The invention comprises a method of analyzing the results obtained from the mass analysis of an ensemble or population of multiply charged ions comprising large polyatomic molecules to each of which is attached a plurality of charges. These molecules can be charged either by the attachment of charged mass or by the loss of charged mass. The charged mass is referred to as the "adduct" ion mass. The measured mass spectrum for such a population of ions generally comprises a sequence of peaks for each distinct polyatomic molecular species, the ions of each peak differing from those of adjacent peaks in the sequence by only a single charge. The method of analysis taught by the invention produces a deconvoluted spectrum in which there is only one peak for each distinct molecular species, the magnitude of that single peak containing contributions from each of the multiplicity of peaks for that species in the measured spectrum. A unique feature of the method taught by the invention is that the deconvoluted spectrum becomes a three dimensional surface in which the three coordinates of the single peak for a particular species represent respectively the molecular weight Mr of the parent polyatomic molecular species, the effective mass ma of the adduct ion charges, and the relative abundance of the ions of the polyatomic molecular species in the population of ions that gave rise to the measured spectrum. Consequently, there is no need to assume a priori a particular value for the mass of the adduct ion.