Apparatus and method for parallel flow ion mobility spectrometry combined with mass spectrometry
First Claim
1. A combination spectrometer that analyzes ions by parallel flow ion mobility and by mass comprising:
- a mechanism that entrains the sample ions in a carrier gas;
a mass spectrometer having a vacuum system with an extended ion funnel and a mass analyzer located inside the vacuum system;
a mechanism that introduces the sample ions and the carrier gas into an entrance end of the extended ion funnel, the vacuum system drawing the carrier gas and the sample ions through the extended ion funnel to an exit end of the extended ion funnel and towards the mass analyzer;
wherein the extended ion funnel is constructed with a plurality of segmented electrodes that are connected to an RF voltage source so that an ion focusing section is formed inside the extended ion funnel near the entrance end and an ion mobility analyzing section with an RF containment field is formed inside the extended ion funnel near the exit end and the sample ions are separated by ion mobility as they move through the extended ion funnel.
0 Assignments
0 Petitions
Accused Products
Abstract
Analyte ions entrained in a carrier gas are analyzed by parallel flow ion mobility spectrometry prior to analysis by a mass analyzer. An extended ion funnel is located in the vacuum system of the mass analyzer and has an ion focusing section and an ion mobility analyzing section. The carrier gas together with entrained ions is introduced into the ion focusing section where the ions are focused to the axis of the funnel by applied RF voltages. In the ion mobility section, the action of an RF quadrupolar field, the movement of the carrier gas and axial DC field, separates the ions on the basis of their mobilities. The mobility separated ions are released into the mass analyzer where the ions may be further separated on the basis of mass.
129 Citations
22 Claims
-
1. A combination spectrometer that analyzes ions by parallel flow ion mobility and by mass comprising:
-
a mechanism that entrains the sample ions in a carrier gas; a mass spectrometer having a vacuum system with an extended ion funnel and a mass analyzer located inside the vacuum system; a mechanism that introduces the sample ions and the carrier gas into an entrance end of the extended ion funnel, the vacuum system drawing the carrier gas and the sample ions through the extended ion funnel to an exit end of the extended ion funnel and towards the mass analyzer; wherein the extended ion funnel is constructed with a plurality of segmented electrodes that are connected to an RF voltage source so that an ion focusing section is formed inside the extended ion funnel near the entrance end and an ion mobility analyzing section with an RF containment field is formed inside the extended ion funnel near the exit end and the sample ions are separated by ion mobility as they move through the extended ion funnel. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21)
-
-
22. A method for analyzing sample ions by parallel flow ion mobility spectrometry in combination with a mass spectrometer having,
an ion source, a vacuum system having an extended ion funnel and a mass analyzer located therein, a deflection electrode located in the vacuum system that introduces the sample ions and the carrier gas into an entrance end of the extended ion funnel, the vacuum system drawing the carrier gas and the sample ions through the extended ion funnel to an exit end of the extended ion funnel and towards the mass analyzer, an extended ion funnel located in the vacuum system and having a plurality of segmented electrodes that are connected to voltage sources so that an ion focusing section is formed inside the extended ion funnel near the entrance end and an ion mobility analyzing section with an axis and an RF containment field is formed inside the extended ion funnel near the exit end and the sample ions are separated by ion mobility as they move through the extended ion funnel, and an ion detector, the method comprising: -
(a) forming a DC barrier in the ion mobility analyzing section; (b) applying an RF voltage to the ion mobility analyzing section for focusing ions towards the axis; (c) generating ions in the ion source; (d) entraining generated ions in a carrier gas; (e) pulsing a group of entrained ions into extended ion funnel focusing section by applying a pulsed electrical potential to the deflection electrode; (f) forcing the group of ions into ion mobility analyzing section by applying a first set of DC potentials to electrodes of the ion focusing section; (g) preventing additional ions from entering the ion mobility analyzing section by applying a second set of DC potentials to the deflection electrode and the electrodes of the ion focusing section; (h) inducing a carrier gas flow through the ion mobility analyzing section away from the ion focusing section with a vacuum pump in the vacuum system; (i) gradually reducing the DC barrier formed in step (a) to allow the carrier gas flow to push ions from the group of ions over the DC barrier in order of the ions'"'"' mobilities; (j) focusing ions that have been pushed over the DC barrier with the second ion focusing section; and (k) detecting ions that have been focused in step (j) with the ion detector.
-
Specification