Worldwide proficiency test for routine analysis of δ2H and δ18O in water by isotope-ratio mass spectrometry and laser absorption spectroscopy
Article first published online: 22 JUN 2012
Copyright © 2012 John Wiley & Sons, Ltd.
Rapid Communications in Mass Spectrometry
Volume 26, Issue 15, pages 1641–1648, 15 August 2012
How to Cite
Wassenaar, L. I., Ahmad, M., Aggarwal, P., van Duren, M., Pöltenstein, L., Araguas, L. and Kurttas, T. (2012), Worldwide proficiency test for routine analysis of δ2H and δ18O in water by isotope-ratio mass spectrometry and laser absorption spectroscopy. Rapid Commun. Mass Spectrom., 26: 1641–1648. doi: 10.1002/rcm.6270
- Issue published online: 22 JUN 2012
- Article first published online: 22 JUN 2012
- Manuscript Revised: 4 MAY 2012
- Manuscript Accepted: 4 MAY 2012
- Manuscript Received: 17 APR 2012
The interpretation of stable hydrogen and oxygen isotope data in isotope hydrology relies on accurate, high-precision analytical measurements of the 2H:1H and 18O:16O ratios in liquid H2O samples.
A synthesis of the International Atomic Energy Agency (IAEA) worldwide proficiency test for analytical laboratories conducting routine analysis of δ2H and δ18O values in water (WICO2011) by isotope-ratio mass spectrometry (IRMS) and laser absorption spectroscopy (LAS) technology has been carried out.
This test revealed that >96% of the 160 laboratory submissions provided acceptable results within ±2‰ for δ2H values and ±0.2‰ for δ18O values of the established reference values for four test waters, and no difference in outcomes based on IRMS vs. LAS technology was found for good performing laboratories.
The leading cause of outliers appeared to be improper calibration or compromised storage of laboratory standard and primary reference waters; hence the importance of judicious storage of lab standards cannot be understated. The deprecated practice of single standard normalization was identified as a problem for some laboratories. We further recommend that laboratories strive to report parsimonious long-term precisions based upon control standards, and to improve quantification and correction for LAS instrumental drift and inter-sample carryover effects. Copyright © 2012 John Wiley & Sons, Ltd.