Rationale: Aminoindanes are one class of many new psychoactive substances that have emerged over the last decade. Analogues of 2-aminoindane (2-AI) are being encountered in crime laboratories and analytical data for most aminoindanes are limited. Interpretation and optimization of gas chromatography-mass spectrometry data will enhance reliability in characterizing aminoindanes.
Methods: This study focuses on the electron ionization mass spectrometric fragmentation of eight aminoindane analogues and the gas chromatographic separation of these eight aminoindane analogues using four different column stationary phases, Rxi®-1Sil MS, Rxi®-5Sil MS, Rxi®-35Sil MS, and Rxi®-624Sil MS. Split injection (25:1) was utilized and each column had the same configuration (30 m × 25 mm × 0.25 μm), with the exception of the Rxi®-624Sil MS column (30 m × 25 mm ×1.4 μm).
Results: Mass spectra showed strong molecular ions for all aminoindanes, except for rasagiline that produced a uniquely abundant [M - 1] ion. Other characteristic fragmentation that was present for all the aminoindanes included indane and indene ions (m/z 115-117), the tropylium ion (m/z 91), and subsequent loss of diene to produce smaller ions that followed: phenyl (m/z 77), cyclopentadienyl (m/z 65), cyclobutadienyl (m/z 51), and cyclopropenyl (m/z 39).
Conclusions: Separation of eight aminoindanes was optimized, and linear retention indices were determined for the compounds on four capillary columns. Based on the retention data, all eight aminoindanes were resolved on an Rxi®-624Sil MS column. Each aminoindane exhibited unique fragmentation ions in the mass spectra to distinguish between similar analogues. The results of this study will strengthen the analytical profiles of 2-AI and seven analogues, assisting forensic scientists in their analysis and identification of these substances.
© 2021 John Wiley & Sons Ltd.