Reducing contamination parameters for clumped isotope analysis: The effect of lowering Porapak™ Q trap temperature to below–50 C

Carbonate clumped isotope thermometry examines the thermodynamic preference of 13C–18O bonds to form within the carbonate crystal lattice. The 13C18O16O isotopologue in analyte CO2 has a natural abundance of 44.4 ppm necessitating stringent purification procedures to remove contaminant molecules that may produce significant isobaric effects within range of the mass 47 isotopologue. Strict purifications of analyte CO2 are thus required as well as reliable contamination indicators.