Superfund Research Program
Trace Elements Analysis Core
The principal goal of this core continues to be to serve the analytical needs of the research projects of this program. However, this core was recently converted to a university cost center and as such, now also provides analytical services for other researchers within the Dartmouth research community as well as outside researchers. The departure in late 2004 of the previous director, Dr. Stefan Sturup, who returned to his native Denmark, and the completion of Dr. Lorenzo Perna’s post-doctoral fellowship in the Core from 2002 – 2004, meant that 2005 was a time or reorganization for TEA core operations. Under the direction of the Associate Director, Dr. Celia Chen, and the assistance of the TEA research technician, Angela Lacroix-Fralish, the core continued to keep the sample throughput at a high level during the six months when the program was conducting an international search for a new director. This search was successful in recruiting its top candidate and one of the premiere scientists in this field, Dr. Brian Jackson who previously ran a similar core facility at the Savannah River Federal Facility. Since his arrival in July 2005, the lab is now fully staffed and the sample backlog has been cleared.
The highlight of 2005 for the laboratory was the replacement of the older High Resolution Element 1 ICP-MS with a new Element 2 ICP-MS. The original Element had been purchased in 1994 and was at the time one of only four ICP-MS instruments in the U.S. and the first at a research university. The new Element 2 (E2) represents the state-of-the-art in sensitivity and resolution for ICP-MS and is the only high-resolution single collector instrument currently offered commercially. The instrument was purchased with matching contributions from the Dartmouth SBRP program, Dartmouth College, and the Center for Environmental Health Sciences, and once again places Dartmouth College at the forefront of trace metals research. The E2 provides detection limits in the parts per quadrillion range for most trace elements. Significant improvements in the speed of magnet scanning (over the Element) mean that the E2 can be used as an element-specific detector for chromatographic analysis. Both of these instrument enhancements will be of direct benefit to Superfund projects. The improvement in detection limits will allow us to quantify lower concentrations of Hg which will be beneficial to the Folt/Chen project, where environmentally relevant Hg concentrations are frequently in the low parts per trillion to parts per quadrillion range. By interfacing cold vapor generation to the E2 we expect to achieve detection limits on the order 0.05 µg L-1. Additionally, a main focus of the TEA involvement with Dr. Karagas’ studies will be the development of speciation methods for As. The E2 will be very useful in this regard as an element specific detector for the chromatographic separation. Core scientists continue to develop the methodology for Hg speciation in low level/low mass samples and to this end we have purchased a commercial purge and trap system from Brooks Rand Company. This commercial system will improve sample throughput by providing additional gas bubblers and Tenax traps allowing processing of four samples at a time and up to 25 per day; this represents a significant improvement over the current in-house developed purge and trap system.