Separation of Mo from Nb, Zr and Y. Applicability in the purification of the recovered enriched ¹⁰⁰Mo used in the direct production of ^99mTc in cyclotrons

The direct production of ^99mTc in cyclotrons by the proton irradiation of highly enriched ¹⁰⁰Mo requires recovery of the costly enriched ¹⁰⁰Mo from the irradiated target to keep the cost of ^99mTc within the affordable limit. Various isotopes (both radioactive and stable) of Mo, Nb, Zr, and Y may be concomitantly produced directly or indirectly by several nuclear reactions. As a result of this, the recovered ¹⁰⁰Mo may be contaminated with those impurities. This paper describes a simple chemical separation method to near complete removal of Nb, Zr, and Y impurities in Mo. Even the chance of contamination of recovered ¹⁰⁰Mo due to ⁹⁷Mo, arising from ¹⁰⁰Mo(p, α)⁹⁷Nb → ⁹⁷Mo, may be reduced by 56 % if the purification is completed in 1 h after the end of irradiation. (author)