| 摘要 |
A mass spectrometer and method of mass spectrometry in which polyatomic and doubly charged ion interferences are attenuated by establishing an electron population through which a beam of particles containing elemental sample ion s and the interfering ions is passed such that the interfering ions preferentially undergo ion-electron recombination and thus dissociation to remove a significant number of the interfering ions. Means (30 or 32) for providing a population of electrons (34 or 36) in an ICP-MS (22) may compris e a magnetic field means such as an electric coil, or an electron generating device. The population of electrons has an electron number density (>1011 cm-3 to 1014cm-3), a free electron energy (>0.01eV to <5eV) in a region at a low pressure (<10 Torr), such that for a predetermined path length (1-4 cm) o f the ions through the electron population, the interfering ions will preferential ly be attenuated by the dissociative recombination process. The ion beam (40) then passes to a mass analyser (42) and ions which have been separated according to their mass-to-charge ratio are detected by ion detector (44).</ SDOAB>
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