Carbon isotope analysis of dissolved organic carbon in fresh and saline (NaCl) water via continuous flow cavity ring-down spectroscopy following wet chemical oxidation

This work examines the performance and limitations of a wet chemical oxidation carbon analyser interfaced with a cavity ring-down spectrometer (WCO-CRDS) in a continuous flow (CF) configuration for measuring δ¹³C of dissolved organic carbon (δ¹³C-DOC) in natural water samples. Low-chloride matrix (22.5 µg C/aliquot) may be analysed. The WCO-CRDS approach requires more total carbon (µg C/aliquot) than conventional CF-isotope ratio mass spectrometer, but is nonetheless applicable to a wide range of DOC concentration and water types, including brackish water, produced water, and basinal brines.