Fast ATOM Bombardment Mass Spectra of Nucleosides. Comparison with Electron Impact and Chemical Ionization Mass Spectra

Abstract

Abstract The fast atom bombardment (FAB) mass spectra of the eight major nucleosides found in RNA and DNA, pseudouridine and 2′,3′-O-isopropylidene adenosine are described and compared to El, CI, and desorption chemical ionization (DCI) spectra reported in the literature or obtained in this laboratory. Bcty, cocltl nun FAB spectra are reported. The FAB spectra are simple and provide unambiguous molecular weight information along with structurally significant fragment ions. Mechanisms of ion formation are thought to closely parallel those suggested earlier to be operating in the CI mode. Advantages and disadvantages of FAB relative to the standard ionization modes are discussed.