Optimization of parameters for differential pulse voltammetry at the hanging mercury drop electrode

Abstract

Abstract The detection limit of differential pulse voltammetry at a hanging mercury drop electrode is investigated. The most important result of this study is that very small pulse amplitudes considerably improve the signal‐to‐background ratio and lead to lower detection limits. Due to the fact that (in practice) the background current does not originate only from capacitive properties of the electrode, an optimal pulse duration also exists, which guarantees the highest signal‐to‐background ratio. It is shown that the background current consists of the capacitive current and a very noisy but, on average, constant component, presumably of a faradaic nature that originates from impurities. The effects of the prepulse time, the pulse amplitude, the pulse duration, the step height of the staircase ramp, and the duration of the current sampling time on the signal and background intensity and noise are described.