SLAP2 , Water

2H and 18O in water samples , Water

SLAP2 (Standard Light Antarctic Precipitation 2) is an international measurement standard for stable isotope analysis. This water material was prepared at the IAEA Isotope Hydrology Laboratory in 2006 to replace the exhausting SLAP material. SLAP2 was mixed from several carefully calibrated natural water samples from the Antarctic in order to obtain a stable isotope composition as similar as possible to the original SLAP. Three selected laboratories provided calibration measurements in direct comparison to SLAP. All δ-values will continue to be reported in the VSMOW/SLAP scale, using VSMOW2 and SLAP2 as calibration materials with their assigned stable isotope reference values.

Analyte Value Unit SD R/I/C
δ18O -55.50 0.02 R
δ2H -427.5 0.3 R

(SD) Standard uncertainty at 1 sigma level calculated from results of calibrations performed at three laboratories. 
(R/I/C) Classification assigned to the property value for analyte (Recommended/Information/Certified)


  1. GRÖNING, M., VAN DUREN, M., ANDREESCU, L., Metrological characteristics of the conventional measurement scales for hydrogen and oxygen stable isotope amount ratios: the δ-scales. In: Combining and Reporting Analytical Results, Eds. A. Fajgelj, M. Belli, U. Sansone. Proceedings of an International Workshop on “Combining and reporting analytical results: The role of traceability and uncertainty for comparing analytical results”, Rome, 6-8 March 2006. Royal Society of Chemistry (2007) 62-72.


Help and Service
Copyright © 2009 International Atomic Energy Agency, P.O. Box 100, Wagramer Strasse 5, A-1400 Vienna, Austria