A field intercomparison of three passive air samplers for gaseous mercury in ambient air

Abstract. Passive air samplers (PASs), which provide time-averaged concentrations of gaseous mercury over the timescale weeks to months, are promising for filling a gap in monitoring atmospheric worldwide. Their usefulness will depend on their ease use and robustness under field conditions, availability affordability, most notably, ability results acceptable precision accuracy. Here we describe comparative evaluation three PASs with respect precisely accurately record background at sites both southern Italy Ontario, Canada. The study includes CNR-PAS gold nanoparticles as sorbent, developed by Italian National Research Council, IVL-PAS using an activated carbon-coated disk, Swedish Environmental Institute, MerPAS® sulfur-impregnated carbon University Toronto commercialized Tekran. Detection limits deduced from variability amount quantified more than 20 blank samples each PAS. Analytical sampling is through 22 triplicate deployments PAS, ranging duration 2 12 weeks. Accuracy bias assessed comparison elemental recorded Tekran 2537 automated analyzers operating alongside locations. performance was significantly better Italy, all them providing that not different average instruments. In Canada, where weather conditions were much harsher variable during February April deployment period, there differences amongst PASs. At sites, currently sensitive, precise, accurate among A key reason this larger size radial configuration MerPAS®, lower levels relative sequestered amounts when compared other two PASs, rely axial diffusion geometries. Since correction becomes relatively smaller longer deployments, tends be closer 8