Patent ID: 8278622
Filing Date: 2012-10-02
Classification: G01N,H01J

Abstract:
1. A method to establish the presence of one or several target ions within a mixture of ions, including the following steps: a) placing in series at least two narrow band ion filters, each allowing passage only of ions having narrowly defined values of a characteristic filtering parameter, where at least one of said ion filters is a differential mobility analyzer, where the filtering parameters associated to at least one of said differential mobility analyzers are set such as to pass one of said target ions, b) setting all said characteristic filtering parameters such that said at least two ion filters will pass one among said target ions, c) placing a detector following the last of said ion filters to measure an output signal associated to ions passing through all said filters, d) passing said mixture of ions through said at least two filters and read said output signal of said detector, e) modifying said target ions after passage through a first of said ion filters, said modifying being conducted by attachment of vapor molecules or by fragmentation or by chemical reaction, f) providing a signal based on said output signal of said detector.