Anion formation in gas-phase potassium-uridine collisions
In this study we report negative ion fragmentation patterns obtained from time-of-flight (TOF) mass spectrometry in potassium-uridine collisions at 30, 70 and 100 eV. The dominant fragments from uridine are also the most abundant from the individual units in potassium collisions with uracil, tetrahydrofuran (THF) and d-ribose. We observe no dehydrogenated parent anion formation. Special emphasis is given to the dissociation mechanisms lending support to the breaking of the N-glycosidic bond as an initial step in the fragmentation of the transient negative ion (TNI). Within their role as sugar unit surrogates, THF and d-ribose (DR) provide useful information for the study of uridine, and presumably other nucleosides from the point of view of DNA/RNA subunits integrity in the biological environment.