When performing structural investigation of macromolecular systems using tandem mass spectrometry, an important matter is the choice of the cation and how that does affect the tandem mass spectra. Moreover, when studying mechanistic aspects, the role of the adduct ions in the mechanism of the fragmentation processes is often discussed: Is the process charge-induced (more accurately described as charge-catalyzed) or charge-remote (more accurately described as charge-independent). In a previous study[1], we shed light on the catalytic effect of lithium in the case of cationized poly(ethylene glycols) (PEGs). The activation energy of the main fragmentation process for the trimer was shown, by means of Density Functional Theory calculations, to decrease by as much as 0.3 eV in the presence of lithium. To further sketch our picture of the role of cation adducts on the fragmentation of even electron ions, we present in this communication the results obtained on the fragmentation of poly (n-butyl acrylate), PBA, with different alkali ions and various degrees of polymerization. Thus, we present a method to clarify the role of the charge on the fragmentation processes.