biostudies-literatureKohyama EMinistry of Health, Labour and WelfareGifu Prefectural Research Institute for Health and Environmental Sciences56-65https://www.ebi.ac.uk/biostudies/studies/S-EPMC5215287biostudies-literatureUnknown35(1)Differentiation among regioisomers of synthetic cannabinoids in forensic drug analysis is a crucial issue, since all isomers are not regulated by law. New equivalent analogs obtained via minor modification of their preexisting molecules keep on emerging. Isomers formed via substitutional exchange are also a cause for concern. This study is focused on the isomeric molecules that stem from minor modifications of 5F-PB-22. The analytical properties of these molecules and methods of differentiation are reported. Scan mode analysis using gas chromatography-electron ionization-mass spectrometry (GC-EI-MS) was performed using the authentic 5F-PB-22 standard, five regioisomeric quinolinyl ester indoles, and five regioisomeric isoquinolinyl ester indoles. Because it was not possible to separate 5F-Forensic toxicologyAnalytical differentiation of quinolinyl- and isoquinolinyl-substituted 1-(5-fluoropentyl)-1<i>H</i>-indole-3-carboxylates: 5F-PB-22 and its ten isomers.PMC521528727170401Ito TChikumoto TKitaichi KKohyama ETada HfalseAnalytical differentiation of quinolinyl- and isoquinolinyl-substituted 1-(5-fluoropentyl)-1<i>H</i>-indole-3-carboxylates: 5F-PB-22 and its ten isomers.Differentiation among regioisomers of synthetic cannabinoids in forensic drug analysis is a crucial issue, since all isomers are not regulated by law. New equivalent analogs obtained via minor modification of their preexisting molecules keep on emerging. Isomers formed via substitutional exchange are also a cause for concern. This study is focused on the isomeric molecules that stem from minor modifications of 5F-PB-22. The analytical properties of these molecules and methods of differentiation are reported. Scan mode analysis using gas chromatography-electron ionization-mass spectrometry (GC-EI-MS) was performed using the authentic 5F-PB-22 standard, five regioisomeric quinolinyl ester indoles, and five regioisomeric isoquinolinyl ester indoles. Because it was not possible to separate 5F-2017-01-01T00:00:00Z20172025-04-05T14:13:07.459Z2019-03-27T02:33:15ZS-EPMC52152872812740810.1007/s11419-016-0334-9