We measure carbon and oxygen isotopes in air and ice to better understand Earth systems, including the carbon cycle, past climate, and methane.  We excel at measurements of (1) δ13C and δ18O atmospheric carbon dioxide, (2) δ13C of atmospheric methane and local sources of elevated methane, and (3) water from ice cores as well as environmental waters.  We provide our analytical services to scientists around the world.

Photo of Bruce Vaughn

Bruce Vaughn
Lab manager

Photo of Bradley Markle

Bradley Markle
Faculty fellow

Photo of Sylvia Englund Michel

Sylvia Michel
Assistant lab manager

Photo of Valerie Morris

Valerie Morris
Research staff

Photo of John Ortega

John Ortega
Research staff

Photo of Kevin Rozmiarek

Kevin Rozmiarek
Research staff

Photo of Kerstin Braun

Kerstin Braun
Research staff

Photo of Reid Clark

Reid Clark
Research staff

  • Chloe Brashear, lab technician
  • Abigail Thayer, PhD, 2021
  • Seth Kurtz, lab technician
  • William Skorski, PhD Student
  • Isaac Vimont, PhD 2017
  • Karen Alley, PhD 2017
  • Amy Steiker
  • Caroline Alden, PhD 2013 in Geological Sciences
  • Emily Longano, undergraduate researcher


Panorama of the INSTAAR Stable Isotope Lab showing mass spectrometers, preparation stations, gas cylinders, computers, and more

Panorama of the INSTAAR Stable Isotope Lab


Contact & services

Bruce Vaughn    Lab phone: 303 492-5495  
Come visit! We are in the southeast corner of SEEC (Sustainability, Energy, and Environment Complex) at 4001 Discovery Dr.

  • Contact us with questions you may have about your analysis.
  • Please email us notification and an electronic sample list PRIOR to shipping your samples.

Information on our types of measurements
Analysis   Analysis Mode Sample Volume Precision (‰) Cost Per Analysis Time
C & O: carbon dioxide δ13C
dual inlet 400 cc minimum
1 Liter preferred
$60 4-6 wks
C: atm. methane δ13C continuous flow 40 cc minimum
1 Liter preferred
±0.04 $240 4-6 wks
C: soil carbon dioxide δ13C
continuous flow 1 ml minimum
50 ml preferred
Contact us Contact us
H: liquid water & ice δD dual inlet 2ml minimum
15 ml preferred
±0.5 $50 4-6 wks
O: liquid water & ice δ18O dual inlet 2 ml minimum
15 ml preferred
±0.07 $50 4-6 wks
C: organics δ13C continuous flow 10-50mg Carbon required ±0.30 $24 4-6 wks
H: atm. methane δD continuous flow 150 cc minimum ±1.5 Contact us Contact us

  • Sample Volume First line is amount needed for analyses; second line is the desired amount of sample to be submitted, to allow enough for replicate analyses.
  • Precision is the average standard deviation (1-sigma) in per mille units.
  • Cost Per Analysis is an estimate for off-campus non-academic research, including commercial parties and governmental agencies. Prices are lower for academic projects and university research. Assistance with interpretation of data is available. We do not attempt to compete with commercial labs. Students, please see note below.
  • Analysis time is an average turnaround time for a small number of samples (1-50). Actual time may be shorter or longer depending on machine performance, barring mechanical failures beyond our control.

In development

We are currently developing a system to analyse atmospheric water vapor for both hydrogen and oxygen isotopes based on GC-IRMS (Gas Chromatography - Isotope Ratio Mass Spectrometry). The amount of water needed in this technique is many orders of magnitude less than in conventional techniques, nanoliters as opposed to milliliters. The volume of air sample needed, ~1 to 40 cm3, is small enough to permit sampling via aircraft based systems, eddy flux accumulators, and other low volume samplers. Samples can be taken rapidly, and with high temporal resolution heretofore impractical, if not impossible.


