title: Mass spectrometric investigation of N-sulfonylated purine nucleic bases and nucleosides.
abstract: 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 H(3)O(+), self-chemical ionization, M(+.)/M, and chemical ionization, H(3)O(+)/M, are detected. Investigation of specific EI expulsion of SO(2), SO(2)H and/or SO(2)H(2) from M(+.) and/or [M+H](+) shows that oxygen protonation in bond;SO(2)bond; proceeds faster than nitrogen protonation. Expulsion of SO(2) from molecular ions is not observed in MALDI mass spectra of nucleosides.
authors.affiliation: Ruder Bosković Institute, Zagreb, Croatia. dunja@joker.irb.hr
authors.forename: Dunja
authors.initials: D
authors.lastname: Srzić
authors.forename: Marko
authors.initials: M
authors.lastname: Rozman
authors.forename: Irena
authors.initials: I
authors.lastname: Krizmanić
authors.forename: Biserka
authors.initials: B
authors.lastname: Zinić
mesh_terms: D005583:Fourier Analysis; D009696:Nucleic Acids / Q000032:analysis* / Q000737:chemistry; D011684:Purine Nucleosides / Q000032:analysis* / Q000737:chemistry; D011687:Purines / Q000032:analysis* / Q000737:chemistry; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013451:Sulfonic Acids / Q000737:chemistry
chemical_list: D009696:Nucleic Acids; D011684:Purine Nucleosides; D011687:Purines; D013451:Sulfonic Acids