Fragrances are added to food, cosmetics and other products primarily for enhancement of their sensory quality (taste and/or aroma). However, the usage of these compounds is associated with the wide range of various adverse biological effects. Some fragrances widely used in cosmetics are proved to cause e.g. skin sensitization, rashes, dermatitis, headache, cough etc. To protect the health of consumers, European union approved the cosmetic directive (ES/1223/2009) that requires the labeling of 26 allergen fragrances on the final product label, if concentration exceeds the given level (0,01 % for rinse-off and 0,001 % for leave-on product). However, some producers hide the presence of allergens in the final product under the general term „aroma“. For this reason it is very important to monitor the content of these substances in cosmetic products. Fragrances are found not only in cosmetics, but the various types of food are also aromatized by them. Unlike cosmetics, the food producers are not obliged to label the presence of fragrance allergens on the packaging. Therefore, the monitoring of these fragrances is highly desirable because of the potential health risks they pose. The aim of this study was to develop a method for simultaneous determination of regulated fragrance allergens in food and everyday use products. The method based on extraction of analytes by solid phase microextraction coupled to gas chromatography with FID detection (HS-SPME-GC-FID) was chosen on the basis of the literature review. The fiber CAR/PDMS provided the highest extraction efficiency among the SPME fibers tested. Univariate and multivariate data analysis were used to optimize the main parameters affecting microextraction process. The final method validation was performed in terms of linearity, repeatability, reproducibility, recovery, limits of detection and quantification. The optimized and validated method was applied to a wide range of products including cosmetics, aromatized food and fragranced toys. These products were also subjected to sensory evaluation especially in terms of taste and/or aroma (i.e. flavour), which may be associated with the content of the monitored fragrances. The profile test (EN ISO 13299) and seven-point category ordinal scale (ISO 4121) were used for sensory evaluation.

Water is one of the most abundant substances on Earth and it is an essential part of our lives. Its pollution has an impact on the whole ecosystem. Polybrominated diphenyl ethersare synthetic persistent organic pollutants used as flame retardants in various commercial and household products. This thesis is focused on assesing the degree of elimination of PBDEs in wastewater treatment plants with different technological processes of purification. The samples were collected in the three wastewater treatment plants in the south-moravian region, that means WTP Brno – Modřice, WTP Mikulov and WTP in VFU Brno.

Biomass is a renewable source of energy and represents an acceptable alternative to fosil fuels. Usable methods of energetic use of biomass are combustion and gasification. Main interest is focused on gasification in last years. Gasification is based on conversion of organic material to usable gaseous product called syngas, which can be used as a fuel for energy production. Large amount of tar is formed as a by-product of incineration and gasification of biomass. Tar is composed by various mixture of organic substances, has a negative effect on operating conditions and is a potential threat to environment. Experimental part of this study was focused on analysis of tar obtained by gasification of various kind of biomass. Selected groups of hydrocarbons and oxygen compounds were identified in analysed samples. Individual biomass samples were compared regarding to determined relative content of selected substances. Analysis was done by complete twodimensional gas chromatography with mass spectrometric detection (GCxGC/TOF-MS).

This diploma thesis is focused on study of chemical and enzymatical hydrolysis of raw wood material. The aim of this work was to find the suitable method for pretreatment of selected lignocellulose materials. The theoretical part deals with characterization of lignocellulosic material and its components. There are also subscribed various pretreatment methods and their effect on hydrolysis of sawdust. In experimental part of the work the most appropriate approach of pretreatment and hydrolysis of sawdust was studied. Criteria for the selection of suitable method was concentration of saccharides as desired product of hydrolysis and also concentration of the most important microbial inhibitors - polyphenols. Application of 96% ethanol or 5% H2O2 were identified as the most promising pretreatment methods which enhanced yields of fermentable sugars about 30 %. Further, we also performed cultivation of bacteria Burkholderia cepacia and bacteria Burkholderia sacchari using solution obtained by hydrolysis of lignocellulose material.

Polychlorinated biphenyls (PCB) represent relevant persistent organopollutants of the environment and the estimated amount of PCB released into the environment is 750000 metric tons. White-rot fungi have been studied for long time due to their degradative potential toward various aromatic pollutants and it is known that these fungi are able to decompose PCB in vivo. Biodegradation of PCB by the fungus Pleurotus ostreatus was studied in the frame of this work. A high degradative efficiency of P. ostreatus was observed in the first set of experiments, even in the presence of relative high amount of added PCB. Fungus was able to transform 780±50 µg out of the intial amount 1000 µg in 20 ml of a cultivation media within 42 days. A decrease in toxicity was recorded during the degradation that suggests the suitability of this organism for a practical use in decontamination. In vitro experiments with purified laccase induced with Cu2+ from this fungus did not prove any participation of the enzyme in the first step of PCB transformation. The enzyme did not show an ability to degrade PCB even after purification from cultivation media containing PCB. It was found that the first step of PCB transformation can be performed by an intracellular process with microsomal fraction. A degradation of 44-67% was observed for...

