Negative ion fab mass spectroscopy of some Ribose Alkylated 5′-ump derivatives

Characteristic fragment ions obtained in Fast atom bombardment (FAB) mass spectroscopy of ribose alkylated Uridine 5′-monophosphate (5′-UMP) derivatives in negative ion mode are described. All the compounds examined exhibited either [M]− or quasimolecular ion [M − H]− the fragmentations can be used to characterize these nucleotides.