Separation of no-carrier-added 203Pb, a surrogate radioisotope, from proton irradiated natTl2CO3 target using calcium alginate hydrogel beads

Pb-203 is a promising radioisotope in the field of medical science as an imaging surrogate of Pb-212. In the present investigation Pb-203 was produced by proton irradiation of natural Tl2CO3 target and was separated from the bulk Tl target using calcium alginate (CA) hydrogel beads with a high separation factor (3.8 x 10(4) at 10(-3) M HNO3). During the separation process Pb-203 was encapsulated in CA beads and desorption of the radioisotope could only be achieved in 1M HNO3. Possibility of Tl uptake was also checked in Fe doped CA (Fe-CA) beads after oxidation of Tl(I) to Tl(III) by sodium bismuthate. No significant uptake of Tl(III) was noticed in the Fe-CA beads. The matrix is therefore suitable for isolation of Pb-203 from the target as well as its storage in the bead for therapeutic as well as diagnostic purpose.