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Determination of polycyclic aromatic hydrocarbons in hydrosphere solid matrices by QuWChERS - comparision with present methods
Sudová, Petra ; Nesměrák, Karel (advisor) ; Čabala, Radomír (referee)
Thesis are aimed to the optimization and validation of the QuEChERS method for determination of polycyclic aromatic hydrocarbons in solid matrices of hydrosphere. The QuEChERS method was also used for determination of polycyclic aromatic hydrocarbons in real samples and for comparison of measured results, time and material costs of the method with currently employed methods: (1) accelerated solvent extraction connected with gel permeation chromatography (ASE/GPC), and (2) ultrasonic extraction connected with solid phase extraction (UZ/SPE). According to the validation criteria, the QuEChERS method is suitable for the determination of polycyclic aromatic hydrocarbons in solid matrices of hydrosphere. The QuEChERS technique provides comparable results to ASE/GPC and UZ/SPE. In terms of price and time for sample preparation, the QuEChERS method allows (unlike the methods ASE/GPC and UZ/SPE) fast and inexpensive determination of polycyclic aromatic hydrocarbons in solid samples of hydrosphere.
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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...
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Biodegradation of polycyclic aromatic hydrocarbon in wood treated with creosote oil
Fabiánová, Tereza ; Cajthaml, Tomáš (advisor) ; Gabriel, Jiří (referee)
Wood contaminated by polycyclic aromatic hydrocarbons (PAH) represent a serious environmental risk. Composting seems to be an effective method for decontamination of such waste material. PAHs are degraded mainly under aerobic conditions the efficiency of composting could be strongly affected by the process conditions. This work is aimed at the comparison of PAH removal by a 340-days-long composting in laboratory scale composting pilots and a 240-days-long process in a pilot scale. To set up composting piles a "green substrate" commercially used for button-mushroom production and a grass substrate were used. The use of the grass substrate led to a higher PAHs removal (97% of the initial sum of PAHs) in comparison to the green substrate (81% of the initial sum of PAHs). Further, the effect of the size of wood particles on the PAHs removal efficiency was demonstrated. Analysis of phospholipid fatty acids showed an enhanced growth of gramm-negative bacteria and fungi during the composting processes. During the degradation process the enzyme activity of laccase was detected. The ecotoxicological test using a bioluminescent bacteria Vibrio fischeri and a seed germination test using seeds of Hordeum vulgare L. showed that probably no toxic products were formed during the PAHs degradation in these experiments.
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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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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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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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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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The danger from thermal heat proccesing of food focused on grilling and hygienic knowledge of boarders
SELINGEROVÁ, Šárka
This bachelor's thesis deals with the risks following from the heat processing of food with focus on grilling and hygienic knowledge of boarders. It is split into the theoretical and practical parts. The theoretical part describes and clarifies at first the heat processing of food generally as well as the changes taking place there, based on professional books and internet sources. Afterwards, the attention is devoted to operational and personal hygiene. Finally the thesis presents kinds of grills and analyzes chemical and microbial risks. In the practical part, the research was carried out by the quantitative method of questionnaires (CAWI), sent and handed over to a certain sample of inhabitants of the South-Bohemian Region. The questionnaires were anonymous and they included addressing the respondent and introduction for him/her, stating the reasons of the research and information to questionnaire treatment and processing. The questionnaire elaboration within this thesis was focused on the degree of the knowledge of public concerning microbial risks following from insufficiently treated food and chemical (first of all carcinogenic) substances coming into being during the heat processing of food, observing hygienic principles and comparing procedures while grilling in households and restaurants. The questionnaire for the lay public (households) consisted of 31 questions in total. The questionnaire for the professional public (employees of restaurant facilities) consisted of 41 questions. Both of these questionnaires contained open, half-open and closed questions. The practical part involved also the secondary analysis of the data to occurrence of illnesses caused by food based on monthly reports acquired from the department of epidemiology of the Regional Hygienic Station of the South-Bohemian Region, which was statistically evaluated by me. The main target of this thesis was to find out the level of knowledge of the professional and lay public about the risks following from grilling, to accentuate them and to compare the grilling procedure in the restaurant facilities and in households. Two hypotheses were set for the purpose of the research. Hypotheses, H1: ?The knowledge of risks of boarders following from home grilling depends on education? and H2: ?Risks of health problems following from grilling due to failure to observe the personal hygiene occur in more households?, were processed statistically by means of Pearson's chi-squared-test. All the acquired data were processed by Microsoft Office Excel in the form of charts and diagrams. During the thesis, the set targets were achieved and based on the statistic findings, both hypotheses were confirmed. It follows from the results that the questioned sample of the public from the South-Bohemian Region is not sufficiently informed of the risks following from grilling and how to eliminate these risks or prevent them. It was proved that the personal hygiene is observed more strictly in the restaurants than by the family members living in one household and therefore there is a higher risk of occurrence of health problems from grilling in households. Moreover the employees of restaurant facilities shall not only respect the personal hygiene, but also the operational hygiene and shall proceed according to the critical control points system (HACCP). But these rules are not respected in some cases, the reason of a complaint in 30% (3 of 10) restaurant facilities was that the grilled meal was not roasted enough. The thesis may serve as information material for the wide public, for boarders as well as operators and employees of various restaurant facilities. Its target is to point out the possible health risks following from the consumption of grilled food and also to describe how to decrease these risks on the lowest possible level, or to prevent them completely.
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