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

Abstract

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 185Re(n, γ)186gRe produces low specific activity 186gRe, thereby limiting its therapeutic application. Work is underway to develop an accelerator-based, charged particle induced production method for high specific activity 186gRe from targets of enriched 186W. To optimize the chemical 186gRe recovery method, batch studies have been performed to characterize the adsorption behavior of Re and W on a strongly basic anion exchange resin. An in-depth 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 (HNO3) 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 WO4 2– strength of up to 1.9 mol kg –1 does not significantly compromise ReO4 – retention on the resin.

Monooxorhenium(V) complexes with 222-N2S2 MAMA ligands for bifunctional chelator agents: Syntheses and preliminary in vivo evaluation

“…No carrier added 186 Re was produced at the Los Alamos National Laboratory Isotope Production Facility (LANL-IPF) using an encapsulated target of enriched 186 WO 3 Powder (99.9%; Isoflex USA) in a 40 MeV incident proton beam. The 186 Re was recovered as previously reported [27,28] with a slight modification: the anion exchange column was eluted with 8 M HNO 3 (2 x 50 mL) for ReO 4 − desorption. The nitric acid was removed by evaporation and the residue reconstituted in 0.1 M HCl.…”

“…The nitric acid was removed by evaporation and the residue reconstituted in 0.1 M HCl. The specific activity was determined to be 790 ± 90 GBq/mg (21 ± 2 Ci/mg) [27,28]. PC-3 tumor cells were obtained from ATTC (Manassas, VA) and cultured by the MU Cell and Immunobiology Core (CIC).…”

Chromatographic separation of germanium and arsenic for the production of high purity 77As

“…Several media were evaluated in room temperature batch studies for their ability to separate Ge and As following a previously published method [16]. The removal of Ge and As from varying pH (1-13) solutions was measured by mixing 50 mg of each substrate (silica, acidic alumina, and zirconium oxide) with 1.5 mL of a 77 Ge- or 76 As-spiked solution (154 kBq (4.17 μCi) and 81 kBq (2.19 μCi) per sample, respectively); each solution was adjusted to the desired pH using either 0.1 M HCl or NaOH, 1-2 μL of the spiked solution was added, and the pH retested.…”

Development of novel radionuclides for medical applications

“…126 More recent experimental works attempt to achieve high specific radioactivity of 186 Re. [127][128][129][130][131] High-current targetry and efficient separation methods are in development to produce this radionuclide in quantities sufficient for medical applications. A clinical scale production has hitherto not been reported.…”