A method of processing multiple precursor ions in a tandem mass spectrometer includes generating a plurality of precursor ions with an ion source. At least some of the plurality of precursor ions is trapped in an ion trap. At least two precursor ions of interest are isolated from the plurality of precursor ions with a filtered noise field. Precursor ions of interest are sequentially ejected toward a collision cell. The sequentially ejected precursor ions of interest are fragmented in a collision cell. The mass-to-charge ratio spectra of the fragmented ions are then determined with a mass spectrometer.