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Contribution to optimization of parameters of speciation analysis of As based on selective hydride generation in direct transfer mode and detection by atomic absorption spectrometry
Vyvadilová, Tereza ; Dědina, Jiří (advisor) ; Korunová, Vlasta (referee)
The presented thesis deals with optimization of parameters speciation analysis based on a selective hydride generation in a direct transfer mode of hydrides and on-line atomization in an atomic absorption spectrometer. In the first part of the thesis processes during generation were investigated. Important indicator of a reactions taking place in a generator is volume of hydrogen (created by decomposition of NaBH4) which is subsequently introduced to the atomizer. In this part of the thesis a new approach to determine a flow rate of hydrogen delivered to the atomizator was developed. An influence of relevant paremeters of the atomizers and atomic absorption spectrometers on basic analytical characteristics of arsenic determination based on hydride generation was performed in the second part. Three atomic absorption spectrometers were used and three sources of radiation were compared. The most important analytic characteristic was the limit of detection which is influenced by standard deviation of measurement values of blank samples and by sensitivity. The best values of the limit of detection were achieved with electrodeless discharge lamps. Key words: hydride generation, arsenic, speciation analysis, atomic absorption spectrometry
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Modular design for in-atomizer preconcentration of hydride forming elements with AAS detection
Novák, Petr ; Kratzer, Jan (advisor) ; Korunová, Vlasta (referee)
Modular design of hydride trap-and-atomizer device for AAS is constructed and tested. Modular design enables to test different preconcentration surfaces easily. Efficient in- atomizer preconcentration allows to reach detection limits of hydride forming elements at ultratrace levels. Bismuth and arsenic were chosen as model analytes and their preconcentration efficiencies were quantified employing quartz and sapphire as preconcentration surfaces. The results reached in the modular design were compared to those found previously in the compact quartz trap-and-atomizer device. The performance of the modular design is fully comparable with that of compact trap-and-atomizer design. Modular design can thus be employed for testing of novel preconcentration surfaces.
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Modular design for in-atomizer preconcentration of hydride forming elements with AAS detection
Novák, Petr ; Kratzer, Jan (advisor) ; Korunová, Vlasta (referee)
Modular design of hydride trap-and-atomizer device for AAS is constructed and tested. Modular design enables to test different preconcentration surfaces easily. Efficient in- atomizer preconcentration allows to reach detection limits of hydride forming elements at ultratrace levels. Bismuth and arsenic were chosen as model analytes and their preconcentration efficiencies were quantified employing quartz and sapphire as preconcentration surfaces. The results reached in the modular design were compared to those found previously in the compact quartz trap-and-atomizer device. The performance of the modular design is fully comparable with that of compact trap-and-atomizer design. Modular design can thus be employed for testing of novel preconcentration surfaces.
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Contribution to optimization of parameters of speciation analysis of As based on selective hydride generation in direct transfer mode and detection by atomic absorption spectrometry
Vyvadilová, Tereza ; Dědina, Jiří (advisor) ; Korunová, Vlasta (referee)
The presented thesis deals with optimization of parameters speciation analysis based on a selective hydride generation in a direct transfer mode of hydrides and on-line atomization in an atomic absorption spectrometer. In the first part of the thesis processes during generation were investigated. Important indicator of a reactions taking place in a generator is volume of hydrogen (created by decomposition of NaBH4) which is subsequently introduced to the atomizer. In this part of the thesis a new approach to determine a flow rate of hydrogen delivered to the atomizator was developed. An influence of relevant paremeters of the atomizers and atomic absorption spectrometers on basic analytical characteristics of arsenic determination based on hydride generation was performed in the second part. Three atomic absorption spectrometers were used and three sources of radiation were compared. The most important analytic characteristic was the limit of detection which is influenced by standard deviation of measurement values of blank samples and by sensitivity. The best values of the limit of detection were achieved with electrodeless discharge lamps. Key words: hydride generation, arsenic, speciation analysis, atomic absorption spectrometry
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Fishes as important indicators of environmental quality in the upper sections of the Tichá Orlice and Divoká Orlice rivers
Lusk, Stanislav ; Lusková, Věra ; Korunová, Vlasta
Investigations, implemented in the river network of the "Orlice" region over the past twenty years, made it possible to obtain data on the fish communities inhabiting the Tichá Orlice and Divoká Orlice rivers. The rivers are inhabited by salmonid fish communities dominated by Salmo trutta, Thymallus thymallus, Cottus gobio, and Lampetra fluviatilis. Water pollution was gradually limited by building water treatment plants as well as by the significant decrease in the intensity of agricultural activities. The environmental pollution with mercury in the Králíky region, lying on the upper reaches of the Tichá Orlice River, is a specific problem. Nevertheless, the mercury content in fish muscles has exceeded the hygienic limit (0.1 mg.kg-1). Fishermen consuming fish angled in the Tichá Orlice River have shown increased mercury contents in their hair.
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The mercury load in fishes inhabiting the upper section of the Divoká Orlice and Tichá Orlice rivers
Korunová, Vlasta ; Lusková, Věra ; Lusk, Stanislav
In the boundary section of Divoká Orlice R. the mercury content in the tissues of brown trout did not exceed 0.2 mg.kg-1. WHO risk limit, 1.6 µ mercury per 1 kg human body weight per week, is attained by a person weighing 75 kg and consuming 0.63 kg trout muscular tissue a week. In Divoká Orlice drainage area, the mercury content was determined in roach (Rutilus rutilus) in 1987-1995. In a majority of specimens analysed, the values of mercury contents in their muscular tissue exceeded 0.2 mg.kg-1 (max. 0.683 mg.kg-1). In the upper part of Tichá Orlice R., increased mercury contents were found in brown trout. Below the Králíky profile, the mercury contents varied around 0.50 mg.kg-1 in the muscular tissue, and up to 0.85 mg.kg-1. The mercury loads in the fishes decreased gradually in the downstream direction down to the value around 0.20 mg.kg-1. In the uppermost part of Tichá Orlice R. below the town of Králíky, the risk limit is only 0.24 kg trout meat consumed per week.
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