A multipole rod set of an ion guide is adapted to receive a radial RF trapping voltage and a radial dipole direct current DC voltage. A lens electrode of the ion guide is positioned at one end of the multipole rod set to extract ions from the multipole rod set and adapted to receive an axial trapping AC voltage and a DC voltage. A radial dipole DC voltage is applied to the multipole rod set and an axial trapping AC voltage is simultaneously applied to a lens electrode in order to extract a bandpass mass range of ions trapped in the multipole rod set. Alternatively, a radial RF trapping voltage amplitude is applied to the multipole rod set and an axial trapping AC voltage is simultaneously applied to the lens electrode in order to extract a bandpass mass range of ions trapped in the multipole rod set.