Rapid Determination of Sr in 50g Soil Samples
Published Time：2016-12-09
Summary of Method
Strontium is separated and concentrated from 50 gram soil samples. Soils are leached with concentrated nitric and hydrochloric acid. The leachate is evaporated to dryness, and the residue is dissolved in 1M HCl. A ferric hydroxide-calcium phosphate precipitate concentrates strontium and removes matrix components leached from the soil. A calcium fluoride precipitate further concentrates and purifies the strontium fraction. Strontium is separated from matrix impurities and potentially interfering radionuclides in the sample using two stacked 2mL
cartridges of Eichrom Sr Resin. Radiostrontium is measured on a low background gas flow proportional counter. Average chemical recovery of strontium, determined by gravimetric yield of stable strontium carrier, is 91 + 4%. Measured values of 90Sr agreed to within 2% of reference values for 90 minute count times. The minimum detectable activity for 90Sr in 50g samples with 90 minute count times is 0.41Bq/g. A single operator can prepare batches of 12 samples for the measurement of 90Sr in less than 16 hours.
