Solvent extraction of microamounts of strontium and barium from water into nitrobenzene using hydrogen dicarbollylcobaltate in the presence of benzo-18-crown-6

Extraction of microamounts of strontium and barium by a nitrobenzene solution of hydrogen dicarbollylcobaltate (H(+)B) in the presence of benzo18- crown-6 (B18C6, L) has been investigated. The equilibrium data have been explained assuming that the complexes HL(+), ML(2+), ML(2)(2+) and MHL(2)(3+) (M(2+) = Sr(2+), Ba(2+)) are extracted into the organic phase. The values of extraction and stability constants of the species in nitrobenzene saturated with water have been determined.