Improvements to the Accuracy of Atmospheric Oxidized Mercury Measurements.

Autor: Lyman SN; Bingham Research Center, Utah State University, Vernal, Utah 84078, United States.; Department of Chemistry and Biochemistry, Utah State University, Logan, Utah 84322-0305, United States., Gratz LE; Environmental Studies Program, Colorado College, Colorado Springs, Colorado 80903-3298, United States., Dunham-Cheatham SM; Department of Natural Resources and Environmental Science, University of Nevada-Reno, Reno, Nevada 89557, United States., Gustin MS; Department of Natural Resources and Environmental Science, University of Nevada-Reno, Reno, Nevada 89557, United States., Luippold A; Department of Natural Resources and Environmental Science, University of Nevada-Reno, Reno, Nevada 89557, United States.
Jazyk: angličtina
Zdroj: Environmental science & technology [Environ Sci Technol] 2020 Nov 03; Vol. 54 (21), pp. 13379-13388. Date of Electronic Publication: 2020 Oct 19.
DOI: 10.1021/acs.est.0c02747
Abstrakt: We developed a cation-exchange membrane-based dual-channel system to measure elemental and oxidized mercury and deployed it with an automated calibration system and the University of Nevada, Reno-Reactive Mercury Active System (UNR-RMAS) at a rural/suburban field site in Colorado during the summer of 2018. Unlike oxidized mercury measurements collected via the widely used KCl denuder method, the dual-channel system was able to quantitatively recover HgCl 2 and HgBr 2 injected by the calibrator into the ambient sample air and compared well with the UNR-RMAS measurements. The system measured at 10 min intervals and had a 3-h average detection limit for oxidized mercury of 33 pg m -3 . It was able to detect day-to-day variability and diel cycles in oxidized mercury (0 to 200 pg m -3 ) and will be an important tool for future studies of atmospheric mercury. We used a gravimetric method to independently determine the total mercury permeation rate from the permeation tubes. Permeation rates derived from the gravimetric method matched the permeation rates observed via mercury measurement devices to within 25% when the mercury permeation rate was relatively high (up to 30 pg s -1 ), but the agreement decreased for lower permeation rates, probably because of increased uncertainty in the gravimetric measurements.
Databáze: MEDLINE
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