0000000000138931
AUTHOR
Horst Geckeis
X-ray absorption spectroscopic study of trivalent and tetravalent actinides in solution at varying pH values
Abstract We perform X-ray absorption spectroscopy (XAS) investigations to monitor the stabilization of redox sensitive trivalent and tetravalent actinide ions in solution at acidic conditions in a pH range from 0 to 3 after treatment with holding reductants, hydroxylamine hydrochloride (NH2OHHCl) and Rongalite (sodium hydroxymethanesulfinate, CH3NaO3S). X-ray absorption near edge structure (XANES) measurements clearly demonstrate the stability of the actinide species for several hours under the given experimental conditions. Hence, structural parameters can be accurately derived by extended X-ray absorption fine structure (EXAFS) investigations. The coordination structure of oxygen atoms be…
Separation of plutonium and neptunium species by capillary electrophoresis-inductively coupled plasma-mass spectrometry and application to natural groundwater samples.
Capillary electrophoresis (CE) was coupled to ICPMS in order to combine the good performance of this separation technique with the high sensitivity of the ICPMS for the analysis of plutonium and neptunium oxidation states. The combination of a fused-silica capillary with a MicroMist AR 30-I-FM02 nebulizer and a Cinnabar small-volume cyclonic spray chamber yielded the best separation results. With this setup, it was possible to separate a model element mixture containing neptunium (NpO2(+)), uranium (UO2(2+)), lanthanum (La3+), and thorium (Th4+) in 1 M acetic acid. The same conditions were also suitable for the separation of various oxidation states of plutonium and neptunium in different a…
Isotope selective ultratrace analysis of plutonium by resonance ionisation mass spectrometry
Abstract Resonance ionisation mass spectrometry (RIMS) is a sensitive and selective method for isotopically resolved ultratrace analysis of long-lived radionuclides. For the routine analysis of plutonium three titanium–sapphire lasers pumped by a pulsed Nd:YAG laser in combination with a time-of-flight mass spectrometer are used. The detection limit of this system is as low as 106–107 atoms for the plutonium isotopes 238Pu to 244Pu. The RIMS technique was applied to investigate the isotopic composition and the content of plutonium in a depleted uranium penetrator as used during the Balkan conflict delivering important information on the origin of the depleted uranium in this type of ammunit…