You Are What You Eat: A Technique for Isotopic Analysis of Archaeological Amino Acids

Faculty Mentor: James O. McCullagh Stable isotope analysis of archaeological remains offers a wealth of information about the diets of ancient peoples. Many studies have shown that both stable isotope and radiocarbon measurements of individual amino acids offer greater insight than does measurement of bulk protein alone. Therefore a particular interest exists in a process that can separate amino acids in proteins, particularly human bone collagen, while maintaining the integrity of the isotopic signal. Previous methods have either undesirably used organic reagents or have failed to separate several interesting amino acids. This paper presents the development of a chromatography method that achieves separation of 15 amino acids in a mock collagen sample, without introducing any outside carbon. The method has also been success- fully tested on an archaeological sample. Further development of this method will allow for more routine and accurate isotopic measure- ments of individual amino acids in archaeological collagen samples, which could greatly expand the data available for reconstructing pale- odiets. Results for hair protein as an isotopic indicator of migration are also presented. From the Washington University Undergraduate Research Digest: WUURD, Volume 2, Issue 2, Spring 2007. Published by the Office of Undergraduate Research. Henry Biggs, Director of Undergraduate Research and Associate Dean in the College of Arts & Sciences; Joy Zalis Kiefer, Undergraduate Research Coordinator, Editor, and Assistant Dean in the College of Arts & Sciences; Kristin Sobotka, Co-editor