SEPARATION OF SR-89 AND SR-90 FROM CALCIUM IN MILK WITH A MACROCYCLIC ETHER

A small amount of strontium ion (20 mg) was simply separated from a large amount of calcium ion (0.5-13.6 g) by liquid-liquid extraction using dicyclohexyl 18-crown-6 chloroform solution. The extraction was applied to a part of the procedure for determining radiostrontium in ash of milk. The overall recovery of strontium was 75% on the average for 5-10 g of milk ash. Decontamination factors for Mg, Ca, Ru, I, Cs, Ba, and La in the final fraction were 1 × 105, 1 × 104, >1 × 106, >1 × 106, >2 × 106, 2 × 105, and 3 × 104, respectively. The chemical procedure for three samples took about 2 days. © 1979, American Chemical Society. All rights reserved.