Systems and methods described herein utilize a multipole ion guide that can receive ions from an ion source for transmission to downstream mass analyzers, while preventing unwanted/interfering/contaminating ions from being transmitted into the high-vacuum chambers of mass spectrometer systems. In various aspects, RF and/or DC signals can be provided to auxiliary electrodes interposed within a quadrupole rod set so as to control or manipulate the transmission of ions from the multipole ion guide.