EIEIO: Electron Impact Excitation of Ions from Organics (or Electron Induced Dissociation) for Near Complete Structural Characterization in Lipidomics

摘要

We describe a novel mass spectrometry-based workflow for enhanced structural lipidomics that can yield a "nearly" complete information for a given glycerophospholipid (GPL) species in a single experiment, except Z/E orientations at carbon-carbon double bonds in acyl groups. This includes the lipid's Brutto composition from the accurate mass measured for the intact lipid ion and the characteristic head group fragment, the regioisomer composition from fragment ions unique to the sn-1 and sn-2 positions, and the positions of carbon-carbon double bonds in the acyl chains. Here, positively charged GPL ions are fragmented using electron impact excitation of ions from organics (EIEIO) - a technique where the singly charged lipid ions are irradiated by an electron beam, producing diagnostic product ions.