Development of a high-resolution gas source isotope ratio mass spectrometer

California Institute Of Technology, Pasadena CA

Investigators

Abstract

0949336 Eiler This award provides funding to develop a high-performance gas-source isotope ratio mass spectrometer (IRMS) for analyzing multiply-substituted isotope patterns in various materials. The PIs will collaborate directly with engineers from Thermo Fisher Scientific ('Thermo'). The new instrument designs relies on combining an inlet system and ion source from an existing gas-source IRMS (the MAT 253) with the analyzer and detector array of an existing large-radius, double-focusing multi-collector mass spectrometer (the Neptune). The design goal will be to increase maximum mass resolution for rare isoptologues. The hybrid will achieve high mass resolution, high sensitivity, and high precision. The primary motivation is to advance "clumped isotope geochemistry" - the study of naturally occurring multiply substituted isotopologues. Current analytical limitations make isotopologue measurement extremeley challenging. Clumped isotope geochemistry is a rapidly developing new field with potential extensions to materials other than carbon dioxide will potentially provide many new scientific insights. The overall scientific near-term goals are to advance "clumped isotope" thermometers for methane and other hydrocarbon gases, understand reduced atmospheric gas photochemical lifetimes, and determining possible origins for organic materials. Carbonate clumped isotope thermometry, the most developed current application will immediately benefit from the new instrumentation. The instrument will have broad applicability in paleoclimatology, biogeochemistry, tectonics, atmospheric chemistry, geobiology and environmental science, and will ultimately provide new analytical approaches to organic and inorganic geochemistry. The new instrument will be a resource for training the next generation of isotope geochemists - offering a "new" analytical tool for opening new research avenues. Studies into the basic principles of molecular bonding and reaction mechanisms will also be supported with the enhanced analytical capabilities. The partnership with Thermo will eventually lead to a commercially-available instrument. ***