South American plant Clusia blattophila, growing on Nouraghes of French Guiana, produces relatively large amounts of volatile substances in the fragrance of its flowers. C. blattophila is dioecious plant with different flowering time of monosex flowers Male flowers bloom for one night, while female flowers bloom two nights. The volatiles were adsorbed to the adsorbent and washed out with hexane with internal standard. Analysis was performed by two-dimensional gas chromatography with mass spectrometric detection. The aim of my thesis was to determine the qualitative and quantitative characteristics of flower scents of both sexes. I also studied, whether there are differences in production of the major fragrance component, acetoin, during the first night of blooming. The flower fragrance is complex blend of volatiles. In total, 43 different chemicals were identified. Among them were monoterpenes (α-pinene, camphene, β-pinene, myrcene, limonene, (E)-β-ocimene, camphor) sesquiterpenes (α-copaene, β-caryophyllene, cis-α-bergamotene, trans-α-bergamotene, aromadendrene, (E,E)-α-farnesene, δ-cadinene), aldehydes (1-pentanal, 1-hexanal, 1-octanal, n-decanal), also four ketones (acetoin and its dimer, 2,5-hexanedione, 6-methylhept-5-en-2-one), alcohol butane-2,3-diol, carboxylic acid 2-methylpropanoic,...

Males of South American fruit fly Anastrepha fraterculus form leks and release sex pheromone to attract females during the reproductive behavior. The aim of my diploma thesis was to collect samples of volatiles released by variously old males, subsequently to analyze and to determine the changes in the quantitative composition of the sex pheromone depending on age. The volatiles were trapped on adsorbent, eluted with hexane containing internal standard and analyzed by gas chromatography with mass detection. Males release twenty volatiles, including fourteen terpenes: α-pinene, camphene, -pinene, myrcene, Δ3-carene, limonene, (Z)--ocimene, (E)--ocimene, aromadendrene, trans-α-bergamotene, (Z)-β-farnesene, (Z,E)-α-farnesene, germacrene D, (E,E)-α-farnesene; one aldehyde: nonanal; two alcohols: (3Z)-non-3-en-1-ol, (3Z,6Z)-nona-3,6-dien-1-ol and three lactones: suspensolide, anastrephin a epianastrephin. From the list of named compounds there were proved antenal activity of six compounds in previous work, namely trans-α-bergamotene, (Z,E)-α-farnesene, (E,E)-α-farnesene, (3Z)-non-3-en-1-ol, (3Z,6Z)-nona-3,6-dien-1-ol and epianastrephin.

Analytical chemistry plays a crucial role in studies on chemical ecology and only the development of sophisticated methods enables the detection of biologically active compounds that are usually present in minute quantities and often in very complex mixtures. My thesis is dedicated to the application of modern analytical techniques and instrumentation to unravel the identity, chemical diversity and function of semiochemicals and defensive compounds used by various species of termites. The first section of this thesis aims at the identity of chemicals used in communication, the pheromones. I studied the chemistry of the trail-following communication in three selected species of termites. Besides the identification of (3Z,6Z,8E)-dodeca-3,6,8-trien-1-ol, the most frequent termite trail-following pheromone, as the trail-following pheromone in Psammotermes hybostoma (Rhinotermitidae), I participated in the description of two new structures, (10Z,13Z)-nonadeca-10,13-dien-2-one in Glossotermes oculatus (Serritermitidae) and syn-4,6-dimethylundecan-1-ol in Hodotermopsis sjoestedti (Archotermopsidae). We identified (3Z,6Z,8E)-dodeca-3,6,8-trien-1-ol to be the female sex pheromone in Psammotermes hybostoma, and syn-4,6-dimethylundecanal to be the male sex pheromone in Hodotermopsis sjoestedti. I also...

(EN) The solvation model based on LSER was applied to study the retention behaviour of analytes in liquid and gas chromatography. In a first chapter, a retention description of 21 solutes was investigated by using the solvation model in a wide range of mobile phase composition methanol-water and acetonitrile-water. Generally, the retention of aromatic compounds was better described by the solvation model, compared to aliphatic compounds. Effect of the particular analytes used to formulate the LSER model on ability of retention description was studied. Different results of a retention estimation was achieved by using the regression set of compounds including aromatic solutes only or by contrast aliphatic solutes only. The solvation model developed on the basis of oxygen derivatives provided distinct results in comparison to model formulated with nitrogen derivatives only. The second chapter of this work, focused on gas chromatography, dealt with a description of retention of 152 isomers C5-C8 alkenes by the LSER model. The solvation descriptor L was obtained by using two estimation methods Havelec-Ševčík (HS) and Platts-Butina (PB), the descriptor E was calculated according to its definition. Two models for retention description of alkenes were constructed, the HS model and the PB model, derived...

Mechanical properties of aluminium alloys highly depend on their phase composition and microstructure. High strength can be achieved among others by introduction of a high volume fraction of fine, homogeneously distributed second phase particles and by a refinement of the grain size. Powder metallurgy allows to prepare fine grained materials with increased solid solubility which are favourable precursors for further precipitation strengthening. Gas atomization was used for the preparation of powders of the commercial Al7075 alloy and its modification containing 1 wt% Zr. A part of gas atomized powders was mechanically milled at different conditions. Mechanical milling reduced the grain size down to the nano-size range and the corresponding microhardness exceeded the value of 300 HV. Powders were consolidated by the spark plasma sintering method to nearly fully dense compacts. Due to a short time and relatively low temperature of sintering the favourable microstructure can be preserved in the bulk material. The grain size of compacts prepared from milled powder was retained in the submicrocrystalline range and the microhardness close to 200 HV exceeded that of the specially heat treated ingot metallurgical counterparts. The prepared compacts retained their fine grained structure and high...