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Separation of toxicologically relevant arsenic species for speciation analysis by RP-HPLC-ICP-MS
Kanásová, Mária ; Matoušek, Tomáš (advisor) ; Červený, Václav (referee)
The thesis is mapping possibilities of separation of toxicologically relevant arsenic species complexed with peptides by reversed-phase high-performance liquid chromatography-inductively coupled plasma mass spectrometry (RP-HPLC-ICP-MS). The C18 chromatography column and gradient elution of the mobile phase (0,1% formic acid with gradient of acetonitrile) was used. At these conditions the separation of simple arsenic species - arsenite (As(III)), arsenate (As(V)), monomethylarsenic acid (MA(III)), monomethylarsenous acid (MA(V)), dimethylarsenic acid (DMA(III)) and dimethylarsenous acid (DMA(V)) was not successful. However, separation of arsenic- -glutathione complexes - arsenic triglutathione (ATG), methylarsenic diglutathione (MADG) and dimethylarsenic glutathione (DMAG) was obtained. Several chromatographic peaks were observed at higher concentration of acetonitrile in mobile phase. The analysis of two in vitro methylation mixtures was also examined. Mixtures contained arsenite (As(III)), S-(5'-adenosyl)methionine chloride (SAM), tris(2-carboxyethyl)phosphine (TCEP) and arsenic(3+)methyltrasferase enzyme (AS3MT) probably participating in human arsenic metabolism. Second mixture also included glutathione (GSH). Several chromatographic peaks of complex species were obtained by analyzing these...
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Evaluation of sequential extraction for speciation of arsenic in mining wastes
Grösslová, Zuzana ; Drahota, Petr (advisor) ; Vaněk, Aleš (referee)
ii SUMMARY This master thesis deals with selectivity assessment of an arsenic sequential extraction procedure for evaluating mobility in mine wastes. A modified sequential extraction procedure was designed on the basis of preliminary tests of extraction efficiency and selectivity for the synthetic As mineral phases (scorodite, amorphous iron arsenate, schwertmannite, goethite, jarosite) and five natural samples (Kaňk, Dlouhá Ves, Giftkies, Roudný) that were previously characterized for As concentration and speciation. The modified sequential extraction has five steps. The first leaching step was performed in nitrogen-purged deionized H2O for 10 hours; next step involved 0.01M NH4H2PO4 leaching for 16 hours. Phases in the third step were dissolved with 0.2M Tamm`s reagent in darkness for 2 hours. The fourth step was represented by 0.2M of Tamm`s reagent heated in water bath at 80řC for 4 hours. Strong acid solutions HCl/KClO3/HNO3 were used to leach sulphide phases in the last step. The testing of the sequential extraction procedure using model mixtures showed a good discrimination of several fractions: adsorbed arsenic, arsenic associated with poorly crystalline oxyhydroxide, hydroxosulfate and arsenate phases (amorphous iron arsenate, schwertmannite, ferrihydrite), arsenic associated with crystalline...
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Diel variations of selected elements in arsenic-rich stream at the Mokrsko
Nováková, Barbara ; Drahota, Petr (advisor) ; Skřivan, Petr (referee)
The filtration and ultrafiltration experiment was applied on the stream water at the Mokrsko gold deposit and the results revealed that most of the elements were in the dissolved form and the 0,45 or 0,1 m filters could be used. During two 24-h field experiments, water samples were collected at 1-h intervals in order to prove the diel changes in the concentration and speciation of several trace elements. The determination of sorption processes at the surface of or within the veneer of biofilm has been determined by collecting natural and artificial priphyton. The results showed regular diel changes of As, Sb and Mo with highest concentrations occurring after the moon and the lowest concentrations in the early morning. The dissolved concentrations of other elements are conservative or their values were closed to their detection limits. The diel cycles are caused by changes in adsorption/desorption equilibria induced by diel cycles of temperature. The samples of biofilm revealed increased concentrations of the elements under the study and their diel variation were significant (approximatelly 35-96%); however, biofilm-controlled diel cycles of dissolved concentrations have not been proved.
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Construction of miniature flow-through cells for electrochemical generation of volatile compounds
Hraníček, Jakub ; Rychlovský, Petr (advisor) ; Spěváčková, Věra (referee) ; Komárek, Josef (referee)
(EN) The presented dissertation thesis summarizes the new results of electrochemical generation of volatile compounds usable in atomic spectral methods. The main aim of this work is to develop and to characterize new types of electrolytic flow-through cells and to examine their possibilities of determination of arsenic, selenium and antimony by using the electrochemical hydride generation technique coupled with atomic absorption spectrometry with a quartz tube atomizer. Individual electrolytic cells were designed and constructed to comply with two important requirements. The cathode chamber of the electrolytic cell should have a minimal volume and a high efficiency of analyte conversion to the volatile hydride. Constructed electrolytic cells are divided into the construction groups and described in the experimental part. Selenium was chosen as the first analyte. The relevant working parameters (such as type, concentration and flow rate of electrolytes, generation current and carrier gas flow rate) were optimized for each newly constructed electrolytic cell. Under the optimal working parameters, the basic characteristics of selenium determination were found out by using electrochemical hydride generation. The electrolytic cells were compared to each other and with the classical electrolytic cell...
