|
|
Electrochemical generation of tellurium hydride for AAS
Resslerová, Tina ; Hraníček, Jakub (advisor) ; Červený, Václav (referee)
Tellurium is non-biological element which is not common in the earth. It can be accumulated in a body and cause many health problems. In this work, tellurium is determined by the electrochemical hydride generation technique coupled with atomic absorption spectrometry with quartz tube atomizer. In the first part of this work, various relevant parameters of tellurium hydride generation were optimized to achieve high sensitivity. Under the optimal working parameters, calibration dependences and other basic characteristics were measured. Finally, the influence of oxygen added on the different places of set up was carried out. Optimized parameters were flow rate of the carrier gas, generation current, flow rate and concentration of electrolytes. Optimizations were measured for two different catholytes: hydrochloric and sulfuric acid, with similar results. In addition the calibration was measured with orthophosporic acid. Further experiments with oxygen were performed for sulfuric acid as the catholyte. Influence of oxygen on the baseline and the process of determination were performed, for both continuous and limited time addition.
|
|
|
Mercury Electrodes as Tools for Voltammetric Determination of Biologically Active Organic Compounds and for Detection of Their Interaction with DNA
Horáková, Eva
The main aim of this work was to use traditional mercury electrodes for the development of voltammetric methods of determination of organic xenobiotics and for the electrochemical study of the interaction between double-stranded deoxyribonucleic acid (DNA) and these compounds. In relation to my previous research work (conducted in the framework of my diploma thesis), firstly, 4-nitrobiphenyl (4-NBP), the suspected carcinogen, was studied. Interaction of DNA with 4-NBP was studied using differential pulse voltammetry (DPV), cyclic voltammetry (CV), and chronocoulometry at a hanging mercury drop electrode (HMDE), and using CV and alternating current voltammetry at a DNA modified HMDE. Using CV, the reduction mechanism was investigated. The interaction of DNA with 4-aminobiphenyl (4-ABP), a metabolite of 4-NBP, and 4-NBP reduction intermediates was studied. It was found that the interaction of DNA with 4-NBP or 4-ABP results in a formation of a DNA aggregate with these analytes. The second studied analyte was methyl violet 2B (MV). For determination of MV in a buffered solution were used: direct current tast polarography and differential pulse polarography at a dropping mercury electrode, and direct current voltammetry, DPV, and differential pulse adsorptive stripping voltammetry (DPAdSV) at HMDE. The...
|
|
|
Fluorinated micropollutants in the environment
Hatasová, Nicolette ; Cajthaml, Tomáš (advisor) ; Klusoň, Petr (referee)
Perfluorinated compounds (PFCs) are considered as persistent organic pollutants. Their extensive use in various products leads to increase of their occurence in surface and ground water, soil, air and, generally, in the global ecosystem. In this diploma thesis, method for detection and quantification of 19 perfluorinated compounds was developed. This method was used for analysis of real drinking water and sewage sludge samples from Czech Republic. It is based on pre-extraction step and consecutive liquid chromatography with mass spectrometry, using negative chemical ionization (LC-MS). We developed a method for analysis of water samples, using solid-phase extraction (SPE). Using this method, concentrations of PFCs in 8 samples of drinking water from Czech Republic were evaluated. Total concentration of analyzed PFCs was 4 - 23 ng/L. Processing of sewage sludge samples using accelerated solvent extraction (ASE) showed matrix effect, which influenced ionization and led to false positive/negative results. For supression of the matrix compounds, we used SPE Envi-Carb columns. Using this optimised method, 23 sewage sludge samples from different locations in Czech Republic were analyzed. The most represented PFC in the environment, perfluoroctane sulfonate (PFOS), was detected in concentrations 5 - 386...
|
|
| |
|
|
Development and evaluation of computer application for teaching and determination of natural species
PECHAR, Luboš
Available e-learning applications for teaching and recognition of natural species and testing the level of achieved knowledge were evaluated in this thesis. Problems and limits of these tools were identified. Based on the evaluation the unique tool for test developing was designed which can be used for self-learning as well as for testing within the school program. The outcome of the theses is a new application "Poznávačka". New application allows teachers to create lists of species which are available as a study material for their students.
|
|
|
Detection, Localization and Determination of Chronic Wounds
Gulán, Filip ; Dvořák, Michal (referee) ; Drahanský, Martin (advisor)
The aim of this diploma thesis is to design and implement a multiplatform application for detection, localization and determination of the extent of chronic wounds. The application is intended to assist nurses, doctors and healthcare assistants to monitor and evaluate chronic wounds in the course of treatment. The application is based on the Typescript programming language, on the Ionic hybrid application framework and on the Electron desktop application framework. Chronic wound assessment runs on the server-side where the Python programming language is used. The Flask application framework is used for the RESTful application interface and the OpenCV library is used for image processing.
