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 aim of this work was development of high-performance liquid chromatography method with DAD detection for determination of nicotine in tobacco. Standard operating procedure used by World Health Organization was chosen as comparison of the developed method. Optimized high performance chromatography method is suitable for determining nicotine in tobacco. Limit of detection for this method was 0,0003 mg/ml and limit of quantification was 0,0010 mg/ml. Optimization of preparation of samples was significant part of this thesis. Sample preparation procedure was made substantially easier in comparison to other commonly used methods. Nicotine content was determined from real tobacco leaves samples, cigarette tobacco filler, nicotine cartridge for electronic cigarettes and pipe tobacco. Satisfactory relative standard deviation was achieved for all types of samples. Next part of this thesis focused on study of determining polyphenols using high-performance liquid chromatography with diode array detector. Chosen analytes were chlorogenic acid, caffeic acid, rutine, scopoletine and quercitrine. Among the five tested analytes, the highest sensitivity was achieved for chlorogenic acid and caffeic acid. All of the analytes achieved low limits of detection and quantification. Key words Liquid chromatography,...

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 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.

The aim of the diploma thesis „Possibilities of using non-traditional fats in food technology“ was to suggest a recipe with the addition of fats and oils, which are not often used in food production technology and then evaluate the influence of the added fats and oils to quality of muffins. The main evaluation method was a bakery experiment, during which a total of 10 muffins samples with different fats and oils were baked. The bakery experiment found that fats and oils affect sensory properties like a taste, smell and flexibility. A sensory least acceptable sample was a muffin sample with the addition of linseed oil. This sample had, in a negative sense, an overly pronounced smell and taste. The best sensory samples were muffins with safflower oil, almond oil and cocoa butter. In the second part of the practical part, fats and oils were subjected to gas chromatography (GC), where the proportion and representation of MK were detected and subsequently the results were compared with the values reported by the importer.

The diploma thesis is devided into two parts – theoretical and practical. The theoretical part deals with fatty acids, their nomenclature and chemical composition. Further the diploma thesis focuses on polyunsaturated fatty acids (PUFAs) – their analytical determination, metabolism, important representatives and influence on human nutrition. The practical part deals with the experiment, in which the fatty acids content was determined in mg/100 g using gas chromatography. Testing was carried out using model animals – rats Wistar Albino and pigs Landrace and Large White. By using statistical processing, the differences in the deposition of PUFAs in the livers of these animals, were compared.

Literar review of thesis is focused on clasification of lipids, fatty acids characteristics, particularly polyunsaturated acids n3 alpha linolenic, eicosapentaenoic and docosahexaenoic acid; and polyunsaturated acids n6. There is description of metabolic reactions. Degradation by beta oxidation, biosynthesis and conversion to eicosanoids. Function and effect of eicosanoids to organism and health, nutritional representation of this fatty acids, fortification of food sources, feed in interest of improvement health condition and functional foods producing. The practical part is focused on fatty acids analysis in muscular, liver and adipose tissue of pigs after feed fortification by 2,5 % fish oil and 2,5 % palm oil in the diet. Lyofilizated samples were derivatized and determinated by gas chromatography method. Results were evaluated by statistics program.

The aim of this diploma thesis was to determine, using gas chromatography, fatty acids in selected animal tissues. Specifically, the muscle, liver, pulmonary and adipose tissues were observed. A total of 32 piglets were divided into two groups with 16 pigs in each group. During 75 days of fattening, each group was given a feed mixture differing in the type of oil added. The experimental group was fed a basic feed mixture with the addition of 2,5 % fish oil, whilst the control group with the addition of 2,5 % palm oil. The animals were fed ad libitum. After slaughter, samples of selected tissues were taken and the process of lyophilisation was carried out. Using extraction method according to Hara, Radin (1978), lipids from lyophilized tissue samples were extracted. Fatty acids present within these lipids were then transformed into more volatile fatty acid methyl esters by the process of derivatization. These were then determined by gas chromatography and the results were statistically evaluated. The effect of fish oil in the feed mixture resulted in the increase of PUFA n-3 (P < 0.01) in all of the tested tissues. The addition of palm oil, on the other hand, had an effect on the content (P < 0.05) of SFA, MUFA in the tested tissues.

The diploma thesis deals with the determination of lipids and fatty acid profile in a barley caryopsis.(Hordeum vulgare). The theoretical part describes the synthesis of fatty acids and their degradation in plant material, secondly, it described the possibilities of lipid extraction and their determination and the possibilities of determination of fatty acids. In the experimental part method of lipid extraction on automated extractor Fex ®IKA and determination of fatty acids by GC-FID were optimized. For analysis of fatty acids two capillary columns SLB-IL 100 and Supelcowax were compared. Twenty varieties of barley from the year 2008 and twenty varieties from the year 2009 were compared based on the content of lipids and the representation of fatty acids in a barley caryopsis. The diploma thesis was realized in the Research Institute of Brewing and Malting, Plc. in Brno.

The task of the diploma thesis was the theoretical and experimental design of radiators for the central heating and the prepartion of conceptual design for a pension with a wellness centre in Ostrava. The building is a free-standing three-to five-floor cellarless building. The heating system will be designed for pension rooms and a social base; within the wellness centre, the heating of a fitness centre, whirlpools, and locker rooms will be designed. The heat source will be a gas boiler house. Ventilation in the accommodation part will be natural and forced in the wellness centre with respect to thermal comfort of visitors.