Improved precision and throughput for 17O-excess measurements on water with Cavity Ring-Down Spectroscopy
Abstract
Triple oxygen isotope data (denoted as 17O-excess) have been used to constrain meteorological processes, plant fractionation processes, animal metabolism, and a variety of other physical and chemical processes. Measurement precision is key in order to successfully apply this promising new tracer to a range of scientific questions. Up to date, the highest measurement precision for 17O-excess on water was achieved by converting water to O2 and subsequent mass spectrometric analysis of O2 (Barkan and Luz, 2005). This approach allows to reach a measurement precision of about 5-6permeg. However, it is very difficut to setup and only a few laboratories worldwide succesfully use this methodology. A far simpler approach is to use Cavity Ring-Down Spectroscopy (CRDS), i.e. the Picarro L2140-i analyzer that measures δ18O, δ17O, δD and determines 17O-excess. To date, the 17O-excess measurement precision of CRDS was limited to 10-15permeg. Here, we will present a new metholodology that allows to reach a similar or even better precision compared to the mass spectrometric approach. The improved methodology does not require any hardware changes but is solely based on modifications of the injection procedure.
- Publication:
-
EGU General Assembly Conference Abstracts
- Pub Date:
- May 2020
- DOI:
- 10.5194/egusphere-egu2020-20088
- Bibcode:
- 2020EGUGA..2220088H