Stable Isotope Geosciences Facility

Established on the Texas A&M University campus in College Station in 2009, the Stable Isotope Geosciences Facility is designed to provide accessible, reliable and high-quality stable isotope measurements and training for faculty, staff and students within the College of Geosciences and the Texas A&M community. It was also created as a facility where state-of-the-art methodologies and technological developments in stable isotopes could be applied to important societal problems related to energy, ecology, Earth history, and the environment.

Beyond the Texas A&M community, the SIGF has strong research links with scientists and students from other universities and industry who require precise measurements. The facility continues to be recognized for its quality work and research, and to operate on the core values of Texas A&M University.

The Stable Isotope Geosciences Facility (SIGF) in the College of Geosciences, and the Stable Isotopes for Biosphere Science (SIBS) Laboratory in the College of Agriculture and Life Sciences have teamed up to better integrate the two light stable isotope ratio facilities on campus, and to add needed capabilities to serve the greater Texas A&M and regional community.  Funded by a $5 million initiative from the Chancellor’s office to support mass spectrometry, SIGF and SIBS will share $1 million to purchase four new instruments: a clumped isotope mass spectrometer (CIMS) and a gas chromatograph-combustion-isotope ratio mass spectrometer system (GC-C-MS-IRMS), and two additional IRMS to couple with Elemental Analyzers and other peripherals, delivering to Texas A&M a stable isotope capability unmatched in Texas and the region.

The clumped isotope mass spectrometer (CIMS) measures the concentration of molecules with two rare isotopes, for example, 13C18O16O/12C16O2. This ratio in carbonate rocks and minerals is temperature dependent, providing a geothermometer for pore-filling carbonate cements, sedimentary basin temperatures, and ocean and terrestrial paleoclimate studies. The CIMS would be housed at SIGF. A second instrument, the GC-C-MS-IRMS, separates and identifies compounds with gas chromatography and quadrupole mass spectrometry, then quantifies isotopic composition through a combustion or pyrolysis interface to an IRMS. This system would provide cutting-edge capabilities to track sources and fates of specific biochemical compounds through the biosphere, geosphere, hydrosphere, and atmosphere, expanding the interpretation of bulk isotopic measurement. The instrument would be housed in the SIBSLaboratory. 

SIGF houses five dynamic-source isotope ratio mass spectrometers (IRMSs), a cavity ring-down spectrometer, and seven peripheral devices with the capabilities of performing high precision H, C, N, O, S and clumped analyses on carbonates, sediments, waters, and organic matter.

We perform high-precision carbonate δ13C and δ18O analyses with a Thermo Scientific Kiel IV Automated Carbonate Device coupled to a Thermo Scientific  MAT 253 dual inlet IRMS. Our instrument is capable of analyzing CaCO3 samples as small as 10 μg, making our facility a viable option for specialized carbonate samples such as individual foraminifera.

With the new addition of a Thermo Fisher Scientific 253 Plus and modified Kiel IV Automated Carbonate Device, we are now capable of clumped isotope analyses of carbonate samples as small as 1.2 mg.

We have routinely analyzed a broad range of organic sample types for bulk total organic carbon, total organic nitrogen, δ13C, and δ15N compositions via Thermo Scientific DeltaplusXP isotope ratio mass spectrometer with Carlo Erba NA 1500 Elemental Analyzer (EA).

With addition of a new Thermo Fisher Scientific Delta V Advantage with Flash EA, we can now run δ34S along with δ13C and δ15N of organic matter.

With our new Thermo Fisher Scientific Delta V Advantage IRMS with GC-Isolink, we can perform H, C, and N isotope analyses on specific organic compounds.

δ13C analyses of natural water dissolved inorganic carbon (DIC), soil gas, breath gas, etc. are available using continuous flow headspace sampling via a Thermo Scientific GasBench II also connected to our DeltaplusXP or Delta V IRMSs

We perform water δ18O and δD analyses via Picarro Li2120 Cavity Ring-Down Spectrometer (CRDS). Water δ18O and δD analyses are also available using headspace equilibration methods on the GasBench II upon special request, or for samples with high dissolved organic contents that would interfere with cavity ring own analysis.

At SIGF we pride ourselves in method development and in doing everything within our abilities to meet the analytical requirements of our customers. We welcome inquiries regarding unique and unconventional analyses, and we will work to adapt our analytical capabilities to the specific needs of individual researchers, clients and students.