title: Broadband terahertz time-domain spectroscopy of drugs-of-abuse and the use of principal component analysis.
abstract: Terahertz frequency time-domain spectroscopy has been used to analyse a wide range of samples containing cocaine hydrochloride, heroin and ecstasy--common drugs-of-abuse. We investigated real-world samples seized by law enforcement agencies, together with pure drugs-of-abuse, and pure drugs-of-abuse systematically adulterated in the laboratory to emulate real-world samples. In order to investigate the feasibility of automatic spectral recognition of such illicit materials by terahertz spectroscopy, principal component analysis was employed to cluster spectra of similar compounds.
authors.affiliation: Institute of Microwaves and Photonics, School of Electronic and Electrical Engineering, University of Leeds, Leeds, UK LS2 9JT. A.D.Burnett@leeds.ac.uk
authors.forename: Andrew D
authors.initials: AD
authors.lastname: Burnett
authors.forename: Wenhui
authors.initials: W
authors.lastname: Fan
authors.forename: Prashanth C
authors.initials: PC
authors.lastname: Upadhya
authors.forename: John E
authors.initials: JE
authors.lastname: Cunningham
authors.forename: Michael D
authors.initials: MD
authors.lastname: Hargreaves
authors.forename: Tasnim
authors.initials: T
authors.lastname: Munshi
authors.forename: Howell G M
authors.initials: HG
authors.lastname: Edwards
authors.forename: Edmund H
authors.initials: EH
authors.lastname: Linfield
authors.forename: A Giles
authors.initials: AG
authors.lastname: Davies
mesh_terms: D003042:Cocaine / Q000032:analysis*; D003932:Heroin / Q000032:analysis*; D025341:Principal Component Analysis; D015813:Substance Abuse Detection / Q000379:methods*; D055069:Terahertz Imaging; D055068:Terahertz Spectroscopy / Q000379:methods*
chemical_list: D003932:Heroin; D003042:Cocaine