The theoretical part describes the principles of the free-radical induced grafting and the influence of various parameters on the reactions course. The literature research summarizes the latest knowledge in the field of the reactive modification of polypropylene (PP), it is mainly focused on the PP modification using an unsaturated acid anhydrides. Theoretical part describes the various procedures and modification of technology in order to increase the grafting yield of maleation. The experimental part is determined by the influence of the stabilizers concentration, the peroxide structure, and the binary mixture of monomers on the grafting yield and the reaction course. In the first part, the critical stabilizers concentration was determined based on the experimentally obtained relationship between the grafting yield and the stabilizers concentration. A kinetic schema of grafting of MAH onto PP in the presence of stabilizers has been proposed and compared with the experimental results. The effect of the stabilizers on the extent of the undesirable b-scission was evaluated based on the melt flow rate (MFR) and the rheological curves of PP-g-MAH. In the second part, the effect of the peroxide structure and the concentration of reactants on the grafting yield of PP modification with MAH and itaconic anhydride (IAH) was observed. The initial grafting yield Rg has been experimentally determined and compared with a defined area of theoretical values of Rg. The extent of b-scission was significantly influenced by the structure and the concentration of peroxide, as shown by the results of MFR and the rheological curves of PP-g-MAH. The last part of the doctoral thesis is focused on the assessment of the combination of MAH and IAH as comonomers on the grafting yield. At first, the reference polymers were prepared using the solution polymerization of MAH, and IAH, and copolymerization of MAH with IAH. The reference polymers were analyzed by FTIR, DSC, WAXS to confirm the probable copolymerization of MAH and IAH. The dependence of the reaction enthalpy on the reaction time was observed using simulations of bulk polymerization of MAH, IAH and mixtures MAH and IAH "in situ" in isothermal calorimeter. PP was subsequently modified with a combination of MAH and IAH as comonomers in order to assess its effect on the grafting yield

A set of 15 carboxylic acids of various structural types was used to test a new procedure of esterification of these substances in the urine without previous extraction. The acids were first measured by a reference method without the matrix, and then by a procedure, where lyophilized urine was treated with derivatizing reagent alcohol·HCl, which was then evaporated, the residue dissolved in water, esters extracted into an organic solvent and subsequently determined by GC/FID and GC/MS. The work is mainly focused on 2-hydroxyethyl- and carboxymethyl-mercapturic acids, but the procedure was also tested on di-, tri- and hydroxy-carboxylic acids, known as physiological urinary components or markers of metabolic disorders. Key words: carboxylic acids mecapturic acids freeze-dried urine esterification gas chromatography

The goal of this master's thesis was to examine the possibility of oxidation of seven selected bile acids and evaluate whether such processes are suitable for analytical purposes. The secondary goal was to describe the oxidation products of bile acid electrolysis. The experiments were carried out in a non-aqueous medium of acetonitrile and in a mixed medium of acetonitrile:water using linear sweep and cyclic voltammetry. The working electrode materials employed for voltammetric experiments were: highly oriented pyrolytic graphite, -cyclodextrin modified glassy carbon and boron doped diamond. Preparative electrolysis was carried out on a platinum electrode in the non-aqueous medium of acetonitrile. Experiments have shown that neither the highly oriented pyrolytic graphite electrode nor the -cyclodextrin modified glassy carbon electrode are suitable for analytical purposes under conditions used. The results achieved on the boron doped diamond electrode, on the other hand, have not yet been described in the literature. Primary bile acids cholic and chenodeoxycholic were oxidized at approximately 0.5 V lower potential in the mixed medium of acetonitrile:water than in the papers using carbon electrodes published until now. Products of oxidation on the platinum electrode were separated by TLC and...

The prevalence of obesity and type 2 diabetes in the adolescent population has been steadily rising. According to the previous studies, the rs1801282 (Pro12Ala) polymorphism in the PPARγ gene is connected to the development of obesity, hypertension, insulin resistance, hyperlipidaemia, and other metabolic complications of type 2 diabetes. Data collection was undertaken as part of the COPAT project (Childhood Obesity Prevalence and Treatment). A sample of 2246 Czech adolescents aged 13-17 was genotyped using RT-PCR and subjected to further anthropometric and clinical measurements, and biochemical testing. Data on their nutritional intake and dietary habits were collected as well. A randomly selected subgroup of 735 individuals was further tested for serum fatty acids ratios. Our goal was to 1) determine the effect of the rs1801282 polymorphism in the PPARγ gene on the anthropometric, clinical and biochemical parameters, 2) determine the effect of the interaction between the rs1801282 polymorphism in the PPARγ gene and obesity or overweightness on the observed parameters. The frequency of Ala allele in our sample was 15%. Ala allele was associated with lower fasting c-peptide (p=0,006) and fasting insulin levels (p=0,035). In obese Ala boy carriers higher levels of phospholipid and triacylglycerol...

