Radiochemical Study of Re/W Adsorption Behavior on a Strongly Basic Anion Exchange Resin

摘要

Rhenium-186g is a radionuclide with a high potential for therapeutic applications. It emits therapeutic β~- particles accompanied by low energy γ-rays, which allows for in-vivo tracking of the radiolabeled compound and dosimetry estimates. The current reactor production pathway ~(185)Re(n, y) ~(186g) Re produces low specific activity ~(186g)Re, thereby limiting its therapeutic application. Work is underway to develop an accelerator-based, charged particle induced production method for high specific activity ~(186g)Re from targets of enriched ~(186)W. To optimize the chemical ~(186g)Re recovery method, batch studies have been performed to characterize the adsorption behavior of Re and W on a strongly basic anion exchange resin. An indepth physicochemical profile was developed for the interaction of Re with resin material, which showed the reaction to be endothermic and spontaneous. Basic (NaOH) and acidic (HNO_3) matrices were used to determine the equilibrium distribution coefficients for Re and W. The resin exhibits the best affinity for Re at slightly basic conditions and little affinity above moderately acidic concentrations. Tungsten has low affinity for the resin above moderately basic concentrations. A study was performed to examine the effect of W concentration on Re adsorption, which showed that even a high ionic WO_4~(2-) strength of up to 1.9 mol kg~(-1) does not significantly compromise ReO_4~- retention on the resin.