Isotope Ratio Mass Spectrometry
Isotope ratio mass spectrometry (IRMS) leverages magnetic sector mass spectrometry to enable high-precision measurement of the stable isotope content of a sample. Typical measurements target hydrogen, carbon, nitrogen, and oxygen analyses—although elements with masses up to and including sulfur can be measured. Solid, liquid, or gas phase samples are converted to simple gases then introduced to the IRMS. During analysis, an electron impact source ionizes sample-derived gas which is then accelerated down a flight tube, separated by mass, and quantified using a series of Faraday cups. The high precision of IRMS enables enumeration of even very small isotopic fractionation associated with physical, chemical, and biological transformations or natural abundance measurements. The approach is also valuable for quantifying the reactivity and progression of an applied stable isotope tracer to help determine reaction rates and final disposition of applied substrates. Measuring the stable isotope content of samples can therefore provide valuable insights for a variety of field and laboratory-based experiments, targeting a suite of environmental and microbial studies relevant to EMSL’s research efforts.
Research application
- By determining the chemical and isotopic composition of biological molecules, IRMS supports the Biomolecular Pathways Integrated Research Platform in its objective to help explain the detailed molecular mechanisms behind biological processes.
- The stable isotope analyses provided by IRMS assist the Terrestrial-Atmospheric Processes Integrated Research Platform in understanding and quantifying nutrient and material exchanges between ecosystems.
- IRMS provides ultra-precise stable isotope analyses that directly support the Rhizosphere Function Integrated Research Platform as it works to track the impact of different microbial interactions or conditions on rates of photosynthesis, carbon release, various nitrogen processes, and their overall impact on plant phenotypes.
Available instruments
Isotope Ratio Mass Spectrometers (IRMS)
- Thermo Delta V Plus (n = 2)
- Thermo 253 Plus
- Sercon 20-22
IRMS Peripherals
- Thermo GasBench II
- Costech Elemental Analyzer
- Thermo Flash Elemental Analyzer
- CETAC LSX-500 Laser Ablation System for in situ analysis on the scale of 10s of µm.
- Thermo Trace Gas Chromatograph Combustion system for compound-specific isotope analyses
- Thermo Liquid Chromatography IsoLink II for bulk and fraction specific analysis.
- Los Gatos Research Water Isotope Analyzer
- Thermo High Temperature Conversion Elemental Analyzer
Tips for success
- We accept a wide variety of samples for analysis. Reach out to your EMSL science point of contact regarding your project needs to see how we can help.
- The IRMS systems make extremely precise measurements of stable isotope content. It is very important to isolate any isotope tracer materials from control samples. The instrumentation can be very sensitive to unplanned tracer dispersal.