Separation of strontium from a highly saline high level liquid waste solution using di-tert-butyldicyclohexano-18-crown-6 + isodecyl alcohol/n-dodecane solvent

•Strontium-90 separation carried out from high salt content high level waste.•Solvent employed is 0.1 M DtBuDCH18C6 + 50% isodecyl alcohol/n-dodecane.•Stoichiometry of extract showed 1:1:1 M ratio for Sr2+, DtBuDCH18C6 and HNO3.•Stripping of the loaded organic was achieved with deionized water.