Determination of trace amounts of aluminium by ion chromatography with fluorescence detection

Abstract

A method is described for the determination of aluminium by high-performance ion chromatography followed by post-column derivatisation with 8-hydroxyquinoline-5-sulphonate and fluorescence detection at 512 nm (excitation at 360 nm). A short (50 mm) low-capacity cation-exchange resin column was used as the analytical column and 0.1 M K₂SO₄, adjusted to pH 3.0, as the eluent. The calibration graph was linear from 5 to 10 000 µg l^–1 of aluminium with a detection limit (3σ) of 1 µg l^–1. Typical relative standard deviations were 3.4% at the 250 µg l^–1 level. No interference was observed from other commonly occurring metals and aluminium was successfully determined in a certified reference material (Monel Alloy) and in tap water.