Ultra-sensitive radionuclide spectrometry: Radiometrics and mass spectrometry synergy

New, quantitative methods for the determination of actinides have been developed for application to marine environmental samples (e.g., sediment and fish). The procedures include aggressive dissolution, separation by anion-exchange resin, separation and purification by extraction chromatography (e.g., TRU, TEVA and UTEVA resins) with measurement of the radionuclides by semiconductor alpha-spectrometry (SAS). Anion-exchange has proved to be a strong tool to treat large volume samples, and extraction chromatography shows an excellent selectivity and reduction of the amounts of acids. The results of the analysis of uranium, thorium, plutonium and americium isotopes by this method in marine samples (IAEA-384, -385 and -414) provided excellent agreement with the recommended values with good chemical recoveries.