Mass spectrometric identification of the N-monosubstituted N-hydroxylamino functionality in protonated analytes via ion/molecule reactions in tandem mass spectrometry

Rapid Commun Mass Spectrom. 2015 Apr 30;29(8):730-4. doi: 10.1002/rcm.7154.

Abstract

Rationale: N-Monosubstituted hydroxylamines correspond to an important class of metabolites for many bioactive molecules. In this study, a tandem mass spectrometric method based on ion/molecule reactions was developed for the identification of compounds with the N-monosubstituted hydroxylamino functionality.

Methods: The diagnostic ion/molecule reaction occurs between protonated analytes with 2-methoxypropene (MOP) inside a linear quadrupole ion trap mass spectrometer.

Results: Most protonated compounds with N-monosubstituted and disubstituted hydroxylamino and oxime functional groups react with MOP via proton transfer and formation of a stable adduct in a linear quadrupole ion trap mass spectrometer. However, only protonated compounds with N-monosubstituted hydroxylamino groups form the characteristic MOP adduct-MeOH product. Possible mechanisms of this reaction are discussed.

Conclusions: A method based on functional group-selective ion/molecule reactions in a linear quadrupole ion trap mass spectrometer has been demonstrated to allow the identification of protonated compounds with the N-monosubstituted hydroxylamino functionality. Only N-monosubstituted hydroxylamines react with MOP via formation of an adduct that has eliminated methanol.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Hydroxylamine / chemistry*
  • Indoles / chemistry
  • Methanol / chemistry
  • Methyl Ethers / chemistry
  • Oximes / chemistry
  • Protons*
  • Spectrometry, Mass, Electrospray Ionization / methods
  • Tandem Mass Spectrometry* / methods
  • Vinyl Compounds / chemistry

Substances

  • Indoles
  • Methyl Ethers
  • Oximes
  • Protons
  • Vinyl Compounds
  • 2-methoxypropene
  • Hydroxylamine
  • Methanol