title: Do we understand what the mercury speciation instruments are actually measuring? Results of RAMIX.
abstract: From August 22 to September 16, 2012, atmospheric mercury (Hg) was measured from a common manifold in the field during the Reno Atmospheric Mercury Intercomparison eXperiment. Data were collected using Tekran systems, laser induced fluorescence, and evolving new methods. The latter included the University of Washington-Detector for Oxidized Mercury, the University of Houston Mercury instrument, and a filter-based system under development by the University of Nevada-Reno. Good transmission of total Hg was found for the manifold. However, despite application of standard protocols and rigorous quality control, systematic differences in operationally defined forms of Hg were measured by the sampling systems. Concentrations of reactive Hg (RM) measured with new methods were at times 2-to-3-fold higher than that measured by Tekran system. The low RM recovery by the latter can be attributed to lack of collection as the system is currently configured. Concentrations measured by all instruments were influenced by their sampling location in-the-manifold and the instrument analytical configuration. On the basis of collective assessment of the data, we hypothesize that reactions forming RM were occurring in the manifold. Results provide a new framework for improved understanding of the atmospheric chemistry of Hg.
authors.affiliation: Department of Natural Resources and Environmental Science, University of Nevada, Reno, 1664 N. Virginia Street, Reno, Nevada 89557, United States. mgustin@cabnr.unr.edu
authors.forename: Mae Sexauer
authors.initials: MS
authors.lastname: Gustin
authors.forename: Jiaoyan
authors.initials: J
authors.lastname: Huang
authors.forename: Matthieu B
authors.initials: MB
authors.lastname: Miller
authors.forename: Christianna
authors.initials: C
authors.lastname: Peterson
authors.forename: Daniel A
authors.initials: DA
authors.lastname: Jaffe
authors.forename: Jesse
authors.initials: J
authors.lastname: Ambrose
authors.forename: Brandon D
authors.initials: BD
authors.lastname: Finley
authors.forename: Seth N
authors.initials: SN
authors.lastname: Lyman
authors.forename: Kevin
authors.initials: K
authors.lastname: Call
authors.forename: Robert
authors.initials: R
authors.lastname: Talbot
authors.forename: Dara
authors.initials: D
authors.lastname: Feddersen
authors.forename: Huiting
authors.initials: H
authors.lastname: Mao
authors.forename: Steven E
authors.initials: SE
authors.lastname: Lindberg
mesh_terms: D000393:Air Pollutants / Q000032:analysis* / Q000737:chemistry; D001965:Bromides / Q000032:analysis; D002248:Carbon Monoxide / Q000032:analysis; D004784:Environmental Monitoring / Q000295:instrumentation / Q000379:methods; D008628:Mercury / Q000032:analysis* / Q000737:chemistry; D017669:Mercury Compounds / Q000032:analysis; D009505:Nevada; D010126:Ozone / Q000032:analysis
chemical_list: D000393:Air Pollutants; D001965:Bromides; D017669:Mercury Compounds; D010126:Ozone; D002248:Carbon Monoxide; D008628:Mercury; C042720:mercuric bromide