Performance of a new diffusive sampler for Hg0 determination in the troposphere

Henrik Skov; Britt T. Sørensen; Matthew S. Landis; Matthew S. Johnson; Paolo Sacco; Michael E. Goodsite; Christian Lohse; Kenneth S. Christiansen

doi:10.1071/EN06082

RESEARCH ARTICLE

Performance of a new diffusive sampler for Hg⁰ determination in the troposphere

Henrik Skov ^A ^F , Britt T. Sørensen ^B , Matthew S. Landis ^C , Matthew S. Johnson ^B , Paolo Sacco ^D , Michael E. Goodsite ^E , Christian Lohse ^E and Kenneth S. Christiansen ^E

+ Author Affiliations

- Author Affiliations

^A National Environmental Research Institute (DMU), Department of Atmospheric Environment (ATMI), University of Aarhus, Frederiksborgvej 399, DK-4000 Roskilde, Denmark.

^B Copenhagen Center for Atmospheric Research, Department of Chemistry, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen OE, Denmark.

^C US EPA Office of Research and Development, Research Triangle Park, NC 27711, USA.

^D Fondazione Salvatore Maugeri, Centro di Ricerche Ambientali, Via Svizzera 16, Padova 35127, Italy.

^E Department of Physics and Chemistry, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark.

^F Corresponding author. Email: hsk@dmu.dk

Environmental Chemistry 4(2) 75-80 https://doi.org/10.1071/EN06082
Submitted: 16 December 2006 Accepted: 17 March 2007 Published: 17 April 2007

Environmental context. Mercury is of concern to both the public and to the scientific community because it is found at high levels in some marine predators, prompting the US EPA and others to make guidelines restricting the consumption of some species. Most mercury in the environment is emitted to the atmosphere, but it is not known how it is transferred from the atmosphere to the marine environment. Therefore, it is important to study the connection between emission of mercury, its transport and removal from the atmosphere. We have developed a new sampler that is inexpensive, easy to use and with a sufficiently high detection limit that it can be used to measure the low mercury concentrations in the atmosphere at a reasonable time resolution.

Abstract. Mercury behaves uniquely in the atmosphere due to its volatility and long lifetime. The existing methods for measuring atmospheric mercury are either expensive or labour intensive. The present paper presents a new measurement technique, the diffusive sampler, that is portable, inexpensive, easy to use, and does not need a power supply. The sampler is sufficiently sensitive that it can measure mercury at low ambient levels with an exposure time of 1 to 3 days. The sampler is based on the Radiello diffusive sampler, which was used to collect volatile organic compounds. In the present paper, the method is validated under controlled laboratory conditions. The uptake rate of the Radiello diffusive sampler is determined using known concentrations of gaseous elemental mercury, and is measured as a function of wind speed, relative humidity and temperature. The Radiello sampler has a detection limit of 0.14 ng m^–3 for 1 day of exposure and thus can be used to measure mercury concentrations at the low levels found in ambient air. The Radiello sampler is therefore useful for mapping concentrations close to sources and sinks, in addition to ambient concentrations. For example, the sampler can be used to describe the geographical extent of Arctic mercury depletion episodes where gaseous elemental mercury is removed and stays close to 0 ng m^–3 for days, and it can be a powerful tool for mapping gradients around point sources and other areas of interest.

Acknowledgements

We would like to thank the Oticon Foundation, Chemical Society and Arctic Research and Technology Corporation for financial support. This work was financially supported by the Danish Environmental Protection Agency with means from the MIKA/DANCEA funds for Environmental Support to the Arctic Region. The findings and conclusions presented here do not necessarily reflect the views of the Agency. Michael E. Goodsite and Christian Lohse would like to thank The Danish National Science Foundation and Prof. Ole John Nielsen, University of Copenhagen for funding. Michael E. Goodsite would also like to thank the Natural Science Faculty of University of Southern Denmark for funding. Matthew S. Johnson and Britt T. Sørensen thank the Copenhagen Center for Atmospheric Research funded by the Danish Natural Science Research Council and the Copenhagen Global Change Initiative. Finally, this work was partially funded by the United States Environmental Protection Agency Office of Research and Development. It has been subjected to Agency review and approved for publication.

References

Performance of a new diffusive sampler for Hg0 determination in the troposphere

Acknowledgements

Subscriber Login

Performance of a new diffusive sampler for Hg⁰ determination in the troposphere