High-resolution mass spectrometry with a multiple pass quadrupole mass analyzer

Abstract

The peak shape narrows and the resolution improves if the ions are simply reflected back and forth through a conventional quadrupole mass analyzer. CO+ and N2+ at m/z = 28 are separated to 50% valley with haft of the original signal remaining. These two ions can be resolved to baseline (m/Δm) - 5000 with 1% of the original signal remaining.