Abstract

The feasibility of using an anion-exchange resin for on-line separation of trace amounts of Fe, Cu, Mn, Mg, Cr, Ni, Zn, Co, Pb, and Cd from pure aluminium was investigated. A test portion of 50 mg of aluminium drillings was dissolved with 6 ml of a buffer solution, 2.64% m/v NaOH–0.91% m/v KCl (pH = 13.4 ± 0.1). An aliquot of 500 µl of the solution obtained was passed through a micro-column, included in a flow injection (FI) manifold, packed with a 2 + 1 mixture of Metalfix Chelamine and Hyphan Cellulose (the micro-column volume was about 150 µl). The retained trace elements were eluted in the back-direction with 200 µl of a 3 + 1 mixture of 1 mol l⁻¹ HCl–1 mol l⁻¹ HNO₃ and then determined using flow injection inductively coupled plasma mass spectrometry. The operating parameters and operational scheme of the manifold of the FI on-line ion-exchange assembly are given. The accuracy of the proposed method was tested by analysing a pure aluminium standard sample (Aluminium Pechiney, CODE 566). Recoveries from 50 mg test portions of a high-purity aluminium (99.999%) spiked with 2.5 and 25 ng each of the studied analytes were close to 100%, and the relative standard deviations ranged from 1 to 3%. Determination limits (10s) were in the ng g⁻¹ range.