EA: Acquisition of a Gas Source Isotope Ratio Mass Spectrometer and a Thermal Conversion Elemental Analyzer for the Biogeochemistry Stable Isotope Lab at Virginia Tech

Virginia Polytechnic Institute And State University, Blacksburg VA

Investigators

Abstract

This award funds the acquisition of high-temperature pyrolysis elemental analyzer (TC/EA) and coupled gas source isotope ratio mass spectrometer (GS-IRMS) for the Biogeochemistry Laboratory in the Geosciences Department at Virginia Tech (VT). This pair of instruments can measure the stable isotopes of hydrogen and oxygen in a variety of materials. Stable isotopes are stable atoms of elements with different numbers of neutrons in their nuclei; their small differences in mass lead to sorting during chemical reactions, such that stable isotopes act as natural tracers during a host of natural processes. The measurement of the stable isotopes of hydrogen and oxygen provide insight into the behaviors of these elements in different chemical reactions in the environment. This includes tracking the movement of water, the migration of animals, and the transfer of energy in food networks. Stable hydrogen and oxygen isotope analyses can also aid in reconstructing past changes in temperature and precipitation and understanding the formation of mineral deposits. Beyond research activities, the new instruments will also be used in teaching and outreach activities that will engage high school and college students and researchers both regionally and nationally. These instruments will significantly enhance the capabilities of the VT Biogeochemistry Lab and expand its research, education, and outreach activities. It will be critical to on-going, currently funded and future research in the laboratory. Ongoing projects include measuring oxygen isotopes in sulfate to track aspects of the sulfur cycle and measuring hydrogen and oxygen isotopes in bat guano and fossil tooth enamel to evaluate changes in past atmospheric precipitation. Potential future projects with researchers at VT include employing hydrogen and oxygen isotopes to estimate trophic transfer efficiency in aquatic food networks, track bat migration, and reconstruct past temperatures using phosphate minerals. The Biogeochemistry Lab at VT historically has an excellent track record of supporting student research and has enabled the research activity of 20 undergraduate, 52 graduate, and 8 visiting students, as well as 10 postdoctoral researchers and scientists from VT and 17 other institutions located in United States and internationally. The new instrumentation will also be used in hands-on teaching and outreach activities including: 1) a science summer camp for high school students 2) an established course for undergraduate and graduate students on stable isotope biogeochemistry; and 3) a regional stable isotope workshop for institutions in southern Appalachia. 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.