DERIVING STRUCTURAL INFORMATION ON PERACETYLATED MONOSACCHARIDES BY APPLYING DIFFERENT IONIZATION METHODS

Mass spectra of peracetylated monosaccharides can be obtained by various ionization methods, including electron ionization, chemical ionization and fast atom bombardment. The structural information in the spectra of two relatively simple model compounds (acetyl 3,4-di-O-acetyl-D-digitoxose and acetyl 2,3,4-tri-O-acetyl-D-Xylose) was compared. Additional information was obtained from the perdeuteroacetylated analogues and from daughter and precursor ion scans of selected ions. The chemical ionization spectra and the fast atom bombardment spectra are simple and very similar. The electron ionization spectra show far more fragmentations and contain more structural information, but are more difficult to interpret unambiguously.