engleski

Mass spectrometric investigation of N-sulfonylated purine nucleic bases and nucleosides

The gas/phase behaviour of N-sulfonylated purine nucleic bases and nucleosides towards electron impact (EI) and matrix-assisted laser desorption/ionization (MALDI) occurring in a ion trap of a Fourier transform ion cyclotron resonance mass spectrometer is investigated. The influence of the storage time on the protonated molecule ([M+H](+)) abundance under EI conditions confirms that the formation of these ions proceeds through ion/molecule reactions. Using stored-waveform inverse Fourier transform (SWIFT) selective isolation of M+ or H3O+, self-chemical ionization, M+/M, and chemical ionization, H3O+/M, are detected. Investigation of specific EI expulsion of SO2, SO2H and/or SO2H2 from M+ and/or [M+H](+) shows that oxygen protonation in -SO2- proceeds faster than nitrogen protonation. Expulsion of SO2 from molecular ions is not observed in MALDI mass spectra of nucleosides.

mass spectrometry ; sulfonylated purine nucleic bases and nucleosides

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