We present a novel methodology for the determination of gaseous elemental mercury (GEM). It is based on passive sampling of Hg on screen-printed gold electrodes (SPGEs), followed by measurement of the amalgamated mercury by square wave anodic stripping voltammetry (SWASV). We have explored in detail the behaviour of the SPGE electrode surface during the sampling process (by applying Time Of Flight Secondary Ions Mass Spectrometer, TOF-SIMS), the stability of the voltammetric signals and the inter-electrode reproducibility, with acceptable results. The adsorption of mercury on the SPGE follows a nearly linear behaviour until the sorbent becomes saturated (equilibrium phase) for different mercury concentrations, allowing to select a sampling time of 30 minutes for calibration. The theoretical behaviour of the sampling system was modelled, considering the changes in the diffusive path length between the porous diffusive barrier and the absorption surface,
Read the full text at: https://dx.doi.org/10.1021/acs.analchem.0c04347