Separation of 90Y from 90Sr using sequential multiple column extraction chromatography

The distribution coefficient measurements on Y(III) and Sr(II) were performed using ditertiarybutyl dicyclohexano 18-crown-6 (Sr-selective resin) and N,N,N′,N′-tetraoctyldiglycolamide (Y-selective resin) in HNO3, HCl and HClO4 media. Separation factors (90Y/90Sr) based on distribution coefficient data suggested that perchloric acid is distinctly better medium as compared to nitric acid/hydrochloric acid. The mechanism of extraction changes with the nature and concentration of acid and is responsible for the high selectivity in perchloric acid medium. Sequential column studies were carried out on tracers (radioactive/stable) employing Sr-selective/Y-selective extraction chromatographic resins as stationary phases. The final elution of 90Y was done in 0.01 M EDTA at pH 4.0 which can be used for clinical applications after radiochemical processing.