Duel mode ion mobility spectrometer
AssigneeSmiths Detection-Watford Limited
InventorWilliam Angus Munro
Life of this patent
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Abstract
An ion mobility spectrometer (100) comprising a first ion source (102-1, 108-1) for providing positive ions to be analysed, an electric field applier arranged to provide an electric field configured to move the positive ions in a first direction towards a first ion detector (106-1, 110-1) adapted for detecting the positive ions, and a second ion source (102-2, 108-2) for providing negative ions to be analysed, wherein the electric field applier is arranged to move the negative ions in a direction opposite to the first direction, towards the first ion source (102-1, 108-1) and towards a second ion detector (106-1, 110-1) adapted for detecting the negative ions.
Claims47
An ion mobility spectrometer comprising:
- a first ion source for providing positive ions to be analysed, an electric field applier arranged to provide an electric field configured to move the positive ions in a first direction towards a first ion detector adapted for detecting the positive ions, and
- a second ion source for providing negative ions to be analysed, wherein the electric field applier is arranged to move the negative ions in a second direction different from the first direction, towards the first ion source and towards a second ion detector adapted for detecting the negative ions.
The ion mobility spectrometer of any preceding claim wherein the second ion source comprises a second ioniser configured to provide ions by applying ionising energy to a gaseous fluid, and the ion mobility spectrometer comprises a controller configured to select the timing of operation of the first detector based on the timing of operation of the second ioniser.
The ion mobility spectrometer of any preceding claim comprising a first ion gate arranged to control the passage of ions from the first ion source towards the first detector, and a second ion gate arranged to control the flow of ions from the second ion source towards the second detector.
The ion mobility spectrometer of any preceding claim wherein the first ion source and the second ion source are separated from each other by a drift region.
The ion mobility spectrometer of any preceding claim comprising a flow passage arranged to provide a flow of gaseous fluid past a first inlet arranged to provide a sample to be ionised from the flow to the first ion source and past a second inlet arranged to provide a sample to be ionised from the flow to the second ion source.
The ion mobility spectrometer of any preceding claim comprising a controller configured to control the release of ions from one of the first ion source and the second ion source based on the timing of a release of ions from the respective other one of the first ion source and the second ion source.
The ion mobility spectrometer of any preceding claim comprising an ion modifier arranged between the first ion source and the second ion source.
An apparatus comprising an ion gate and an ion detector for an ion mobility spectrometer, the ion gate comprising a first electrode, a second electrode, and a gate controller configured to control the relative voltage of the first electrode and the second electrode to control the passage of ions through the ion gate, wherein the detector is coupled to at least one of the first electrode and the second electrode for detecting the arrival of ions at the ion gate.
A method of operating an ion gate for an ion mobility spectrometer, the method comprising opening the gate to allow first ions to pass through the gate, closing the gate to inhibit the passage of ions through the gate, and while the gate is closed detecting arrival of second ions at the gate, wherein the second ions have charge of a different sign to the first ions.
A method of operating a pair of ion gates, separated from each other by a drift chamber of an ion mobility spectrometer, the method comprising opening a first one of the ion gates to allow ions to pass towards the second ion gate, and detecting arrival of the ions at the second ion gate.
A combined repeller and detector apparatus for ion mobility spectrometer, the apparatus comprising:
- an ioniser for ionising a sample,
- an electrode,
- a voltage provider configured to apply a voltage to the electrode to move first ions away from the ioniser and the electrode, and
- a detector coupled to the electrode and configured to detect the arrival of second ions at the electrode, wherein the second ions have charge of a different sign to the charge of the first ions.
The apparatus of any of claims 39 to 41 wherein the electrode comprises a repeller plate.
A dual polarity IMS cell comprising a source of positive ions and a detector for detecting negative ions separated by a drift chamber from a source of negative ions, and a detector for detecting positive ions.
A method comprising operating an IMS cell simultaneously in both positive and negative modes using a common voltage profile to accelerate both the positive and negative ions through a common drift region.
Dependencies are inferred from the claim text.