Spatially resolved CO carbon stable isotope analyses at the microscale using Raman spectroscopy.

Measuring the carbon stable isotope ratio (C/C, expressed as δC) in geogenic CO fluids is a crucial geochemical tool for studying Earth's degassing. Carbon stable isotope analysis is traditionally performed by bulk mass spectrometry. Although Raman spectroscopy distinguishes CO and CO isotopologue bands in spectra, using this technique to determine CO isotopic signature has been challenging.

Interlaboratory Application of Raman CO Densimeter Equations: Experimental Procedure and Statistical Analysis Using Bootstrapped Confidence Intervals.

Raman spectroscopy has been used extensively to calculate CO fluid density in many geological environments, based on the measurement of the Fermi diad split (Δ; cm) in the CO spectrum. While recent research has allowed the calibration of several Raman CO densimeters, there is a limit to the interlaboratory application of published equations. These calculate two classes of density values for the same measured Δ, with a deviation of 0.