ABSTRACT

δD and δ¹⁸O of natural waters with δ¹⁸O ranging from −24 to −6‰ were measured using a cavity ring-down spectroscopy (CRDS) in order to confirm that the CRDS method can be an alternative to conventional isotope ratio mass spectrometry (IRMS). The deviations of δD and δ¹⁸O values obtained using the CRDS and IRMS methods are less than 0.8‰ and 0.3‰, respectively, which are practically sufficient for geochemical/environmental researches of natural waters, indicating that the CRDS method can be an alternative to the IRMS methods for environmental liquid water samples.