Determination of trace levels of aluminium in biological materials (fish) by graphite-furnace AAS

Abstract

A method for the determination of trace levels of Al in biological materials (fish) by graphite-furnace AAS was studied. Samples were digested with HNO3, since HCLO4 gave great interferences to the determination of Al. The analytical wavelength was selected at 394.4 nm, and the ashing and atomizing temperatures were fixed at 1500 °C and 2600 °C, respectively. Interferences of coexisting inorganic components (Ca, Na, K, Mg, Fe and P) were also studied. The torelable concentrations for respective components were as follows: Ca 500 mg dm-3, Na 50 mg dm-3, K 50 mg dm-3Mg 100 mg dm-3 Fe 20 mg dm-3 and P 200 mg dm-3. Prior to the Al analysis, samples should be diluted with water in order that the concentration of each inorganic component be lower than that mentioned above. In all standard and sample solutions the concentration of HNO3 were maintained in 0.1% (v/v). The Al concentrations in biological reference materials (NRCC DORM-2 and DOLT-2) determined by the present method agreed well with the reported reference values. The detection limit (3σ) was 1 ng g-1 (dry weight of biological samples). The present method is applicable with high accuracy and sensitivity to the determination of Al in biological samples.