Enhanced Ion Utilization Efficiency Using an Electrodynamic Ion Funnel Trap as an Injection Mechanism for Ion Mobility Spectrometry

Abstract

Conventional ion mobility spectrometers that sample ion packets from continuous sources have traditionally been constrained by an inherently low duty cycle. As such, ion utilization efficiencies have been limited to <1% in order to maintain instrumental resolving power. Using a modified electrodynamic ion funnel, we demonstrated the ability to accumulate, store, and eject ions in conjunction with ion mobility spectrometry (IMS), which elevated the charge density of the ion packets ejected from the ion funnel trap (IFT) and provided a considerable increase in the overall ion utilization efficiency of the IMS instrument. A 7-fold increase in signal intensity was revealed by comparing continuous ion beam current with the amplitude of the pulsed ion current in IFT-IMS experiments using a Faraday plate. Additionally, we describe the IFT operating characteristics using a time-of-flight mass spectrometer attached to the IMS drift tube.

Dual Source Ion Mobility-Mass Spectrometer for Direct Comparison of Electrospray Ionization and MALDI Collision Cross Section Measurements

“…The last electrode is supplied with the DC-only stopping potential and is fitted with a grid (300 lpi nickel, Precision Eforming, Cortland, NY) to improve the trapping efficiency of the device. It should be noted here that a recent high pressure ion funnel trap developed by Smith and colleagues for ion trapping and gating into an IM-MS utilizes multiple grids in its design to mitigate undesirable field penetration of the stop potential into the funnel region 34. A multiple grid design applied to the keyhole ion funnel described here is also expected to improve the overall performance in terms of charge capacity and pulse response times.…”

Fundamentals of Trapped Ion Mobility Spectrometry Part II: Fluid Dynamics

“…In the present work, the entrance and exit funnel regions are pumped using a two-stage rotary vane vacuum pump (Alcatel, 2033 SD, 39 m 3 /h; Hingham, MA, USA). The magnitude of the gas velocity was determined at the position of ion elution (z = 23.3 mm, see Figure 4) using the signal at m/z 922 contained in ESI tuning mix (P 3 N 3 (OCH 3 CF 2 CF 2 ) 6 …”

“…In the past few decades, several advances coupling drift tube IMS and other time-dispersive methods (i.e., traveling wave IMS) to mass spectrometry (MS) [1][2][3][4][5][6][7][8][9][10] have extended its versatility for a range of chemical [11][12][13][14][15][16][17], physical [18][19][20][21][22][23], and biomolecular structural studies [24][25][26][27][28][29][30][31][32][33]. Still relatively new to the biomedical field, several groups have recently begun to incorporate LC-IMS-MS workflows in proteomics studies [34][35][36][37], and enhanced performance has been demonstrated [38].…”

Molecular mass spectrometry imaging in biomedical and life science research

“…Commercial DESI stage can be modified and used also for other compatible ambient DI techniques, but their principles and applications are beyond the scope of this article. Efficiency of the ion transport through the atmospheric pressure inlet, a bottleneck in both DESI and conventional ESI, is currently debated in the literature (Clowers et al 2008;Kelly et al 2008;Page et al 2008;Volný and Turecek 2006).…”