Fragmentation pathways of a-pyrrolidinophenone synthetic cathinones and their application to the identification of emerging synthetic cathinone derivatives J. Tyler Davidson a , Zachary J. Sasiene b , Younis Abiedalla c , J. DeRuiter c , C. Randall Clark c , Glen P. Jackson a, b, * a Department of Forensic and Investigative Science, West Virginia University, Morgantown, WV, 26506-6121, USA b C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, WV, 26506-6121, USA c Department of Drug Discovery and Development, Harrison School of Pharmacy, Auburn University, Auburn, AL, 36849, USA article info Article history: Received 29 January 2020 Received in revised form 10 April 2020 Accepted 12 April 2020 Available online 20 April 2020 abstract The expanding use of emerging synthetic drugs is creating a growing problem for both seized drug analysts and toxicologists because the clandestine suppliers continually tweak the chemical structures to keep one step ahead of the law. Synthetic cathinones, commonly referred to as bath salts, are a specific class of emerging synthetic drugs. These substances are derivatives of cathinone, which is the psycho- active component of the Catha edulis plant, commonly referred to as khat. Of the synthetic cathinone class of compounds, the a-pyrrolidinophenone synthetic cathinone derivatives stand out as one of the most abused designer drugs. The fragmentation behavior of a series of a-pyrrolidinophenone synthetic cathinones was studied with three different ionization and fragmentation techniques to enhance the current understanding of a- pyrrolidinophenone synthetic cathinones in mass spectrometers. Gas chromatography-electron ioniza- tion-mass spectrometry (GC-EI-MS) fragmentation is commonly used by seized drug analysts, whereas liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS) is more commonly used in toxicological analyses. Direct analysis in real time mass spectrometry (DART-MS) is becoming more popular as a screening technique, especially in national laboratories. Each ionization and activation method encourage particular pathways of fragmentation, and whereas some pathways are conserved across all platforms, other pathways are unique to a particular instrument. This study com- bines isotope-labeling, multi-stage mass spectrometry (MS n ) and accurate mass measurements with high-resolution mass spectrometry (HRMS) to enhance the current understanding about a-pyrrolidi- nophenone synthetic cathinones. This manuscript provides characteristic protonated tandem mass spectrometry fragmentation pathways and the mechanistic origins of the EI-MS fragmentation observed for this class of synthetic cathinones and provides examples of how this knowledge can be applied to the identification of novel synthetic cathinones. © 2020 Elsevier B.V. All rights reserved. 1. Introduction Synthetic cathinones are phenylalkylamine derivatives designed to mimic the effects of the natural chemical cathinone, the psychoactive component of the Catha edulis plant, commonly referred to as khat [1]. Because of their stimulant-like pharmacological effects, cathinones belong to a larger class of drugs known as novel psychoactive substances (NPS). Synthetic cath- inones are often marketed as “not for human consumption” or “bath salts” to avoid legislative restrictions that have been imposed to decrease the sale and distribution of these compounds [2,3]. Unfortunately, these labels also deceive users into believing the substances are safe, which has resulted in numerous intoxication- related deaths [4]. Reported symptoms of synthetic cathinone abuse include euphoria, hallucinations, psychosis, paranoia, agita- tion, violent behavior, tachycardia, acidosis, seizures and even * Corresponding author. Department of Forensic and Investigative Science, West Virginia University, Morgantown, WV, 26506-6121, USA. E-mail address: glen.jackson@mail.wvu.edu (G.P. Jackson). Contents lists available at ScienceDirect International Journal of Mass Spectrometry journal homepage: www.elsevier.com/locate/ijms https://doi.org/10.1016/j.ijms.2020.116343 1387-3806/© 2020 Elsevier B.V. All rights reserved. International Journal of Mass Spectrometry 453 (2020) 116343