Mass Spectrometry Imaging in Scientific Crime Detection

Abstract

Hair analysis for detection of drug(s) is one of forensic analyses which are carried out in forensic science laboratories of each prefectural police in Japan. Longitudinal drug distribution in hair provides very important information to understand use history of the drug. The authors applied mass spectrometry imaging technique to a drug incorporated in hair. Methoxyphenamine, a noncontrolled analogue of methamphetamine, was systemically administered to volunteers as the model compound, and hair samples were collected from them at appropriate intervals. Imaging of methoxyphenamine in hair achieved by matrix-assisted laser desorption/ionization (MALDI) mass spectrometry applied to longituidinal section cropped out by freeze-sectioning using a rotary microtome. Methoxyphenamine-positive regions were specifically observed to shift toward tips of hair according to its growth. Detailed investigation of methoxyphenamine distribution in hair suggested strongly that its incorporation occur at not only the hair bulb but also the tissue of the upper dermis.