Quantitative measurements of elemental and molecular species using high mass resolution mass spectrometry

Abstract

A method for generating a mass spectrum of sample ions using a multi-collector mass spectrometer is disclosed. The mass spectrometer includes a spatially dispersive mass analyser to direct the sample ions into a detector chamber. The method includes generating sample ions of a first ion species A, a second ion species B, and a third ion species C, wherein the ions of species A have a different nominal mass to the ions of species B and C, and further wherein the ions of species B have the same nominal mass as the ions of species C. The sample ions of the species A, B and C are directed to travel through the mass analyser and towards detectors in the detector chamber, the sample ions being deflected during their travel. The ions of species B and C are scanned across a master aperture defined in a master mask of a master detector, while the ions of species A pass through a lead aperture defined in a lead mask of a lead detector. A lead signal is generated representing the ion intensity received at the lead detector from the ions of species A, and generating a master signal representing the ion intensity received at the master detector whilst the ions of species B and C are scanned across the master aperture. During scanning, ions of the species A are detected by the lead detector while ions of the species B but not C, then both species B and species C, and then species C but not B are detected by the master detector.