Sarah Janssen is an isotope geochemist working in the Mercury Research Lab (MRL) located within the Upper Midwest Water Science Center.
She has a PhD in environmental chemistry from Rutgers University and a bachelor’s in chemistry from
University of the Sciences in Philadelphia. Her work focuses on the application of stable isotope techniques for understanding sources and transformations of mercury (Hg) in the environment. Her research interests include Hg cycling in contaminated ecosystems, the investigation of microbial Hg transformations using stable isotopes, and development of analytical methods to improve Hg isotope measurements.
Current Projects
- Mercury Cycling and Source Identification in the St Louis River Estuary MN/WI (collaboration with US EPA and Minnesota Pollution Control Agency)
- Mercury Isotope Fractionation during Microbial Uptake and Transformations of Hg (collaboration with Rutgers University and University of Ottawa)
- Method Development for the Pre-concentration of Waters and Low Concentration Environmental Samples for Mercury Isotopic Analysis
Science and Products
Mercury Isotope Ratios used to Determine Sources of Mercury to Fish in Northeast U.S. Streams
Mercury isotope analyses were used to distinguish different sources of mercury to fish in 23 streams along a forested-rural to urban-industrial land-use gradient in the Northeastern United States. The use of mercury isotope measurements in fish tissue allow for distinguishing different sources of mercury that are bioaccumulating into the food web. Mercury isotope signatures in fish in forested...
Mercury studies
The USGS Mercury Research Lab is a national leader in advancing mercury research and science, specializing in low-level mercury speciation and isotope analysis and mercury-source fingerprinting. The MRL leads national cutting-edge collaborative studies, including state-of-the-art sample analysis, methods development for field and lab procedures, and data interpretation and dissemination.
Mercury studies
The USGS Mercury Research Lab is a national leader in advancing mercury research and science, specializing in low-level mercury speciation and isotope analysis and mercury-source fingerprinting. The MRL leads national cutting-edge collaborative studies, including state-of-the-art sample analysis, methods development for field and lab procedures, and data interpretation and dissemination.
Science and Products
- Science
Mercury Isotope Ratios used to Determine Sources of Mercury to Fish in Northeast U.S. Streams
Mercury isotope analyses were used to distinguish different sources of mercury to fish in 23 streams along a forested-rural to urban-industrial land-use gradient in the Northeastern United States. The use of mercury isotope measurements in fish tissue allow for distinguishing different sources of mercury that are bioaccumulating into the food web. Mercury isotope signatures in fish in forested...Mercury studies
The USGS Mercury Research Lab is a national leader in advancing mercury research and science, specializing in low-level mercury speciation and isotope analysis and mercury-source fingerprinting. The MRL leads national cutting-edge collaborative studies, including state-of-the-art sample analysis, methods development for field and lab procedures, and data interpretation and dissemination.Mercury studies
The USGS Mercury Research Lab is a national leader in advancing mercury research and science, specializing in low-level mercury speciation and isotope analysis and mercury-source fingerprinting. The MRL leads national cutting-edge collaborative studies, including state-of-the-art sample analysis, methods development for field and lab procedures, and data interpretation and dissemination. - Data
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