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Speciation analysis of arsenic and mercury using postcolumn generation of their volatile compounds for needs of atomic spectroscopic methods
Linhart, Ondřej
The presented dissertation thesis deals with the use of UV-photochemical generation of volatile compounds (UV-PVG) as a derivatization technique for the combination of high-performance liquid chromatography (HPLC) and atomic absorption spectrometry (AAS) detection. Two model elements arsenic and mercury and their compounds were selected for the speciation analysis. The work was divided into several parts that follow. In the first part of the research, the apparatus for the UV-photochemical generation of the volatile mercury compounds and their detection with a new continuum source and high-resolution atomic absorption spectrometer (HR-CS AAS) with an externally heated detection tube was constructed. The analytical method was adapted for use with atomic fluorescence detection with the aim to improve sensitivity of the determination. Furthermore, apparatus for the electrochemical generation of cold mercury vapor with AAS detection was built. The construction of the apparatus was followed by optimization of the reaction conditions (concentration and flow of electrochemical reagents: sulfuric and hydrochloric acid, mobile phase, carrier medium, flow rate of the carrier gas and localization of its introduction), determination of the analytical figures of merit, and comparation of the methods. Both...
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The content of selected group 1 and 2 metals in edible mushrooms
MÁCHOVÁ, Nikola
Edible mushrooms are able to accumulate elements, especially some heavy metals and radionuclides, in their fruiting body. This work engages in accumulation of chosen metals (Groups 1 and 2) in basidiomycete fungi and soil. The first picking happened in autumn 2017. Eleven mushroom specimens were found - several fruiting bodies of each type. The soil where the mushrooms had grown was also taken. During the other picking in autumn 2018 ten types of mushrooms were taken. The locality in the Czech Republic (Ledenice) was chosen, because these fungi were frequently found there: Agaricus campestris, Boletus edulis, Suillus variegatus, Xerocomellus chrysenteron, Neoboletus luridiformis, Leccinum rufum, Macrolepiota procera, Suillus luteus, Imleria badia, Leccinum scabrum, Lactarius deliciosus, Agaricus silvaticus, Suillus bovinus and Amanita rubescens. The chosen metals were Lithium (Li), Strontium (Sr), Cesium (Cs) and Rubidium (Rb). I used methods of atomic absorption spectrometry (AAS). In both analysis (2017 and 2018) the largest content of Lithium was recorded in Agaricus campestris fruiting body (2.3 mg/kg and 1.6 mg/kg) and the largest content of Strontium in Leccinum rufum (3.7 mg/kg and 6.6 mg/kg). It was shown that varieties of the Bolete family demonstrated the biggest accumulation of Rubidium (Boletus edulis 519 mg/kg, Neoboletus luridiformis 398.6 mg/kg). The biggest content of Cesium (about 1.1 mg/kg) was recorded also in this family.
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Speciation analysis of arsenic and mercury using postcolumn generation of their volatile compounds for needs of atomic spectroscopic methods
Linhart, Ondřej ; Červený, Václav (advisor) ; Spěváčková, Věra (referee) ; Šíma, Jan (referee)
The presented dissertation thesis deals with the use of UV-photochemical generation of volatile compounds (UV-PVG) as a derivatization technique for the combination of high-performance liquid chromatography (HPLC) and atomic absorption spectrometry (AAS) detection. Two model elements arsenic and mercury and their compounds were selected for the speciation analysis. The work was divided into several parts that follow. In the first part of the research, the apparatus for the UV-photochemical generation of the volatile mercury compounds and their detection with a new continuum source and high-resolution atomic absorption spectrometer (HR-CS AAS) with an externally heated detection tube was constructed. The analytical method was adapted for use with atomic fluorescence detection with the aim to improve sensitivity of the determination. Furthermore, apparatus for the electrochemical generation of cold mercury vapor with AAS detection was built. The construction of the apparatus was followed by optimization of the reaction conditions (concentration and flow of electrochemical reagents: sulfuric and hydrochloric acid, mobile phase, carrier medium, flow rate of the carrier gas and localization of its introduction), determination of the analytical figures of merit, and comparation of the methods. Both...
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Generation of volatile species of palladium for atomic absorption spectrometry
Vyhnanovský, Jaromír ; Musil, Stanislav (advisor) ; Matoušek, Tomáš (referee)
This thesis deals with optimization of the conditions for chemical generation of volatile species of palladium in combination with atomic absorption spectrometry. The volatile species of palladium were generated in a flow injection system by the reaction of an acidified sample with the solution of sodium borohydride in the presence of reaction modifiers. A diffusion flame atomizer was used due to its high robustness. In the first part of this thesis the optimization of parameters affecting the atomization in the diffusion flame was carried out (flow rates and composition of gases, observation height). In the second part, concentrations of individual reagents used (nitric acid, sodium borohydride, Triton X-100, Antifoam B, sodium diethyldithiocarbamate) were optimized. The positive effect of the reaction modifiers was demonstrated, especially that of sodium diethyldithiocarbamate, which lead to a tenfold increase in the sensitivity. The limits of detection and limits of quantification for the wavelength 244,8 nm were 0,25 mg dm-3 and 0,67 mg dm-3, respectively. The repeatability for this method for the concentration 5 mg dm-3 was 2,8 %. Key words: palladium, chemical generation of volatile species, atomic absorption spectrometry
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Using of chemical mercury cold vapor generation for speciation analysis of selected mercury compounds employing HPLC and AAS
Králová, Pavlína ; Červený, Václav (advisor) ; Kratzer, Jan (referee)
The aim of this diploma thesis was to verify the usability of the chemical generation of mercury cold vapor for speciation analysis of selected mercury compounds using high - performance liquid chromatography coupled within atomic absorption spectrometry in the determination of mercury in real tap water samples. In this work, mercuric chloride, methylmercury, ethylmercury and phenylmercury were selected as model analytes. In the first part, the working conditions of chemical generation of mercury cold vapor for each of the selected specie of mercury were optimized. Optimized equipment was used to measure the calibration dependence for each specie and the basic characteristics of the method were established. After optimization of the chemical generation, HPLC column was connected prior this derivatization step and in resulted combined apparatus HPLC - CVG - QTAAS, the separation step was optimized . At optimized conditions, the calibration dependence was measured for each specie and the basic characteristics of the developed method including HPLC separation were established. In conclusion, the proposed analytical method was tested on real flowing tap water samples. Because of low content of mercury species in these samples, the recovery of the method was established when comparing the signal of...
