Washington and Lee University has received a grant from the National Science Foundation to acquire a stable isotope ratio mass spectrometer, which will be shared through a variety of collaborations with neighboring Virginia Military Institute. In the future, W&L will accept samples from other academic institutions and become a regional hub for isotope analysis.
The powerful and sophisticated instrument, scheduled to be installed this fall, will enhance teaching at W&L as well as elevate a variety of research projects across different academic disciplines such as biology, geology and archaeology and anthropology. It will be an important addition to W&L's scientific instrumentation and will complement an expanding array in laboratories and the new Integrative and Quantitative (IQ) Science Center.
Bill Hamilton, professor of biology at W&L, was the principal investigator and submitted the application along with three other W&L faculty members: Larry Hurd, Herwick Professor of Biology, Robert Humston, associate professor of biology, Lisa Greer, associate professor of geology, as well as Major Pieter deHart, assistant professor of biology at VMI.
According to Hamilton, the mass spectrometer can detect stable isotopes that tend to occur in very low amounts in carbon, hydrogen, oxygen and nitrogen. Peripherals that accompany the machine will allow the combustion and analysis of solid, liquid and gas samples of different types of organic matter, such as soil, plant tissue and hair.
Hamilton expects the instrument to be incorporated into biology and geology undergraduate classes by the academic year 2014-2015, as well into undergraduate research programs.
"Not many undergraduate institutions have this instrument," Hamilton pointed out, "and it fits with W&L's goal of engaging more students in science, whatever their majors or career goals. We plan to expose students in several courses to its different uses early on and then build on that. Beginning students will gain an understanding of what mass spectrometers can do and how to interpret the data, then intermediate level students will be able to prep some of the samples and finally upper division students will learn to actually run the instrument.
"Being able to prepare samples is a very specialized skill and gets students to think about things quantitatively. It also applies across a lot of different areas and for a student who is going to graduate school for geology or biology it will be very beneficial."
On the research side, the instrument will strengthen the projects on which students and faculty collaborate. Applications will range across time scales—from days to millennia—and from bacteria to ecosystems.
Hamilton's research in Yellowstone National Park examines the interactions of large ungulate grazers such as bison and elk with grasses and soil microbes and covers a wide spectrum, from bacterial work to ecosystems. "In my restoration project, most of the organic matter is young, but I can't prove that until I actually get to see the stable isotope data on the nitrogen and carbon ratios," he said. "With this instrument I can, for example, identify a urine hit from a bison from several years ago in Yellowstone."
The mass spectrometer will also benefit Humston's research into fish tissue and scales and show where fish were when they were juveniles and herbivores, before switching to being omnivores. Hurd, in collaboration with deHart, will conduct similar research into mantids (commonly referred to as the praying mantis) since they start as herbivores and then become predators, and the new instrument will allow for the analysis of their bodies and solid excreta.
Greer's research into coral reefs will also greatly benefit from the mass spectrometer. She uses the geochemistry of corals, specifically the stable isotopes, to tell her about past climate change and environmental conditions. "I look at the ratio of heavy to light oxygen in the coral skeleton, which varies with the temperature of the water that the coral is growing in," she said. "Also, fresh water has a distinctly different isotope signature from marine water, so I can actually capture periods of fresh water flooding or high rainfall in the coral skeleton.
"I can also core through living coral and look at the stable isotopes down through time, from the present to 100 years ago, and see changes in the carbon composition of the atmosphere from the burning of fossil fuels. So it's very exciting that we have this instrument at W&L."
The mass spectrometer will also benefit W&L's outreach and service to the community and region in efforts to protect the environment. The instrument is capable of analyzing water and will be used to look for contamination of local water and identify whether the water is coming from municipal water sources or if there's any human waste.
W&L's archaeology program led by Alison Bell, associate professor of archaeology, and Don Gaylord, staff archaeologist/instructor at W&L, will also benefit from the spectrometer. Bell's research concentrates on material culture, consumption, production and social stratification in the 18th and 19th centuries in the eastern United States. The mass spectrometer will enable her to identify human diet from tissue in a skull and particularly cartilage from a bone and, using Colonial history, place the status of an individual within a plantation.