Strontium-90 Determination in ⁹⁰Y by Solid Phase Extraction

Usually, the determination of ⁹⁰Sr impurities is carried out by liquid scintillation counting after decay of the majority of ⁹⁰Y, which would interfere with the measurement. However, to use the ⁹⁰Y eluate obtained from a ⁹⁰Sr/⁹⁰Y generator in patients, the radionuclidic purity determination must be carried out in a freshly eluted ⁹⁰Y sample. In the frame of this coordinated research project, efforts have been devoted to the development of a simple and efficient method to assess whether the ⁹⁰Y solution meets the clinical requirements immediately after elution from the generator, prior to proceeding to radiopharmaceutical preparation (i.e. an absolute ratio of activities of 10^–7 at time of administration