Multi-pole ion trap for mass spectrometry

摘要

An ion trap includes a containment region for containing ions, and a plurality of electrodes positioned on a regular polyhedral structure encompassing the containment region. An electrode is positioned on each vertex of the encompassing structure and at least one of the polygonal surfaces includes additional electrodes configured to form a plurality of quadrupoles on the surface. Alternating RF voltage is applied to the plurality of electrodes, so that directly neighboring electrodes are of equal amplitude and opposite polarity at any point in time. This configuration on the polyhedral structure forms a potential barrier for repelling the ions from each of the regular polygonal surfaces and containing them in the trap. Mass selective filters can be formed from the quadrupoles for parallel mass analysis in different m/z windows. Application of a small DC potential to a plate electrode outside the quadrupoles preferentially depletes single charged ions for enhanced signal-to-noise analysis.

主权项

1. An ion trap device, comprising:
a plurality of first electrodes having a first RF voltage, each of said first electrodes having an annular shape defining edges of a regular polygonal surface, the plurality of first electrodes being arranged together to form a regular polyhedral structure, the structure encompassing a containment region therein for containing ions, wherein the containment region corresponds substantially to a volume encompassed by the regular polyhedral structure; and a plurality of second electrodes having a second RF voltage, the second RF voltage being of equal amplitude and opposite polarity at a point in time as the first RF voltage whereby the first and second electrodes are maintained at opposite phases, each of said second electrodes being disposed at the center of a polygonal surface defined by a first electrode, such that the plurality of first and second electrodes form a potential barrier for repelling the ions from each of the plurality of regular polygonal surfaces forming the regular polyhedral structure.