Patent ID: 8415617
Filing Date: 2013-04-09
Classification: H01J

Abstract:
1. A multipole structure selectively operable in a mass filter mode or an analytical ion trap mode, comprising: four elongated rod electrodes arranged around a centerline of the multipole structure and extending between an inlet end and an outlet end, at least two of the four electrodes each being adapted with an aperture permitting the ejection of ions therethrough; at least one detector located proximate to a corresponding one of the apertures; and a controller, coupled to an RF voltage source, a DC voltage source and an oscillatory resonant excitation voltage source, configured to switch the operation of the multipole structure between the mass filter mode, wherein the RF voltage source applies a filtering DC component to allow selective transmission of ions within a predetermined range of mass-to-charge ratios from the inlet end to the outlet end, and an analytical ion trap mode, wherein the DC voltage source applies DC offsets to axial trapping electrodes or to at least some of the rod electrodes to axially confine ions within the interior of the multipole structure and the resonant excitation source applies a resonant excitation voltage to eject ions through at least one aperture to the corresponding detector in order of their mass-to-charge ratios.