Kläui Ligand Thin Films for Rapid Plutonium Analysis by Alpha Spectrometry

As part of a nuclear forensics capability, rapid and effective methods to analyze for plutonium and other actinide metals are needed. A key requirement of these methods is that they afford a high chemical yield while still providing isotopic information necessary for forensic evaluation. Toward this objective, a new method for binding plutonium for analysis by alpha spectrometry has been developed. Thin films of Kläui-type tripodal oxygen donor ligands were prepared by spin-casting solutions onto glass substrates. Three different ligands were evaluated for plutonium binding, and the best results were obtained using the ethyl-substituted complex Na[Cp*Co(P(O)(OEt)2)3], which bound 80-88% of the dissolved Pu under equilibrium conditions. The thin films are simple and inexpensive to prepare and exhibit excellent alpha spectral resolution, having line widths of ~33 keV. The method has been successfully applied to analyze for plutonium in both an archived nuclear debris sample and a certified environmental soil sample. The results obtained from the soil analysis are in good agreement with the certified values, demonstrating the effectiveness of the method for rapid plutonium analysis.