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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
71

HPLC a možnost jejího využití při vzdělávání budoucích učitelů chemie / HPLC and the Possibility of its Use in Teacher Education

Gabriel, Štěpán January 2017 (has links)
This diploma thesis is focused on theoretical and practical aspects of High performance liquid chromatography (HPLC). This method is introduced as one of the most frequently used current analytical methods. The theoretical part of thesis is focused on instrumentation of HPLC and particular components of HPLC analytical system. The most often used mobile phases and static phases are described as well. Based on these theoretical aspects, laboratory exercise using HPLC for future teachers is designed. Caffeine is used as ideal model material for this exercise. Caffeine is well-known substance, because of its traditional usage for example in food-processing industry. Final part of this thesis is brief view on framework educational programmes for primary and secondary education. As appendix of this thesis, manual for referenced laboratory exercise is provided. KEYWORDS chromatography, caffeine, HPLC, instrumentation of HPLC, teacher training, RVP
72

Validace nutričních parametrů uvedených na obalech vybraných potravin

Pláteníková, Markéta January 2014 (has links)
The main purpose of this diploma thesis was to study legislative requirements about marking food products with nutrition labels and summarize the activities and procedures of supervising organizations connected to problematic of goods marking. One of the goals was to briefly describe technological and producing methods of selected food - ham, cheese, kephir milk, baby food with fruit, wafer, bread, wholemeal puffed bread and chocolate. Next goal was to evaluate the risks of food consumption with deceptive nutrition labels. In the practical part of this thesis I have determined quantity of saccharides, lipids, proteins and salt in selected food products by standard methods. Simple saccharides were determined by Schoorl's method and starch volume by Ewers's method. Lipids were determined by Soxhlet's extraction and after put through derivatization. In gas chromatograph (GC) were detected fatty acids. Apart from the Soxhlet's extraction was made also extraction according to Hara and Radin (1987) for comparison. Proteins were determined by method using nitrogen according to Kjehdal with adjustments according to Winkler. The amount of salt was detected analytically by argetometric precipitating titration. Determination the volume of nutritive parameters was made in three ranks of selected products. From obtained results were evaluated possible risks, which might be caused by consumption of food products with deceptively stated nutritive labels.
73

Vliv relativní vzdušné vlhkosti dřevostaveb na kvalitu jejího vnitřního prostředí

Víšek, Pavel January 2014 (has links)
This thesis deals with the quality of the internal environment of wooden buildings, especially the quality of the indoor environment interior loaded VOC emissions. The main goal of this work is to analyze the influence of relative humidity constructions on the quality of the indoor environment in the region Mountains. As assessed buildings were elected four wooden buildings, one of which is a frame structure, the second is half-timbered, and the other two are made with timber construction.Sampling methodology VOC emissions from the interior of the investigation based on the standard DIN EN ISO 16000 1 and 5. Sampling polluted indoor air was performed using a membrane pump Gilian LFS - 113DC, the collected air samples were collected in metal sorption tubes that are filled with TENAX TA sorbent. Indoor Environmental Quality assessed based constructions of wood was monitored during one calendar year, with the influence of the season on emissions of VOC(Fall, Winter, Spring ).Part of this work was to also assess the impact of age of the building and its material composition on the emission of volatile organic compounds assessed based constructions of wood.Detected concentrations of VOCs elected representatives were subsequently compared with the limit concentration by the Ministry of Health Decree No. 6/2003 Coll. , Laying down the health limits of chemical, physical and biological indicators of residential rooms inside certain buildings.
74

Možnosti stanovení těkavých látek při výrobě piva

Rozsypalová, Markéta January 2015 (has links)
The thesis discusses the possibilities of determination of chlorophenols in beer. A review of literature describes the complex properties of chlorinated phenols. Summarizes their physical, chemical and toxicological properties and characterizes their possible inputs into the environment. In the experimental part is the main theme of the determination of chlorophenols in samples of small breweries and beers called as home brew. These are various types of beer, in which the amount of chlorophenols determined using solid phase extraction (SPE) using gas chromatography with flame ionisation detector (FID). Another part of the experiment is aimed at demonstrating the formation of chlorophenols in beer by simulating conditions in the production of beer in the pilot plant. Chlorphenols amount of boiled beer is again determined by gas chromatography. Samples of beers are compared with each other in the content of chlorophenols. It is evaluated sectional representation monitored chlorophenols and their quantity in the analyzed samples of beer.
75

Studium antioxidantů ve vybraných druzích koření pomocí moderních analytických metod

Lacková, Zuzana January 2016 (has links)
A spice is a natural source of natural substances for humans, containing mainly phenols and flavonoids, which have exceptional antioxidant effects. Presented study described the most advanced analytical technique for evaluation of the presence and concentration of extracted natural antioxidants from ground spices (marjoram, pepper (sweet), black pepper, caraway seeds, anise, thyme, cinnamon, oregano). Subsequently, individual spices were analyzed on the overall efficiency of selected type of extraction. Further, the individual spices were examined on their total antioxidant activity using the DPPH, FRAP and total phenols assays.
76

Chirální a achirální chromatografie ve farmakologii a toxikologii / Applications of chiral and achiral chromatography in pharmacology and toxicology

