Mario Burger

Radiochemical separation of actinides from environmental samples for determination with DF-ICP-MS and alpha spectrometry

Summary The purpose of this study was to develop an optimised sample preparation method for the determination of Pu, Am, and Cm in environmental samples, soils, and sediments, and to compare the sensitivities of DF-ICP-MS, alpha spectrometry, and liquid scintillation alpha spectrometry. Borate fusion was used for sample material digestion. Two methods based on TOPO liquid–liquid extraction and combination of TEVA and TRU extraction chromatography showed highest yields of 92.7% for Pu, 86.8% for Am, and 87.6% for Cm. The detection limits were between 0.014–0.034 Bq/kg for 239Pu, 0.014–0.093 Bq/kg for 240Pu, and 0.011–1.20 Bq/kg for 241Am. Analytical results for 238Pu, 239Pu, 240Pu, 241Pu and 241Am and their isotope ratios in certified reference materials (IAEA-135 and IAEA-300) indicated very good accuracy of the methods proposed.

Determination of neptunium in soil by ICP-MS

Summary A fast and simple method for the determination of 237Np in soil is presented. The borate fusion decreases the sample pre-treatment time and a TEVA extraction chromatography separates neptunium from uranium and the interfering matrix components. A comparison of the sensitivities of alpha spectrometry and sector field ICP-MS for determination of 237Np is presented.

Critical evaluation of the determination of zirconium and hafnium in meteorites by instrumental and radiochemical neutron activation analysis

Abstract Neutron activation analysis (instrumental or radiochemical) is suitable for the determination of zirconium and hafnium in samples of geochemical origin only when sufficient attention is paid to interfering nuclides. The size of the necessary correction for INAA depends on the composition of the sample; this problem is discussed. The radiochemical technique which is recommended involves separation of the samples, precipitations and anion-exchange separation. Results are given for various standard reference materials and for meteorites.

Determination of Refractory Trace Elements in Chinese Meteorites by RNAA

Some refractory trace elements are important target elements for Spallation reactions in meteorites. These elements also serve to characterize the investigated meteorites. The elements Ti, Y, Zr, Hf, W and Ta were measured after radiochemical separation in chondrites from China. After acid digestion of the irradiated samples, the group separations were obtained by precipitation reactions. The necessary radiochemical purification of the pure β emitter Y was realized on a Lewatite OC 1026 column. For all the other elements discrete gamma radiation was measured.

A procedure for the sequential determination of radionuclides in soil and sediment samples

We present a new radiochemical procedure for the sequential determination of Sr, Am, Pu, Th and U radionuclides. For the validation, seven IAEA certified reference materials were analyzed for 239Pu, 240Pu, 241Pu, 238U and 232Th isotopes by ICP-MS, 243Am by alpha spectrometry and 90Sr by low level gas proportional counting. The sequential method was then used for determining the radionuclide profiles in one sediment core collected in the River Rhine, near Augst, downstream of the Swiss nuclear power plants.