The novel fragmentation technique, electron activated dissociation (EAD) of the ZenoTOF 7600 system (SCIEX), was employed for peptide mapping of a multispecific monoclonal antibody (mAb) as well as IgG1 and IgG4 mAb samples. A specific focus was put on assessing challenging PTMs, such as glycosylations, amino acid isomers and the localization of a sulfation on a singly charged peptide.