Mass Analysis with Stability Islands with a Conventional Linear Quadrupole and Quadrupoles with 4percent, 8percent and 12percent Added Hexapole Fields

摘要

Experiments show that mass analysis using islands of stability dramatically improves peak shape, resolution, and, in some cases, transmission, for quadrupoles with added hexapole fields despite the large field distortions. For a damaged conventional quadrupole with poor performance operated without stability islands, the transmission at a resolution of 1000 is 18 times lower compared to the flat portion of the TR curve at low resolution. Mass analysis with the same conventional quadrupole operated with islands of stability yields a TR curve with no losses of transmission for resolutions up to about 1200.