Simulation of Ion Motion in FAIMS through Combined Use of SIMION and Modified SDS

Journal Article · Sun Nov 01 04:00:00 EST 2009 · Analytical Chemistry, 81(21):8749-8757

DOI:https://doi.org/10.1021/ac900880v· OSTI ID:974483

Prasad, Satendra; Tang, Keqi; Manura, David; Papanastasiou, Dimitris; Smith, Richard D

Over the years, the use of Field Asymmetric Ion Mobility Spectrometry (FAIMS) has grown with applications spanning from explosives detection to separation of complex biological mixtures. Although, the principles of ion separation in FAIMS is understood and comprehensively characterized, little effort has been made in developing commercially available computational tools that can simulate ion motion in FAIMS. Such a tool could be of great value for refining theory, optimizing the performance of the instrument for specific applications, and in modeling the fringe-fields caused by rf decay at the entrance and exit of FAIMS which can significantly affect ion transmission. An algorithm using SIMIONTM as its core structure was developed in this study to realistically compute ion trajectory at different ratios of electric field to buffer gas number density (E/N). The E/N can vary from a few Td to ~80 Td in FAIMS as created by an asymmetric square waveform. The Statistical Diffusion Simulation (SDS) model was further incorporated in the algorithm to simulate the ion diffusion in the FAIMS gap. The algorithm was validated using a FAIMS analyzer model similar to the Sionex Corporation model SVAC in terms of its dimensions and geometry. Hydroxyproline and Leucine ions with similar reduced mobility Ko (2.17 and 2.18 cm2.V-1.s-1, respectively) were used as model ions to test the new algorithm and demonstrate the effects of gas flow and waveform (voltage pulse amplitude and frequency) on peak shape and ion current transmission. Simulation results from three ion types: O2-(H2O)3, (A type), (C3H6O)2H+ (B type), and (C12H24O)2H+ (C type) were then compared with the experimental data (available in the literature). The SIMION-SDS-Field Dependent Mobility Calculation (FDMC) algorithm provided good agreement with experimental measurements of the ion peak position in FAIMS compensation voltage (CV) spectrum, peak width, and the ion transmission over a broad range of E/N.

• Research Organization: Pacific Northwest National Laboratory (PNNL), Richland, WA (US)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 974483
• Report Number(s): PNNL-SA-65516; 400412000
• Journal Information: Analytical Chemistry, 81(21):8749-8757, Journal Name: Analytical Chemistry, 81(21):8749-8757 Journal Issue: 21 Vol. 81
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
ALGORITHMS
AMPLITUDES
BUFFERS
DECAY
DETECTION
DIFFUSION
DIMENSIONS
ELECTRIC FIELDS
EXPLOSIVES
FAIMS
SIMION
GAS FLOW
GEOMETRY
HYDROXYPROLINE
ION MOBILITY
LEUCINE
MIXTURES
REFINING
SIMULATION
SPECTROSCOPY
WAVE FORMS