The University of Utah’s Department of Geology & Geophysics has been awarded a million-dollar grant from the National Science Foundation (NSF) to acquire state-of-the-art mass spectrometry instrumentation for measuring isotope ratios of heavier elements at the precision needed to perform cutting-edge research into Earth’s deep past.

Mass spectrometers have been making accurate and precise isotope ratio measurements of elements such as hydrogen (H), carbon (C) and oxygen (O) for many decades. Isotope ratio differences generally scale with mass, with isotope ratios of these lighter-mass elements exhibiting much larger differences than ratios for the heavier-mass elements. Large differences are easier to measure than small differences.

The instrument acquired through the NSF Major Research Instrumentation program is capable of determining very, very small isotope ratio differences. The instrument’s technical name is the Thermo Neoma “multicollector inductively coupled plasma mass spectrometer,” or MC-ICP-MS for short. The instrument routinely makes accurate and precise isotope ratio measurements for magnesium (Mg), iron (Fe), strontium (Sr), molybdenum (Mo), mercury (Hg), thallium (Tl), lead (Pb), uranium (U), calcium (Ca), potassium (K) and many other heavy elements.

“There’s so many things you can do with it. We have a long list of scientists in our department and beyond who rely on isotope ratio data for their projects,” said Chad Ostrander, assistant professor of geology and principal investigator of the grant.

Joining Ostrander in applying for the grant are Diego Fernandez, Juan Carlos de Obeso and Sarah Lambart. Chris Anderson and Issaku Kohl also play instrumental roles in the project. The team’s interests cover many fields of research, tracking the selective movement of isotopes today and in the past from Earth’s interior to its surface, between seawater and the seafloor, from ocean to land and between land and life.

“Isotopes provide fundamental information about the world around us. The rocks that form our planet have been transformed through its history, with few original remaining pieces that are not deformed and twisted. This disfigured and patchy rock record is our only hope for understanding Earth’s past,” states an abstract describing the award. The relative abundances of isotopes in the rock record “are set by specific processes, for example interactions with free oxygen and biology. Isotopes contained in rocks serve as a tool for exploring the geologic history of our planet, past climates and human interactions with the environment.”

One of Ostrander’s research interests is the rise of oxygen on Earth, and what role this played in the evolution of complex life on our planet.

Strontium is another element of particular interest. This element permanently accumulates in teeth enamel and otoliths, reflecting the environment a creature inhabited during its lifetime. Measuring the relative abundances of strontium isotopes helps scientists determine how animals moved around the landscape, according to Fernandez, a research professor who runs the geology department’s ICP-MS Metals and Strontium Isotope facility.

“These are the perfect materials. They are laminated, so you see the growth bands, it’s amazing,” Fernandez said. “For salmon, you can tell the first year in freshwater, second year, summer, winter, summer, winter, summer. Like in a tree, the rings get thinner and thinner as it grows.”

Each growth band is a record of where the animal lived for a particular year, but accurately reading that record requires mass spectrometry of extraordinary precision. “We’re talking parts-per-million precision,” Fernandez said. “Such precision is impossible without this type of machine.”

The new instrument, which is to be installed on the fourth floor of the Sutton building around mid-May, will be open to researchers at the state-wide level and beyond. The ICP-MS facility at the University of Utah has served as a unique collaborative research hub since 2009.

“We are just continuing a precedent,” Ostrander said. “The whole state benefits from the award because we have scientists from across Utah come to use our machinery. A lot of early-career scientists in the geology department will benefit. This is going to be a tool that will help all of us over the coming decades.”

The equipment will also extend opportunities for students. Graduate and undergraduate students have the opportunity to use the new and existing instrumentation in the ICP-MS facility for their personal research—promoting the growth and careers of all.

Banner photo: Pictured in front of the Sutton building’s fish fossil wall are, left to right, Issaku Kohl, Chris Anderson, Chad Ostrander, Juan Carlos de Obeso, Sarah Lambart and Diego Fernandez. Photo by Todd Anderson.

• Brian Maffly Science writer, University of Utah Communications
  801-573-2382 brian.maffly@utah.edu