Ionic fragmentation of methyl methacrylate induced by synchrotron radiation and multiphoton ionization

Ionic fragmentation of methylmethacrylate has been observed using synchrotr on radiation and laser excitation. A recently developed time-of-flight mass spectrometer was used for the ionic identification. In the case of synchro tron radiation, both low energy (12.1 eV) and high energy (287.9 eV) photon s were used. Although a definite increase in fragmentation was observed whi le moving from 12.1 to 287.9 eV, the fragmentation pattern remained basical ly the same in both cases. The parent peak stays clearly visible and intens e fragments, associated with m/q = 15, 39, 41 and 69 dominate both synchrot ron radiation-induced spectra. Multiphoton ionization causes much extensive fragmentation, the parent ion could not be observed, and C+ ion becomes th e most intense peak in the spectrum. Ions at m/q = 15, 39, 41 and 69 are ob served using laser and synchrotron radiation, which demonstrates their high stability. Doubly or multiply-charged ions have not been observed.