Ion chromatographic determination of aluminium with ultraviolet spectrophotometric detection

Abstract

A method for the determination of aluminium by high-performance ion-exchange chromatography followed by post-column derivatisation with 4,5-dihydroxy-1,3-benzenedisulphonic acid, disodium salt and ultraviolet detection at 310 nm is described. The calibration graph was linear from 10 to 5000 µg l^–1 of Al with a detection limit (3σ) of 7 µg l^-1. Typical relative standard deviations in the range 1.3–3.9% were obtained for a 100-µg l^–1 Al standard. Freedom from interference from six cations investigated is reported, the exception being titanium. The method was applied successfully to the determination of aluminium in certified reference materials after conventional wet digestion (NBS SRM 1572 and NIES No. 7). The incomplete digestion of biological materials in a microwave oven is reported. The problems of using a non-destructive analytical technique for the determination of aluminium in a natural riverine water reference material are discussed.