Studies of Adsorption and Complexation of Copper and Lead with Environmental Relevance with an Electrochemical Quartz Crystal Nanobalance

摘要

Electrochemical methods when performed on an electrode of a piezoelectric quartz crystal can givernextra information on mass deposited and stripped from the electrode. Current and mass giverncomplementary information about the electrochemical phenomena. Reagent and products adsorption,rnas well as the importance of transport mechanisms as diffusion, can be easily perceived by followingrnone or both variables. The examples here shown of voltammetric methods performed on copper andrnlead solutions, using one of the gold electrodes of a piezoelectric quartz crystal as the workingrnelectrode, illustrate the power of technique. Besides, it is demonstrated that the mass monitorizationrnallows following non-faradaic processes, as complexation between lead and humic acids. On the otherrnhand, data simplification can be obtained by rendering invisible, for instance, proton reduction. Anodicrnstripping voltammetry is useful to decrease detection limits, due to the addition of the electrochemicalrnpre-concentration step, and mass, as well as current, could be used for quantitative purposes. Anrnenvironmental study of copper levels on the water of a lagoon shows the potential of the technique byrnreaching the ppb level.