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Electrophoretic Determination of Tantalum in Recycled Coolants
Gogulin, Semen ; Křížek, Tomáš (advisor) ; Coufal, Pavel (referee)
This master thesis deals with the development of electrophoretic methods for determination of tantalum in recycled coolants used in the production of tantalum capacitors, as well as the separation of tantalum from chemically similar niobium. Developed methods are based on the formation of negatively charged complexes of tantalum and niobium with a number of ligands added to the separation electrolyte, especially tartaric and citric acid and 4-(2-pyridylazo)resorcinol. The separations were performed in a fused silica capillary of the inner diameter of 50 µm and the effective length of 36.5 cm, a negative voltage of -25 kV was applied to the capillary. Using a separation electrolyte containing 0.1 mol·l-1 of tartaric and citric acid at pH = 2, separation of niobium and tantalum was achieved in less than 3 minutes; the absorption spectrometric detection was carried out in the ultraviolet region at a wavelength of 200 nm, the detection limit was 2.8 ppm of tantalum, and the quantification limit was 9.2 ppm of tantalum. Addition of 4-(2-pyridylazo)resorcinol reduced the detection limit to 0.8 ppm of tantalum and the quantification limit to 2.6 ppm of tantalum; the electrolyte contained 0.1 mmol·l-1 of 4-(2-pyridylazo)resorcinol, 10 mmol·l-1 of tartaric acid, 10 mmol·l-1 of citric acid, and 25 mmol·l-1...
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Applications of chiral and achiral chromatography in pharmacology and toxicology
Chytil, Lukáš ; Slanař, Ondřej (advisor) ; Bultas, Jan (referee) ; Coufal, Pavel (referee)
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...
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Development of electrophoretic method for determination of ethanolamines in antifreeze mixtures
Hamráková, Katarína ; Křížek, Tomáš (advisor) ; Coufal, Pavel (referee)
This bachelor thesis deals with development, optimization and testing of the applicability of electrophoretic method for determination of ethanolamines in antifreeze mixtures. The method was tested with the coolant matrix. For the determination of ethanolamines in antifreeze mixtures a capillary electrophoresis with undirect UV detection was used. Ethanolamines - monoethanolamine, diethanolamine and triethanolamine - are organic compounds, which are used in antifreeze mixtures as corrosion inhibitors because glycols, which are often used in such mixtures, can be, after exposure to high temperatures or oxygen from air, transformed to acids that cause corrosion. The method was optimized by selection of the appropriate composition of background electrolyte, its pH, appropriate ratio of individual buffer components and selection of a suitable internal standard. Background electrolyte was a buffer composed of 60 mM acetic acid and 30 mM histidine, pH 4.59 and lysine was used as an internal standard. Silica capillary with an internal diameter of 50 µm, a total length of 50.0 cm and an effective length of 41.5 cm was used for measurements. Measurement at short end was tested, as well as shortening the capillary to 35.0 cm with an effective length of 26.5 cm, which was further used. The sampling was...
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Analysis of proteins and their changes in biological tissues
Kulhavá, Lucie ; Mikšík, Ivan (advisor) ; Coufal, Pavel (referee) ; Bílková, Zuzana (referee)
(EN) Proteins are the important biologically active substances for the organism, their qualitative and quantitative composition determines thein function in the organism. Protein analysis in biological material is an important part of biological and medical research. This dissertation is focused on the optimalization of sample preparation - the biological materials - namely the pre-analytical phase of sample processing and their preparation for their own analases and also introducing new procedures in theie praparation. The conditions of individual analysis approaches were always optimized by means of one- dimensional and two-dimensional gel electrophoresis and mass spectrometry. The obtained results were statistically evaluated and other possible approaches to futher research were outlined. The main biological material studied was human saliva with regard to oral health. Comparative study of human saliva was performed (human saliva obtained from caries-free and caries-susceptible people). The saliva composition of individual fractions was investigated with regard to oral health. The study was carried out to compare differences in the abundances of proteins in the saliva of caries-free and caries-susceptible persons, based on label-free mass spectrometry quantification, and to perform a gender...
