Dipicolinic acid as eluent for the high-performance liquid chromatographic determination of transition metals using iminodiacetic acid-bonded silica

Abstract

The high-performance liquid chromatographic behaviour of Co²⁺, Zn²⁺, Cu²⁺, Cd²⁺ and Pb²⁺ on a column packed with iminodiacetic acid-bonded silica (250 × 3 mm i.d.) was studied using solutions of dipicolinic acid as eluent. Optimum separation was achieved when the concentration of dipicolinic acid in the eluent was 1 × 10^–3 mol l^–1 and the eluent pH was 3.0. The possibility of the sensitive indirect spectrophotometric detection of transition metals at 295 nm is demonstrated. The detection limits for the investigated metals are in the range 0.1–1 µg ml^–1. The determination of zinc and lead in industrial waste waters was performed.