Patent ID: 7247846
Filing Date: 2007-07-24
Classification: H01J

Abstract:
1. A tandem mass spectrometer comprising: an ion source; a first mass analyzer; a second mass analyzer; and an ion detector, wherein the ion source is configured to provide ions or fragments thereof to the first mass analyzer, the first mass analyzer is configured to provide ions or fragments thereof to the second mass analyzer, and the second mass analyzer is configured to provide ions or fragments thereof to the ion detector; and wherein the first mass analyzer comprises an electric sector time-of-flight (ES-TOF) mass analyzer, the ES-TOF mass analyzer comprising: an ion flight path means defining a flight path for ions and having an ion entrance and an ion exit, the ion flight path means comprising: at least one field free region, at least one electric sector having an entry and an outlet, and at least one trim electrode disposed at the entry or the outlet of at least one of the electric sectors, wherein the at least one trim electrode is configured to modify the potential experienced by an ion entering or exiting the electric sector.