Timothy L. Hubler

A NEW EXTRACTION CHROMATOGRAPHY RESIN CONTAINING KLÄUI LIGANDS FOR APPLICATION IN ACTINIDE SEPARATIONS

Abstract An extraction chromatography resin containing the anionic ligand (η5‐pentamethylcyclopentadienyl)tris‐(diethylphosphito‐P)cobalt(III), Cp * Co[P(O)(OEt)2]3 − (1Et) has been prepared. The resin consists of 1 wt% 1Et on Amberlite® XAD‐7. This resin strongly sorbs Am3+ and Pu4+. The sorption of these ions decreases with increasing nitric acid concentration, but this effect is more pronounced for Am3+. This allows for convenient separation of Am3+ from Pu4+ by simple adjustments in the HNO3 concentration. The tripodal geometry of 1Et disfavors the complexation of UO2 2+, so sorption of U(VI) by the 1Et‐containing resin is weak. An analogous resin containing Cp * Co[P(O)(OPr)2]3 − (1Pr) shows similar Pu4+ sorption behavior.

Spectroelectrochemical Sensor for Technetium Applicable to the Vadose Zone

The general aim of this project is to continue the design and implementation of a new sensor technology that offers the unprecedented levels of specificity needed for analysis of the complex chemical mixtures found at DOE sites nationwide. The new sensor concept combines the elements of electrochemistry, spectroscopy and selective partitioning into a single device that provides three levels of selectivity. The specific goal of this project is the development of a sensor for technetium (Tc) that is applicable to characterizing and monitoring the Vadose Zone and associated subsurface water at the Hanford site. The first goal is a sensor that determines technetium in the chemical form pertechnetate (TcO4 -).

Spectroelectrochemical Sensor for Pertechnetate Applicable to Hanford and Other DOE Sites

The general aim of our work funded by DOE is the design and implementation of a new sensor technology that offers the unprecedented levels of specificity needed for analysis of the complex chemical mixtures found at DOE sites nationwide. The sensor is based on a unique combination of electrochemistry, spectroscopy and selective partitioning into a film that collectively provide an extraordinary level of selectivity for the target analyte. Our goal is a reversible sensor in which the fluorescent Tc-complex formed in the film is re-oxidized to TcO4 ? and free ligand. TcO4 ? in the film would then re-equilibrate with the sample. The sensor would therefore satisfy requirements for both applications described above. Making significant progress towards this goal has required us to discover new chemistry and spectroscopy for technetium itself. Indeed, we needed to find the first technetium complexes which fluoresced in solution at room temperature ? we have made that breakthrough discovery this last year. We are now in the unique position of being able to reach our goal of a reversible sensor for Tc.

Design and Development of a New Hybrid Spectroelectrochemical Sensor; Spectroelectrochemical Sensor for Technetium Applicable to the Vadose Zone

The general objective is the design and implementation of a new sensor technology that offers the unprecedented levels of specificity needed for analysis of the complex chemical mixtures found at DOE sites nationwide. The specific objectives are threefold: demonstration of the general sensor concept on a variety of model systems; development of a sensor for ferrocyanide with testing on waste tank simulant; and development of a sensor for pertechnetate applicable to the Vadose Zone.