Measurement of 90Sr Content in Low-level Environmental Samples

This research focuses on the optimization of analysis conditions for 90Sr in water sample using extraction chromatography method by di- (2-ethylhexy) phosphoric acid based on GB 6766-1986, and makes this method more suitable for 90Sr analysis in environmental water samples with the specific activity lower than 10 mBq/L. In optimized analysis process the P204 resin column was used in separating 90Y from 90Sr-90Y mixture, and the sampling volume as well as the β counting time for the measurements of water samples, detecting efficiency, calibration with electroplating source were optimized. The measurement of 90Sr content in an actual low-level environmental water sample was performed, by optimized extraction chromatography method, and the results showed that the full process recovery was 89.8%-124.0% and the detecting limit to 90Sr was 0.36 mBq/L, which was lower than 10 mBq/L in GB 6766-1986. (authors)