Chemically modified ion mobility separation apparatus and method

Abstract

An ion mobility spectrometry apparatus and method used to separate ions and select some of the ions using an AC gate; the selected ions are further separated along a drift axis of a drift tube, where the AC gate is controlled using a series of AC voltages and/or frequencies to select different ions for the drift tube.

What is claimed is: 
     
         1 . An ion mobility spectrometer apparatus, comprising:
 An ionization source that is in fluid communication with a drift tube;   An AC ion gate, in which at least one power supply applies at least one AC voltage to at least one grid element of the AC ion gate, where the AC ion gate is located between the ionization source and a drift region of the drift tube, and pulses a group of ions into the drift region where the group of ions are separated along a drift axis of the drift region; and   
     
     
         2 . The AC voltage is controlled with a series of AC voltages and/or frequencies to select different ions for the drift tube. An ion mobility spectrometer method, comprising:
 Forming ions in an ionization source that is in fluid communication with a drift tube;   Pulsing a group of ions into a drift region of the drift tube using an AC ion gate;   Separating the group of ions along a drift axis of the drift region; and   Controlling the AC ion gate using a series of AC voltages and/or frequencies to select different ions for the drift tube.