Amber R. Rose

Gas Chromatography-Mass Spectrometry of Aminoindanes, a Lesser-Known Class of Novel Psychoactive Substances

Aminoindanes are one class of many novel psychoactive substances (NPSs) that have emerged over the last decade. 2-Aminoindane (2-AI) and related analogues are being encountered in crime laboratories. Minimal analytical data has been reported on these compounds, and limited standards are available for forensic toxicology and drug analysis laboratories. This presents a challenge to analysts who need the information for identification and differentiation of aminoindanes. In this study, gas chromatography-mass spectrometry (GC-MS) was used to analyze eight aminoindanes using four different column stationary phases, Rxi®-1Sil MS, Rxi®-5Sil MS, Rxi®-35Sil MS, and Rxi®-624Sil MS. The aminoindanes investigated in this study were 2-AI, N-methyl-2-aminoindane (N-methyl-2AI), rasagiline, 5-methoxy-2-aminoindane (MEAI), 5-methoxy-6-methyl-2-aminoindane (MMAI), 5,6-methylenedioxy-2-aminoindane (MDAI), 4,5-methylenedioxy-2-aminoindane (4,5-MDAI), and 5-iodo-2-aminoindane (5-IAI), and all were analyzed as free bases. The columns that were used had the same configuration (30 m x 25 mm x 0.25 μm), excluding the Rxi®-624Sil MS column (30 m x 25 mm x 1.4 μm). Split injection (25:1) was utilized for all samples. Separation of a mixture of the eight aminoindanes was optimized, and retention times and retention indices were determined for the compounds on the four columns. Based on the retention data, all eight aminoindanes could be resolved on the Rxi®-624Sil MS column. For the other three columns, all but two analogues, 4,5-MDAI and MDAI, could be separated within the mixture. Additionally, mass spectral fragmentation patterns were interpreted for further characterization of the aminoindanes. The results of this study will strengthen the analytical profiles of 2-aminoindane and seven analogues, assisting forensic scientists in their analysis and identification of these substances.