title: Application of a portable near infrared spectrometer for presumptive identification of psychoactive drugs.
abstract: A portable near infrared spectrometer was applied to the presumptive identification of psychotropic drugs based on library searching. Data-treatment methods (mathematical pretreatment and library search algorithm) were examined on the basis of differentiation ability. The optimized mathematical pretreatment was a standard normal variate followed by the 2nd derivative. The correlation coefficient showed the best differentiation ability in the library search algorithms. Optimized data-treatment was effective for minimizing the effect of particle size on identification. The optimized data-treatment methods were validated by the spectra of psychotropic substances (n=120). Identification criteria for the psychotropic drugs were decided on the basis of the results of the validation. As a consequence, 8 out of 11 forensic samples containing psychoactive substances were able to be positively identified. Thus, the portable near infrared spectrometer with optimized data-treatment processing is a useful tool for rapid screening and presumptive identification of seized materials.
authors: National Research Institute of Police Science, 6-3-1 Kashiwanoha, Kashiwa, Chiba 277-0882, Japan. Electronic address: tujikawa@nrips.go.jp.
authors: Kenji
authors: K
authors: Tsujikawa
authors: National Research Institute of Police Science, 6-3-1 Kashiwanoha, Kashiwa, Chiba 277-0882, Japan.
authors: Tadashi
authors: T
authors: Yamamuro
authors: National Research Institute of Police Science, 6-3-1 Kashiwanoha, Kashiwa, Chiba 277-0882, Japan.
authors: Kenji
authors: K
authors: Kuwayama
authors: National Research Institute of Police Science, 6-3-1 Kashiwanoha, Kashiwa, Chiba 277-0882, Japan.
authors: Tatsuyuki
authors: T
authors: Kanamori
authors: National Research Institute of Police Science, 6-3-1 Kashiwanoha, Kashiwa, Chiba 277-0882, Japan.
authors: Yuko T
authors: YT
authors: Iwata
authors: Biochemical Toxicology Laboratory, Faculty of Pharmaceutical Sciences, Kobegakuin University, 1-1-3 Minatojima, Chuo-ku, Kobe, Hyogo 650-8586, Japan.
authors: Kazuna
authors: K
authors: Miyamoto
authors: Biochemical Toxicology Laboratory, Faculty of Pharmaceutical Sciences, Kobegakuin University, 1-1-3 Minatojima, Chuo-ku, Kobe, Hyogo 650-8586, Japan.
authors: Fumiyo
authors: F
authors: Kasuya
authors: National Research Institute of Police Science, 6-3-1 Kashiwanoha, Kashiwa, Chiba 277-0882, Japan.
authors: Hiroyuki
authors: H
authors: Inoue
keywords: 2nd derivative; Correlation coefficient; Library search; Near infrared spectrometry; Psychoactive substances; Standard normal variate