Chytil, Lukáš January 2011 (has links)
Development and validation of methods for analysis of several drugs or their metabolites are decribed in this thesis. The document is presented as a commentary to the original papers, which were published in peer reviewed journals. Discussion on the optimization of each method is presented and covers also method development and influence of preanalytical aspects. Additionally, examples of the application of the developed methods in clinical pharmacology and toxicology are shown. This dissertation consists of three parts: enantiomeric determination of tramadol and its metabolite, determination of some antihypertensive drugs, and qualitative analysis of benzodiazepines. Development of a method for chiral analysis of tramadol and its desmethylated metabolite O- desmethyltramadol (ODT) in human urine and plasma is described in the first part of the thesis. Tramadol is a centrally acting analgetic drug, which is used as racemate in clinical practise. Each enantiomer displays different binding properties for various receptors: (+)-tramadol preferentially inhibits serotonin reuptake while (-)-tramadol mainly inhibits noradrenalin reuptake. (+)-tramadol is considered 10-times more potent than (-)-tramadol. Major active metabolite (ODT), which is considered to be the main agent responsible for the...
77

Technologie pěstování ostropestřece mariánského (Silybum marianum) ve vztahu ke kvalitě produktu a jeho zpracování / Cultivation Technology of Milk Thistle (Silybum Marianum)in Relation to the Product Quality and its Processing

GRAMANOVÁ, Hana January 2009 (has links)
Silybum marianum has been a plant known for millenniums thanks to its pharmacological effects especially in fields of liver, gallbladder or even colon cancer treatment. A complex of effective components is called silymarin. Its amount and structure in milk thistle seeds are very important. That{\crq}s why there{\crq}s a tendency to develop methods which could increase silymarin quantity together with silymarin quality in this herb. This was also the aim of this thesis. One of the possibilities to level up the content of effective components in drugs is to bring this plant in stress. There were realized two ground-plot experiments. The stress agens was acetatonsalicylic acid (ASA) of different concentrations applicated on leaves of these plants, concretely in the concentrations of 10-5 mol.l-1, 10-4 mol.l-1, 10-3 mol.l-1. In the case of the application ASA concentration 10-3 mol.l-1 there was proved an effective action. The increase of effective components in seeds reached approximately 116,5 % ratio compared with control application of distilled water on the Silybum marianum leaves. The silymarin complex was determined by High Performance Liquid Chromatography. The preparation of the extract was practised in different ways {--} using ethyl alcohol extract and distilled water in combination with various temperatures of extracts storage. These methods were compared one another. As the best one has been turned out to be using 60% ethanol concentration for the duration of 96 hours in the storage temperature 20°C.
78

Vývoj technik pulsního značení pro studium dynamiky proteinových komplexů. / Development of pulse labelling technology for studying the dynamics of protein complexes.

Fiala, Jan January 2021 (has links)
(IN ENGLISH) Structural mass spectrometry (MS) is an evolving field of structural biology introducing novel techniques for the characterization of biomolecules. Although MS-based techniques only can provide "low-resolution" information compared to standard high-resolution techniques representing by X-ray crystallography, cryo-electron microscopy or nuclear magnetic resonance, its uniqueness lies in the ability to easily obtain structural information about various biomolecules in their native or native-like environment. By employing various approaches, from protein covalent labelling through chemical cross- linking to ion mobility, structural MS provides insight into the structure and dynamics of proteins and their complexes over a broad timescale. This thesis is dedicated to the development of novel structural MS approaches based on pulse covalent labelling and chemical cross-linking. Employing the developed quench-flow microfluidics apparatus, we performed footprinting experiments on proteins and protein complexes in timescale from a few microseconds to single seconds. Specifically, fast photochemical oxidation of proteins (FPOP) and novel fast fluoro alkylation of proteins (FFAP) techniques were utilized to track structural changes of myoglobin upon release of the prosthetic heme group....
79

Stanovení tryptofanu, serotoninu a melatoninu v rostlinném materiálu pomocí HPLC / Determination of tryptophan, serotonine and melatonin in plants by using HPLC

Pavlů, Věra January 2021 (has links)
This thesis deals with the development and optimization of a method for the determination of tryptophan and its metabolites - serotonin and melatonin - in plant material, in grapevine, during one analysis. It uses a high-pressure liquid chromatography. The theoretical part is about tryptophan, its metabolism and basic properties of its metabolites - serotonin and melatonin. Their occurrence in wine is also discussed. Analytical techniques by which these analytes can be determined are also provided. Then information about modern stationary phases, that are suitable for this species, is included. The experimental part consists of optimization of the method, measurement of calibration dependences and measurement of real samples. It is measured by the method of reverse phase chromatography. As first stationary phase it is used a C18 column with core-shell packing, second is a BEH Phenyl column. The mixture of 10 mM acetate buffer (pH = 4.5) and methanol is used as the mobile phase. For detection UV at wavelength 254 nm is used, then for greater sensitivity mass detectionis is used. The basic conditions for the experiment have been set. At the beginning of the analysis, the mobile phase contains 95 % (v/v) buffer and 5 % (v/v) methanol. Then the methanol content is linearly increased to 80 % (v/v) from...
80

Stanovení vybraných mykotoxinů ve vzorcích čajů / Determination of selected mycotoxins in tea

Pustka, Václav January 2020 (has links)
This diploma thesis deals with the development and validation of an analytical method using high performance liquid chromatography method with fluorescence detection for the simultaneous determination of aflatoxins and ochratoxin A in herbal and fruit tea. The theoretical part describes the most common groups of mycotoxins and the most important methods for their determination in food. The great attention is devoted to HPLC method and the overview of the derivatization techniques for aflatoxins B1 and G1 fluorescence response enhancement. The practical part of this study focuses on the optimization of sample extraction and purification, the settings of the instrumental analysis and the photochemical reactor assembly. The thesis also involves the determination of the basic performance characteristics for the successful method validation.

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