Matching and discrimination of single human-scalp hairs by FT-IR micro-spectroscopy and chemometrics

Human-scalp hair samples were discriminated by Fourier transform infrared (FT-IR) micro-spectroscopy and chemometrics. The hairs were flattened with a small metallic roller, and the spectra were collected in the reflectance mode. The effects of gender, race and hair oxidation were examined. The results indicate a clear separation between FT-IR spectra collected from the heads of two different subjects of the same gender, race, hair colour, hair length, and treatment. The same results have also indicated a discrimination between spectra of hairs collected from the LHS and RHS of a head of a given subject. In addition, FT-IR spectra collected from different subjects were discriminated on the basis of treatment and gender. The study has demonstrated that chemometrics provides information that is not readily available by conventional visual methods of spectral interpretation. (C) 1999 Elsevier Science B.V. All rights reserved.