Application of Extraction Chromatography for the Preparation of High Purity 111In for Medical Use

Abstract

Indium isotopes, mainly In‐111, are frequently used in nuclear medicine, both in therapeutics and diagnostics. Therefore the preparation of high‐purity In‐111 solutions from irradiated targets is of great interest. In‐111 can be produced by a large number of nuclear reactions, e.g. from cadmium targets, preferably from enriched Cd‐112 targets, by irradiation with protons or deuterons. Reliable methods for preparing In‐111 radioisotope solutions of high radiochemical and chemical purity are thus needed. This work illustrates a fast and convenient way for further purification of 111In solutions shortly before their use. Elution studies have been undertaken to examine the behavior of cadmium and indium isotopes on four commercially available SPE materials—TRU Resin®, Ln Resin®, and Ac Resin®—all of which are manufactured by Eichrom Technologies, Inc. These resins were found to be best suited for 111In separation. Reaching high yields of 111In with high chemical purity, i.e., very low concentration of unwanted elements (preferably below the limit of detection <10−8).