Identification of novel fragmentation pathways and fragment ion structures in the tandem mass spectra of protonated synthetic cathinones

摘要: Abstract The expanding use of emerging synthetic drugs such as cathinones, or “bath salts”, is a growing public health concern and continual challenge for drug analysts. In the tandem mass spectra protonated α-pyrrolidinophenone tropylium ion at m/z 91 often among most abundant product ions, but its mechanistic origin currently unexplained. This project combined electrospray ionization multi-stage spectrometry (ESI-MSn), high-resolution (HRMS), isotopic labeling spectroscopy to enhance our understanding fragmentation pathways mechanisms variety cathinones. trends derived from these ESI-MS/MS studies are: 1) unlike N-alkylated radical cations are not observed even-electron precursors α-pyrrolidinophenones; 2) loss 71 Da pyrrolidine neutral form an alkylphenone cation always observed; 3) series alkenes lost intermediate with phthalane-like structures. phthalane intermediates then eliminate carbonyl carbon CO C2H2O 91. α-carbon original cathinone almost exclusively retained in ion. If substituted on aromatic ring, will be shifted by substitution. These findings explain characteristic ions cathinones help analysts better employ spectral observations future casework.