Plutonium separation by solvent extraction for the determination by photon electron rejecting alpha liquid spectrometry

The separation of plutonium from marine sediments (IAEA-135 reference material) by solvent extraction and determination with Photon Electron Rejecting Liquid Alpha Spectrometry (PERALS(R)) has been performed. Two extraction schemes, TOANO(3) and HDEHP, were compared for the separation of plutonium, uranium, thorium and americium from the matrix components. The TOANO(3) separation method showed plutonium recovery of 85% with an accuracy of +/-20%, while for the HDEBP separation the plutonium recovery was only 9.3%. Minimum detectable activities of plutonium for a counting time of 120000 seconds for 0.25 g sample material were 0.18 Bq/kg for TOANO(3) and 1.62 Bq/kg for HDEHP separation methods, respectively.