"RATIONALE: Because of the paucity of isotopic reference waters for daily use, a new secondary isotopic reference material has been prepared from Lake Louise water from Alberta, Canada for international distribution.
MOTHODS: This water was filtered, homogenized, loaded into glass ampoules, sealed with a torch, autoclaved to eliminate biological activity, and measured by dual-inlet isotope-ratio mass spectrometry. This isotopic reference water is available by the case of 144 glass ampoules containing 5 mL of water in each ampoule.
RESULTS: The δ2H and δ18O values of this reference water are –150.2 ± 0.5 ‰ and –19.80 ± 0.02 ‰, respectively, relative to VSMOW on scales normalized such that the δ2H and δ18O values of SLAP reference water are, respectively, –428 and –55.5 ‰. Each uncertainty is an estimated expanded uncertainty (U = 2uc) about the reference value that provides an interval that has about a 95-percent probability of encompassing the true value.
CONCLUSION: This isotopic reference material, designated as USGS47, is intended as one of two isotopic reference waters for daily normalization of stable hydrogen and stable oxygen isotopic analysis of water with a mass spectrometer or a laser absorption spectrometer.