Hair Reveals what People Conceal: Biometric Traits from the Chemical Analysis of Human Hair

This presentation reveals the profound ways in which isotope ratio mass spectrometry (IRMS) can provide information about the geographic origin and history of almost everything around us, including our fellow humans. The presentation explains the ways in which we are and are not exactly what we eat, and it explains how researchers use IRMS measurements of hair to determine the geographic origin and travel histories of animals and humans.

Building off these established capabilities, our research develops the ability to objectively classify the hair of different human donors into soft biometric grouping factors such as sex, age group and body mass index (BMI). Classification is accomplished either through the quantitation of amino acids in human hair matrix, which is comprised mainly of structural keratins, or through the precise measurement of naturally occurring stable isotopes of 13C/12C of each amino acid in the hair matrix. Our work also demonstrates that amino-acid-specific analysis of human hair can predict type II diabetes in the donors. In separate applications, the same methodology is used to link individual blowflies to their carrion (flesh) diet.

Before delving into the details of IRMS, the talk will also cover some very brief summaries of other mass-spectrometry based research endeavors in the Jackson group, including: 1) the development of innovative MS-based fragmentation methods for determining the structural composition of biomolecules like oligosaccharides, 2) the development of a new approach to mass spectral comparisons, and 3) the development of a new type of miniature, portable mass spectrometer.