Waveforms in an ion mobility spectrometer
AssigneeBattelle Memorial Institute
InventorsAdam L. Hollerbach, Yehia M. Ibrahim, Richard D. Smith
Life of this patent
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Abstract
Apparatus and methods are disclosed to improve performance of ion mobility separation. Deleterious bend effects are counteracted by adjusting phase shifts between adjoining traveling wave sections at bends; superior trajectories and performance are achieved. Improvements are also achieved by arranging serpentine paths primarily along a lengthwise direction of a substrate, thereby reducing the number of bends. An ion mobility spectrometers is coupled to a mass spectrometer, and intermittent traveling waves improve sample utilization or reduce total time required for combined ion analysis with both modalities.
Claims19
An apparatus comprising:
- an ion transport channel configured to transport ions along a continuous path following a plurality of directions of travel, the path comprising a plurality of major segments, including a first segment defined by a first set of electrodes, one or more bend segments, including a second segment defined by a second set of electrodes, and an intersection between the first and second segments;
- the first set of electrodes, wherein electrodes within the first set, that are adjacent in a longitudinal first direction along the first segment, have distinct oscillatory electrical first signals applied in a first phased relationship, the first signals configured to generate a first traveling wave to direct the transported ions along the first segment in the first direction toward the intersection;
- and
- the second set of electrodes, wherein electrodes within the second set, that are adjacent in a longitudinal second direction along the second segment, have distinct oscillatory electrical second signals applied in a second phased relationship, the second signals configured to generate a second traveling wave to direct the transported ions along the second segment in the second direction, which differs from the first direction;
- wherein the second traveling wave is configured to have an optimal phase relative to the first traveling wave, the optimal phase being selected to control one or more properties of the transported ions, the one or more properties comprising:
- transit time, width of a transit time distribution, resolving power, or ion loss.
A method comprising:
- generating, with a first set of electrodes, a first traveling wave along a major segment of an ion transport channel;
- directing ions, with the first traveling wave, in a first direction along the major segment, toward an intersection between the major segment and a bend segment of the ion transport channel;
- generating, with a second set of electrodes, a second traveling wave along the bend segment;
- and
- directing the ions, with the second traveling wave, in a second direction along the bend segment, the second direction differing from the first direction;
- wherein the improvement comprises:
- selecting a phase of the second traveling wave relative to the first traveling wave to improve one or more properties of the directed ions.
An ion-manipulation system comprising:
- an ion injector;
- an ion receiver;
- an ion transport channel defined by a plurality of electrodes and coupled between the ion injector and the ion receiver, the ion transport channel comprising multiple segments including:
- a plurality of major segments including a first segment and a third segment;
- and
- a plurality of bend segments, each bend segment coupling a respective pair of the major segments, the bend segments including a second segment coupling the first and third segments;
- the electrodes;
- a multiphase power supply coupled to apply oscillatory electrical signals to the electrodes to develop, on each of the segments, a respective traveling wave;
- wherein relative phases of the traveling waves on adjacent pairs of the segments are selected to optimize one or more of:
- ion transit time, resolving power, ion loss, or width of transit time distribution.
Dependencies are inferred from the claim text.