The Evaluation of a Rapid Solvent Extraction Method for the Determination of Strontium-90 in Milk

A procedure for measuring strontium-90, which depends on the solvent extraction of yttrium-90, has been compared with the more widely used method of strontium purification, for the analysis of milk in environmental surveys. A comparison of measurements on eightysix samples shows that the results obtained by the two methods agree closely; both procedures are of similar precision. The solvent extraction method has advantages of speed and simplicity, though it is subject to limitations for samples containing other rare-earth activities.