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US 6,770,875 B1Granted
Apparatus and method for desolvating and focussing ions for introduction into a mass spectrometer
AssigneeNational Research Council of Canada
InventorsRoger Guevremont, Randy Purves
Life of this patent
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Abstract
This invention provides an apparatus and method for desolvating and selectively transmitting and focussing ions, including ions produced by electrospray ionization (ESI), based on the ion focussing principles of high field asymmetric waveform ion mobility spectrometry (FAIMS), for introduction into a mass spectrometer. The ion focussing, trapping and desolvating effects of FAIMS, as identified by the inventors, provides high ion transmission efficiency and high sensitivity for the detection of ions. An apparatus comprising an ESI source, a FAIMS device and a mass spectrometer provides a way of desolvating and selectively transmitting highly solvated ions for introduction into a mass spectrometer for analysis.
Claims46
An apparatus for selectively transmitting and determining the mass to charge ratio of ions, comprising:
- at least one ionization source for producing ions;
- a high field asymmetric waveform ion mobility spectrometer, comprising:
- i) an analyzer region defined by a space between first and second spaced apart electrodes, said analyzer region having a gas inlet at a first end and a gas outlet at a second end for providing a flow of gas through said analyzer region, said analyzer region having an ion inlet and an ion outlet, said ion inlet for introducing a flow of ions produced by said ionization source into said analyzer region and said ion outlet for supporting extraction of ions from said analyzer region;
- ii) an electrical controller connectable to said electrodes and capable of applying an asymmetric waveform voltage and a direct-current compensation voltage to selectively transmit a type of ion in said analyzer region between said electrodes at a given combination of asymmetric waveform voltage and compensation voltage;
- and
- iii) a mass spectrometer having a sampler orifice, said sampler orifice being positioned proximate to said ion outlet to receive said selectively transmitted ions for analysis within said mass spectrometer,
- wherein, said first and second electrodes comprise curved electrode bodies and provide a non-constant electric field therebetween, said ions being selectively focussed in a focussing region created between said curved electrode bodies in said analyzer region.
4 more elements
An apparatus for desolvating and selectively transmitting ions, comprising:
- a) at least one electrospray ionization source for producing ions from a sample in liquid phase;
- b) a high field asymmetric waveform ion mobility spectrometer, comprising:
- i) an analyzer region defined by a space between first and second spaced apart electrodes, said analyzer region being in communication with a gas inlet, a gas outlet, an ion inlet and an ion outlet, said ion inlet introducing a flow of said ions into said analyzer region, and said ion outlet allowing extraction of ions from said analyzer region;
- ii) a source of gas for providing a gas flow into said gas inlet and within said analyzer region, and out of said gas outlet, at least some of the gas flow being counter-current to said flow of ions being introduced at said ion inlet;
- and
- iii) an electrical controller connectable to said electrodes and capable of applying an asymmetric waveform voltage and a direct-current compensation voltage to selectively transmit a type of ion in an analyzer region between said electrodes at a given combination of asymmetric waveform voltage and compensation voltage.
3 more elements
An apparatus for selectively fitting ions, comprising:
- a) at least one electrospray ionization source for producing ions from a sample in liquid phase;
- and
- b) a high field asymmetric waveform ion mobility spectrometer, comprising:
- i) an analyzer region defined by a space between first and second spaced apart electrodes, said analyzer region being in communication with a gas inlet and a gas outlet for providing, in use, a gas flow through said analyzer region, an ion inlet and an ion outlet, said ion inlet introducing a flow of ions produced by said electrospray ionization source into said analyzer region, and said ion outlet allowing extraction of ions from said analyzer region;
- and
- ii) an electrical controller connectable to said electrodes and capable of applying an asymmetric waveform voltage and a direct-current compensation voltage to selectively transmit a type of ion in an analyzer region between said electrodes at a given combination of asymmetric waveform voltage and compensation voltage;
- wherein, said electrospray ionization source is positioned external to said inner electrode so as reduce the effect of said asymmetric waveform voltage on said electrospray ionization source.
4 more elements
A method for desolvating and selectively focussing ions produced by electrospray ionization for introduction into a mass spectrometer, comprising the steps of:
- a) providing at least one electrospray ionization source for producing ions from a sample in liquid phase;
- b) providing an analyzer region defined by a space between first and second spaced apart electrodes, said analyzer region being in communication with a gas inlet, a gas cutlet, an ion inlet and an ion outlet;
- c) providing a gas flow into said gas inlet, and within said analyzer region, and out of said carrier gas outlet, at least some of said gas flow being counter-current to ions being introduced at said ion inlet;
- d) providing an electrical controller connectable to said electrodes and capable of applying an asymmetric waveform voltage and a direct-current compensation voltage, to at least one of said electrodes;
- e) adjusting said asymmetric waveform voltage and said compensation voltage to selectively focus a type of ion;
- and
- f) extracting said selectively transmitted ions from said analyzer region at said ion outlet for introduction into a sampler cone of a mass spectrometer.
4 more elements
An apparatus for desolvating and selectively transmitting ions, comprising:
- a) at least one ionization source for producing ions;
- b) a high field asymmetric waveform ion mobility spectrometer, comprising:
- i) an analyzer region defined by a space between at least first and second spaced apart electrodes, said analyzer region being in communication with at least one of each of a gas inlet, a gas outlet, an ion inlet and an ion outlet, said ion inlet for introducing a flow of said ions into said analyzer region, and said ion outlet for allowing extraction of said ions from said analyzer region;
- ii) at least one source of gas for providing a gas flow into said gas inlet, a gas flow through said analyzer region, a gas flow out of said gas outlet, and a gas flow being which is flowing counter-current to said flow of ions being produced by said ion source so as to desolvate said flow of ions entering said ion inlet;
- iii) an electrical controller connectable to said electrodes and capable of applying an asymmetric waveform voltage and a direct-current compensation voltage to selectively transmit a type of ion in said analyzer region between said electrodes at a given combination of asymmetric waveform voltage and compensation voltage;
- and,
- iv) a terminus provided on at least one of said electrodes and shaped for directing said ions generally radially inwardly toward said ion outlet, said terminus being a part of said one of said electrodes which part is closest to said ion outlet.
4 more elements
A method for desolvating and selectively focusing ions produced by electrospray ionization for introduction into a mass spectrometer, comprising the steps of:
- a) providing at least one electrospray ionization source for producing ions including two ionic species from a sample in liquid phase;
- b) providing an analyzer region defined by a space between at least first and second spaced apart electrodes, said analyzer region being in communication with at least one of each of a gas inlet, a gas outlet, an ion inlet and an ion outlet;
- c) providing a terminus on at least one of said electrodes and shaped for directing said ions generally radially inwardly toward said ion outlet, said terminus being a part of said one of said electrodes which part is closest to said ion outlet,
- d) providing a gas flow into said gas inlet, and within said analyzer region, and out of said gas outlet, at least some gas flow being count-current to ions being produced at said ion source so as to desolvate said flow of ions entering said ion inlet;
- e) providing an electrical controller connectable to said electrodes and capable of applying an asymmetric waveform voltage and a direct-current compensation voltage, to at least one of said electrodes;
- f) setting said asymmetric waveform voltage in order to affect a difference in net displacement between said two ionic species in the time of one cycle of said applied asymmetric waveform voltage;
- g) setting said compensation voltage to a determined value to selectively focus one of said two ionic species;
- and,
- h) extracting said selectively focused ions from said analyzer region at said ion outlet for introduction into a sampler orifice of a mass spectrometer.
6 more elements
Dependencies are inferred from the claim text.