18O and 2H Analysis of Water
The SIF provides analysis of 18O and 2H isotope ratios of water samples by GasBench-IRMS. Freshwater samples, metabolic waters, plant-extracted waters, isotopically enriched waters, saline waters, corrosive waters, etc. are analyzed as headspace gas using CO2-H2O and H2-H2O equilibration methods on a GasBench-II device interfaced with a Delta Plus XL isotope-ratio mass spectrometer (Thermo-Finnigan, Bremen, Germany). Sample isotope ratios are standardized using a range of reference waters which have been calibrated against IAEA reference waters (VSMOW2, GISP2, and SLAP2). Precision for water samples at natural abundance is typically ≤0.2 per mil for 18O and ≤2.0 per mil for 2H. Final 18O and 2H values are reported relative to VSMOW.