Preliminary Validation of Handheld X‐Ray Fluorescence Spectrometry: Distinguishing Osseous and Dental Tissue from Nonbone Material of Similar Chemical Composition

Abstract

One of the tasks of a forensic anthropologist is to sort human bone fragments from other materials, which can be difficult when dealing with highly fragmented and taphonomically modified material. The purpose of this research is to develop a method using handheld X-ray fluorescence (HHXRF) spectrometry to distinguish human and nonhuman bone/teeth from nonbone materials of similar chemical composition using multivariate statistical analyses. The sample materials were derived primarily from previous studies: human bone and teeth, nonhuman bone, nonbiological materials, nonbone biological materials, and taphonomically modified materials. The testing included two phases, testing both the reliability of the instrument and the accuracy of the technique. The results indicate that osseous and dental tissue can be distinguished from nonbone material of similar chemical composition with a high degree of accuracy (94%). While it was not possible to discriminate rock apatite and synthetic hydroxyapatite from bone/teeth, this technique successfully discriminated ivory and octocoral.

Chemical Differentiation of Osseous, Dental, and Non-skeletal Materials in Forensic Anthropology using Elemental Analysis

“…More recently, Zimmerman and colleagues [3] published a study regarding the utility of handheld X-ray fluorescence (HHXRF) in distinguishing human and nonhuman bone/teeth from non-skeletal material using multivariate statistical analysis. The study examined a variety of materials (Table 3), which included several examples found in previous studies on the topic [1,2].…”

“…Multiple chemical analysis techniques focusing on the elemental composition of materials have been shown to be reliable laboratory methods that can be used to determine if questionable fragments are osseous, dental, or non-skeletal in nature [1][2][3]. Once the forensic anthropologist determines that questionable material is osseous or dental in nature, the next step in the analysis is to determine if osseous/dental material is human or non-human.…”

“…Further, in the case of DNA, this method is routinely used for individual determination of commingled remains when sorting through fragmentary material. More recently, studies suggest that elemental analysis combined with multivariate statistical analysis [3,[17][18][19] may be useful in the discrimination, or the initial sorting Science and Justice xxx (2014) xxx-xxx prior to DNA analysis, of multiple individuals when presented with highly fragmentary and taphonomically modified material.…”

Use of an Alternate Light Source to Detect Tooth and Bone

“…The speed with which ALS can be deployed makes this technique well suited to be an adjunct method in forensic dental examinations (17). Inspection with light by ALS is rapid and can reveal evidence that would otherwise be difficult to observe (7,11,17); its use can provide additional information that contributes to identify positively the crime victims.…”

“…This is important, because incomplete analyses may result in the loss of crucial evidence such as teeth and small bones. In some cases, bone and dental tissue may not always be easily identifiable from non-osseous material (7). Moreover, some authors (2,4) have suggested that new research should be performed to perfect the ALS technique.…”