title: Isomeric discrimination of synthetic cannabinoids by GC-EI-MS: 1-adamantyl and 2-adamantyl isomers of N-adamantyl carboxamides.
abstract: N-(1-adamantyl)-1-pentyl-1H-indazole-3-carboxamide (APINACA) and N-(1-adamantyl)-1-pentyl-1H-indole-3-carboxamide (APICA) are carboxamide-type synthetic cannabinoids comprising indazole/indole-3-carboxylic acid and adamantan-1-amine moieties. However, in the case of compounds like APINACA or APICA, adamantyl positional isomers exist, wherein either adamantan-1-amine or adamantan-2-amine is present. These adamantyl positional isomers have not been reported in previous studies, and no analytical data are available. To avoid misidentification of adamantyl carboxamide-type synthetic cannabinoids, it is important to develop methods to discriminate these adamantyl positional isomers. In this study, we report the analytical characterization by gas chromatography-electron ionization-mass spectrometry (GC-EI-MS). For providing analytical standards, we synthesized eight carboxamide-type synthetic cannabinoids (APINACA 2-adamantyl isomer, APICA 2-adamantyl isomer, 5 F-APINACA 2-adamantyl isomer, 5 F-APICA 2-adamantyl isomer, 5Cl-APINACA, 5Cl-APINACA 2-adamantyl isomer, adamantyl-THPINACA, 2-adamantyl-THPINACA) and purchased four 1-adamantyl derivatives (APINACA, APICA, 5 F-APINACA, 5 F-APICA). Although the retention times of the isomers are similar, 1-adamantyl carboxamides can be clearly discriminated from their 2-adamantyl isomers based on their different fragmentation patterns in the EI-MS spectra. Specifically, EI-MS spectra for adamantylindazole carboxamides showed remarkable differences between the 1-adamantyl and 2-adamantyl isomers. On the other hand, EI-MS spectra for adamantylindole carboxamides were similar, but the diagnostic ions of the 2-adamantyl isomers were observed. The method described herein was applicable to all compounds tested in this study and is expected to be of use for isomeric differentiation between other untested adamantyl carboxamide-type synthetic cannabinoids. Copyright © 2016 John Wiley & Sons, Ltd.
authors: Osaka Prefectural Institute of Public Health, 1-3-69 Nakamichi, Higashinari-ku, Osaka, 537-0025, Japan.
authors: Akiko
authors: A
authors: Asada
authors: Osaka Prefectural Institute of Public Health, 1-3-69 Nakamichi, Higashinari-ku, Osaka, 537-0025, Japan.
authors: Takahiro
authors: T
authors: Doi
authors: Osaka Prefectural Institute of Public Health, 1-3-69 Nakamichi, Higashinari-ku, Osaka, 537-0025, Japan.
authors: Takaomi
authors: T
authors: Tagami
authors: Osaka Prefectural Institute of Public Health, 1-3-69 Nakamichi, Higashinari-ku, Osaka, 537-0025, Japan.
authors: Akihiro
authors: A
authors: Takeda
authors: Osaka Prefectural Institute of Public Health, 1-3-69 Nakamichi, Higashinari-ku, Osaka, 537-0025, Japan.
authors: Yoshiyuki
authors: Y
authors: Sawabe
mesh_terms: D000218:Adamantane / Q000031:analogs & derivatives* / Q000737:chemistry; D002186:Cannabinoids / Q000737:chemistry*; D008401:Gas Chromatography-Mass Spectrometry; D013287:Illicit Drugs / Q000737:chemistry*; D007191:Indazoles / Q000737:chemistry*; D007211:Indoles / Q000737:chemistry*; D007536:Isomerism; D021241:Spectrometry, Mass, Electrospray Ionization
chemical_list: D002186:Cannabinoids; D013287:Illicit Drugs; D007191:Indazoles; D007211:Indoles; C000606545:N-(1-adamantyl)-1-pentylindazole-3-carboxamide; D000218:Adamantane
keywords: 2-adamantyl isomer; adamantane; fragmentation pattern; mass spectrometry; synthetic cannabinoids