Development of a Branched Radio-Frequency Ion Trap for Electron Based Dissociation and Related Applications

Abstract

Collision-induced dissociation (CID) is the most common tool for molecular analysis in mass spectrometry to date. However, there are difficulties associated with many applications because CID does not provide sufficient information to permit details of the molecular structures to be elucidated, including post-translational-modifications in proteomics, as well as isomer differentiation in metabolomics and lipidomics. To face these challenges, we are developing fast electron-based dissociation devices using a novel radio-frequency ion trap (i.e., a branched ion trap). These devices have the ability to perform electron capture dissociation (ECD) on multiply protonated peptide/proteins; in addition, the electron impact excitation of ions from organics (EIEIO) can be also performed on singly charged molecules using such a device. In this article, we review the development of this technology, in particular on how reaction speed for EIEIO analyses on singly charged ions can be improved. We also overview some unique, recently reported applications in both lipidomics and glycoproteomics.

Analytical Challenges and Recent Advances in Mass Spectrometry Based Lipidomics

“…However, because of the low reaction efficiency of the technique, which is compounded by the necessity for long irradiation times and low signal-to-noise ratios of many of the products due to the extensive nonselective nature of the fragmentation reactions, EID is best suited for application in direct introduction workflows. Campbell and Baba have also reported the near-complete structural characterization of lipids using EIEIO-MS/MS, via irradiation of mass selected singly charged lipid ions with 9–10 eV electrons within the electron-capture dissociation cell of a modified hybrid quadrupole time-of-flight mass spectrometer . Similar to EID, EIEIO also provides more structural information compared to CID, allowing identification of lipid class, acyl chain identity and regioisomer positions, and the locations of CC double bonds, as demonstrated for a series of GP lipid standards and multiple PC species within an egg yolk lipid extract.…”

Electron‐ion reaction‐based dissociation: A powerful ion activation method for the elucidation of natural product structures

“…Voinov et al also described an ECD‐enabled quadrupole time‐of‐flight (qTOF) mass spectrometer, which was modified with a branched radio frequency ion trap arrangement. This device also allowed for the application of other electron‐based dissociation methods, such as EID . In 2004, Syka et al developed ETD, which is a dissociation technique similar to ECD.…”

“…B, Electronic excitation dissociation (EED) of the [M+Li]+ ion of reduced, 2‐AB labeled, permethylated maltotetraose at m/z 1031.5721. Reprinted with permission from Ref . Copyright ©2013 American Chemistry Society…”

“…This device also allowed for the application of other electron-based dissociation methods, such as EID. 61,62 In 2004, Syka et al 23 ExD behavior of the different NP groups will be discussed in detail in the following sections.…”

“…B, Electronic excitation dissociation (EED) of the [M+Li]+ ion of reduced, 2-AB labeled, permethylated maltotetraose at m/z 1031.5721. Reprinted with permission from Ref 62. Copyright ©2013 American Chemistry Society requires a large amount of low-energy electrons (<0.2 eV); hence, it was initially used solely with Fourier transform ICR (FTICR) MS, which is the most expensive and sophisticated mass spectrometer 56.…”