TY - JOUR
T1 - Automated calibration of atmospheric oxidized mercury measurements
AU - Lyman, Seth
AU - Jones, Colleen
AU - O'Neil, Trevor
AU - Allen, Tanner
AU - Miller, Matthieu
AU - Gustin, Mae Sexauer
AU - Pierce, Ashley M.
AU - Luke, Winston
AU - Ren, Xinrong
AU - Kelley, Paul
PY - 2016/12/6
Y1 - 2016/12/6
N2 - The atmosphere is an important reservoir for mercury pollution, and understanding of oxidation processes is essential to elucidating the fate of atmospheric mercury. Several recent studies have shown that a low bias exists in a widely applied method for atmospheric oxidized mercury measurements. We developed an automated, permeation tube-based calibrator for elemental and oxidized mercury, and we integrated this calibrator with atmospheric mercury instrumentation (Tekran 2537/1130/1135 speciation systems) in Reno, Nevada and at Mauna Loa Observatory, Hawaii, U.S.A. While the calibrator has limitations, it was able to routinely inject stable amounts of HgCl2 and HgBr2 into atmospheric mercury measurement systems over periods of several months. In Reno, recovery of injected mercury compounds as gaseous oxidized mercury (as opposed to elemental mercury) decreased with increasing specific humidity, as has been shown in other studies, although this trend was not observed at Mauna Loa, likely due to differences in atmospheric chemistry at the two locations. Recovery of injected mercury compounds as oxidized mercury was greater in Mauna Loa than in Reno, and greater still for a cation-exchange membrane-based measurement system. These results show that routine calibration of atmospheric oxidized mercury measurements is both feasible and necessary.
AB - The atmosphere is an important reservoir for mercury pollution, and understanding of oxidation processes is essential to elucidating the fate of atmospheric mercury. Several recent studies have shown that a low bias exists in a widely applied method for atmospheric oxidized mercury measurements. We developed an automated, permeation tube-based calibrator for elemental and oxidized mercury, and we integrated this calibrator with atmospheric mercury instrumentation (Tekran 2537/1130/1135 speciation systems) in Reno, Nevada and at Mauna Loa Observatory, Hawaii, U.S.A. While the calibrator has limitations, it was able to routinely inject stable amounts of HgCl2 and HgBr2 into atmospheric mercury measurement systems over periods of several months. In Reno, recovery of injected mercury compounds as gaseous oxidized mercury (as opposed to elemental mercury) decreased with increasing specific humidity, as has been shown in other studies, although this trend was not observed at Mauna Loa, likely due to differences in atmospheric chemistry at the two locations. Recovery of injected mercury compounds as oxidized mercury was greater in Mauna Loa than in Reno, and greater still for a cation-exchange membrane-based measurement system. These results show that routine calibration of atmospheric oxidized mercury measurements is both feasible and necessary.
UR - http://www.scopus.com/inward/record.url?scp=85011694827&partnerID=8YFLogxK
U2 - 10.1021/acs.est.6b04211
DO - 10.1021/acs.est.6b04211
M3 - Article
C2 - 27934266
AN - SCOPUS:85011694827
SN - 1520-5851
VL - 50
SP - 12921
EP - 12927
JO - Environmental Science and Technology
JF - Environmental Science and Technology
IS - 23
ER -