Mass-to-charge (m/z) ratio calculations. This figure shows how to perform m/z calculations starting from an analyte with a given m/z value for a given ionization agent (a proton, in our example). It is possible to ask for m/z ratios to be computed for any z value interval. Further, if the ionization has changed (by switching from protonation to cationization, for example), it is possible to stipulate the new ionization agent and its mass is taken into account for the calculation of the m/z values in the asked z range. The results are shown in the bottom part of the window.