Analysis of Biological Elements of Scalp Hairs With Sem-Edx and Tem and its Application to the Hair Comparison

Abstract

Personal identification of hair samples collected from the crime scene has been principally made on basis of precise comparison of morphological features and the result of blood grouping of hair samples. For the present only ABO blood types can be routinely examined on hair samples, and therefore, other additional informations for the hair comparison have long been required, among which the trace element composition of hairs has been utilized as giving a clue to the hair comparison. Here, scanning electron microscope equipped with energy dispersive X-ray microanalyzer (SEM/EDX), which has been widely used to examine many kinds of physical evidences in forensic laboratories, was applied to the elemental analysis of hairs. Since SEM/EDX enables us to analyze very small amount of sample, it is very efficient in the hair comparison in which each single hair strand collected from crime scenes has its own evidential value. But SEM/EDX analysis of hairs involves the intrinsic problem that trace elements other than sulfur and chlorine are very hard to detect from raw hair samples.