Sensitive voltammetric determination of gallium in aluminium materials using renewable mercury film silver based electrode

Abstract

Simple cyclic renewable silver amalgam film electrode (Hg(Ag)FE), applied for the determination of gallium(III) using differential pulse anodic stripping voltammetry (DP ASV), is presented. The effects of various factors such as: preconcentration potential and time, pulse height, step potential and supporting electrolyte composition are optimised. The calibration graph is linear from 5 nM (0.35 µg L⁻¹) to 80 nM (5.6 µg L⁻¹) for a preconcentration time of 60 s, with correlation coefficient of 0.995. For a Hg(Ag)FE with a surface area of 9.9 mm² the detection limit for a preconcentration time of 120 s is as low as 0.1 µg L⁻¹. The repeatability of the method at a concentration level of the analyte as low as 3.5 µg L⁻¹, expressed as RSD is 3.2% (n = 5). The proposed method was successfully applied by studying the synthetic samples and simultaneously recovery of Ga(III) from spiked aluminium samples.

Keywords:

• gallium
• aluminium materials
• mercury film electrodes
• stripping voltammetry

Acknowledgements

The study was financed as an R&D project by the Polish Ministry of Science and Education from research funds for the years 2007-2010 (No. 15 020 02).