MRI: Track 1 Acquisition of an Isotope Ratio Mass Spectrometer for Ecology, Paleolimnology, and Biogeochemical Research at the Large Lakes Observatory

Understanding how Earth functions and how it has changed over time requires precise measurements of chemical signatures found in natural materials like lake sediments, fossils, and organic matter. This project supports the acquisition of a new isotope ratio mass spectrometer (IRMS) at the University of Minnesota Duluth’s Large Lakes Observatory (LLO), enhancing the capacity for high-precision analyses of stable isotopes of carbon, nitrogen, oxygen, hydrogen, and sulfur. The new instrument will provide researchers and students across multiple scientific disciplines (ecology, biogeochemistry, paleoclimatology, and limnology) with tools to investigate critical questions related to Earth system change, ecosystem dynamics, and hydroclimate variability. It will also provide hands-on training opportunities for undergraduate and graduate students, supporting the next generation of scientists with practical experience in advanced analytical techniques. This project involves the acquisition of a state-of-the-art isotope ratio mass spectrometry system consisting of an IRMS unit paired with a gas chromatograph–combustion interface, elemental analyzer, and a Kiel IV carbonate preparation device. This instrument package will replace LLO’s aging equipment and enable a wide array of new and ongoing research initiatives. The system will support paleolimnological reconstructions of past hydroclimate through the isotopic analysis of small carbonate samples and will facilitate studies of nutrient cycling, greenhouse gas fluxes, and ecological food web structure through measurements of isotopic signatures in organic matter, water, and gases. Researchers will be able to trace sources and transformations of carbon and nitrogen in aquatic systems, assess ecosystem responses to stressors, and better understand the biogeochemical functioning of lake systems both regionally and globally. These questions are vital to our understanding of freshwater resources worldwide, which is the primary research mission of LLO. The instrument will be available to investigators from a range of academic departments at UMD and regional collaborators, strengthening interdisciplinary research and supporting graduate and undergraduate education in the natural sciences. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.