This invention relates to graphical user-interactive displays for use in MS-based analysis of protein impurities, as well as methods and software for generating and using such. One aspect provides a user-interactive display comprising an extracted mass chromatogram (XIC), an MS1 spectrum and an MS2 spectrum, all simultaneously representing a user-selected peptide. Another aspect provides a user interactive display simultaneously presenting paired spectra (XIC, MS1 and/or MS2) for a variant peptide and its corresponding wildtype counterpart.