MULTIPOLE ION GUIDE INTERFACE FOR REDUCED BACKGROUND NOISE IN MASS SPECTROMETRY

摘要

PROBLEM TO BE SOLVED: To provide an apparatus in which a multipole ion guide is configured to efficiently transport ions through multiple vacuum stages, while preventing background particles produced both in an ion source and along an ion transport pathway from reaching a detector to thereby improve signal-to-noise in mass spectra.SOLUTION: The RF multipole ion guide extends in a multiple vacuum pumping stage vacuum system continuously through one or more vacuum partitions between an upstream region (farther from the mass analyzer detector) of higher gas pressure and a downstream region of lower gas pressure. The ion guide is configured with an axis curved with respect to the direction of an ion beam and to prevent any line of sight between an upstream ion source region, as well as any or all higher pressure regions in which collisions between ions and background gas molecules occur, and the mass analyzer detector.