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Center for Stable Isotopes

Center for Stable Isotopes

The University of New Mexico Center for Stable Isotopes is a non-profit research focused laboratory and analytical facility founded in 2014. The mission of UNM-CSI is to support world-class stable isotope research by scientists and students across disciplines from Earth and Planetary Sciences, Biology, Anthropology, Chemistry and the Biomedical Sciences. We aim to do this by:

  1. Providing broad access to state-of-the-art analytical instrumentation capable of measuring stable isotope ratios of light elements-–carbon, nitrogen, oxygen, hydrogen, sulfur and chlorine-–in organic and inorganic substrates at affordable rates.
  2. Providing educational support in the form of training programs with hands-on instruction for undergraduate and graduate students on how to collect, prepare, and analyze sample, as well as aid in the interpretation of results.
  3. Encourage cross-disciplinary exchange of ideas and techniques at UNM and beyond regarding the application of stable isotopes in the planetary, life and medical sciences.


Hot Off the Mass Spectrometer

Wostbrock et al. (2020, Chemical Geology) suggest that the Δ′17O value of the water standard SLAP2 is -0.015‰ and not 0.00‰, as typically reported. This figure is a literature compilation of Δ′17O values that shows a relationship with δ18O values for SLAP2, where higher δ18O values result in higher Δ′17O values (circles). The blue square is the data point from Wostbrock et al. that has a δ18O value closest to the IAEA reported value for SLAP2, and gives a Δ′17O value of -0.015‰.

Characteristic δʹ18O – Δʹ17O fields for different materials. See Sharp et al., Geochem. Persp. Lett. 2018 for publication

δ13C and δ15N values of coyotes (circles) and their potential prey (diamonds) from Cape Breton Highland National Park, Nova Scotia. Coyotes involved in attacks on humans are represented by white circles while individuals known to consume anthropogenic resources are represented by black circles. Isotope values for local humans (black diamond) are also shown for comparison.

δ13C and δ15N values of silky pocket mouse (Perognathus flavus) blood plasma captured in 2014 from the Sevilleta National Wildlife Refuge, NM; sample sizes are in parentheses. Standard ellipse areas (SEAs) increase by ~50% during the onset of the summer monsoon from July through October and shift towards greater use of C4 resources.

Hydrogen isotope (δ2H) values of tilapia (Oreochromis niloticus) muscle (A) and liver (B) tissue versus environmental (tank) water δ2H values. The slopes of the regressions for various diet treatments (black, gray, white circles) estimate the proportion of hydrogen in each tissue derived from environmental water.  

Highlighted Student Abstract

Author/s: Erin E. Ray, Paige Lynch, Emily Moes, Keith M. Prufer

In Mesoamerica, it is clear the advent of agriculture brought unprecedented population expansion. However, as with many questions about this transition, a lack of archaeological remains has made determining the details such as when population growth began and the demographic profile of the population growth difficult to determine. The rockshelter sites of Saki Tzul and Mayahak Cab Pek, located in Southern Belize, provide a unique opportunity to answer certain questions about changes in the... read more

Highlighted Faculty Research

The hydrogen isotopic composition (δ2H) of animal tissues has become as a valuable tool in the investigation of animal movements and the study of habitat use. The biochemical foundation needed for animal ecologists to confidently apply δ2H analyses to ecological problems has yet to be adequately revealed. This project will uncover some of the fundamental underpinnings of δ2H in tissues of vertebrates. New methods developed by the PIs to analyze compound-... read more