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 such as chromatographic or electrophoretic retention time; a second device 4 for receiving at least some of said ions or ions derived from said molecules, said device preferably comprising an ion mobility separator of filter; a gas supply 6-10 for supplying gas to said ion mobility separation device 4; and a control system 11 configured to adjust said gas supply so as to change the composition of gas within the ion mobility separator 4 as a function of time. Dynamically changing the composition of a drift, buffer or carrier gas within the mobility separator during, for example, a single experimental run allows mobility separation conditions to be optimised for different analyte ions eluting from the first device. |