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PCP sorption of lignite
Šnédarová, Gabriela ; Taraba, Boleslav (referee) ; Pekař, Miloslav (advisor)
Within the framework of this diploma thesis, the sorptive capability of a lignite as a natural adsorbent was applied on an aqueous solution of pentachlorophenol. The aqueous solution of this substance, which is very dangerous for the environment, was prepared in various concentration ranges according to reached solubility. The solubility is noticed in different literatures variously and then is not applicable. That is why it was necessary to find out the ”real“ solubility. The aqueous solution of pentachlorophenol of given concentration was subsequently put to adsorption with exactly defined quantity of the lignite and as a result the adsorptive isotherms were obtained. These isotherms represent the adsorption capability in dependence on the adsorption duration, quantity of used lignite and concentration of pentachlorophenol solution. By the adsorption with duration longer than one hour, the quantity of adsorbed PCP does not increase markedly.
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Use of plasma for degradation of ibuprofen in water
Bača, Ondřej ; Landová, Pavlína (referee) ; Mravcová, Ludmila (advisor)
This Bachelor’s thesis deals with the current problem of increasing concentrations of nonsteroidal anti-inflammatory drugs in water. The concentration increase of these drugs is due to rised anti-inflammatory drugs intake in modern era. Wastewater treatment plants are not capable of sufficient elimination of these drugs in wastewater. That leads to contamination of groundwater and surface water. The long-term impacts of these drugs on human health is not fully understood, so it is necessary to develop new methods, which will lead to complete degradation of nonsteroidal anti-inflammatory drugs and other pollutants. Theoretical part of the Bachelor’s thesis focuses on description and properties of nonsteroidal anti-inflammatory drugs and their consumption in the Czech Republic. Furthermore, the paper deals with advanced oxidation processes especially with plasma. This part of the paper also deals with determination of nonsteroidal anti-inflammatory drugs in water. For degradation of ibuprofen was used plasma. During the plasma treatment, samples were taken in regular time intervals, which were afterwards determined by an appropriate analytical method LC-ESI-MS. The results were compared with scientific studies dealing with this topic.
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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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Determination of cholesterol, 7-dehydrocholesterol and cholecalciferol by HPLC with spectrophotometric and electrochemical detection
Dostálková, Lucie ; Schwarzová, Karolina (advisor) ; Vyskočil, Vlastimil (referee)
The aim of this thesis is to verify the possibility of simultaneous determination of three structurally related biologically active substances (cholesterol, 7-dehydrocholesterol and cholecalciferol) after previous separation by high-performance liquid chromatography followed by electrochemical (on a boron-doped diamond electrode) and spectrophotometric detection, which were compared in this work. The influence of the water content in the mobile phase (in the range of 0-10 %) on the retention factor of the analytes and their response for both types of detectors was investigated. Using all mentioted water contents, the analytes baseline-separated. As the water content increased, the retention factor of the analytes increased as well as the background current for higher positive detection potentials. Based on the recorded hydrodynamic voltammograms, the optimum detection potential + 1.8 V was chosen. The optimum wavelength for spectrophotometric detection was 200 nm. The concentration dependence was measured in an of 50 mmol l−1 sodium perchlorate in acetonitrile mixed with water (95:5, v/v). The spectrophotometric detector provided lower detection limits compared with the electrochemical detector, which had detection limits of 2.3 μmol l−1 for cholesterol, 1.4 μmol l−1 for 7-dehydrocholesterol and...
