title: Differentiation of regioisomeric chloroamphetamine analogs using gas chromatography-chemical ionization-tandem mass spectrometry.
abstract: In recent years, a large number of clandestinely synthesized new psychoactive substances with high structural variety have been detected in forensic samples. Analytical differentiation of regioisomers is a significant issue in forensic drug analysis, because, in most cases, legal controls are placed on only one or two of the conceivable isomers. In this study, gas chromatography-tandem mass spectrometry (GC-MS-MS) was used to differentiate the regioisomers of chloroamphetamine analogs (chloroamphetamines and chloromethamphetamines) synthesized in the authors' laboratories. Free bases, trifluoroacetyl derivatives, and trimethylsilyl derivatives were subjected to GC-MS-MS using DB-1ms, DB-5ms, and DB-17ms capillary columns, respectively. The regioisomers of chloroamphetamine analogs in all forms were well separated on the DB-5ms column. The electron ionization mass spectra of the chloroamphetamine analogs gave very little structural information for differentiation among these analogs, even after trifluoroacetyl and trimethylsilyl derivatization of the analytes. Characteristic product ions of the 2-positional isomers were observed by electron ionization-MS-MS. In contrast, chemical ionization-MS-MS of the free bases provided more structural information about chloride position on the aromatic ring when [M+H-HCl]+was selected as a precursor ion. The results suggest that a combination of chromatographic analysis and MS-MS supports differentiation for regioisomers of chloroamphetamine analogs.
authors.affiliation: National Research Institute of Police Science, 6-3-1 Kashiwanoha, Kashiwa, 277-0882 Japan ; Technopro R&D, Company, 1-15-1 Benten, Chuo-ku, Chiba, 260-0045 Japan.
authors.forename: Shoko
authors.initials: S
authors.lastname: Negishi
authors.affiliation: National Research Institute of Police Science, 6-3-1 Kashiwanoha, Kashiwa, 277-0882 Japan ; Technopro R&D, Company, 1-15-1 Benten, Chuo-ku, Chiba, 260-0045 Japan.
authors.forename: Yukiko
authors.initials: Y
authors.lastname: Nakazono
authors.affiliation: National Research Institute of Police Science, 6-3-1 Kashiwanoha, Kashiwa, 277-0882 Japan.
authors.forename: Yuko T
authors.initials: YT
authors.lastname: Iwata
authors.affiliation: National Research Institute of Police Science, 6-3-1 Kashiwanoha, Kashiwa, 277-0882 Japan.
authors.forename: Tatsuyuki
authors.initials: T
authors.lastname: Kanamori
authors.affiliation: National Research Institute of Police Science, 6-3-1 Kashiwanoha, Kashiwa, 277-0882 Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Tsujikawa
authors.affiliation: National Research Institute of Police Science, 6-3-1 Kashiwanoha, Kashiwa, 277-0882 Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Kuwayama
authors.affiliation: National Research Institute of Police Science, 6-3-1 Kashiwanoha, Kashiwa, 277-0882 Japan.
authors.forename: Tadashi
authors.initials: T
authors.lastname: Yamamuro
authors.affiliation: Technopro R&D, Company, 1-15-1 Benten, Chuo-ku, Chiba, 260-0045 Japan ; Biochemical Toxicology Laboratory, Faculty of Pharmaceutical Sciences, Kobegakuin University, 1-1-3 Minatojima, Chuo-ku, Kobe, 650-8586 Japan.
authors.forename: Kazuna
authors.initials: K
authors.lastname: Miyamoto
authors.affiliation: Biochemical Toxicology Laboratory, Faculty of Pharmaceutical Sciences, Kobegakuin University, 1-1-3 Minatojima, Chuo-ku, Kobe, 650-8586 Japan.
authors.forename: Takuya
authors.initials: T
authors.lastname: Yamashita
authors.affiliation: Biochemical Toxicology Laboratory, Faculty of Pharmaceutical Sciences, Kobegakuin University, 1-1-3 Minatojima, Chuo-ku, Kobe, 650-8586 Japan.
authors.forename: Fumiyo
authors.initials: F
authors.lastname: Kasuya
authors.affiliation: National Research Institute of Police Science, 6-3-1 Kashiwanoha, Kashiwa, 277-0882 Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Inoue
keywords: Chemical ionization; Chloroamphetamine analogs; GC–MS–MS; Regioisomeric differentiation