Separation and determination of metal ions as picolinaldehyde 4-phenyl-3-thiosemicarbazone chelates by reversed-phase high-performance liquid chromatography

Abstract

Picolinaldehyde 4-phenyl-3-thiosemicarbazone (PAPT) was used as a pre-column chelating reagent for the reversed-phase high-performance liquid chromatographic separation and determination of Bi^III, Cd^II, Co^II, Cu^II, Ni^II, and Fe^III. The metal–PAPT chelates were separated on an ODS column with acetonitrile–water (50 + 46), containing 1.5% methanol, 2.5% pyridine, 7.5 × 10^–5 mol dm^–3 PAPT and 0.02 mol dm^–3 acetate buffer (pH 6.0), as eluent. The detection limits for Bi^III, Cd^II, Co^II, Ni^II and Fe^III were 3.0, 2.6, 0.6, 1.2 and 1.9 µg dm^–3, respectively. The addition of pyridine to the eluent, as modifier, was effective in improving peak shapes. Nickel(II) in river water was determined by the proposed method.