Clumped Isotopes and High-Resolution Mass Spectrometry

The investigation of clumped isotopes, pioneered by J. Eiler and colleagues (CalTech), is a revolutionary opportunity to advance understanding of atmospheric, oceanic, and lithospheric interactions between C-O-H-S-N gases. "Clumped isotopes" refers to the substitution of two or more rare isotopes into a gas molecule, for example 13C16O18O. In this case the two rare isotopes 13C and 18O constitute a "clump" with lower zero-point energy than molecules substituted with a single rare isotope. There are important applications of the study of isotope clumping in minerals, as well. Extending the study of clumping beyond CO2, however, is impossible at the present time owing to the low mass resolution of commercial mass spectrometers as they are limited to integer mass resolution. Using a newly designed high-resolution mass spectrometer with a resolution of 30,000 to 50,000, it is proposed to extend clumping studies to SO2, CH4, and other crustal and atmospheric gases.