A micro Planar high-Field Asymmetric waveform Ion Mobility Spectrometer (P-FAIMS) operating at ambient pressure and temperature has been simulated using COMSOL Multiphysics software. P-FAIMS is based on ion gas-phase separation due to the dependence of ion mobility with electric field. Ions are selected by a DC voltage characteristic of each ion kind. Physics of ion behaviour in high electric fields conditions is well known but not the chemistry behind ion reactions and kinetics. The aim of this work is the modelling of different kind of ions in a P-FAIMS having account of the main factors involved in their movement in the drift tube. Simulations of vapour phase ions of three compounds have been studied for different values of drift electric field amplitude to gas number density (E/N) ratio: protonated water clusters H +(H 2O) n and O 2- ions obtained in air, and a chemical warfare agent simulant DMMPH + that emulates gas sarin. Ions were selected due to simulation needs of experimental data of the main quantities involved in the definition of ions mobilities. Results show that simulations of ions behaviour in a P-FAIMS are possible with COMSOL Multiphysics software and that the time and intensity at which ions are detected are in good agreement with experimental data from literature. © 2010 Springer Science+Business Media, LLC.
- FEM gas simulation
- Ion mobility spectrometer