Patent ID: 8008619

Claim:
A mass spectrometer interface, comprising: a) a plurality of ion sources each producing a beam of analyte ions; b) an inlet structure for passing at least one beam of ions from at least one of said plurality of ion sources into a sample entrance of a mass spectrometer; c) selection mechanism for selecting a pre-selected number of the ion beams for passage through the inlet structure into the sample entrance of the mass spectrometer while blocking any remaining ion beams, said selection mechanism including a plurality of steering gas sources with each of said plurality of steering gas sources being associated with a respective ion source so that gas emitted from a selected steering gas source intersects with the beam of analyte ions emitted by respective ion source associated therewith and directs said beam of analyte ions into said inlet structure, and including a pulse controller for independently pulsing each of said plurality of steering gas sources on and off, depending on which ion beam or ion beams are to be selected.