Summary of Method
Strontium is separated and concentrated from up to 400mL water samples using calcium phosphate precipitation. The precipitate is dissolved in nitric acid and aluminum nitrate. Strontium is then separated from matrix impurities and potentially interfering radionuclides in the sample using a 2mL cartridge of Eichrom Sr Resin. Radiostrontium is measured on a low background gas flow proportional counter or liquid scintillation counter. Chemical yield of strontium is determined by gravimetric recovery of stable strontium or ICP-AES measurement. Typical chemical
recovery of strontium is >80%. Measured values of 90Sr agreed to within 14% of reference values for 10 minute count times, although longer count times can be used to improve detection limits and uncertainty. A single operator can complete the separation method for batches of 12-24 samples in as little as 3-4 hours.