PLEASE DO NOT SEND SAMPLES BY STANDARD US POSTAL SERVICE.  Choose a street delivery service such as FedEx, UPS, etc. We request that you email us with an electronic list (spreadsheet) of sample IDs, so that we can avoid any possibility of data entry typos on our end. If possible, especially with large sample sets, we appreciate some organization of the samples in the shipping container, so we don't have to re-order them. Send samples to:

Bruce H. Vaughn
INSTAAR Stable Isotope Laboratory
1560 30th Street
Boulder, CO 80303

phone 303 492-7985 lab


  • We will bill your university/party/agency after the work is completed.
  • Most universities pay with a purchase order or credit card.
  • We can pre-bill if requested.

Note to students

  • We strongly support student projects, both graduate and undergraduate.
  • If you have a limited number of samples, and an even more limited source of funding, we may be able to help.
  • Email us for details.

Standard gases

We also perform calibration of clean dry air cylinders typically filled at the Niwot clean air site by NOAA personnel. Calibrated tanks can be obtained from NOAA CMDL, analyzed for mixing ratios of a suite of greenhouse gases, including CO, CO2, N2O, and CH4. For more information, visit the NOAA CMDL standard-gases web site: If in doubt, please contact us. Reference cylinders usuallly require analyses made over a period of weeks to verify the stability of the standard air before it can be released and certified for use. Turnaround times can vary, depending on the performance of the cylinder. Tyically we make approximately 30 measurements over a period of 6 to 12 weeks. Actual time may be shorter or longer depending on machine and cylinder performance, barring any mechanical failures beyond our control. Please contact us for current estimates.


Who we are


Collage of people for the INSTAAR Stable Isotope Lab" Bruce Vaughn, Brad Markle, Sylvia Michel, Valerie Morris, Reid Clark, Chloe Brashear, Seth Kurtz, Kevin Rozmiarek

The lab team, left to right: Bruce Vaughn, Brad Markle, Sylvia Michel, Valerie Morris, Reid Clark, Chloe Brashear, Seth Kurtz, Kevin Rozmiarek



Blog headlines

  • SIL survives the covid times.
  • SIL finds solidarity at GGMT.
  • SIL is flying skyward!

See our blog >


  • We study the carbon cycle by measuring stable isotopes of greenhouse gases from a global air sampling network.
  • We study climates of the past by measuring stable isotopes of water in ice cores from Greenland and Antarctica.
  • We fly drones over the Greenland Ice Sheet to measure isotopes of water vapor, and to better understand water fluxes from the cryosphere.
  • We measure methane on a local scale to study the sustainability of oil and gas extraction in the Rocky Mountain West.
  • We continually improve our methods with new, automated techniques for measuring environmental stable isotopes.
  • We provide analytical services to scientists and institutions around the world.

The INSTAAR Stable Isotope Lab is a focal point of interdisciplinary research programs: we partner with a global array of researchers from a variety of academic institutions and governmental agencies. Isotopes provide a unique tool because they indicate, record, integrate, and trace processes in the global environment.

Rachel Edie changes gas flasks out on Spock, a mass spectrometer that measures stable isotopes of carbon and oxygen in atmospheric CO2, primarily from the NOAA CMDL Cooperative Air Sampling Network. Photo by Ethan Welty.

Rachel Edie changes gas flasks out on Spock, a mass spectrometer that measures stable isotopes of carbon and oxygen in atmospheric CO2, primarily from the NOAA CMDL Cooperative Air Sampling Network. Photo by Ethan Welty.

We measure the stable isotopes of carbon dioxide and methane in order to understand global sources and sinks of these greenhouse gases.

As the concentrations of greenhouse gases increase, the Earth's climate is changing. Two of the most important heat-trapping gases are carbon dioxide and methane, yet we don't fully understand their sources - where and how these gases are released - and their sinks - how they are taken up or destroyed.  Stable isotopes are very useful for understanding sources and sinks due to processes that discriminate against one isotope over the other. For instance, because plants strongly discriminate against the heavy isotope of CO2, we can use d13CO2 to estimate ocean versus land uptake of carbon dioxide. Because sources of methane have different isotopic signatures, we can use d13CH4 to calculate emissions of methane from differerent sources. The isotope measurements, along with concentrations of greenhouse gases in our atmosphere, constrain models of these gases, and increase their predictive capability for understanding future climate regimes and making policy decisions.

