Isotopic Water Analyzer for highly precise measurements of δ2H, δ18O and δ17O

Measurements of the isotope ratios (δ2H, δ18O, δ17O) of both liquid water and water vapor are widely used in hydrology, atmospheric sciences, and biogeochemistry to determine the migration of water through an ecosystem. Previously, discrete samples were collected (or condensed) and transported to an isotope ratio mass spectrometer for characterization. Due to the expense and labor associated with such sampling, isotope studies were generally limited in scope and in temporal resolution. We report on the continued development of a field-portable Isotopic Water Analyzer that exploits cavity-enhanced absorption spectrometry (Off-Axis ICOS) to accurately and rapidly quantify δ2H, δ18O and δ17O of both liquid water and water vapor.