Figure 4.
Changes in mobilities of selected ions with modifiers in the buffer gas. (a) and (c) The mobilities of tetraalkylammonium and arginine ions did not change, and for DTBP and atenolol ions changed minimally with modifiers in the buffer gas due to steric hindrance, which impeded the attachment of modifier molecules to the positive charge of these ions. Analytes ions with lower steric hindrance such as 2,4-lutidine, desipramine, ethanolamine, serine, and valinol showed larger changes in mobility. (b) Changes in mobilities of ethyl lactate cluster ions with increasing concentrations of ethyl lactate. The mobilities of both cluster ions coincided within families: protonated, hydrated, and sodiated clusters had the same mobility.