraction cycles. The flush volume is 60 % and the purge time 120 sec. During the extraction silicagel adsorb koextracted lipids and thus the obtained extract is suitable for immediate HPLC-FLD analysis. On the contrary, the classical extraction procedures with nonpolar solvent require difficult purification of extract for removal of unwanted lipids. Mostly applied techniques here are GPC and SPE. The new procedure was validated for determination of B[a]P as well as for determination of 4 PAH (B[a]A, CHR, B[b]F, B[a]P) in smoked sausages. It meets all requirements to be set by Regulation (EC) No 333/2007, respective by new Regulation (EC) No 836/2011. After the method validation, the content of 4 PAH was investigated in twelve samples of various smoked sausages manufactured in Slovakia. Two analyzed products showed high PAH levels exceeding maximum legislation limits set for B[a]P as well as for sum of 4 PAH by Regulation (EC) No 835/2011.
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Needles as bioindicators for assessing contamination levels of PAHs
Mikulíková, Iva ; Zlámalová Gargošová, Helena (referee) ; Vávrová, Milada (advisor)
Bioindicators are used to monitor the level of the environmental pollution. Plant bioindicators are most frequently used, particularly mosses, lichens and conifers. This thesis focuses of the monitoring of polycyclic aromatic hydrocarbons alkyl-derivates concentration in the needles, that were taken in different locations in the Czech Republic. Analytes were extracted by mixture of n-hexane and dichlormethane. The acquired extract was cleaned up by column chromatography with activated silicagel and florisil. Gas chromatography - mass spectrometry was used for final analysis.
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Kinetics of benzo[a]pyrene destruction and identification of its products
Ryšavý, Jan ; Kolek, Emil (referee) ; Šimko, Peter (advisor)
This diploma thesis is focused on the study of conditions of benzo[a]pyrene, one of the major contaminant of foods, photodegradation under different conditions (solvents with different polarity, light sources, presence of antioxidants). In another part of the thesis, the degradation process of benzo[a]pyrene at various concentrations was studied, in order to characterise the kinetic aspects of photoinduced degradation. The attempt to identify the products of benzo[a]pyrene photodegradation was performed involving methods of gas chromatography and high performance liquid chromatography coupled with mass detectors, as well.
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Determination of organic substances in tar formed after biomass combustion and gasification
Hájek, Radek ; Mravcová, Ludmila (referee) ; Vávrová, Milada (advisor)
Biomass pyrolysis and gasification techniques count among basic technological procedures for its use as a source of energy. As a side-effect, production of tar can be considered. Tar is a complex mixture of various organic compounds and affects negatively both the environment and the facilities where biomass is processed. Within the scope of this master thesis the analysis of tar samples from different materials was performed. As an appropriate analytical method the gas chromatography combined with flame ionization detection (GC-FID) and time-of-flight mass spectrometry (GC-TOF-MS) was chosen. The concentrations of volatile organic compounds known as BTEX, polycyclic aromatic hydrocarbons (PAH) and phenolic compounds were assessed.
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Substituted polyaromatic compounds in environmental components
Kubalík, David ; Mravcová, Ludmila (referee) ; Vávrová, Milada (advisor)
This work is focused on substituted polycyclic aromatic hydrocarbons (PAHs) in environmental compartments. The thesis examined the development of these compounds and their entry into the ecosystem. Due to their proven negative characteristics to be addressed also their toxicology. The next section discusses the appropriate methods, including sampling, sample preparation and final determination. The conclusion of this work forms draft standard operating procedure for their determination.
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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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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.
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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).
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