The prevalence of obesity and type 2 diabetes in the adolescent population has been steadily rising. According to the previous studies, the rs1801282 (Pro12Ala) polymorphism in the PPARG gene is connected to the development of obesity, hypertension, insulin resistance, hyperlipemia, and other markers of type 2 diabetes. Data collection was undertaken as part of the COPAT project (Childhood Obesity Prevalence and Treatment). A sample of 2246 Czech adolescents aged 13-17 was genotyped using RT-PCR. 735 individuals from this sample were subjected to further anthropometric and clinical measurements, and biochemical testing. Data on their nutritional intake and dietary habits were collected as well. Our goal was to 1) determine the effect of the polymorphism on the anthropometric, clinical and biochemical parameters, 2) determine the effect of the genotype-phenotype interaction on the lipid spectra. We measured the frequency of Ala allele as 15%. Ala allele was associated with lower fasting c-peptide (p=0,006) and fasting insulin levels (p=0,035). In obese Ala carriers we detected higher levels of phospholipid and triacylglycerol ω-3 polyunsaturated fatty acid than in lean Ala carriers or obese noncarriers. Keywords: PPARγ2, Pro12Ala, fatty acids, obesity, COPAT project

Efforts to reduce sulphur dioxide in wine have been the subject of wine interest for several years. Research over recent years has shown the effectiveness of saturated higher fatty acids as an alcohol fermentation inhibitor, even in the production of wine with higher residual sugar. The principle of the function of C8, C10 and C12 fatty acids is simple. They enter the body yeast, which subsequently change their structure and the cell will become permeable to other substances, and thus is not working - yeast stops working and alcoholic fermentation is stopped. The mixture of higher fatty acids of C8, C10 and C12 in the ratio 2 : 7 : 1 can during application of 10 mg.l-1 reduce the necessary dose of SO2 to several tens mg.l -1. The results show that administration of 10 mg.l-1 of a mixture of higher fatty acids in combination with 30-40 mg.l-1 SO2 is as effective as a dose of 60 mg.l-1 SO2 itself. In addition to the demonstrable effect of stopping alcohol fermentation, the HFA (resp. MCFA) mixture appears to be promising before referral (especially for wines with higher residual sugar).

This Diploma thesis was focused on the study of changes in the berry components during the ripening of the grape. Four vine varieties, Pinot Blanc, Sauvignon, Grüner Veltliner, and Riesling were subjected to the investigation. Grapes were collected on four dates. The following parameters were evaluated during maturation: the weight of 10 berries, the soluble solids content, the titratable acid content and the penetration strength of the berry. From the parameters of soluble solids, titratable acids content and berry strength, the maturity index for individual varieties was calculated at the given collection date. All varieties were monitored for the development of set parameters over time and the difference between the different grape varieties. The observed varieties showed an increase in the soluble solids content during the ripening of the grapes.

The diploma thesis consists of theoretical and practical part. In the theoretical part it deals with lipids and their role in human nutrition. I also characterized fatty acids and evaluated their health effects. Subsequently, I studied the theoretical basis of chromatographic methods focusing on gas chromatography, its instrumentation and evaluation. In the practical part I analysed the selected assortment of müsli bars by several producers. I focused on the quality of some müsli bars available on the Czech market, focusing mainly on fat content and fatty acid composition. As far as preparation of samples are concerned, it was necessary to lyophilize them first and then Soxhlet extraction followed. The actual determination of fatty acids was carried out using the method of gas chromatography and the results were statistically evaluated.

The thesis Phthalates in yoghurts during storage focuses on monitoring of phthalic acid esters in yogurt samples in relation to their storage period. The analyzed phthalates are di-2-(ethylhexyl)-phthalate (DEHP) and di-n-butyl-phthalate (DBP), which are among the most commonly used polymeric plasticizers, especially polyvinyl chloride. I analyzed samples of yoghurt with 1 % and 5 % chia and bamboo fiber and then subsequently compared them with natural yogurts. In total, I analyzed 120 samples of yoghurt, for which I measured DBP concentrations ranging from 0.2 mg.kg-1 to 7.7 mg.kg-1 of the original raw material and concentration of undetected values of DEHP in range up to 2.6 mg.kg-1 of the original raw material. While analyzing the yoghurt packaging, I measured average DBP values of 174.1 μg.dm-2 (68.0 μg.g-1 plastic) and DEHP values of 26.2 μg.dm-2 (10.2 μg.g-1 plastic). After prior preparation of samples, I used high performance liquid chromatography to do the phthalates analysis.

The aim of the diploma thesis was to monitor the influence of grass in feed on fatty acid content in eggs. The experiment was carried out on Lohmann Brown Classic hybrids at the age of 12 weeks. Layers were divided into five groups. The feed was enriched by a 5% drop of Trifolium pretense, Trifolium repens, Medicago sativa and Lolium perenne. The control group were fed in a diet containing color-promoting additives. The fattening took three months. Egg samples were collected at the end of the month. Feedin and the power was run ad libitum. The effect of the addition of dried plants was significantly (P < 0,05) to the color of the yolk. A statistically significant (P < 0,05) incerease in palmitic acid in eggs was recorded during the experiment in eggs produced by laying hens which were in diet containing addition of Trifolium pretense and Medicago sativa. A demonstrable increase (P < 0,05) was also observed in laying hens which were fed with a mixture enriched with Trifolium pretense in percent α-linolenic acid content.