|
|
|
Analysis of nanopartical systems by atomic spectrometry
Jeníková, Eva ; Hraníček, Jakub (advisor) ; Nováková, Eliška (referee)
EN The present diploma thesis is focused on optimization methods of titanium and phosphorus concentration for their use in the colloidal solution of TiO2 nanoparticles modified by bisphosphonates. For these analyses was used atomic absorption spectrometry with flame and electrothermal atomization. The characteristics of the two analytes were compared to two different spectrometers. Using the F-AAS technique on the GBC 933 AA spectrometer has been achieved a detection limit of 5,2 mg l-1 for titanium and a detection limit of 163 mg l-1 for the phosphorus. Using the ContrAA 700 spectrometer, F-AAS has been achieved an almost five times lower detection limit of 1,1 mg l-1 for titanium determination. For determination of phosphorus using this spectrometer, was obtained a similar value of 151 mg l-1 , as using the GBC 933 AA spectrometer. The determination of phosphorus by the ET-AAS technique using the ContrAA 700 spectrometer resulted in a detection limit of 1,23 mg l-1 , which is a significant difference compared to the flame system. It has been proved that optimized methods are consistent with the intention, which was confirmed by the analysis of real titanium and phosphorus samples in the colloidal solution of TiO2 nanoparticles modified bisphosphonates.
|
|
|
Determination of the Exchange Rate
KRČMOVÁ, Daniela
This bachelor thesis deals with determination of the exchange rate. The main aim of the thesis is verification of chosen methods of the determination of a particular exchange rate in real market conditions. In the first part, the bachelor thesis deals with basic terms related to the currency market and are essential for understanding of a given matter. In this part there are described: the currency market, exchange rate quotation and different exchange rate systems. To understand given matter it is necessary to find out, how the given exchange rate works, what we can expect from it in the following years and thus estimate the future development of currency exchange rate. At the end of the theoretical part there are three basic theories of determination of the exchange rate introduced. Those are the purchasing power parity, the interest rate theory, and the last theory deals with the balance of payments. In the practical part I introduce three methods of determination on the exchange pair CZK/GBP, which is observed in the time frame from 2006 to 2017. To prove the validity and consequently compare the theoretical exchange rates with real exchange rates, uncovered interest parity, absolute and relative version of the purchasing power parity and lastly the theory of balance of payments of both countries were used. The future development according to the theory of balance of exchange rate is compared on the basis of current account and overall balance of payments of given countries. Based on the results, a best method of determining the future exchange rate development is suggested.
|
|
|
HPLC Determination of Potential Drugs
Paličková, Karolína ; Kubíček, Vladimír (advisor) ; Drastík, Martin (referee)
1 ABSTRACT Charles University Faculty of Pharmacy in Hradec Králové Department of Biophysics and Physical Chemistry Candidate: Karolina Palickova Consultant: Ing. Vladimir Kubicek, CSc. Title of Thesis: HPLC Determination of Potencial Drugs The diploma thesis describes selection of the most suitable conditions for HPLC determination of a recently prepared potential bronchodilatans. The aim of the thesis was to find a suitable isocratic method for the HPLC determination of the substance in rat plasma to be used during pharmacokinetic experiments. The chromatographic column Ascentis® Express RP - Amide was utilized. Best results were achieved with mobile phase consisting of acetonitrile and phosphate buffer (pH = 3,0) in volume ratio 12:88. The column was thermostated at 20 řC. Fluorescence detection (λex = 228 nm, λem = 380 nm) was applied to get a sufficient sensitivity. 4-quinazolinole was chosen as an internal standard. Biological samples were processed by LLE before the HPLC analyses. The proposed method was validated successfully and then employed in pharmacokinetic studies.
|
|
|
Mercury Electrodes as Tools for Voltammetric Determination of Biologically Active Organic Compounds and for Detection of Their Interaction with DNA
Horáková, Eva ; Vyskočil, Vlastimil (advisor) ; Ludvík, Jiří (referee) ; Vytřas, Karel (referee)
The main aim of this work was to use traditional mercury electrodes for the development of voltammetric methods of determination of organic xenobiotics and for the electrochemical study of the interaction between double-stranded deoxyribonucleic acid (DNA) and these compounds. In relation to my previous research work (conducted in the framework of my diploma thesis), firstly, 4-nitrobiphenyl (4-NBP), the suspected carcinogen, was studied. Interaction of DNA with 4-NBP was studied using differential pulse voltammetry (DPV), cyclic voltammetry (CV), and chronocoulometry at a hanging mercury drop electrode (HMDE), and using CV and alternating current voltammetry at a DNA modified HMDE. Using CV, the reduction mechanism was investigated. The interaction of DNA with 4-aminobiphenyl (4-ABP), a metabolite of 4-NBP, and 4-NBP reduction intermediates was studied. It was found that the interaction of DNA with 4-NBP or 4-ABP results in a formation of a DNA aggregate with these analytes. The second studied analyte was methyl violet 2B (MV). For determination of MV in a buffered solution were used: direct current tast polarography and differential pulse polarography at a dropping mercury electrode, and direct current voltammetry, DPV, and differential pulse adsorptive stripping voltammetry (DPAdSV) at HMDE. The...
|
guest ::
