PNNL

Abstract

An experimental approach for increasing efficiency of Electron Capture Dissociation (ECD) with Fourier transform ion cyclotron resonance mass spectrometry (FTICR MS) is presented. This approach is based on manipulation of the spatial distribution of ion cloud inside an FTICR trap during electron irradiation, which is realized using both on-resonance pre-excitation of the ions and sustained off-resonance irradiation (SORI). Fragmentation efficiency achieved is compared with theoretical prediction. The method may be useful in biological applications of FTICR where ECD technique is most applicable, such as identification of posttranslational modifications in proteins and de novo sequencing.