title: Differentiation of AB-FUBINACA positional isomers by the abundance of product ions using electron ionization-triple quadrupole mass spectrometry.
abstract: Mass spectrometric differentiation of structural isomers is important for the analysis of forensic samples. Presently, there is no mass spectrometric method for differentiating halogen positional isomers of cannabimimetic compounds. We describe here a novel and practical method for differentiating one of these compounds, N-(1-amino-3-methyl-1-oxobutan-2-yl)-1-(4-fluorobenzyl)-1H-indazole-3-carboxamide (AB-FUBINACA (para)), and its fluoro positional (ortho and meta) isomers in the phenyl ring by electron ionization-triple quadrupole mass spectrometry. It was found that the three isomers differed in the relative abundance of the ion at m/z 109 and 253 in the product ion spectra, while the detected product ions were identical. The logarithmic values of the abundance ratio of the ions at m/z 109 to 253 (ln(A109/A253)) were in the order meta < ortho < para and increased linearly with collision energy. The differences in abundances were attributed to differences in the dissociation reactivity between the indazole moiety and the fluorobenzyl group because of the halogen-positional effect on the phenyl ring. Our methodology, which is based on the abundance of the product ions in mass spectra, should be applicable to determination of the structures of other newly encountered designer drugs. Copyright © 2016 John Wiley & Sons, Ltd.
authors.affiliation: Forensic Science Laboratory, Ishikawa Prefectural Police H.Q., 1-1 Kuratsuki, Kanazawa, Ishikawa, 920-8553, Japan. murakami@forensic-sci-lab.net.
authors.forename: Takaya
authors.initials: T
authors.lastname: Murakami
authors.affiliation: Forensic Science Laboratory, Ishikawa Prefectural Police H.Q., 1-1 Kuratsuki, Kanazawa, Ishikawa, 920-8553, Japan.
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Iwamuro
authors.affiliation: Forensic Science Laboratory, Ishikawa Prefectural Police H.Q., 1-1 Kuratsuki, Kanazawa, Ishikawa, 920-8553, Japan.
authors.forename: Reiko
authors.initials: R
authors.lastname: Ishimaru
authors.affiliation: Forensic Science Laboratory, Ishikawa Prefectural Police H.Q., 1-1 Kuratsuki, Kanazawa, Ishikawa, 920-8553, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Chinaka
authors.affiliation: Materials Characterization Central Laboratory, Waseda University, 3-4-1 Ohkubo, Shinjyuku, Tokyo, 169-8555, Japan.
authors.forename: Natsuhiko
authors.initials: N
authors.lastname: Sugimura
authors.affiliation: Forensic Science Laboratory, Ishikawa Prefectural Police H.Q., 1-1 Kuratsuki, Kanazawa, Ishikawa, 920-8553, Japan.
authors.forename: Nariaki
authors.initials: N
authors.lastname: Takayama
mesh_terms: D002186:Cannabinoids / Q000737:chemistry; D015198:Designer Drugs / Q000737:chemistry; D004583:Electrons; D007191:Indazoles / Q000737:chemistry*; D007477:Ions / Q000737:chemistry; D007536:Isomerism; D008956:Models, Chemical; D021241:Spectrometry, Mass, Electrospray Ionization; D053719:Tandem Mass Spectrometry / Q000379:methods
chemical_list: D002186:Cannabinoids; D015198:Designer Drugs; D007191:Indazoles; D007477:Ions; C000615602:AB-FUBINACA
keywords: AB-FUBINACA; abundance of product ions; dissociation reactivity; electron ionization-triple quadrupole mass spectrometry; positional isomeric differentiation