Comparison of the planar and coaxial field asymmetrical waveform ion mobility spectrometer (FAIMS)

A method and apparatus for ion separation in gases using the dependence of ion mobility coefficient on electric field strength are briefly described (including effect of ion focusing in apparatus with coaxial design of separation chamber). A mathematical model described ions transition for both coaxial and planar separation chamber design is proposed. The model has been verified by our own and published experimental data. Using the proposed model comparative analysis of the planar and coaxial apparatus is conducted by comparison of ion diffusion losses (sensitivity) and response time (speed of operation). Qualitative and quantitative advantages and disadvantages of both variants are considered. (C) 2002 Elsevier Science B.V. All rights reserved.