Sorption of Mo(VI) on Zirconium Molybdosilicate Gel and Potential Application as a 99Mo/99mTc Generator

Sorption of Mo(VI) from aqueous nitrate solutions onto zirconium molybdosilicate (ZrMoSi) gel was studied using Mo-99 radiotracer. The acid-base titration curve showed that the prepared ZrMoSi gel was an amphoteric material with the point of zero charge (PZC) at pH 2.5. The highest distribution coefficient (600 mL g(-1)) of Mo-99(VI) on ZrMoSi from nitrate media was achieved at pH 2.1. The sorption kinetics of Mo-99(VI) onto ZrMoSi obeyed the pseudo-second-order model. The breakthrough sorption capacity of ZrMoSi gel was found to be 4.25 x 10(-2) [mmol Mo(VI)] g(-1). The prepared Mo-99/Tc-99m chromatographic column generator showed a good performance: The Tc-99m elution yield was 87.7%, pH of the eluate ranged from 5.6 to 7.2, and the radionuclidic purity of the eluted Tc-99m was > 99.99% with a radiochemical purity of 98.31% (as (TcO4-)-Tc-99m).