U.S. Department of Energy

Pacific Northwest National Laboratory

Experimental evaluation and optimization of structures for lossless ion manipulations for ion mobility spectrometry with time-of-flight mass spectrometry.

TitleExperimental evaluation and optimization of structures for lossless ion manipulations for ion mobility spectrometry with time-of-flight mass spectrometry.
Publication TypeJournal Article
Year of Publication2014
AuthorsWebb IK, Garimella SVB, Tolmachev AV, Chen T-C, Zhang X, Norheim RV, Prost SA, LaMarche B, Anderson GA, Ibrahim YM, Smith RD
JournalAnal Chem
KeywordsElectricity, Electrodes, Ions, Radio Waves, Spectrometry, Mass, Electrospray Ionization
Abstract

We report on the performance of structures for lossless ion manipulation (SLIM) as a means for transmitting ions and performing ion mobility separations (IMS). Ions were successfully transferred from an electrospray ionization (ESI) source to the TOF MS analyzer by means of a linear SLIM, demonstrating lossless ion transmission and an alternative arrangement including a 90° turn. First, the linear geometry was optimized for radial confinement by tuning RF on the central "rung" electrodes and potentials on the DC-only guard electrodes. Selecting an appropriate DC guard bias (2-6 V) and RF amplitude (≥160 V(p-p) at 750 kHz) resulted in the greatest ion intensities. Close to ideal IMS resolving power was maintained over a significant range of applied voltages. Second, the 90° turn was optimized for radial confinement by tuning RF on the rung electrodes and DC on the guard electrodes. However, both resolving power and ion transmission showed a dependence on these voltages, and the best conditions for both were >300 V(p-p) RF (685 kHz) and 7-11 V guard DC bias. Both geometries provide IMS resolving powers at the theoretical limit (R ~ 58), showing that degraded resolution from a "racetrack" effect from turning around a corner can be successfully avoided, and the capability also was maintained for essentially lossless ion transmission.

DOI10.1021/ac502055e
Alternate JournalAnal. Chem.
PubMed ID25152066
PubMed Central IDPMC4165449
Grant ListP41 GM103493 / GM / NIGMS NIH HHS / United States
P41 GM103493 / GM / NIGMS NIH HHS / United States
R21 GM103497 / GM / NIGMS NIH HHS / United States
R21 GM103497 / GM / NIGMS NIH HHS / United States
Area of Research: 
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