Extraction of plutonium using DIPEX immobilized in polystyrene thin films

We previously reported the development of thin films functionalized with P,P′-di(2-ethylhexyl) methanediphosphonic acid (DIPEX) applied to the extraction and analysis (by alpha spectrometry) of actinide samples. Here we report the full characterization of the films' ability to extract Pu(III), Pu(IV), Pu(V), Pu(VI), and colloidal Pu(IV) under various chemical conditions. For all oxidation states, plutonium partitioning onto DIPEX-polystyrene thin films was less effective than that onto liquid DIPEX. The weight distribution ratios calculated for the thin film extraction efficiency for the different oxidation states were Pu(IV) > Pu(III) > Pu(VI) ≅ Pu(V) ≅ colloidal Pu(IV) and were > 103 times lower than the distribution ratios observed for liquid DIPEX. Application of the DIPEX-polystyrene thin films for the qualitative processing of contaminated soil samples was very effective; however, the films were less effective for the processing of large water samples with trace levels of plutonium.