Fragmentations:

It is not feasible to describe every peak observed in a mass spectrum and just only the more intense ones or those of high mass should be analyzed. These will be because of comparatively stable daughter ions. Alternatively, a fragmentation might result in a stable radical. The radical being neutral is not observed, but another half of the fragmentation will result in a cation that is observed.

Several fragmentations provide a series of daughter ions which are indicative of a specific functional group. Other words, the molecular ion fragments to a daughter ion, which in turn fragments to other daughter ion and so on. The intensity of a peak may sometimes point to a favored fragmentation route. Though, care has to be taken because intense peaks can arise due to different fragmentation routes leading to similar ion, or be because of different fragmentation ions of similar m/e value.