Determination of trace aluminium by adsorptive stripping voltammetry on a preplated bismuth-film electrode in the presence of cupferron.

This work reports the use of adsorptive stripping voltammetry (AdSV) for the determination of aluminium on a rotating-disc bismuth-film electrode (BiFE). Al(III) ions in the non-deoxygenated sample were complexed with cupferron and the complex was accumulated by adsorption on the surface of the preplated BiFE. The stripping step was carried out by using a square-wave (SW) potential-time voltammetric excitation signal. The experimental variables as well as potential interferences were investigated and the figures of merit of the method were established. Using the selected conditions, the 3sigma limit of detection for aluminium was 0.5 microg l(-1) at a preconcentration time of 240 s and the relative standard deviation was 4.2% at the 5 microg 1(-1) level for a preconcentration time of 120 s (n=8). The accuracy of the method was established by analysing water and metallurgical samples.