Former address: CNR – College of Natural Resources, University of Idaho, Moscow, ID, USA.
An inexpensive, fast, and reliable method for vacuum extraction of soil and plant water for stable isotope analyses by mass spectrometry
Article first published online: 26 SEP 2011
Copyright © 2011 John Wiley & Sons, Ltd.
Rapid Communications in Mass Spectrometry
Volume 25, Issue 20, pages 3041–3048, 30 October 2011
How to Cite
Koeniger, P., Marshall, J. D., Link, T. and Mulch, A. (2011), An inexpensive, fast, and reliable method for vacuum extraction of soil and plant water for stable isotope analyses by mass spectrometry. Rapid Commun. Mass Spectrom., 25: 3041–3048. doi: 10.1002/rcm.5198
- Issue published online: 13 SEP 2011
- Article first published online: 26 SEP 2011
- Manuscript Accepted: 20 JUL 2011
- Manuscript Revised: 19 JUL 2011
- Manuscript Received: 16 JUN 2011
- CNR, University of Idaho, USA, National Research Initiative of the USDA Cooperative State Research, Education, and Extension Service. Grant Number: 2003–01264
The stable isotopes of water (hydrogen and oxygen isotopes) are of utmost interest in ecology and the geosciences. In many cases water has to be extracted directly from a matrix such as soil or plant tissue before isotopes can be analyzed by mass spectrometry. Currently, the most widely used technique for water is cryogenic vacuum extraction. We present a simple and inexpensive modification of this method and document tests conducted with soils of various grain size and tree core replicates taken on four occasions during 2010. The accuracies for sandy soils are between 0.4‰ and 3‰ over a range of 21‰ and 165‰ for δ18O and δ2H, respectively. Spiking tests with water of known isotope composition were conducted with soil and tree core samples; they indicate reliable precision after an extraction time of 15 min for sandy soils. For clayey soils and tree cores, the deviations were up to 0.63‰ and 4.7‰ for δ18O and δ2H, respectively. This indicates either that the extraction time should be extended or that mechanisms different from Rayleigh fractionation play a role. The modified protocol allows a fast and reliable extraction of large numbers of water samples from soil and plant material in preparation for stable isotope analyses. Copyright © 2011 John Wiley & Sons, Ltd.