Abstract: A method of separating ions is disclosed. The method includes a step of providing a FAIMS analyzer region for separating ions, the FAIMS analyzer region including at least one region of segmentation. The segmentation permits ion trapping, and a combination trapping and gating that permits high efficiency of ions collection from continuous ion sources. The ions are separated in segmented FAIMS, according to their high-field mobility properties, and by using the method described herein according to their low-field mobility. The ions are separated by low field mobility using stationary potential gradients formed by voltages applied to the segments, and by traveling potential gradients of various shapes. The ions are separated along the longitudinal direction in cylindrical FAIMS, and may be detected in a time-of-arrival fashion as the ions leave the ion outlet of FAIMS or optionally the ions other than selected are caused to collide with the electrodes and only the selected ions transmitted.

Abstract: An apparatus for controllably varying specificity of a FAIMS-based ion separation includes a FAIMS analyzer region defined between a first electrode surface and a second other electrode surface. The FAIMS analyzer region is in communication with an ionization source for providing a flow of ions including a known ion, and with an ion outlet for extracting ions including the known ion from the FAIMS analyzer region. The first and second electrode surfaces are for having an asymmetric waveform voltage applied thereacross for defining an average ion flow path for the known ion traversing therebetween. An actuator is provided for controllably moving the first electrode surface relative to the second electrode surface for controllably varying the length of the average ion flow path.