Mass Spectrometer will aid studies of environment

Posted 11/18/02

A new tool for research

Like Harry Potter and his new Nimbus 2000, a group of Dartmouth researchers who study how the environment works are excited by a new acquisition that can break down organic samples and reveal molecular species of the elements.

With funding from the National Science Foundation (NSF) the team has just purchased a new mass spectrometer - but not just any mass spectrometer. The new one is an Octapole ICPMS (inductively coupled plasma mass spectrometer) with an added GC (gas chromatograph) component. The combination of GC and ICPMS is a powerful tool for speciation analysis. It's a combination only available to a couple of institutions in the United States.

"This new instrument allows us to distinguish elements at the species level, so for example, we will now be able to separate the highly toxic methylated form of mercury from total mercury in our biological samples of fish and plankton," says Carol Folt, Professor of Biology. "The other powerful mass spectrometer in the core allows us to analyze the total mercury, arsenic or other elements. This new instrument provides more exact information on the way elements move through the environment."

Xiahong Feng, Associate Professor of Earth Sciences, the principal investigator on the grant, together with Stefan Sturup, Research Assistant Professor in Earth Sciences, and Folt submitted the grant requesting the new machine.

"We are a group of researchers who want to understand the movement of essential elements through the environment," says Feng. "I think it's our shared intellectual focus and our strong interdisciplinary experience that was attractive to NSF, and that helped us with this award."

Housed in the Sherman Fairchild Center in Steele Hall, the Trace Elements Core Facility was established as a common resource for Dartmouth researchers in all departments and schools. Dartmouth's Center for Environmental Health Sciences oversees this core as well as the Molecular Biology and Proteomics Core Facility. This is the third successful NSF or NIH instrument grant sponsored by the Center in the past two years, and it greatly expands the research tools available on campus, thus providing the latest in detection capabilities.

"The scope of the projects that will use this new instrument encompasses many people across campus," says Sturup, who also is the director of the Trace Elements Core Facility. "It's a great example of many departments working together to acquire this equipment and collaborate on new research."

Some of the projects include: Xiahong Feng and Carl Renshaw from earth sciences who both study the transport of chemicals through watersheds; Margaret Karagas at Dartmouth Medical School is looking at arsenic loads in humans; Carol Folt and Celia Chen from biology study the biomagnification of mercury in aquatic systems; Dean Wilcox from chemistry studies metal transport in proteins, to name a few.

With Sturup and a technician running this core facility, there is both a strong research collaboration component along with the service of helping process the samples here. Sturup is trained as an analytical chemist, and he helps develop new methodologies, assists with analyzing data and can also guide and shape new projects. The facility is also highly unusual in that Sturup trains graduate and undergraduate students in the sample processing skills required to analyze trace levels of elements in the environment.

"It's a genuine, successful research and education facility - not just a processing facility. The emphasis on research and training is a big distinction of Dartmouth's approach," says Folt.

For more information about the new machine or about the Trace Elements Core Facility, call (603) 643-1272 or visit www.dartmouth.edu/~cehs/indexTE.html.