Preparation of a carrier free ${}^{124}$Sb tracer produced in the Sn (p, n) reaction

A carrier-free ${}^{124}$Sb tracer was prepared for determining radioactive ${}^{125}$Sb in highly contaminated and radioactive soil like one taken near the Fukushima Daiichi Nuclear Power Plant. The excitation function for the ${}^{124}$Sb production was measured and compared to previous works to identify the optimum proton energy for the ${}^{124}$Sn (p, n) reaction by a stack method. The maximum production of ${}^{124}$Sb in the reaction was found at an incident proton beam energy of 8-9 MeV. Except for ${}^{124}$Sb, the reaction produced short-lived by-products and practically no ${}^{125}$Sb. Antimony was isolated from tin matrix by dissolving the irradiated target and extracting to isoamyl acetate. Then the carrier-free ${}^{124}$Sb tracer solution was purified by passing it through an anion exchange resin column. The radioactivity of ${}^{124}$Sb was recovered to more than 50% of the production, and provided successfully as a tracer solution free from tin due to the examined chemical procedure.