Ion extraction method for ion trap mass spectrometry

摘要

A method is provided for processing ions in a multipole ion trap, comprising generating RF radial confinement fields within a first and second multipole rod set positioned in tandem, a ratio of q value exhibited by the second rod set relative to the first rod set being greater than one for any m/z, said RF axial confinement fields within the first and second rod sets interacting in an interaction region between the first and second rod sets so as to produce a fringing field; transmitting ions through said first rod set towards said second rod set; and increasing the radial oscillation amplitude of at least a portion of the ions within said first rod set such that at least a portion of said ions having an increased radial oscillation amplitude are repulsed by said fringing field.

主权项

1. A method for processing ions in a multipole ion trap, comprising:
introducing ions into a first multipole rod set positioned in tandem with a second multipole rod set, each rod set having a first end and a second end, the ions being introduced into the first and second rod sets through said first end of said first rod set; generating RF fields within the first and second rod sets so as to radially confine the ions, said RF fields within the first and second rod sets interacting in an interaction region between the second end of the first rod set and the first end of the second rod set to produce a fringing field; generating a barrier field at the second end of said second rod set so as to repel at least a portion of said ions away from the second end of the second rod set and toward the first rod set; and energizing said repelled ions within said second rod set so that at least a portion of said energized ions are repulsed by the fringing field back toward the second end of the second rod set.