Path to Resolving Power Beyond 250: A Comprehensive Trapped Ion Mobility Spectrometry Analytical Model

In trapped ion mobility spectrometry (TIMS), ions are radially confined in a quadrupolar field and axially trapped by an electric field gradient (EFG) that counteracts the drag force exerted from a flow of gas. After ions reach a mobility-dependent equilibrium position inside the trap, the magnitude of the EFG is decreased such that ions elute over a user defined timescale (~10 ms to 1 s). Recently, an analytical model for TIMS was derived and, in part, experimentally verified. A central, but not yet fully explored component of the model involves the fluid dynamics at work in the analyzer (i.e.: gas velocity, pressure gradient, flow profile, etc.). This poster characterizes the fluid properties using computational fluid dynamics (CFD) simulations and ion mobility experiments.