Method and apparatus for selective ion delivery using ion polarity independent control

摘要

The present invention relates to a method for selectively delivering ions to a mass analyzer operating in a vacuum region. The method involves providing a dielectric conduit having an axial bore originating in an inlet opening that communicates with an ion source and terminating in an exit opening disposed within the vacuum region. A gas stream comprising an ion having a polarity and traveling at a drift velocity is flowed through the bore from the inlet opening toward the exit opening. A motion component is altered in a manner that does not substantially depend on the polarity of the ion to effect a change in the drift velocity of the ion. The invention also provides an apparatus to carry out the method.