The first part of this study involves the adaptation of a matrix-assisted laser desorption/ionisation (MALDI) ion source for a tandem double-focusingltime-offlight instrument (MAG-TOF). Ion trajectory modelling was carried out for defining the optimum ion optical configuration for a new extraction region and associated ion optics that were designed and constructed. Installation of the new ion source resulted in increased sensitivity and no loss of resolution. The second part of this study involves the analysis of fullerenes and fullerene derivatives by high-energy collision-induced dissociation (CID). The structure of fullerenes formed by coalescence under the conditions of laser desorption were shown to be that of a single fullerene closed-cage structure. The dissociation of exohedral fullerene hydride derivatives was investigated. The third part of this study investigates the high-energy collision-induced dissociation of polyglycol polymer ions generated by MALDI. Mechanisms have been proposed for the dissociation of poly(ethylene glycol) and poly(propylene glycol). High-energy CID has been shown to be particularly useful for the determination of polymer end-group structure.