Trace analysis of lead at a Nafion-modified electrode using square-wave anodic stripping voltammetry

ASV using square-wave voltammetry was used with Nafion-coated glassy carbon electrodes for lead analysis and it was found that square-wave frequencies greater than 100 Hz could be employed satisfactorily for trace lead detection. Peak current increases with frequencies up to 1000 Hz at step potentials of up to 10 mV, though not linearly. However, the enhanced sensitivity allows the analysis of low levels of lead with concentrations down to 1 ppb detectable. This technique gave a value of 15.0 ± 1.3 ppb lead in a diluted certified reference material with lead concentration of 14.7 ppb.