Fig. 3: Distinctive behaviour types of single ions within the Orbitrap analyser.
a, Single-particle mass spectrum with four individual AaLS-neg ions highlighted (colour coded). The 1 s transients were divided into 15 segments and separately analysed. The frequency and thus m/z of each colour-coded ion over these 15 segments was chased (bottom). b, Most single ions displayed no shifts and were stable in frequency and m/z (95% confidence interval of centroiding is shown as coloured area) over the whole transient (annotated by ‘no loss’). A smaller percentage of the ions displayed gradual frequency shifts, and thus m/z shifts, due to a gradual increase in desolvation (annotated by ‘small to large loss’). The loss of several neutral molecules (most likely primarily water and ammonium acetate molecules) leads to observed mass shifts of on average 157 Da and 692 Da, respectively. A few ions experienced a quantized jump in frequency and thus m/z (grey bar indicates broken x axis), to higher m/z, which is attributed to events whereby the ion loses a single charge.