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Anomalous occurences of arsenic in natural waters in the Czech Republic
Rodovská, Zuzana ; Drahota, Petr (advisor) ; Redlich, Aleš (referee)
This bachelor thesis reviews the data on the distribution of arsenic in surface and underground natural waters of the Czech Republic. In addition the thesis focuses on the occurrence of anomalous arsenic concentrations and tries to detect sources of arsenic contamination. Results of the thesis suggest high quality of the surface and groundwater in the Czech Republic with respect to arsenic. Its anomalous concentrations in the natural waters in Czech Republic have been rarely documented only in areas with strong anthropogenic impact and in areas affected by historical mining operations. Keywords: Arsenic, toxicity, contamination, surface water, groundwater, Czech Republic
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How do plants manage to survive on toxic spoil-mining sites? Physiological and structural properties of plants on substrates with high As and Hg contents
Kovářová, Monika ; Albrechtová, Jana (advisor) ; Soudek, Petr (referee)
The heavy metals contamination of environment represents a worldwide problem lately. Heavy metals cause harmful effects not only to plants, but also to other organisms. Throught their acumulation in plant biomass, heavy metals enter a food chain and could negatively influence the human health. The impact of heavy metals on plants and their defence mechanisms against toxicity of heavy metals have been in focus of plant physiology and ecology research for decades. Importance of this topic arises from plant role in environment, ecosystem services and in human nutrition. Investigation in proces and mechanisms of heavy metal hyperacumulation in plants offer progress in fytoremediation and genetic engineering. The experiments on agricultural crops show how heavy metals enter the food chain and how they affect the crop yield. The aim of this thesis is to summarize information about heavy metals' effects on plants. The thesis is focused on arsenic and mercury, because the Czech Republic have also problem with heavy metals contamination and these two metals occur in high concentration in the spoil banks and soils adjacent to the lignite mining areas of Sokolovsko. The spoil banks with heavy metal content have to be revegatated, thus, the topic of their effect on plants is of high importance. In the first part of the...
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Contributions to Volatile Compound Generation of Arsenic, Silver and Gold by Tetrahydroborate Reaction for Atomic Absorption Spectrometry
Musil, Stanislav ; Rychlovský, Petr (advisor) ; Kanický, Viktor (referee) ; Spěváčková, Věra (referee)
(EN) The presented dissertation thesis summarizes the results contained in five original research papers that were published in prestigious international scientific journals in the field of analytical chemistry and atomic spectrometry. It is devoted to the method of generation of volatile compounds using a tetrahydroborate reaction and detection in a quartz multiatomizer by atomic absorption spectrometry. The thesis can be divided into two thematic parts - speciation analysis of arsenic based on hydride generation technique with collection and separation in a cryogenic trap and generation of volatile species of transition metals. In the first thematic part pre-reduction of pentavalent inorganic and methylated arsenicals has been studied. A simple setup for on-line pre-reduction employing thioglycolic acid as a fast pre-reductant has been developed, connected with a current hydride generator and applied/verified to oxidation state specific arsenic speciation analysis of human urine samples. In the same method the possibility of drying the gaseous phase from water vapor has been investigated to avoid incidental blocking the cryogenic trap by frozen water and to decrease fluctuations of signal baseline. Pronounced losses of methylated species have been discovered on Nafion tube dryer currently used in...
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The Speciation Analysis of the Toxicological Important Forms of the Arsenic in Urban Particulate Matter Samples with the Detection QF-AAS
Jelínek, Petr ; Rychlovský, Petr (advisor) ; Červený, Václav (referee)
The topic of this diploma thesis was the speciation analysis of the toxicological important forms of the arsenic in urban particulate matter samples. The detection technique used in this work was atomic absorption spectrometry with quartz atomizer. Acetic acid, ammonium acetate, hydroxylamine, potassium hydroxide and sodium carbonate are recommended leaching agents for extraction of metals from urban particulate matter samples. Results of the presenting work are following: Acidic extraction reagents can be not recommended for the speciation analysis of the arsenic, because these reagents lower sensitivity of the determination of As3+ and As5+ too and destroy the quartz atomizer. Alkaline extraction reagents don't lower sensitivity of the determination of As3+ and these reagents don't destroy the atomizer, but lower sensitivity of the determination of As5+ was obtained. Recommended reagents aren't useful for extraction of the metals from urban particulate matter samples for the speciation analysis.
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