In:
Atmospheric Measurement Techniques, Copernicus GmbH, Vol. 14, No. 5 ( 2021-05-20), p. 3657-3672
Abstract:
Abstract. Passive air samplers (PASs), which provide time-averaged concentrations of
gaseous mercury over the timescale of weeks to months, are promising for
filling a gap in the monitoring of atmospheric mercury worldwide. Their
usefulness will depend on their ease of use and robustness under field
conditions, their availability and affordability, and most notably, their
ability to provide results of acceptable precision and accuracy. Here we
describe a comparative evaluation of three PASs with respect to their
ability to precisely and accurately record atmospheric background mercury
concentrations at sites in both southern Italy and southern Ontario, Canada. The study includes the CNR-PAS with gold nanoparticles as a sorbent, developed by the Italian National Research Council, the IVL-PAS using an activated carbon-coated disk, developed by the Swedish Environmental Research Institute, and the MerPAS® using a sulfur-impregnated activated carbon sorbent, developed at the University of Toronto and commercialized by Tekran. Detection limits are deduced from the variability in the amount of mercury quantified in more than 20 field blank
samples for each PAS. Analytical and sampling precision is quantified
through 22 triplicate deployments for each PAS, ranging in duration from 2 to 12 weeks. Accuracy and bias are assessed through comparison with
gaseous elemental mercury concentrations recorded by Tekran 2537 automated
mercury analyzers operating alongside the PASs at both locations. The
performance of the PASs was significantly better in Italy, with all of them
providing concentrations that are not significantly different from the
average concentrations of the Tekran 2537 instruments. In Canada, where
weather conditions were much harsher and more variable during the February
through April deployment period, there are differences amongst the PASs. At both sites, the MerPAS® is currently the most sensitive, precise, and accurate among the three PASs. A key reason for this is the larger size and the radial configuration of the
MerPAS®, which results in lower blank levels relative to the sequestered amounts of mercury when compared to the other two PASs, which rely on axial diffusion geometries. Since blank correction becomes relatively smaller with longer deployments, performance tends to be closer amongst the PASs during deployments of 8 and 12 weeks.
Type of Medium:
Online Resource
ISSN:
1867-8548
DOI:
10.5194/amt-14-3657-2021
DOI:
10.5194/amt-14-3657-2021-supplement
Language:
English
Publisher:
Copernicus GmbH
Publication Date:
2021
detail.hit.zdb_id:
2505596-3
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