article 70 priority journal 37 unclassified drug 35 chemistry 34 Mass spectrometry 31 Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization 27 mass spectrometry 24 matrix assisted laser desorption ionization time of flight mass spectrometry 23 chemical structure 22 controlled study 20 photochemistry 20 nonhuman 18 electrospray mass spectrometry 17 Spectrometry, Mass, Electrospray Ionization 16 carbohydrate analysis 13 harman 13 Carbohydrates 12 chemical reaction 12 gentisic acid 12 proton nuclear magnetic resonance 12 ultraviolet radiation 12 Article 11 Desorption 11 Electrospray ionization 11 Harmine 11 Ionization 11 Molecular Structure 11 Ultraviolet Rays 11 Water 11 harmine 11