Comparison of two stable hydrogen isotope-ratio measurement techniques on Antarctic surface-water and ice samples

A comparison of the new hydrogen isotope-ratio technique of Vaughn et al. ([Vaughn, B.H., White, J.W.C., Delmotte, M., Trolier, M., Cattani, O., Stievenard, M., 1998. An automated system for hydrogen isotope analysis of water. Chem. Geol. (Isot. Geosci. Sect.), 152, 309–319]; the article immediately preceding this article) for the analysis of water samples utilizing automated on-line reduction by elemental uranium showed that 94% of 165 samples of Antarctic snow, ice, and stream water agreed with the δ2H values determined by H2–H2O platinum equilibration, exhibiting a bias of +0.5‰ and a 2−σ variation of 1.9‰. The isotopic results of 10 reduction technique samples, however, gave δ2H values that differed by 3.5‰ or more, and were too negative by as much as 5.4‰ and too positive by as much as 4.9‰ with respect to those determined using the platinum equilibration technique.