2-AEP, 2-aminoethylphosphonic acid; 2P1EA, 2-phenyl-1-ethanolamine; CIVP, cryogenic ion vibrational predissociation spectroscopy; CLIO, Centre Laser Infrarouge d'Orsay; DFT, density functional theory; FA, fluoroamphetamine; FEL, free electron laser; FELIX, Free Electron Laser for Infrared eXperiments; FMA, fluoromethamphetamine; FTICR, Fourier transform ion cyclotron resonance; GC­MS, gas chromatography-mass spectrometry; GSNO, S- nitro glutathione; GlcNAc, n-Acetylglucosamine; IR, infrared; IR2MS3, infrared-infrared double-resonance multi-stage mass spectrometry; IRMPD, infrared multiple photon dissociation (IRMPD); IRMPD-MS, infrared multiple photon dissociation spectroscopy mass spectrometry; IRPD, infrared predissociation spectroscopy; IVR, intramolecular vibrational redistribution; Infrared multiple photon dissociation spectroscopy; LC, liquid chromatography; LC-MS, liquid chromatography-mass spectrometry; LC-MS/MS, liquid chromatography-tandem mass spectrometry; MDA, methylenedioxyamphetamine; MDMA, methylenedioxymethamphetamine; MMC, methylmethcathinone; MS/MS, tandem mass spectrometry; MSn, multi-stage mass spectrometry; Mass spectrometry; Metabolites; NANT, N-acetyl-N-nitrosotryptophan; OPO/A, optical parametric oscillator/amplifier; PTM, post-translational modification; Pharmaceuticals; Post-translational modifications; SNOCys, S-nitrosocysteine; UV, ultraviolet; UV-IR, ultraviolet-infrared; Vibrational spectroscopy; cw, continuous wave; α-PVP, alpha-pyrrolidinovalerophenone