Separation of 103Pd from a Rh target using an alloying pretreatment with bismuth

Abstract

Abstract Palladium-103 is one of the most attractive radionuclides for internal radiotherapy. It is not only used as a brachytherapy seed but is also a feasible candidate for Auger electron therapy and gold-nanoparticle therapy. In this study, we propose a new method for the separation of 103Pd from a rhodium target to obtain no-carrier-added 103Pd. Rhodium powder target was irradiated under the following conditions: proton, 50 MeV, 1–3 μA, 1–4 h for the separation study; and H2 +, 24 MeV, 5 μA, 1 h to produce 103Pd. The irradiated target was pretreated using an alloying reaction between Rh and Bi on a hotplate at 500 °C. Rhodium in the chemical form of a Bi–Rh compound could then be dissolved with nitric acid and 103Pd was extracted using dimethylglyoxime as an extractant. The target rhodium was recycled using sodium tetrahydroborate (NaBH4). We obtained 103Pd with a yield of 87%. The activity of the product was 26 ± 2 MBq at the end of bombardment (EOB), and the radionuclidic purity of 103Pd was greater than 99%. The decontamination factors of rhodium and bismuth in the 103Pd product were estimated to be greater than 104 and 105, respectively. The target rhodium was recycled with a yield of 91% with a trace of bismuth (9 μg/50 mg Rh). The total separation time for 103Pd was within 3.5 h.