4′,4″(5″)-Di-tert-butyldicyclohexano-18-crown-6 is a lipophilic crown ether compound used in extraction chromatography for separation of strontium from nitric acid media. 4′,4″(5″)-Di-tert-butyldicyclohexano-18-crown-6 as a solution in 1-octanol is sorbed onto an inert substrate, where it serves to selectively isolate strontium from the chromatography mixture.