Validation of rapid methods for the determination of radiostrontium in milk.

A rapid method of (89)Sr and (90)Sr comprising ion chromatography for preconcentration and Sr extraction chromatography for separation of Sr from Ca, Ba and Y was validated with spiked milk samples. An (89)Sr/(90)Sr activity ratio of up to 12 showed the relative bias was within +/-20%. The separation time of Sr was 7h and the chemical recovery of Sr ranged from 80% to 95%. The detection limit for 500 mL milk and 90 min counting time was 0.1 Bq L(-1).