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

摘要

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 μgL-1) to 80nM (5.6 μgL-1) for a preconcentration time of 60s, 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 μgL-1. The repeatability of the method at a concentration level of the analyte as low as 3.5μgL-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.