SEPARATION AND DETERMINATION OF TRACE-METALS IN CONCENTRATED SALT-SOLUTIONS USING CHELATION ION CHROMATOGRAPHY

A high-performance ion chromatography system using chelating dye coated columns for the determination of trace metals in high-ionic-strength media is described. All the preconcentration and separation studies of metal ions were carried out using a single chelating column. Spectrophotometric detection using 4-(2-pyridylazo)resorcinol and' Pyrocatechol Violet post-column reagent was employed to investigate divalent and trivalent metal ions. A number of metal ion determinations in 1 M laboratory salt solutions, concentrated brines and sea waters were achieved under isocratic and step gradient elution conditions, where up to nine metal ions could be separated in a single injection. Standard addition was used for calibration and good linearity was obtained in the low mug l(-1) range.