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[Hair Testing for Drugs in the Field of Forensics]
Noriaki Shima1, Keiko Sasaki1, Tohru Kamata1
1Forensic Science Laboratory, Osaka Prefectural Police H.Q.
Summary
Drug incorporation into hair occurs in two root regions, with pathways varying by drug properties. This research clarifies drug incorporation mechanisms for accurate forensic analysis and drug use history interpretation.
Area of Science:
- Forensic Science
- Analytical Chemistry
- Toxicology
Background:
- Hair testing is crucial in forensics for drug ingestion evidence and chronological use data.
- Understanding drug incorporation mechanisms in hair is vital for accurate interpretation, yet remains debated.
- Illicit drugs and hypnotics are frequently analyzed in criminal cases.
Purpose of the Study:
- To investigate the specific pathways and mechanisms of drug incorporation into human hair.
- To determine the temporal aspects of drug incorporation in hair.
- To correlate drug properties with their incorporation routes into hair.
Main Methods:
- Utilized matrix-assisted laser desorption/ionization-mass spectrometry (MALDI-MS) imaging.
- Performed sectional hair analysis of 1-mm segments using liquid chromatography-tandem mass spectrometry (LC-MS/MS) on single-strand hair.
- Analyzed time-course drug distribution along hair strands.
Main Results:
- Drug incorporation into hair was identified in two regions: the hair bulb and the upper hair root.
- Incorporation from the hair bulb was observed to continue for approximately two weeks.
- Different drugs exhibited varying primary incorporation pathways (hair bulb vs. upper root) based on their physicochemical properties.
Conclusions:
- The findings elucidate the dual-region incorporation of drugs into hair, with distinct temporal dynamics.
- Drug incorporation pathways are drug-specific, influenced by molecular properties.
- These insights are critical for refining the interpretation of hair analysis results in forensic toxicology and drug use history assessments.
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