Surface-induced dissociation of benzene on a PFPE liquid insulator in a time-of-flight mass spectrometer

A perfluorinated polyether (PFPE) surface is used to enhance the fragment ion yield for surface-induced dissociation (SID) in a tandem time-of-flight mass spectrometer. Selection of the parent ion by separation of M(+.) from (M - H)(+) is obtained with unit resolution by pulsing the voltage on the collision surface. The benzene radical cation is used as a model compound to characterise the instrument. Fragment ions are collected with a mass resolution of 100. The distribution of recoil energies of the SID fragments leaving the collision surface is not sufficient to clarify the limited mass resolution. We estimate an average conversion efficiency of kinetic into internal energy of 30+/-7% between 20 and 40 eV collision energy by analysing the relative intensities of the SID fragments as a function of collision energy.