Preparation of Microvolume Anion-Exchange Cartridge for Inductively Coupled Plasma Mass Spectrometry-Based Determination of 237Np Content in Spent Nuclear Fuel

Microvolume anion-exchange porous polymer disk-packed cartridges were prepared for Am/Np separation, which is required prior to the measurement of Neptunium-237 (237Np) with inductively coupled plasma mass spectrometry (ICPMS). Disks with a volume of 0.08 cm3 were cut out from porous sheets having anion-exchange-group-containing polymer chains densely attached on the pore surface. Four different amine-based groups, N,N-dimethylaminoethyl methacrylate, trimethylammonium, diethylamine, and triethylenediamine (TEDA), were selected as the anion-exchange groups to be introduced into the porous sheets. The separation performances of Am/Np were evaluated using a standard solution of 243Am, which had the same activity as its daughter nuclide 239Np in secular equilibrium. 239Np recovery of close to 100% with practically no contamination of 243Am was achieved using the TEDA-introduced disk-packed cartridge. The time to elute 239Np from the cartridge was approximately 40 s. The TEDA-introduced disk-packed cartridge ...