“…5,12,13 Liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) is always a t-for-purpose analytical tool in response to a peptide mapping strategy. [14][15][16] LC is responsible for chromatographing the proteolytic peptide pool into pure fractions and subsequently transmitting to MS/MS for the acquisition of both MS 1 and MS 2 spectra for each peptide. Aerwards, those quasi-molecular ions, e.g., [M + 2H] 2+ and [M + 3H] 3+ , together with the featured fragment ion species, such as a + , b + , c + , x + , y + , and z + , resulting from the dissociations around the amido bond, 17,18 facilitate the conguration of each peptide, usually through searching relevant databases.…”