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Determination of iron in beer using atomic absorption spectroscopy
Jandovská, Vladimíra ; Tesařová, Eva (advisor) ; Frantík, František (referee)
This thesis describes the development and optimisation of a method for determination of iron in beer using electrothermal atomic absorption spectroscopy as a more sensitive option to routinely used flame atomic absorption spectroscopy. While a fully functional method has been developed for aqueous solutions, matrix effects in real beer samples made this determination impossible. Therefore, a method of sample preparation has been developed, beer purifying through column with adsorbent Florisil. After this adjustment the interfering substance was eliminated and the detection limit of ETAAS was six times lower than the detection limit of FAAS. The content of iron in the real beer sample using ETAAS was measured as 30 % lower than using FAAS, it is therefore necessary to optimise this method. This will be the subject of further experiments.
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Spectrometric determination of selected metals in the samples from old ecological burden area
Zurynková, Pavla ; Kratzer, Jan (advisor) ; Spěváčková, Věra (referee)
This bachelor thesis is focused on heavy metals pollution in the Králíky town and its vicinity, located in the Pardubice region. This region was selected because there had been a Tesla factory producing fluorescent lamps. Moreover, there is also a waste disposal of the fluorescent lamps wasters and other dangerous waste located about two kilometers far from the former factory. Soil samples from the waste disposal area as well as river sediment, samples taken in the Tichá Orlice river and the Králický brook have been analyzed Mercury, cadmium, lead, chromium, nickel, copper and arsenic levels in the samples were measured by inductively coupled plasma - mass spectrometry. The total mercury content has also been measured with single-purpose atomic absorption spectrometer AMA-254. An optimization of leaching conditions of the elements was performed prior the analysis of the samples employing certified reference material. High levels of mercury, cadmium, lead, chromium, nickel and copper have been found in the waste disposal area. Regarding the sediment samples the highest levels of pollution have been detected near outfall of the sewage water from the industrial area in the Králíky town (former Tesla factory and recent metal plating industry). The concentration of heavy metals in other sediment...
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Generation of volatile species of copper for atomic absorption spectrometry
Šoukal, Jakub ; Musil, Stanislav (advisor) ; Rybínová, Marcela (referee)
This thesis deals with optimization of conditions of chemical generation of volatile species of copper for atomic absorption spectrometry. The volatile species of copper were generated in the flow arrangement in a special generator by the reaction of the acidified sample with the solution of sodium borohydride in the presence of reaction modifiers. A diffusion flame was used as the atomizer of volatile species of copper due to its high robustness. First, all the parameters affecting atomization in the diffusion flame were optimized (flow rates and composition of gases, observation height). In the next section, concentration of individual reagents for chemical generation of volatile species was optimized, especially the concentration of nitric acid, sodium borohydride and reaction modifiers. Triton X-100 and Antifoam B were chosen as the best combination of modifiers with respect to threefold increase in sensitivity, tailing of measured signals and because of long-term repeatability. There was not observed any significant positive effect on the sensitivity of measurement for other tested reaction modifiers. The limits of detection and quantification were 62 mg dm−3 and 208 mg dm−3 , respectively. The repeatability of this method for concentration 2,5 mg dm−3 was 2,4%. Key words copper, chemical...
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Hydride generation study for arsenic speciation analysis with AAS and AFS detection
Svoboda, Milan ; Dědina, Jiří (advisor) ; Spěváčková, Věra (referee) ; Komárek, Josef (referee)
The general aim of this work was a development of methodology and instrumentation for speciation analysis based on the combination of the selective generation of substituted hydrides with atomic absorption or atomic fluorescence spectrometry detection. The first topic of this work was the development of methodology and instrumentation for arsenic speciation analysis based on selective generation of substituted arsines with trapping in the cryogenic trap (U-tube packed with chromosorb) with AAS detection (HG- CT-AAS). The conditions of the selective hydride generation approach as well as working procedure of the cryogenic trap were optimized (appropriate approach for hydride generation, set up of heating program of cryogenic trap, new dryer - cartidge with NaOH, elimination of unspecific absorption, decreasing of the detection limits). The second important part of the work lay in applying of the developed method for arsenic speciation analysis in a homogenized mouse liver tissue. The direct slurry sampling to hydride generator was develop. Moreover the information about oxidation state (iAsIII,V , MAsIII,V a DMAsIII,V ) was obtain. The effect of relevant experimental parameters such as tetrahydroborate concentration, TRIS buffer concentration and time of pre-reduction of the samples by L-cysteine...
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