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

Summary

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.

This Resource is Part of the Following Collections

• Society for American Archaeology 82nd Annual Meeting, Vancouver, BC (2017)

Keywords

Record Identifiers

Abstract Id(s): 17156