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Analysis of XAD as a Pre-Treatment Method for Radiocarbon Dating Bone

Author(s): Kat Loftis ; Robert Speakman

Year: 2017

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The presence of exogenous organic carbon is a major concern when radiocarbon dating bone. A particular source of error and frustration in the field of radiocarbon dating has been the analysis of bone that has undergone humification. Humification occurs during burial and results from a combination of two distinct processes: Maillard reactions involving indigenous organic carbon, and the complexation of collagen with soil humic substances. Soil humic substances—composed of fulvic acids, humic acids and humins— are hydrophilic, predominately aromatic, heterogeneous complexes that originate from the polymerization of plant and animal biomolecules. As such, the ages of humic substances reflect the numerous and composite geochemical reactions that lead to their formation. The radiocarbon date of humified bone, then, reflects the age of the bone as well as the exogenous humic carbon. Pre-treatment methods, such as XAD solid-phase extraction and single-amino acid radiocarbon dating, have been developed to eliminate contaminant carbon and provide a purified collagen sample for dating. Here we present results from our study in which collagen was reacted with a soil humic standard and the effectiveness of chemical purification of the collagen using XAD resin was assessed.

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Analysis of XAD as a Pre-Treatment Method for Radiocarbon Dating Bone. Kat Loftis, Robert Speakman. Presented at The 81st Annual Meeting of the Society for American Archaeology, Vancouver, British Columbia. 2017 ( tDAR id: 430160)


14C Radiocarbon XAD

Record Identifiers

Abstract Id(s): 17156

Arizona State University The Andrew W. Mellon Foundation National Science Foundation National Endowment for the Humanities Society for American Archaeology Archaeological Institute of America