Differentiation of AB-FUBINACA and its five positional isomers using liquid chromatography-electrospray ionization-linear ion trap mass spectrometry and triple quadrupole mass spectrometry

作者：Murakami Takaya^*; Iwamuro Yoshiaki; Ishimaru Reiko; Chinaka Satoshi; Takayama Nariaki; Hasegawa Hiroshi

来源：Forensic Toxicology, 2018, 36(2): 351-358.

DOI：10.1007/s11419-018-0410-4

• AB-FUBINACA
• Positional isomer differentiation
• Liquid chromatography
• Electrospray ionization
• Linear ion trap mass spectrometry
• Triple quadrupole mass spectrometry

Positional isomer differentiation is crucial for forensic analysis. The aim of this study was to differentiate AB-FUBINACA positional isomers using liquid chromatography (LC)-electrospray ionization (ESI)-linear ion trap mass spectrometry (LIT-MS) and LC-ESI-triple quadrupole mass spectrometry (QqQ-MS).
AB-FUBINACA, its two fluorine positional isomers on the phenyl ring, and three methyl positional isomers in the carboxamide side chain were analyzed by LC-ESI-LIT-MS and LC-ESI-QqQ-MS.
Four of the positional isomers, excluding AB-FUBINACA and its 3-fluorobenzyl isomer, were chromatographically separated on an ODS column in isocratic mode. ESI-LIT-MS could discriminate only three isomers, i.e., the 2-fluorobenzyl isomer, the N-(1-amino-2-methyl-1-oxobutan-2-yl) isomer, and the N-(1-amino-1-oxobutan-2-yl)-N-methyl isomer, based on their characteristic product ions observed at the MS3 stage in negative mode. ESI-QqQ-MS differentiated all six isomers in terms of the relative abundances of the product ions that contained the isomeric moieties involved in collision-induced dissociation reactions. The six isomers were more clearly and significantly differentiated upon comparison of the logarithmic values of the product ion abundance ratios as a function of collision energy.
The present LC-MS methodologies were useful for the differentiation of a series of AB-FUBINACA positional isomers.

• 出版日期2018-7