The UW Facility for Compound-Specific Isotope Analysis of Environmental Samples provides the ability to measure ratios of light stable isotopes on individual chemical compounds that can be separated from complex mixtures using gas chromatography.  Applications range from fisheries food-web analysis, to reconstruction of past climates, to archeological investigation of human livelihoods. The facility is a joint venture of the UW College of the Environment School of Aquatic & Fishery Sciences, School of Oceanography, School of Environmental & Forest Sciences, and the Quaternary Research Center, with additional support from the Department of Civil & Environmental Engineering.

The facility is based around a new Thermo Delta V Plus isotope ratio mass spectrometer (irMS) coupled to a Thermo GC IsoLink II and TraceGC 1310.  This system can be configured to measure either ¹³C:¹²C or ¹⁵N:¹⁴N of combusted compounds separated using the TraceGC.  An additional interface allows for the measurement of ¹⁸O:¹⁶O of O₂, ⁴⁰Ar: ³²O2, and ¹³C:¹²C of CO₂ from the headspace of 12 mL vials.  The irMS is also equipped with a specialized cup configuration and dual inlet for analysis of purified gases.  With the ability to measure a very wide variety of elements—from hydrogen, carbon and nitrogen to oxygen and argon—we have named the instrument NACHO.  NACHO lives on the 4^th floor of the Ocean Sciences Building.

The facility is directed by Gordon Holtgrieve, Assistant Professor in Aquatic & Fishery Sciences.  Terry Rolfe (trolfe@uw.edu) is in charge of day-to-day operations including scheduling and training.  A growing list of collaborators include Julian Sachs, Jodi Young, and Paul Quay (Oceanography), David Butman (Environmental & Forest Sciences), and Mike Brett (Civil & Environmental Engineering).  The facility is operated under a cost center model with per sample rates.