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Chromatographic characterization of an ion-exchange column
Štverková, Kateřina ; Sobotníková, Jana (advisor) ; Coufal, Pavel (referee)
This bachelor thesis deals with the characterization of the anion exchange column by the linear solvation energy relationship (LSER) model. The aim of this bachelor thesis was to find optimal conditions suitable for separation of thiazide diuretics (trichlormethiazide, bendroflumethiazide, buthizide, chlorthalidone, mefrusid) on PhenoSphereTM 5μm SAX 80 Ǻ column. These experimental conditions were used for measuring the retention factors of LSER analytes. The multiple linear regression was consequently applied to the retention factors to calculate the LSER regression coefficients, describing the interactions between the stationary phase, the mobile phase and the analytes.
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Electrophoretical determination of corrosion inhibitors in engine coolants
Smrž, Dominik ; Kubíčková, Anna (advisor) ; Coufal, Pavel (referee)
A determination of corrosion inhibitors in engine coolants represent a difficult analytical problem due to their different physicochemical properties. Nowadays a lot of instrument methods are needed to determine them. The aim of this work was the development of methods for their determination using only one instrumentation. Capillary zone electrophoreses was chosen as a suitable technique. Three electrophoretic methods for three groups of corrosion inhibitors were developed. Firstly, method for determination of inorganic anions was developed in range from 5 to 50 ppm with limit of detection around 1 ppm. Background electrolyte contains sodium chromate, CTAB and CHES solution. Analytes were detected indirectly at 450 nm. Another method was for determination of organic acids anions. They were determined in range from 5 to 500 ppm. Limit of detection for each analyte was around 1 ppm. Measurement was made with PDC a CTAC water solution. Indirect detection was used for this determination at 350 nm. Last developed method can be use for determination of aryltrizoles in range from 5 to 500 ppm. Limit of detection was around 1 ppm. As a background electrolyte was used sodium tetraborate solution. The developed methods were validated and their suitability for determination of corrosion inhibitors in real...
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Study of Boron-Carbohydrate Interaction
Vejvodová, Tereza ; Jelínek, Ivan (advisor) ; Coufal, Pavel (referee)
The interaction between boron and sugars is significant for understanding the role of boron as a carrier for nucleotides and carbohydrates. Arylboronic acids also have wide application as sugars sensors because they are small and flexible molecules. Boron complexes play a key role in boron neutron capture therapy. This radiotherapy is important in the treatment of melanoma, glioblastoma multiforme and other types of cancer. Boron complexes with ascorbic acid and glucose were prepared in this thesis and then characterized by high-resolution mass spectrometry (HRMS). Synthesised complexes were studied using collision-induced dissociation (CID), which led to the clarification of their fragmentation mechanism. Key Words Boron complexes, ascorbic acid, glucose, carbohydrates, mass spectrometry, electrospray ionization, ESI-MS, collision-induced dissociation
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Extraction of nucleotides from plant matrix and their determination by ion-exchange high performance liquid chromatography
Konečná, Markéta ; Sobotníková, Jana (advisor) ; Coufal, Pavel (referee)
In this thesis chromatographic conditions for the HPLC analysis of ribonucleotides AMP, ADP and ATP were optimized. For their separation chromatographic column, Nucleogel SAX 1000-8, 50 x 4,6 mm, from the German company Marcherey-Nagel was used. The mobile phase of a 0,2 mol/L solution of KH2PO4, its pH was adjusted with 1mol/L with potassium hydroxide to pH = 5,00. As the most suitable flow rate was selected 1,0 mL/min. The analysis was conducted using an isocratic elution. Detection was conducted by a DAD detector at a wavelength of λ = 260 nm. Substances were eluted in the following order AMP (tr = 0,911 min), ADP (tr = 1,667 min) and ATP (tr = 7,262 min). The total analysis time of the mixture of standards, under the conditions mentioned above, lasted for 10 minutes. For the extraction of adenosine-5-ribonucloetides the real matrix frozen and lyophilized leaves of tobacco virginia (Nicotiana tabacum L.) have been used. Two methods of extraction were applied. The first procedure was based on the extraction of AMP, ADP and ATP from the leaves of the tobacco plant by boiling deionized water. In the second method 0,07 mol/L HClO4 for the extraction instead of deionized water was used. Keywords: HPLC, adenosine ribonucleotides, AMP, ADP, ATP, tobacco virginia
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