Efficiency of combined FTIR and Raman spectrometry for online quantification of soil gases: Application to the monitoring of carbon dioxide storage sites

► Raman spectroscopy adaptation to on line soil gas monitoring (N2, O2, H2O and CO2) in a CO2 sequestration site. ► Comparison between on-line Raman and FTIR CO2 concentration measurements. ► Definition of continuous baselines (N2, O2, H2O and CO2) on the CCS site. ► Deciphering and interpretation of “normal” or “abnormal” CO2 measurements.