20.500.12556/RUL-117077 Analiza aktinidov v netopnih ostankih po razkroju tal in sedimentov z različnimi razkrojnimi tehnikami Analysis of actinides in the insoluble residues after decomposition of soil and sediment samples by various decomposition techniques V magistrskem delu sem izvedla raziskavo primerjave treh različnih tehnik za razkroj vzorcev: kislinski razkroj z mešanico kislin HNO3, HClO4 in HF, fuzija z litijevimi borati ter izluževanje z 8 M HNO3. Z omenjenimi tehnikami sem razkrojila različne vzorce ter v njih določala koncentracijo aktivnosti urana, torija, americija in plutonija ter poleg tega analizirala tudi morebitne ostanke po razkroju. Ostanki so bili opaženi le pri kislinskem razkroju z mešanico kislin. V njih sem nato določala tudi morebitno prisotnost urana in torija, ker se kot naravna radioizotopa vežeta v strukturo mineralov in sta tako težje razgradljiva. Koncentracijo aktivnosti sem določala s predhodno separacijo z ekstrakcijsko kromatografijo s pomočjo radioaktivnih indikatorjev ter nadaljnjo detekcijo s spektrometrijo alfa in gama. Dobljeni ostanki po kislinskem razkroju so predstavljali od 1 do 50 % mase celotnega vzorca, kar je predstavljalo od 1 pa tudi do 50 % celotne koncentracije aktivnosti urana in torija v vzorcu. Delež ostanka in koncentracija aktivnosti v ostanku je bila odvisna od mineralne sestave oziroma vrste vzorca. In the presented work a comparison of conventional acid digestion with mixtures of acids HNO3, HClO4, and HF, thermal fusion using Li-borate as fusion agent and leaching with 8 M HNO3 was performed for solid samples. These techniques were used to analyse the decomposition of various samples and to determine the activity concentrations of uranium, thorium, americium, and plutonium, and to study their contents in possible residues obtained after decomposition. The results obtained showed that acid decomposition with an acid mixture is not complete and visible residues were observed after acid decomposition. A possible presence of uranium and thorium as natural radioisotopes was detected in the residues. They bind to the structure of minerals and are therefore more difficult to decompose. The activity concentrations of radionuclides were determined by preliminary separation by extraction chromatography using radioactive indicators and further detection by alpha and gamma spectrometry. The results obtained showed that acid digestion residues accounted from 1 to 50 % by weight of the total sample analysed, which represented 1 to 50 % of the total activity concentrations of uranium and thorium in the sample. The residual content and activity concentration in the residue depended strongly on the type and mineral composition of the samples. aktinidi tehnika razkroja ostanki ekstrakcijska kromatografija spektrometrija alfa spektrometrija gama actinides decomposition techniques residues extraction chromatography alpha-particle spectrometry gamma spectrometry true false false Slovenski jezik Angleški jezik Magistrsko delo/naloga 2020-06-23 14:20:01 2020-06-23 14:20:08 2022-08-29 03:40:59 0000-00-00 00:00:00 2020 0 0 0000-00-00 NiDoloceno NiDoloceno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 6722 20915715 Pilar_Anja_marija_-_Analiza_aktinidov_v_netopnih_ostankih_po_razkroju_tal_in_sedimentov_z_razlic.pdf Pilar_Anja_marija_-_Analiza_aktinidov_v_netopnih_ostankih_po_razkroju_tal_in_sedimentov_z_razlic.pdf 1 D31006A2C1B5E65BDD5C2A8B4A720B0C ef0670a4ee3b3d1ed7ff5005825d798aff1a3f44d0ee7e035cc9137004e64842 1792407d-a1b9-11eb-a523-00155dcfd717 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=130868 Fakulteta za kemijo in kemijsko tehnologijo 0 0 0