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.