The INSTAAR Stable Isotope Lab (SIL) has collaborated with the Carbon Cycle Greenhouse Gases Group (CCGG) at NOAA Environmental Research Laboratory Global Monitoring Division to measure C13 and O18 of carbon dioxide since 1990, and C13 of methane since 1998. This involves measuring flasks and programmable flask packages from the NOAA Cooperative Sampling Network. We are currently working on our system for analysis of deuterium of methane, are developing a method for analyzing C13 and O18 of carbon monoxide as part of the INFLUX project, and have completed a pilot project studying atmosperic N2O isotopes and isotopomers.

See NOAA ESRL for more information, go directly to the data, and learn more about why isotopes are useful for understanding sources and sinks of carbon.

We measure the stable isotopes of oxygen and hydrogen in water from Ice cores.

On Earth's great ice sheets, Greenland and Antarctica, snow accumulates and never melts, creating a repository of precipitation back in time. Stable isotopes of precipitation are a proxy for temperature when the snow fell, making ice cores a rich paleoclimate archives. In addition, ice cores preserve records of atmospheric gases, chemistry, and physical properties, and they are unique for their combination of high resolution and long time scales.  Understanding the climates of the past is essential for predicting the Earth’s responses of human-caused climate change, and ice cores are invaluable in this effort.

3-minute video tour by Tyler Jones of work and life at the North Greenland Eemian Ice Drilling (NEEM) station atop the Greenland ice sheet. The international NEEM team retrieved an ice core from the top of the ice sheet down to bedrock, containing climate records reaching back 115,000 years.

For more than 15 years, SIL has been involved in ice core projects in Greenland, Antarctica, the high-altitude tropics (Ecuador, Peru, Tibet), and other regions. Over this time, SIL has become a world leader in measurement of both deuterium/hydrogen and oxygen-18/16 ratios of ice. In addition to the stable isotope analysis, we are involved with the coring, processing, and modeling/analysis of the data.

We have recently completed ice core projects at NEEM, Greenland, and WAIS Divide, Antarctica. We measured the ice from WAIS Divide on a custom-built continuous melter system connected to a Picarro cavity ring-down mass spectrometer, resulting in higher-than ever measurement resolution on a deep core. We will use this system to measure the core from South Pole, and will develop the next generation core for analysis of the Renland Ice Core.

The Mobile Methane Analyze mounted on a white truck with white cab. Photo by Christi Turner.

The Mobile Methane Analyzer. Photo by Christi Turner.

Software visualizing the real-time data collected when methane sampling along roads in Weld County, Colorado. 

Visual display of a mobile methane sampling along roads in Weld County. 


SIL is participating in the CU-based, NSF funded Sustainability Research Network called the Air Water Gas project which is aimed at studying the oil and gas industry in the Rocky Mountain West.

The mission of this project is to provide a logical, science-based framework for evaluating the environmental, economic, and social trade-offs between development of natural gas and protection of water and air resources. The project also aims to educate the public and influence the development of policies and regulations governing natural gas and oil development.

Unlike all of our lab-based measurements, Mobile Methane measurements are recorded on the fly as the vehicle drives. The data is plotted onto an interactive map and Landsat image.

Carbon isotope ratios of organic material are useful tools in ecology and ecosystem science. We have measured thousands of leaf, soil, and other organic materials in studies aimed at understanding plant physiology, hydrology, and biogeochemistry.

The hydrologic cycle plays an important role in ice core research.

Many of the discoveries made from polar ice cores have deepened our understanding of long term climate signals in both temperature and precipitation; likewise, understanding isotopes in precipitation today are essential to understanding the ice core record. Stable Isotopes are a unique tracer that can reveal volumes about the origin and distribution of precipitation on our planet.

The SIL has collaborated in a large scale effort of analyze the stable isotopes of archived samples obtained from the Global Network of Isotopes in Precipitation (GNIP) program. Students at CU have produced and analyzed seasonal patterns of isotopes in precipitation over the United States.


