CONTROLLING GAS-PHASE ION INTERACTIONS

摘要

A mass spectrometer or ion mobility spectrometer is disclosed comprising: a first device for separating ions or molecules according to a physicochemical property (3); an ion mobility separation device (4) for receiving and separating at least some of said ions or ions derived from said molecules according to their ion mobility; a gas supply (6-10) connected to said ion mobility separation device (4) for supplying gas into said ion mobility separation device (4); and a control system (11) configured to adjust said gas supply (6-10) so as to change the composition of gas within the ion mobility separation device (4) as a function of time.