Abstract
Diazapolyoxabicyclic ligands (cryptands) have been applied as ion-size selective masking reagents with the aim of establishing a quantitative extraction-separation system among alkaline earths. Calcium can be quantitatively separated from strontium in the synergistic solvent extraction with 1-phenyl-3-methyl-4-benzoyl-5-pyrazolone (HPMBP) and tri-n-octylphosphine oxide (TOPO), and with benzoyltrifluoroacetone (BFA) and tri-n-butylphosphate (TBP) into cyclohexane in the presence of cryptand[2.2.2] as a masking reagent. Magnesium can also be quantitatively separated from calcium in the synergistic extraction with BFA and TBP into cyclohexane in the presence of cryptand[2.2.1] as a masking reagent.