MASS SPECTROMETER

摘要

A mass spectrometer is disclosed comprising an ion mobility spectrometer (8) and an ion gate (9). A collision cell (10) is arranged downstream of the ion gate (9). The operation of the ion mobility spectrometer (8) and the io n gate (9) are synchronised so that only ions having a particular mass to ch arge ratio and a desired charge state are onwardly transmitted to the collis ion cell (10).