Collect. Czech. Chem. Commun. 2001, 66, 456-464

Adsorptive Stripping Voltammetric Determination of Aluminium Using Arsenazo III

Alena Komersováa, Martin Bartoša, Kurt Kalcherb and Karel Vytřasa,*

a Department of Analytical Chemistry, University of Pardubice, nám. Čs. legií 565, CZ-532 10 Pardubice, Czech Republic
b Institute for Analytical Chemistry, Karl Franzens University, Universitätsplatz 1, A-8010 Graz, Austria


A new analytical method for the indirect determination of trace amounts of aluminium(III) is based on the adsorptive accumulation of an azo dye, Arsenazo III, on the hanging mercury drop electrode. In the presence of Al(III) forming complexes with the dye, its peak occurring at -330 mV decreases. Optimized experimental conditions were found as follows: supporting electrolyte, acetate or chloroacetate-acetate buffer (pH 3.6); accumulation potential, -50 mV vs SCE; accumulation time, 120 s; Arsenazo III concentration, 5 · 10-7 mol l-1; scan rate, 20 mV s-1; initial potential, -500 mV; final potential, 0 mV; FSDPV mode; pulse amplitude, 50 mV; pulse duration, 100 ms; pulse interval, 10 ms. Under these experimental conditions, the calibration dependence was linear in the concentration range 0-6 μmol l-1 with a detection limit of 3.7 · 10-8 mol l-1 (1 ppb, calculated as 3σ for n = 10). Interference of iron(III) can be suppressed by addition of L-ascorbic acid, the effect of numerous divalent metal ions is negligible. Serious interfering effects were observed for U(VI) as UO22+, both Cr(III) and Cr(VI), and F-. The method developed was verified using a certified reference material (SRM 1575 Pine Needles); no statistically significant differences between the determined and declared contents were found.

Keywords: Stripping voltammetry; Electrochemistry; Hanging mercury drop electrode; Adsorption; Azo dyes; Al complexes.

References: 39 live references.