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Optimization of a method for the determination of inorganic ions using capillary electrophoresis
Špačková, Simona ; Bezděková, Jaroslava (referee) ; Vaculovičová, Markéta (advisor)
Inorganic ions are one of the most important group chemicals. Their importance is crucial for all living organisms on the planet and monitoring of their content is essential for this purpose in clinical or environmental analysis but also in the food industry, agriculture or many other industries. Many analytical methods for ion detection have been designed and used, depending on the area of their use. Recently, numerous methods have been adapted to areas where not primarily intended. One such methods may be, for example, laser ablation with inductively coupled plasma mass spectrometry, which has recently begun to affect the analysis of biological samples. As a complementary method, able to detect also non-metallic ions is capillary electrophoresis. In this master thesis, the possibility of applying capillary electrophoresis with indirect photometric detection for the separation of inorganic ions in cell lysates of HeLa cells by capillary electrophoresis was verified. Main attention was paid to chloride ions. The ability to separate inorganic compounds in cellular material using salicylic acid as an absorbing anion in the base electrolyte was tested.
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Application of polymer membranes in microextraction techniques for analysis of biological samples
Ryšavá, Lenka ; Diviš, Pavel (referee) ; Dvořák, Miloš (advisor)
The thesis presents experimental study on application of various polypropylene membranes (with different thicknesses, porosity and pore size) for direct coupling of membrane microextractions with capillary electrophoresis. No comprehensive study, which describes effect of these membrane parameters on extraction recoveries, was published in the past. Previous scientific works prefer application of 100 µm polypropylene membranes for their easy handling and satisfactory extraction efficiencies. Experimental part includes examination of selected polypropylene membranes as supported liquid membranes in-line coupled to capillary electrophoresis for analysis of basic drugs from complex samples. Membranes with three thicknesses (25, 100 and 170 µm) were tested. The highest extraction recoveries were achieved for the 25µm thick polypropylene membrane. Various pH conditions of donor and acceptor operational solutions were examined for extractions from real complex matrices (urine, plasma). The optimal extraction conditions were 10 mM NaOH as donor phase and 10 mM HCl as acceptor phase. 25µm membranes offer higher extraction recoveries, reduced consumption of organic solvents for membrane impregnation, similar mechanical stability and similar clean-up ability compared to thicker polypropylene membranes.
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On-chip and capillary electrophoresis for cancer research
Hájková, Tereza ; Babula, Petr (referee) ; Provazník, Ivo (advisor)
The thesis deals with cancer disease and its genesis. The prostate cancer is the second most dangerous disease in male population. It is very important to detect it in early stage. This thesis deals with the proteins which are or could be used as potential cancer markers. For example in current commonly used the prostate-specific antigen and newly the metallothionein. Metallothionein is a protein occuring in fauna and flora in four basic isoforms. There is a hypothesis that the isoform content or/and their ratio may have a diagnostic implication and could be used in clinical practise. For this reason they are studied and developed methods for specific and sensitive analysis of individual isoforms. In this work, capillary electrophoresis is used for the separation of the isoforms. The influence of the parameters such as type of background electrolyte, its pH and separation voltage etc. on the final separation are discussed.
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Analysis of cow milk caseins by capillary electrophoresis
Dvořáková, Irena ; Zemanová, Jana (referee) ; Vespalcová, Milena (advisor)
The diploma thesis is dealing with the determination of caseins in lyophilised samples of milk using the method of capillary electrophoresis (CE). This method was optimised and verified by Ivana Micikova in her diploma thesis in 2009. The theoretical part of the diploma thesis gives information about the chemical compound of cow's milk. Caseins and their usage in the food and non-food industries are described in a separate unit. Impact of both the nutritional and non-nutritional factors on the composition of the milk is discussed further. The description and the principles of the CE and a list of the methods of CE used in the last several years are stated at the end of this part. The experimental part is focused on the preparation of the solutions, process of casein isolation and its analysis. It summarises the setting of the experiment, sampling and sample processing and the composition of the feeding mixtures. The diploma thesis has arisen on the basis of the cooperation of the Institute of Food Science and Biotechnology, the Faculty of Chemistry, Brno University of Technology and the Research Institute for Cattle Breeding, Ltd., Department of Animal Nutrition Physiology in Pohorelice.
