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New instrument will enable stable isotope measurements

NPL acquires new capability for isotope ratio measurements of atmospheric greenhouse gases

1 minute read

Anthropogenic greenhouse gas emissions are driving climate change. To effectively mitigate against the effects of climate change and enable a transition to a carbon neutral economy, it is important to distinguish between the contribution of different anthropogenic activities and industrial sectors.

Scientists from the Gas Metrology & Emissions and Atmospheric Metrology Group at NPL have acquired a new instrument which will allow them to perform stable isotope measurements with improved precision and produce new gas reference materials for the isotopic composition of carbon dioxide (CO2) and methane (CH4) in air mixtures.

Each source of atmospheric greenhouse gases, such as the combustion of fossil fuels or land-use changes, emits gases with a very specific isotopic signature, describing very small differences in the atomic mass of otherwise identical gas molecules. The new instrument at NPL, an Isotope Ratio Mass Spectrometer (IRMS), will be able to measure these differences in mass to the required precision. First steps will be to ensure measurements using the NPL IRMS are traceable to international measurement scales, with NPL already participating in international comparison activities to establish this global comparability. International collaboration is crucial to ensure that all measurements around the world are comparable, particularly when performing measurements to address the global problem of climate change.

This research will fill an existing traceability gap in the measurement of isotopic composition of carbon dioxide and methane by providing new infrastructure for delivering gaseous carbon dioxide and methane reference materials and methods. The reference materials will enable the dissemination of traceable isotope ratio measurements to monitoring sites and can be used to establish measurement networks that can provide the data required to support inventory verification targets and enable pledges of emissions reductions to be demonstrated.

Christoph Nehrbass-Ahles, Senior Research Scientist, NPL, and lead scientist on this project said: “With this new capability NPL will underpin the UK’s efforts to achieve Net Zero by 2050 and take a leading role in ensuring traceability of greenhouse gas isotope ratio measurements for the global measurement community.”

Eric Mussell Webber, Higher Research Scientist, NPL, said: “This instrument is a key step in isotope ratio metrology and measurements for climate monitoring at NPL. Established infrastructure for preparing gas reference materials, coupled with the analytical precision of the IRMS, will help NPL push forward the science in the fight against climate change.”


Find out more about NPL’s gas metrology

05 Jan 2023