Mass spectrometer

摘要

A mass spectrometer is disclosed comprising a first ion trap or ion guide (2), a single ion mobility spectrometer or separator stage (3) and a second ion trap or ion guide (4) arranged downstream of the ion mobility spectrometer or separator (3). In a mode of operation ions from the second ion trap or ion guide (4) are passed from the second ion trap or ion guide (4) back upstream to the ion mobility spectrometer or separator (3).