|
|
Spectrometric analytical methods for the analysis of metallic materials and the issue of measuring the carbon content in graphitic cast irons
Osička, Ondřej ; Pernica, Vítězslav (referee) ; Kaňa, Václav (advisor)
Competitive metallurgical production is almost impossible without the knowledge of the chemical composition of manufactured and finished melt, or the produced product. With growing customer demands for product quality and product characteristics, increasing technology speed and increasing product purity, there is growing demand for analyzes of chemical composition. These demands are very often against each other, especially the increasing demands on the speed and accuracy of analyzes. Analytical requirements may not only apply to the test technique, but also to the quality of the sample, which is inseparable from it. What is recently seen as the biggest drawback, the new technology is trying to use as its main priority. This is undoubtedly true of atomic emission spectrometry.
|
|
|
Investigation of Miniature Devices for Collection of Hydride Forming Elements in Atomic Spectrometry Methods
Krejčí, Pavel ; Čelechovská, Olga (referee) ; Janoš, Pavel (referee) ; Otruba, Vítězslav (referee) ; Dočekal, Bohumil (advisor)
Capability of a prototype of miniature collection device based on a strip of the molybdenum foil for collecting hydride forming elements (As, Se, Sb and Bi) was studied. The device was combined with a miniature hydrogen diffusion flame for detection by atomic absorption spectrometry. The conditions for trapping and subsequent vaporization of analytes of interest were optimized. A twin-channel hydride generation system was used for study of mutual interference effects of co-generated hydride forming elements. The influence of modification of the molybdenum surface with noble metals - Rh, Pt and Ir on trapping and vaporization processes was also studied and changes of microstructure of the foil surface after modification were investigated using scanning electron microscope equipped with energy dispersive x-ray analyzer and electron backscattered diffraction system. Complementary radiotracer and radiography experiments were performed in order to determine trapping efficiency and to assess the spatial distribution of collected analytes within the device. Practical application of the method was demonstrated on determination of antimony in water samples at trace level. Possibility of multi-element analysis was demonstrated by combining the collection device with atomization and excitation of the analyte in microwave induced plasma and with detection by atomic emission spectrometry method. The results of the experiments proved that tested miniature collection device is capable of trapping analytes that form volatile hydrides. This device can be coupled to various types of atomizers, typically used in spectrometry methods. Thus, very sensitive and specific detection of hydride forming elements can be performed.
|
|
| |
|
|
Determination of heavy metals in gread tits blood and feathers
Labancová, Katarína ; Hraníček, Jakub (advisor) ; Nováková, Eliška (referee)
CZ Tato bakalářská práce se zabývá analýzou vybraných těžkých kovů (olovo, kadmium, měď, chrom, arsen) ve vzorcích krve a peří sýkor koňader (Parus major) metodou atomové absorpční spektrometrie s elektrotermickou atomizací a technikou generování těkavých sloučenin s detekcí křemenného atomizátoru. Za optimálních podmínek byla sestavena kalibrační závislost a zjistěné základní charakteristiky pro jednotlivé prvky. Klíčová slova Atomová absorpční spektrometrie, elektrotermická atomizace, chemické generovaní, těžké kovy, krev, peří, sýkora
|
|
|
Determination of heavy metals in gread tits blood and feathers
Labancová, Katarína ; Hraníček, Jakub (advisor) ; Nováková, Eliška (referee)
CZ Tato bakalářská práce se zabývá analýzou vybraných těžkých kovů (olovo, kadmium, měď, chrom, arsen) ve vzorcích krve a peří sýkor koňader (Parus major) metodou atomové absorpční spektrometrie s elektrotermickou atomizací a technikou generování těkavých sloučenin s detekcí křemenného atomizátoru. Za optimálních podmínek byla sestavena kalibrační závislost a zjistěné základní charakteristiky pro jednotlivé prvky. Klíčová slova Atomová absorpční spektrometrie, elektrotermická atomizace, chemické generovaní, těžké kovy, krev, peří, sýkora
|
|
|
Spectrometric analytical methods for the analysis of metallic materials and the issue of measuring the carbon content in graphitic cast irons
Osička, Ondřej ; Pernica, Vítězslav (referee) ; Kaňa, Václav (advisor)
Competitive metallurgical production is almost impossible without the knowledge of the chemical composition of manufactured and finished melt, or the produced product. With growing customer demands for product quality and product characteristics, increasing technology speed and increasing product purity, there is growing demand for analyzes of chemical composition. These demands are very often against each other, especially the increasing demands on the speed and accuracy of analyzes. Analytical requirements may not only apply to the test technique, but also to the quality of the sample, which is inseparable from it. What is recently seen as the biggest drawback, the new technology is trying to use as its main priority. This is undoubtedly true of atomic emission spectrometry.
|
|
|
The content of selected metals in soil as an indicator of contamination due to the road traffic
VOLAVKA, Tomáš
The soil, as a part of ecosystem, is permanently endangered by pollution and exposed to degradation. A large share on this pollution has a human. This problem is caused mainly by industrial production, agriculture and transport. Intensive chemical maintenance is necessary during winter. It is because of better driving on the roads. Chemicals gradually soak into the soil and contaminate it. This master thesis deals with the analysis of soil samples from close proximity of road from Veseli nad Luznici to Trebon. There was analyzed the concentration of copper, sodium and zinc. Samples were collected in two depths: from 0 to 15 cm (surface sample) and 15 to 30 cm (subsurface sample). The mentioned metals were analyzed by atomic spectrometry. The measured value concentration of copper was between 2.24 mg-kg-1 and 84.35 mg-kg-1, the sodium concentration was from 11 mg-kg-1 to 1 697 mg-kg-1 and the zinc concentration was in the range of 9 mg-kg-1 526 mg-kg-1. The highest concentration of copper (84.35 mg-kg-1) was found in the subsurface sample taken from the immediate proximity of the railway in February 2017. The highest concentration of sodium (1 697 mg-kg-1) was measured near the road in February 2016. The highest concentration of zinc (526 mg-kg-1) was measured near railway in October 2015.
|
|
|
Investigation of Miniature Devices for Collection of Hydride Forming Elements in Atomic Spectrometry Methods
Krejčí, Pavel ; Čelechovská, Olga (referee) ; Janoš, Pavel (referee) ; Otruba, Vítězslav (referee) ; Dočekal, Bohumil (advisor)
Capability of a prototype of miniature collection device based on a strip of the molybdenum foil for collecting hydride forming elements (As, Se, Sb and Bi) was studied. The device was combined with a miniature hydrogen diffusion flame for detection by atomic absorption spectrometry. The conditions for trapping and subsequent vaporization of analytes of interest were optimized. A twin-channel hydride generation system was used for study of mutual interference effects of co-generated hydride forming elements. The influence of modification of the molybdenum surface with noble metals - Rh, Pt and Ir on trapping and vaporization processes was also studied and changes of microstructure of the foil surface after modification were investigated using scanning electron microscope equipped with energy dispersive x-ray analyzer and electron backscattered diffraction system. Complementary radiotracer and radiography experiments were performed in order to determine trapping efficiency and to assess the spatial distribution of collected analytes within the device. Practical application of the method was demonstrated on determination of antimony in water samples at trace level. Possibility of multi-element analysis was demonstrated by combining the collection device with atomization and excitation of the analyte in microwave induced plasma and with detection by atomic emission spectrometry method. The results of the experiments proved that tested miniature collection device is capable of trapping analytes that form volatile hydrides. This device can be coupled to various types of atomizers, typically used in spectrometry methods. Thus, very sensitive and specific detection of hydride forming elements can be performed.
|
|
| |
guest ::
