Fig. 1: Electron-activated dissociation (EAD)-based tandem mass spectrum facilitates efficient lipid structure elucidation.
From: MS-DIAL 5 multimodal mass spectrometry data mining unveils lipidome complexities
a Spectrum entropy value distributions for 716 small molecules, with the x- and y-axes representing spectrum entropy and fragmentation conditions, respectively. b EAD-MS/MS spectra of 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) at kinetic energies (KE) of 10 and 14 eV, highlighting only the hydrogen (H) loss (blue), radical (black), and H-gain (red) fragment ions related to acyl chain properties. The proposed mechanism explaining the increased abundance of H-loss and radical fragments is also depicted. c EAD-MS/MS spectrum of 1,2-dioleoyl-sn-glycero-3-phosphatidylethanolamine (DOPE) at a 14 eV KE. d EAD-MS/MS spectra of 1,2-diarachidonoyl-sn-glycero-3-phosphocholine (DAPC) at KEs of 10, 14, and 18 eV. The mechanism behind the observed increase in H-gain fragment abundance at the delta-6 and 9 carbon positions is also illustrated. Numbers atop each fragment ion denote the carbon count remaining in a single acyl chain. Source data are provided as a Source Data file.
