Rapid Screening and Identification of Tryptamines Based on Characteristic Ions

Psychoactive tryptamines are naturally found in toads, plants, and mushrooms. However, due to the hallucinogenic effect of tryptamine derivatives, they have been abused illegally by more and more users. The wide distribution of designer tryptamines has become a serious social problem, because they can cause serious damage to health and their psychotropic effects can lead to criminal activity. Some of tryptamines are controlled as narcotics under the Administration of Non-Pharmaceutical Narcotic Drugs and Psychotropic Substances in China, such as 5-MeO-DALT, 5-MeO-DiPT, 5-MeO-MT and so on. However, if they become controlled, new compounds with similar structures will then spread throughout the drug market. For known new psychoactive substances, mass spectra are compared with reference standards to identify the detected compounds. Nevertheless, in the case of such dynamic growth in the number of new substances on the drug market, the novel compound is often not already added to the spectra library. Without a reference standard, the compound must be identified from a detailed study of its mass spectra. Due to the limited applicability of spectral libraries, knowledge on fragmentation patterns of particular groups of new psychoactive substances is necessary to predict the structures of novel compounds. In 2015-2019, a series of eleven tryptamines were identified as new psychoactive substances in China. In this work, a fast and simple approach for the screening and identification of tryptamines was proposed using gas chromatography-mass spectrometry (GC-MS) and ultra performance liquid chromatography-quadrupole time-of-flight-mass spectrometry (UPLC-QTOF MS). Compounds were analyzed on Aglient DB-5 MS column (30 m×0.25 mm×0.25 μm) with an initial temperature of 140 ℃ for gradient increased temperature by GC-MS and Acquity UPLC CSHTM C18 column (10 cm×2.1 mm×1.7 μm) with 0.1% formic acid aqueous solution (A)-acetonitrile (B) as mobile phase for gradient elution by UPLC-QTOF MS. The fragmentation behaviors especially the MS fragmentation rules were compared and summarized. According to the structure and the typical fragmentations, these compounds can be easily identified. This method is fast and accurate, and can be used for analysising different types of tryptamines. So this work will be helpful to assist forensic laboratories in identifying these kinds of compounds or other substances with similar structure in their case work.