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Updated: May 31, 2026

Sampling and Pretreatment of Tooth Enamel Carbonate for Stable Carbon and Oxygen Isotope Analysis
Published on: August 15, 2018
Alteration of micromilled carbonate δ18O during Kiel Device analysis
Thomas S Tobin1, Andrew J Schauer, Evan Lewarch
1Department of Earth and Space Sciences, University of Washington, 4000 15th Ave NE, Seattle, WA 98195, USA. ttobin@uw.edu
Abstract:
Isotopic analysis of carbonate material has been greatly facilitated by the development of autosampling devices such as the Kiel III Carbonate Device, allowing rapid automated analysis of small sample sizes. This analysis is facilitated by holding samples and acid at temperatures around 70 °C prior to reaction. In most situations this has no measurable effect on sample powders on practical timeframes, but, when analyzing exceptionally fine-grained material produced by micromilling, the δ(18)O of both aragonite and calcite is altered by -0.1 ‰/day. Laboratories that use this technique should thoroughly test and correct for this phenomenon and avoid storing pre-weighed materials within the Kiel Device or similar drying oven prior to analysis.

