A cation exchange method for separation of 111In from inactive silver, copper, traces of iron and radioactive gallium and zinc isotopes

111In was produced by the 109Ag(α, 2n)111In reaction. A simple radiochemical separation technique, using Dowex-50 cation exchange resin (with prior removal of copper bulk, if present), has been employed to separate radioindium from inactive contaminants like Ag, Cu, Fe and active contaminant like 67Ga and 65Zn. The radiochemical separation yield was 90–99%. The radionuclidic purity of 111In was >99% at 60 h after EOB. The level of all the inactive contaminants was < 5 μg/mL in the final product.