The application of mercury (Hg) stable isotopes has become an important tool for tracking Hg sources and delivery pathways in the environment. With the onset of the Minamata Convention, a global treaty aimed to mitigate environmental Hg emissions, Hg stable isotopes may be important in assessing whether reductions under the treatise are actively resulting in Hg declines across matrices. Here, we present the application of a low-cost active sampler for the measurement of Hg stable isotopes in total gaseous mercury (TGM). We will discuss modifications to the sampler to operate on both gold and carbon traps as well as compare isotope measurements between this unit and passive sampling devices to determine potential offsets between the methods. TGM isotope collectors were further used to assess regional sources of Hg emissions we deployed a national scale network as well as targeted study locations including contaminated sites, volcanic regions, and offshore oceanic measurements (i.e., representative of global emission pools). From this work we were able to characterize local and regional emission sources of Hg as well as seasonal patterns in isotope composition.

¹ U.S. Geological Survey, Upper Midwest Water Science Center, Madison, WI

* Corresponding author: mttate@usgs.gov