Comparison of high-field ion mobility obtained from drift tubes and a FAIMS apparatus

High-field asymmetric waveform ion mobility spectrometry (FAIMS) separates ions by application of a high-voltage asymmetric waveform to closely spaced electrodes such that ions experience (transient) electric fields that are sufficiently high that the mobility deviates from its low field limit. We d escribe the use of FAIMS to determine the mobility of the chloride ion, m/z -35, at similar to 760 Torr and similar to 300 K in fields up to similar t o 65 Td. The high-field mobility of chloride was determined from FAIMS data using linear and nonlinear least squares techniques, and was found to agre e well with published values of mobility determined by drift tube systems u p to 50 Td. (C) 2000 Elsevier Science B.V.