ITD: Development of a laser (TILDAS) system for simultaneous and rapid measurement of clumped and triple-oxygen isotopes in carbonates

University Of Arizona, Tucson AZ

Investigators

Abstract

The proposed research seeks to continue to develop lasers for measurement of rare varieties of certain common elements of carbon and oxygen. Historically, these measurements have been done by mass spectrometry but recent successes in our laboratory suggest that lasers are a faster and more effective approach. Rare varieties (technically called isotopes) of many elements provide important data of significant interest to earth science, atmospheric and ocean chemistry, and biology. The research team at the University of Arizona has completed development of an automated, tunable infrared laser direct absorption spectroscopy (TILDAS) system that measures multiply substituted or “clumped” isotopologues of CO2 as precisely as existing methods using mass spectrometry, but at lower cost, using small samples, and much more rapidly. This proposal includes the purchase of the prototype instrument and expansion of it by adding a new laser unit to perform δ17O measurements. The sample preparation line will be modified to split a CO2 sample and deliver it to both laser systems. The result is an integrated laser monitor system that can measure clumped ∆638 (≈∆47), δ18O, δ13C, and d17O of carbonate at high precision in less than 50 minutes on a single sample aliquot of ~2mg. Combining these measurements in one instrument is unprecedented and will significantly benefit the scientific community. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.