Stable Isotope Lab by the numbers



Full-Time Employees
+ students & postdocs



of operations



in Nature or Science



assoc. with the lab



Square Feet
of freezer space
at -20°C/-4°F



of liquid nitrogen
on demand



Square Feet
of lab space



per year



Our equipment includes

  • Dual-inlet and continuous-flow isotope-ratio mass spectrometers
  • Laser-based cavity ring-down spectrometers.


Collage for instrument Spock, including the mass spectrometer, flask stand, etc

Spock is a Micromass dual inlet mass spectrometer that measures the stable isotopes of carbon and oxygen in atmospheric CO2, primarily from flasks and standard cylinders with the NOAA CMDL Cooperative Air Sampling Network. CO2 is extracted from an air sample by pulling the air through a water trap and into a liquid nitrogen trap. The sample is then heated to expand into the sample bellows of the mass spectrometer. The sample and reference gas are then iteratively allowed into the source where they are ionized, repelled down the flight tube, and separated by isotopic mass. Reliable measurements of CO2 isotopes depends on careful data crunching and quality controls—please contact us if you'd like more information on our procedures.


Collage for instrument T'Pol, including the mass spectrometer, connections to flask packages inside black cases, etc

T'Pol is a GV Isoprime dual inlet mass spectrometer dedicated to running isotopes of CO2 from programmable flask packages. These collect air from aircraft and from tall towers, allowing for sampling along vertical gradients. The sample extraction is almost identical to Spock: CO2 is cryogenically separated from air and expanded into the sample bellows for dual inlet analysis against a CO2 reference gas. Careful monitoring ensures that different instruments measure samples with high accuracy and precision.


Collage for instrument Picard, including the mass spectrometer, connections to air samples, etc

Picard is also a GV Isoprime with a similar extraction system as T'Pol and Spock. Although it can measure samples from flasks and programmable flask packages, it is primarily devoted to measuring air from calibration cylinders. Picard has the capacity to measure CO2 extracted from carbonates, as this is the reference material for CO2 isotopes.


Collage for instrument Troi, including the mass spectrometer, sample preparation, etc

Troi measures carbon isotopes of methane. Since there is not enough methane in a network flask to measure using dual inlet techniques, we rely on continuous flow measurements, where the sample moves on a stream of helium gas. Methane and other gases are frozen on a pre-concentrator of hayesep-D, cryo-focused, and separated on a GC column. The CH4 is combusted to CO2, and then the sample is "sniffed" from an open split into the mass spectrometer.


Collage for instrument Crusher, including the mass spectrometer, pyrolysis furnace, and more

Crusher will soon measure hydrogen isotopes of methane. This measurement is challenging due to the high-temperature pyrolysis furnace which converts CH4 to H2 gas.


Collage for instruments Julian and Phlox, including the mass spectrometers, sample system, and workstations

Julian and Phlox are Picarro cavity ring-down mass spectrometers dedicated to measuring hydrogen and oxygen isotopes of water from discreet samples.


Collage for instrument Kes, including the mass spectrometer, sampler, and more

Kes measures water isotopes from ice-cores. Kes represents is a breakthrough in our ability to obtain high resolution records from ice cores. As the ice is melted, peristaltic pumps move the water into a de-bubbler, splitter (where a portion of the sample is archived), a nebulizer, then vaporized and measured by CRMS.




Overview video (90 sec)

Watch an 90 second overview of the Stable Isotope Lab.  The video will automatically start at the 2:30 mark. This overview is part of a tour of two INSTAAR labs.  The first part of the video gives an overview of the Laboratory for AMS Radiocarbon Preparation and Research.  



Logo for National Oceanic and Atmospheric Administration (NOAA)

National Oceanic and Atmospheric Administration (NOAA). We work closely with NOAA’s Global Monitoring Lab, providing critical isotopic constraints on the sources and sinks of major greenhouse gases and related carbon- climate feedback processes—constraints which are not otherwise available from observations of trace gas concentration alone.

Logo for the National Science Foundation (NSF)

National Science Foundation (NSF). Many of our projects have been supported under the leadership of the National Science Foundation.


We also collaborate with colleagues at many universities, government labs, and other science organizations and communities around the world.