RAPID AND EFFICIENT SEPARATION OF STRONTIUM FROM LIQUID MILK WITH A CATION-EXCHANGE RESIN DOWEX 50WX8 TREATED WITH CRYPTAND-222

The presence of cryptand 222 on the strongly acidic cation exchange re sin Dowex 50WX8 (D) considerably increases its ability to remove stron tium (Sr) from liquid milk. Dowex resin treated with cryptand (D/222) sorbs more than 95% of the Sr in milk at pH 5.2 and 22 degrees C after 4 hours contact in a batch process with a resin to milk volume ratio of 1 : 50. Hot (90 degrees C) 6M hydrochloric acid elutes Sr quantitat ively but rather unspecifically from the resin. The isolation of Sr fr om this eluate by chromatography with the commercially available Sr Sp ec Resin(R) is described. The usefulness of this technique for the rap id, routine determination of Sr-90 in liquid milk is discussed.