AMS dating groundwater

Stable Isotope Analysis of Water (δ18O and δD)

recommended sample size Sample size recommended
  • 2-5 mL (Use a small vial with no prior use and fill to the top with no headspace.)
carbon dating services Turnaround time
  • 14 business days
recommended container Recommended Packaging
  • Please use a box with sufficient packing to prevent breakage during shipment.
lab recommendation
  • Please let us know if your water samples contain salt or have been in the proximity of any location using labeled 14C (artificial 14C).

Our AMS dating fees for water samples are currently inclusive of δ13C, δ18O and δD measurements; quality assurance reports; calendar calibration when applicable; and 24/7 web access to past results and pending analyses.

Stable oxygen-18 and deuterium isotope measurements are also available on a standalone basis, without radiocarbon dating. The δ18O and δD measurements are performed on the water samples in an isotope ratio mass spectrometer (IRMS) or cavity ring-down spectrometer (CRDS). For stable isotope analysis on BaCO3 and SrCO3 samples, the lab charges a pretreatment fee.

The interpretation of δ18O and δD values, as required in hydrological studies, lies with the submitter.

Submittal – Please use this online form. For more details about how to collect and submit water samples, please see our Radiocarbon Dating Groundwater page.

If you have any questions about your sample, please contact the lab.

Note – The laboratory also automatically includes stable oxygen isotope measurements for carbonates in the radiocarbon dating service and offers the service on a standalone basis.

Stable Isotope Analysis Cost

When requesting for a formal estimate/quote, please indicate in this form the number of water samples for stable isotope analysis and the billing details of the paying institution. Note: The lab does not accept water samples that still need to be pretreated.

Disclaimer: This video is hosted in a third-party site and may contain advertising.

This video excerpt is part of Beta Analytic’s webinar: Isotopes in Hydrology

Stable Isotope Analysis for Saline and Hypersaline Waters

Beta Analytic employs the isotope equilibrium method to determine δ18O and δD of liquid water samples. This method is ideal for freshwater samples. Marine waters (with salinity (S) of 35 g L-1) can be successfully analyzed given extended equilibration time. Some limitations exist for highly saline natural waters (e.g. S > 100g L-1) such as those in certain salt marshes, hypersaline lakes and lagoons, or hydrothermal brines. These limitations are due to salinity-dependent fractionation factors between CO2 and H2O and will routinely result in accuracy loss on the order of 0.5+ o/oo for δ18O and 5.0+ o/oo for δD.

For highest accuracy in results, application of post-analysis correction factors may be needed contingent upon the activity coefficient of the isotope species and the salinity of the original sample.


Kendall C., Caldwell, E., Isotope Tracers in Catchment Hydrology (1998) Elsevier Science B.V., Amsterdam. Pp 51-86.

Christophe Lécuyer, Véronique Gardien, Thomas Rigaudier, François Fourel, François Martineau, Alexandre Cros, “Oxygen isotope fractionation and equilibration kinetics between CO2 and H2O as a function of salinity of aqueous solutions”, Chemical Geology, Volume 264, Issues 1–4, 30 June 2009, Pages 122-126.

François Martineau, François Fourel, Anne-Marie Bodergat, Christophe Lécuyer, “D/H equilibrium fractionation between H2O and H2 as a function of the salinity of aqueous solutions”, Chemical Geology, Volume 291, 6 January 2012, Pages 236-240.

Beta Analytic Webinars:
Isotopes 101: An Introduction to Isotopic Analysis
Isotopes in Hydrology
Nutrient Source Tracking
Dissolved Carbon

Page last updated: December 2020