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Astatine-211 ( T 1/2 = 7.214 h) is an α-emitter at secular equilibrium by EC with its ultra-short-lived α-emitting daughter, polonium-211g ( T 1/2 = 0.516 s), with a high Linear Energy Transfer (LET — 130 eV·nm−1) and a half-life suitable for metabolic radiotherapy; the overall α branching of the 211At/211gPo system is 100%. The direct production of 209Bi(α,2n)211At/211gPo seems the most satisfactory method; Bi targets were irradiated at JRC-Ispra Cyclotron of European Commission, EC, using α-energy higher than 28.61 MeV in order to produce, via 209Bi(α,3n) reaction, small amounts of the γ-emitter 210At (used as internal spike). [ABSTRACT FROM AUTHOR]

We present a fast and effective wet-chemistry method, used to obtain the pure alpha-emitter 211At/211gPo ( T 1/2 = 7.214 h/516 ms), produced by 209Bi(α,2n) reaction in NCA form. It is a selective radiochemical separation of the At radionuclides from the target and the impurities, characterized by a radionuclidic purity close to 100%, based on the dissolution and the dilution of the irradiated target in acidic medium, on the extraction with DIPE, followed by the back-extraction with NaOH. As a result, we obtain a yield greater than 90–97% in a range from 0.75M to 2.00M. [ABSTRACT FROM AUTHOR]

Many labeled compounds are used as radiopharmaceuticals (RP), for emission imaging and metabolic radiotherapy and contain as labeling agentsγ,β-,β+, monochromatic e-andα emitting radionuclides (RN). These labeled compounds very often contain unexpected radionuclidic impurities. Some long-lived isotopic and non-isotopic impurities lead to undesirable radiation doses to the patient and his relatives, as well as to medical/paramedical personnel, other than the general population, due to rad-waste of contaminated specimen and excretion of biological fluids. Use was made of liquid scintillation counting/spectrometry (LSCS) for the detection of tiny amounts of charged particle emitting impurities in RPs labeled with64Cu,67Ga,90Y,90Sr/90Y,123I,153Sm,177Lu and201Tl. [ABSTRACT FROM AUTHOR]