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Analysis of selected nutraceuticals by liquid chromatography
Ibrahim, Laureen Reda Youssef ; Jenčo, Jaroslav (advisor) ; Opletal, Lubomír (referee)
39 ABSTRACT Charles University, Faculty of Pharmacy in Hradec Králové Department: Department of Pharmacognosy and Pharmaceutical Botany Candidate: Laureen Reda Youssef Ibrahim Supervisor: RNDr. Jaroslav Jenčo, Ph.D. Title of dissertation thesis: Analysis of selected nutraceuticals by liquid chromatography The extract obtained pellets of Humulus Lupulus L. var Columbus was subjected to a phytochemical study and isolation of its bitter acid constituents. The summary extract was separated into individual fractions by liquid-liquid extraction. After performing HPTLC, GC-MS, and LC-MS analysis, the fraction HL-Hex B was selected and purified further by preparative chromatography. A monocomponent pale yellow solid substance of lupulone was obtained after the final preparative separation. Based on instrumental analysis by reversed phase HPLC with core-shell particles, the analyte was compared to the extract of dietary supplement HopsVital where the presence of bitter acids in the supplement was shown. Key words: nutraceuticals, high performance liquid chromatography, sample preparation, modern stationary phases
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Study of retention and separation of peptides in HPLC
Boudová, Hana ; Kalíková, Květa (advisor) ; Kubíčková, Anna (referee)
This diploma thesis deals with the study of retention and separation of structurally different peptides and digest products of cytochrome c using reverse phase and mixed modes of liquid chromatography. As the model peptides, five unmodified dipeptides, nine dipeptides containing a protective benzoyl group on the N-terminal amino acid and eight therapeutic peptides containing five to ten amino acids were selected. The chromatographic behaviour of the model peptides was tested on three different columns: XBridge C18, XSelect CSH C18 and Atlantis Premier BEH C18 AX under different conditions. The influence of the pH of the aqueous part of the mobile phase, i.e. 2,1; 3,0; 4,7 and 6,8, and the amount of acetonitrile in the mobile phase on retention and separation of model peptides was tested. The effect of the concentration of ammonium acetate buffer, pH = 6,8 in the mobile phase on the retention and peak symmetry in the concentration range of 10-50 mmol L-1 was assessed. The chromatographic conditions for the baseline separation of 20 different model peptides were optimized. The conditions were as follows: XSelect CSH C18 column, mobile phase composed of acetonitrile/10mM ammonium acetate, pH = 6,8 (v/v) under gradient elution. The suitable chromatographic conditions for the analysis and identification...
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Antioxidative parameters of fruit model product.
KRATOCHVÍLOVÁ, Lenka
The content of the main components (anthocyanins, quercetin, chlorogenic acid, L-ascorbic acid, rutin, total polyphenols) was determined in the syrup of elderberries (Sambucus nigra L.) by spectrophotometry or high-performanceliquid chromatography. Furthermore, the antioxidant activity of this syrup was determined using three methods: ABTS, FRAP, and DPPH. The measurement results were statistically processed and compared using correlation analysis, specifically using the Pearson correlation coefficient. It was found that the prepared product contains 2160 mg/kg anthocyanins, 201 mg/kg rutin, 26 mg/kg chlorogenic acid and 679 mg/l polyphenols. No free quercetin was found. The content of L-ascorbic acid in the original elderberries was relatively low and therefore for study purposes, the syrup was enriched with this substance in the amount of 0.5% (w/w) to study the connection of its content with other substances. It is clear from the statistical processing that the concentration of chlorogenic acid correlates with the antioxidant activity measured by the FRAP method and the concentration of polyphenols to the antioxidant activity measured by the DPPH method.
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Multidisciplinary characterization of interactions between oestrogen hormones and their receptors during sperm capacitation.
Bosáková, Tereza
This doctoral thesis was focused on the multidisciplinary characterizatrion of interactions between hormones and their receptors during sperm capacitation, which is the final step in sperm maturation in mammals and the key event to achieve egg fertilization. Three oestrogenic hormones (17β-estradiol (E2), 17α-estradiol (αE2), 17α-ethynylestradiol (EE2)), which are part of environmental pollution, were selected for the study. These hormones are called endocrine disruptors as they can cause disorders of the hormonal system in animals, thereby adversely affecting physiological processes, including reproduction. A new analytical HPLC-MS/MS method was developed for monitoring of concentration changes of oestrogens (E2, αE2 and EE2) during time-dependent capacitation of mouse and rat sperm in vitro. For individual oestrogens, the concentration dependences of free, unbound hormone on the capacitation time were measured for three concentrations of individual hormones (200, 20 and 2 μg/L). The obtained concentration data were converted into values of relative concentrations, which were subjected to kinetic analysis. Kinetic models were proposed for the interaction of individual hormones with sperm, which were described by a system of differential equations with optimization of rate constants and molar...
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Determination of antibiotics in the soil ecosystem
Brož, Tomáš ; Zlámalová Gargošová, Helena (referee) ; Mravcová, Ludmila (advisor)
This work deals with a current issue of increasing drug concentrations and thus the growing number of resistant bacteria in the soil. One of the problem helping this issue is the fertilization of agricultural fields with animal faeces, in which antibiotics occur in an unchanged and still active form, as well as the insufficient effectiveness of conventional methods used in wastewater treatment plants. In an effort to improve the monitoring of this problem, a method for the determination of these antibacterial agents in the soil matrix, using solid phase extraction, and also a UPLC/MS method for their evaluation have been developed and optimized. From the group of sulfonamide antibiotics, sulfacetamide, sulfadiazole, sulfamerazine, sulfamethazine, sulfamethoxazole, sulfapyridine, sulfasalazine, sulfathiaosal and trimethoprim were selected. The lowest limit of detection for the method is 0.3 µg/g for sulfathiazole and the highest of 8.1 µg/g for sulfasalazine. The highest average yields were achieved with sulfamethoxazole, namely 63 ±8 %.
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