Solvent extraction separation of germanium(IV) with N-n-octylaniline as an extractant

The extraction behavior of germanium(IV) from aqueous hydrochloric acid solution with N-n-octylaniline in xylene was investigated. Hydrochloric acid concentration higher than 9 M remained effective for quantitative extraction of germanium(IV). Phenylfluorone ion as a counter anion was used. More than 2% N-n-octylaniline provided quantitative extraction at 1 min equilibrium time and germanium(IV) was back extracted by 7 M ammonia. The method was free from the interference of a large number of metal ions and anions, except for Te(IV) and Sn(IV); this was avoided using the masking effect. Germanium(IV) was separated from associated elements in its binary mixture with Si(IV), Te(IV), Sb(III), Bi(III), Au(III), Cu(II), Zn(II), and its ternary mixture with Se(IV), Te(IV); Sb(III), Bi(III); and Au(III), Cu(II). The proposed method was applied to a synthetic sample containing associated metal ions. The results indicated that trace amounts of germanium(IV) could be separated effectively from higher amounts of other elements.