From literature data for 14 mixed aminocarboxylato cobalt(III) complexes, the effect of the sorbent on RM values, salting-out efficiency (m) and separation factors (α) of adjacent members of homologous series was investigated in salting-out, thin-layer chromatography on silica gel, polyacrylonitrile and cellulose sorbents, using ammonium sulphate solutions as developers. For complexes belonging to the same homologous series, linear dependence was found between RM,m and log α values, respectively, on two different sorbents. Polyacrylonitrile was shown to be the most suitable sorbent for the separation of the complexes since it gave the highest values for RM,m and α.