Stable Isotope Laboratory Research Group

Stanford University
Geological and Environmental Sciences, Bldg. 320
Stanford, CA 94305-2115
Tel: 650-723-0817, Fax:650-725-2199

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Welcome to the Stanford University Stable Isotope Laboratory Research Group(SIL) headed by Dr. Robert B. Dunbar and managed by David A. Mucciarone. We are a research facility that is committed to our own research goals, method development, and grants. Our group works in parallel with the Stable Isotope Biogeochemical Laborator (SIBL) - Environmental Measurements II (EM-2)to keep this facility on the leading edge of analytial capability.

Our mission is to provide a laboratory that will continue to excel in the areas of global environmental change, with a focus on the hydrological cycle, air-sea interactions, tropical ecosystems, and polar biogeochemistry. After 10 years at Stanford, the SIL has teamed up with the Biogeochemical Isotope Laboratory to form the Stable Isotope Biogeochemical Laboratory (SIBL) – Environmental Measurements II in an effort to provide more instrumentation and expertise to the SU community. .

By working in parallel with SIBL, the SIL will continue provide high precision analyses and methodology using state-of-the-art instrumentation with experienced personnel allowing SU users to not only meet scientific objectives and commitments but also to develop new approaches that assist them in being more competitive in the research arena. As an educational facility the SIL provides an environment for SU students to accomplish their research and academic objectives while also providing them with valuable training necessary to compete in a competitive job and academic market. We have provided part-time employment opportunities for numerous undergraduate students to assist with various laboratory tasks. We have also opened the lab to allow local high school students, interested in pursuing science after graduation, to volunteer their time and work with post-docs and graduate students. The lab manager, post-docs, and graduate students work together with the high school students to provide a positive educational experience.

SIL Equipment:

Our facility has two Finnigan MAT isotope ratio mass spectrometers (IRMS) and a Carlo Erba (now CE Elantech, Inc.) NA1500 Series II elemental analyzer that is shared with EM-2.

The Finnigan MAT 252 IRMS equipped with 24X multiport manifold for analyzing CO₂ gases in sealed tubes, a Kiel III carbonate device for analyzing oxygen and carbon isotopes from up to 46 carbonates/run, and a 24 port H₂O/CO₂ equilibration device for measuring oxygen isotopes in water. In addition, See the Finnigan MAT 252 and Kiel III specification sheets for more detailed information.

The Finnigan MAT Delta plus IRMS is connected to an elemental analyzer via a continuous flow system (ConFlo II) for automated analyses of carbon, nitrogen, and sulfur for both elemental and isotopic analysis. Normally both the EA and Delta plus are connected and setup to analyze N and C. See the Finnigan MAT Delta plus and Carlo Erba elemental analyzer specification sheets for more detailed information.

The elemental analyzer can be used for inorganic and/or organic analyses and is capable of analyzing for weight percent C, H, N, S in solids and liquids. Usually the EA is connected to the Delta plus. See the Carlo Erba NA1500 Series II specification sheet for more detailed information.

The lab is also equipped with a Li-cor 7000 NIR detector with custom built injection/sparging system for automated TDIC analyses in waters with the precision of 1 micromole.

Miscellaneous lab equipment include an Ocean Optics USB2000 spectrophotometer for various nutrient analysis and pH, UIC 5014 and 5011 coulometer for DIC and a 5240 auto carbonate device for % inorganic C, misc. ocean mooring equipment, and Tech2000 hydraulic coral-drilling rig.

Over the past few years we have found alternative supplies or direct suppliers for replacement parts for our instrumentation in the laboratory. See our vendor list for these suppliers.

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