On the Feasibility of Establishing Individuality by Activation Analysis of Human Hair

Abstract

Neutron activation analysis of hair samples from 10 Japanese persons (5 males and 5 females) was performed to investigate the feasibility of establishing individuality. Hair samples were irradiated for 5 hours in a thermal neutron flux of 2×10¹² n/cm². sec. The gross gamma activity and the decay of the activity were determined, and gamma spectrometry was performed with a 256 channel pulse height analyzer without chemical separation. Micro contents of trace elements as Na, Mn, Cu, Br and Au were determined by the spectra. The patterns of spectra were slightly different each other in micro parts and useful for establishing individuality. The individuality was remarkable at the 0.41 MeV energy peak of gold. A simple way to individualize samples was to compare the patterns of spectra of samples which had resembling Na contents, as the Na content was correctly determined by the nondestructive method.