Measuring triple oxygen (16O, 17O and 18O) and carbon (12C, 13C) isotopes in small samples of carbon dioxide by laser spectroscopy

Lead Research Organisation: University of Cambridge
Department Name: Earth Sciences


I propose to spend 5 months at Harvard University developing and learning a new analytical method for measuring triple oxygen (16O, 17O, 18O) and carbon (12C, 13C) isotopes in small samples of CO2 produced from carbonate minerals using mid-infrared spectroscopy. The development will be conducted collaboratively with Prof. Daniel Schrag at the Harvard Center for the Environment (see letter of support) and Aerodyne Research, a private-sector company specializing in spectroscopy located in Billerica, Massachusetts, only 20 miles northwest of Boston. The method will permit the simultaneous analysis of 18O/16O, 13C/12C, and 17O/16O in CO2 in small samples of CO2 gas equivalent to microgram quantities of calcium carbonate with no spectral interferences. Laser spectroscopy offers a distinct advantage over conventional isotope ratio mass spectrometry (IRMS) for the measurement of isotopic ratios in CO2 because isobaric interferences on mass 45 precludes the direct measurement of 17O/16O by IRMS. This new approach will open new avenues of research for measuring 17O/16O in CO2 and carbonate minerals that has been hitherto difficult to measure by IRMS. The collaboration will lead to a proposal to acquire a similar system for the Godwin Laboratory at the University of Cambridge to keep the analytical facility at the forefront of innovative technology for stable isotope geochemistry.

Planned Impact

The primarily beneficiary will be members of the academic community who are engaged in measurement of stable isotopes in carbonate minerals. The primary non-academic beneficiaries of this work will be the UK isotope ratio mass spectrometer industry. This industry is largely based on conventional technology and it is therefore important for UK companies to be aware of developing technologies in this competitive market. Engagement will be through presentation of results at national and international meetings (EGU, AGU, Goldschmidt, British Mass Spectrometry Society), which are attended by both the academic community and mass spectrometry instrumentation companies.


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Description The visit of PI Hodell to Harvard/Aerodyne was accomplished with this "Overseas Travel Grant". Hodell spent 6 months in Boston and worked with host Prof. Daniel Schrag, postdoc Alison Piasecki, and Aeordyne applications engineer Dave Nelson to use the TILDAS instrument to measure oxgyen (16O, 17O, 18O) and carbon (12C, 13C) isotopes in carbon dioxide gas. The method proved sucessful and the next step is to measure CO2 gas produced from the reaction of calcium carbonate and phosphoric acid. We have now been funded for an Aerodyne TILDAS instrument to be installed in the Godwin Laboratory in Cambridge where this research will continue.
Exploitation Route This funding will bring new technology to the UK academic community that will enable researchers to measure carbonate samples for triple oxygen and carbon isotopes at greater ease and in greater numbers than is currently possible by conventional isotope ratio mass spectrometry. The Godwin Lab will eventually offer analytical services to the UK science community for the measurement of triple oxygen in carbonate minerals. We expect the instrumentation will also be adopted by other stable isotope laboratories in the UK, thereby broadening the capacity for measurement.
Sectors Environment

Description LASER-ENVI - A LASER spectrometer-based ENVIronmental Gas and Gas-Isotope Facility
Amount £850,000 (GBP)
Funding ID NE/V015435/1 
Organisation Natural Environment Research Council 
Sector Public
Country United Kingdom
Start 03/2021 
End 03/2022
Title Measurement of triple oxygen (16O, 17O, 18O) and carbon (12C, 13C) isotopes in carbon dioxide by laser spectroscopy 
Description Application of tunable infrared laser direct absorption spectroscopy (TILDAS) at mid-IR for simultaneous analysis of 18O/16O, 13C/12C, and 17O/16O of CO2 gas with no interferences. The method has been demonstrated on pure tank gases and will now be applied to CO2 evovled from the reaction of carbonate minerals with phosphoric acid. 
Type Of Material Improvements to research infrastructure 
Year Produced 2021 
Provided To Others? No  
Impact None yet. 
Description Development of a TILDAS system for measurement of 17O in carbonate minerals 
Organisation Harvard University
Country United States 
Sector Academic/University 
PI Contribution The project involved a direct international collaboration between the University of Cambridge (Godwin Laboratory), Harvard University and Aerodyne Research, a private-sector company located in Billerica, Massachusetts. Cambridge provided experience with the measurement of 17O in water by laser spectroscopy. The Godwin Laboratory has now been funded through a NERC capital equipment scheme to purchase a Tunable Infrared Laser Direct Absorption Spectrometer (TILDAS) from Aerodyne Research to continue development of the method in Cambridge.
Collaborator Contribution Harvard (Prof. Daniel Schrag) provided a full-time postdoc (Alison Piasecki) who was positioned at Aerodyne to work with the TILDAS instrument. Aerodyne provided state-of-the-art experimental laboratories for this product development project. The site location includes instrument and component fabrication, assembly, testing and user training facilities to support instrument products.
Impact The only direct outcome thus far has been the successful award of a grant in response to a NERC Science Capital Call to obtain an Aerodyne TILDAS instrument in Cambridge.
Start Year 2019