Enabling scientific discovery through stable isotope analysis
Analysis of Water δD and δ18O
Summary: We employ both Los Gatos Research and Picarro liquid water laser analyzers to measure δD and δ18O of water.

Reference Materials: We are tied to the VSMOW international scale via VSMOW and SLAP for our water isotope measurements.

Sample submission: If you would like to submit water samples for δD and δ18O analysis, we prefer a minimum of 5 mL of frozen sample in a labeled water tight plastic container that is large enough and strong enough to withstand water expansion upon freezing. Simple legible sample IDs are appreciated. We need to know if it is fresh or salt water. Please include in your shipment container the following form (pdf or doc) and email Andy.

Exhaustive description of analysis: Vials are loaded with 1 mL of sample or reference water and placed in a PAL autosampler tray. The δD and δ18O are measured three times for each vial from 1 µL of water per injection. Between each injection, the cavity is purged with dry nitrogen gas and partially evacuated with a small pump.

Calculations:

Suggested reading:

O'Keefe A, Deacon DAG. Cavity ringdown optical spectrometer for absorption measurements using pulsed laser sources. Review of Scientific Instruments, 59, 2544 (1988). doi: 10.1063/1.1139895
Zalicki P, Zare RN. Cavity ringdown spectroscopy for quantitative absorption measurements. Journal of Chemical Physics, 102, 2708 (1995). doi: 10.1063/1.468647
Gupta P, Noone D, Galewsky J, Sweeney C, Vaughn BH. Demonstration of high-precision continuous measurements of water vapor isotopologues in laboratory and remote field deployments using wavelength-scanned cavity ring-down spectroscopy (WS-CRDS) technology. Rapid Commun. Mass Spectrom. 23, 2534 (2009). doi: 10.1002/rcm.4100