Determination of trace cadmium in steel by inductively coupled plasma-atomic emission spectrometry after removal of iron matrix with an adsorption column

Abstract

An inductively coupled plasma-atomic emission spectrometry method is established for the determination of trace cadmium in steel. The steel sample was dissolved with hydrochloric acid, then the sample solution was passed through a mini-column packed with anion exchange resin DOWEX 1 × 8-200. Cadmium was selectively adsorbed on the column, while iron was passed through. The analyte Cd was then eluted with 1.6 mol L⁻¹ nitric acid and collected in a volumetric flask, thus Cd was enriched and effectively separated from the matrix iron. Separation conditions were optimized via experimental determination of distribution coefficient for Cd and Fe, respectively. Detection limit of Cd was 0.12 μg g⁻¹. Recovery was in the range of 90% to 98%. The relative standard deviation was in the range 5.8%–7.3% (n = 7). The proposed method is applied to the determination of trace cadmium in the steel industry.