Measuring heavy metal content in bone using portable X-ray fluorescence

Abstract

The ability of inorganic-based analytical chemistry techniques to quantify trace amounts of heavy metals in skeletal remains has been integral for understanding health and social status in human populations. Low detection limits and the sensitivity of inductively coupled plasma- mass spectrometry (ICP-MS) and other techniques to most elements on the periodic table are ideally suited for the quantification of lead (Pb) and other heavy metals in bone. However, the time required for sample preparation and analysis, expense, destructive analytical process, and availability of instrumentation often limit researchers’ ability to utilise these techniques for archaeological applications. This paper explores the use of portable X-ray fluorescence (XRF) instrumentation for heavy metal analysis of bone as an alternative to more traditional analytical techniques. XRF has been shown to be an extremely useful tool for archaeologists seeking to conduct quantitative analyses of cultural materials such as obsidian and metals. However, little research has been undertaken to assess the usefulness of portable XRF for measuring heavy metals found in low concentrations in archaeological bone. This paper compares data derived from ICP-MS and portable XRF analyses of bone. Results demonstrate that XRF analyses of bone are problematic due to diagenesis and variability of Pb content in bone.