Pneumatic ion beam focusing in high-field asymmetric waveform ion mobility spectrometry (FAIMS)

摘要

A FAIMS device for separating ions has a pair of electrodes for providing a compensation voltage and an asymmetric waveform that are separated and insulated where at least one porous spacer reside in the proximity of the analyzer region of the FAIMS cell. The porous spacers allow a focusing gas to flow into the analyzer region to provide pneumatic focusing of the ions traversing the analyzer region to improve the ion transmission.