Self‐chemical ionization Fourier transform ion cyclotron resonance mass spectrometry: Identification and characterization of modified and unmodified bases and nucleosides

Self‐chemical ionization Fourier transform ion cyclotron resonance (FT‐ICR) mass spectra are reported for bases, nucleosides, and alkylated and exocyclic adducts of bases and nucleosides. The technique always produces a protonated molecular ion and in the majority of cases this is a single, intense peak. Analysis of a base mixture and a nucleoside mixture demonstrates the technique as an excellent method to identify the constituent compounds qualitatively. The high resolution capabilities and tandem mass spectrometric techniques (ms n ) in FT‐ICR are discussed with respect to developing the technique as a future method to identify and characterize nucleic acid constituents, specifically adducts.