Simulation study of three new quadrupole ion funnels to improve low-mass
ion transmission
Abstract
Rationale: By applying RF (radio frequency) and DC (direct
current) voltages to corresponding ring electrodes, ion funnel (IF) can
efficiently focus and transmit ions. However, IF has an inherent mass
discrimination problem that will greatly limit ion focusing and
transmission. In order to improve the transmission efficiency (TE) of
the IF and remove this limitation, this paper explores the new
quadrupole ion funnel (QIF). Methods: Computer simulations of
the potential field distributions of QIF and conventional IF were
performed to assess their focusing characteristics. To compare the TE,
using the ion optics simulation programmes SIMION and AXSIM, a series of
simulations were carried out. Toroidal, cylindrical and hyperbolic
configurations are used to improve ion TE. And compare transmission and
focus performance with conventional IF. Results: By simulating
the trajectories of low m/z ions in the IF with SIMION and AXISM
software, in this paper, the optimum electrical parameters for three new
QIFs are obtained, and compared them with the conventional IF, which can
improve the TE of m/z < 100 by about 16%, 20% and 13%,
respectively. Conclusions: The results indicate that the study
of these three new configuration IF has great research significance for
improving the sensitivity of low m/z ions in mass spectrometer
instruments.