Mass spectrometer system and method for transporting and analyzing ions
AssigneeVarian Associates, Inc.
InventorsAlexander Mordehai, Sidney E. Buttrill, Jr.
Life of this patent
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Abstract
A mass spectrometer system for performing a separation of ions from neutrals and mass analyzing ions comprising an ion generating source with an ion introduction system, a radio-frequency ion guide and a mass analyzer disposed within a vacuum chamber. The radio-frequency ion guide is positioned with respect to the ion introduction system so that a main axis of the radio-frequency ion guide is angled toward a central axis of the ion introduction system. The trajectory of the ions is diverted toward the main axis of the radio-frequency ion guide while neutrals continue their flow along the central axis. The ions from the ion introduction system are transported via the radio-frequency ion guide to the mass analyzer.
Claims18
A mass spectrometer system comprising:
- an ion source for generating ions in an ionization region;
- a vacuum chamber disposed in proximity to said ion source, said vacuum chamber having at least a pair of vacuum regions with a progressively reduced pressure from a front region to a back region of said pair, wherein the front region is adjacent to said ion source;
- an ion sampling device comprising an inlet and an outlet openings with a narrow passage therebetween, said passage defining a central axis of said device for transporting ions contained in gas from the ionization region to said vacuum chamber;
- a radio-frequency ion guide for passing ions to said back region, said ion guide positioned along a main axis within an intermediate region between the front and back regions and being adjacent to said outlet opening of said sampling device, wherein a space between the outlet opening of said ion sampling device and an entrance of said radio-frequency ion guide is defined an aerodynamic jet region;
- said aerodynamic jet region having a pressure in a range of about 10-10.sup.-4 torr;
- the central axis of said ion sampling device being tilted toward the main axis of said radio-frequency ion guide, whereby a trajectory of ion flow is altered by said ion guide and ions are directed along the main axis;
- and
- mass analyzer for analyzing ions received from said radio-frequency ion guide, said mass analyzer positioned along a core axis within the back region of said vacuum chamber.
A mass spectrometer system comprising:
- an ion source for generating ions in an ionization region;
- a vacuum chamber disposed in proximity to said ion source along a central axis, said vacuum chamber having at least a pair of vacuum regions with a progressively reduced pressure from a front region to a back region of said pair, wherein the front region is adjacent to said ion source;
- a nozzle for transporting ions contained in gas from the ionization region to the front region, said nozzle positioned along a central axis between said ion source and said vacuum chamber and having an ion sampling orifice;
- a radio-frequency ion guide for passing ions to said back region, said radio-frequency ion guide positioned along a main axis within an intermediate region between the front and back regions and being adjacent to said nozzle, wherein a space between said nozzle and an entrance of said ion guide defines an aerodynamic jet region;
- said aerodynamic jet region having a pressure in a range of about 10-10.sup.-4 torr;
- the central axis of said nozzle being positioned at an angle with respect to the main axis, whereby the trajectory of ion flow is altered by said ion guide and ions are guided along the main axis;
- and
- mass analyzer for analyzing ions received from said radio-frequency ion guide, said mass analyzer positioned to receive ions from said ion guide within the back region of said vacuum chamber.
A method of analyzing ions from sample molecules comprising the steps of:
- evacuating a vacuum chamber for providing at least a pair of regions with a progressively reduced pressure in any subsequent region in a direction from a front region to a back region of said chamber;
- generating ions in an ionization region by an ion source;
- transporting ions from the ionization region to the front region of said vacuum chamber through a narrow passage of an ion sampling device in the direction of a central axis of said device, wherein an aerodynamic jet region is developed within an outlet of said device having a pressure in an range of about 10-10.sup.-4 torr;
- extracting ions from a gas in the aerodynamic jet region and directing ions along a main axis of a radio-frequency ion guide by altering the trajectory of the ion flow by said radio-frequency ion guide disposed in an intermediate region of said vacuum chamber between the front and the back regions;
- guiding ions from the intermediate region to the back region of said vacuum chamber into a mass analyzer;
- and
- analyzing ion mass of sample molecules by said mass analyzer.
Dependencies are inferred from the claim text.