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Evaluation of glutathione content in plants as a marker of heavy metals environmental contamination
Borková, Marie ; Stoupalová, Michaela (referee) ; Opatřilová,, Radka (advisor)
Dependence of glutathione concentration on the amount of thallium in the plant was studied. Observed plant was maize (Zea mays) which was divided to two parts – root and overground. Two culture procedures were elaborated where seeds and young seedlings were cultivated in a solution of thallium of concentration 0, 1, 3, 5, 8, a 10 µmol/l. Extraction agents used during extraction were phosphate buffer and solution of ascorbic acid. Determination of glutathione was realized by capillary electrophoresis (CE) and high performance liquid chromatography (HPLC). Diode array detector (DAD) was used in both methods. Quantification of the thallium amount in the plant was done by method of inductively coupled plasma-atomic emission spectrometry (ICP-AES).
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Use of capillary electrophoresis to determine a selected group of flavonoids
Tran Xuan, Tiep ; Mravcová, Ludmila (referee) ; Řezáčová, Veronika (advisor)
In recent years, the use of natural medicinal properties of plants has again come to the forefront of interest of the public. Because of their therapeutic properties, these plants are commonly used in alternative treatments for minor ailments. This thesis deals with the determination of polyphenolic acids in extracts from aronia, echinacea, tetradenia and centella. One of the aims of the thesis was to compare the amount of polyphenolic acids in individual plants with their antioxidant properties. The theoretical part includes a general introduction to flavonoids, introduction to polyphenolic acids, introduction to the principles of capillary zone electrophoresis and a summary of selected foreign studies for the determination of flavonoids. An important chapter of the theoretical part is a description of individual plants with an explanation of their possible therapeutic use. The experimental part is devoted to the process of optimization of electrophoretic determination of selected polyphenolic acids and evaluation of their content. It was found that in the extracts six representatives of polyphenolic acids occur in minimal amounts, often below the limit of quantification or detection of the method.
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Multidimensional Liquid Phase Separations
Šesták, Jozef ; Čáslavský, Josef (referee) ; Pulkrabová, Jana (referee) ; Česla, Petr (referee) ; Kahle, Vladislav (advisor)
This dissertation is dedicated to the topic of multidimensional liquid phase separations. This separation techniques are developed for analysis of complex samples containing thermally labile, low volatile or high molecular weight components that can´t be analysed by two-dimensional (2D) gas chromatography. Concepts of peak capacity and orthogonality are explained and various methods of their determination are stated in theoretical part of dissertation. High performance column liquid chromatography (HPLC) and high performance capillary electrophoresis (HPCE) are suggested as the most suitable methods for automated multidimensional liquid phase separations on-line coupled to mass spectrometry. Configuration of simplified miniaturized liquid chromatograph is described in experimental part of this thesis. Original concept of the system has been extended by simple mobile phase gradient generation technique. Correct function was demonstrated on repeatable separation of alkylphenones, peptides, nitroaromatics, and nitroesters. This system has been utilized as a base for a couple of simple two-dimensional separation platforms for HILIC-MALDI-MS analysis of glycans, for separation of peptides based on off-line coupling of isoelectric focusing and capillary liquid chromatography, and finally for on-line IEC×RPLC, RPLC×RPLC, and HILIC×RPLC two-dimensional liquid chromatography. Correct operation of submitted platforms has been proved.
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Vliv zpracování kávy na obsah kofeinu a jeho účinky na lidský organismus
Odehnalová, Barbora
This diploma thesis focuses on the comparison of caffeine content in coffee processed in different ways. It involves dry and wet processing, where in the first mentioned case the coffee beans are dried in the sun to the ideal moisture level after collection and sorting. In the wet method, the coffee is fermented in vats with added microorganisms and then dried. The work also includes the effects of caffeine on the human organism.
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Detekce nukleových bazí pomocí kapilární elektroforézy
Hendrychová, Kateřina
Capillary electrophoresis (CE) is one of the most important techniques used for high-throughput separations in modern analytical chemistry. Its main advantages include the possibility of using different detection techniques, speed and efficiency of separation as well as reproducibility. These properties are used in the separation of a wide variety of analytes ranging from inorganic ions to nanoparticles and were also verified in this work, in which the basic building blocks of DNA and RNA, nucleic bases, which serve as biomarkers for many disorders, diseases and food safety, were measured using capillary electrophoresis with a UV detector. The bachelor thesis is focused on the development and optimization of a method to detect and separate 5 nucleobases and purine. The separation was achieved by using 40 mM borate buffer pH 9,8 with the addition of 60 mM SDS as a detergent which forms micelles.
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