Determination of aluminium in dialysate fluids by atomic-absorption spectrometry with electrothermal atomisation

Abstract

Matrix effects in the determination of aluminium in dialysate fluids by electrothermal atomic-absorption spectrometry are overcome by the addition of nitric acid (to give a final concentration of 2%V/V) to the fluid. Analyses may be made by a rapid two-step heating programme giving a total time per injection of 59 s; in the first step, drying and ashing are combined. A detection limit of 1 µg l^–1 is achieved and reproducibility is better than 2% in the range 30–120 µg l^–1. Concentrations of aluminium of <1–11 µg l^–1 were determined in various batches of commercially supplied peritoneal dialysis fluid. Haemodialysate fluid concentrations varied from <1 to 31 µg l^–1 with 62% of the samples examined having concentrations less than 5 µg l^–1.