Reversed-phase high-performance liquid chromatography of several metal-8-quinolinethiol complexes

The reversed-phase high-performance liquid chromatography of 8-quinolinethiol (Hqt) complexes of Fe, Co, Ni, Cu, Zn, Hg and Pb on an octadecyl-bonded silica gel stationary phase was examined. The Pb complex dissociated in the column. The retention and separation of other complexes depended on the composition of the mobile phase. EDTA as an additive displaced the Zn complex and eliminated its peak. All the other metal complexes and also Hqt and its disulphide were separated in 23 min by using methanol-water (82:18, v/v) as the mobile phase. The complexes formed by the reaction of Co(II) and Hqt gave three peaks, which were assigned as fac(S)-CoIII(qt)3, mer(S)-CoIII(qt)3 and CoII(qt)2, respectively. This method is applicable to the simultaneous determination of Fe, Co, Ni, Cu and Hg.