High-temperature Raman spectroscopic study of H2O-CO2-CH4 mixtures in synthetic fluid inclusions: first insights on molecular interactions and analytical implications

Raman spectra of fluids of the CO(2)CH(4)H(2)Oand CO2H2O stems contained in synthetic fluid inclusions: have been obtained above the homogenization te mperature to 500 degrees C. Spectra of the CO2 and CH4 gases do not vary al ong the portion of the studied isochore, whereas they do for the symmetric stretching band of water. The spectra clearly show that molecular interacti ons are stronger between CO2 and H2O molecules than between CH4 and H2O mol ecules. Gas molecules decrease the signature of hydrogen bonding in the Ram an spectrum of water For water-rich fluids, the ratio of Raman scattering c ross-section of CH4 and H2O does not vary to a wide extent, showing that th e calibration of this ratio is feasible.