REDOX REACTION CATALYZED BY A POROUS GRAPHITE CARBON PACKING AND ITS APPLICATION TO SELECTIVITY ENHANCEMENT OF HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY SEPARATION OF METAL-COMPLEXES

A new HPLC method was developed for the selective separation of metal complexes by using a redox reaction as a secondary chemical equilibriu m, In a study of the reversed-phase ion-pair liquid chromatography of trans-1,2-diaminocyclohexanetetraacetate (DCTA) complexes of transitio n metal ions, it was noted that the redox reaction between the divalen t and trivalent cobalt complexes were extremely accelerated by using a porous graphite carbon (PGC) column, This finding was ascribed to the catalytic effect of the PGC. The retention of Co-DCTA complex can be modified by treating the PGC column with the eluent containing sodium sulfite, The cobalt complex was completely separated from 1000-fold mo lar excess of the Bi-III, Fe-III, Cu-II, and Ni-II complexes.