New ion exchange materials for use in a 82Sr/82Rb generator

82Rb is a short-lived positron-emitting isotope (T1/2 = 75 s) that is increasingly being used in positron emission tomography for the evaluation of myocardial perfusion. The short half-life of 82Rb results in rapid decay of the administered radioactivity allowing repeat scans to be performed after a relatively short time interval. The 82Rb is available from a 82Sr/82Rb generator in which the 82Sr parent is immobilized on an ion exchange column and 82Rb eluted when required. Consequently, suitable ion exchangers for use in a generator must have a very high affinity for strontium and a negligible affinity for rubidium, allowing the pure 82Rb to be safely and efficiently eluted in high yields. This study evaluated a number of strontium-selective ion exchange materials using batch experiments and identified sodium nonatitanate as the best material for use in a 82Sr/82Rb generator.