Water - δD, δ¹⁷O, δ¹⁸O, Δ¹⁷O

Overview

We employ the Picarro L2140i water isotope analyzer for analysis of δD, δ¹⁷O, and δ¹⁸O. We routinely compare results from this instrument to the traditional water fluorination IRMS technique that we also employ. We are tied to the VSMOW international scale via VSMOW and SLAP for our water isotope measurements. 300 uL vials are loaded with 200 uL of sample or reference water and placed in a PAL autosampler tray. The δD, δ¹⁷O, and δ¹⁸O are measured 6-10 times for each vial from a 2 µL water injection. Between each injection, the cavity is purged with dry air and partially evacuated with a small pump. We maintain a suite of in-house reference waters measured against VSMOW and SLAP using GISP as a quality standard.

Standard Operating Procedures

• CRDS Water Isotope Analysis - δD δ17O δ18O

Suggested Reading

• Steig EJ, Gkinis V, Schauer AJ, Schoenemann SW, Samek K, Hoffnagle J, Dennis KJ, Tan SM. (2014) Calibrated high-precision 17O-excess measurements using cavity ring-down spectroscopy with laser-current-tuned cavity resonance. Atmospheric Measurement Techniques 7. doi: 10.5194/amt-7-2421-2014
• Schoenemann SW, Schauer AJ, Steig EJ. (2013) Measurement of SLAP2 and GISP δ¹⁷O and proposed VSMOW-SLAP normalization for δ¹⁷O and 17Oexcess. Rapid Communications in Mass Spectrometry 27. doi: 10.1002/rcm.6486.