# US 11,029,282 B2 · Liquid phase ion mobility spectrometer > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,029,282 B2 - Document ID: US11029282B2 - Status: Granted - Kind: B2 - Application number: 16/548,489 - Filed: 2019-08-22 - Published: 2020-02-27 - Granted: 2021-06-08 - Earliest claimed: 2018-08-24 - Assignees: Analytical Detection LLC - Applicants: Analytical Detection LLC - Inventors: Andrey N. Vilkov - Web page: https://patentgrep.com/patent/US11029282B2 ## CPC - G01N 27/622: Ion mobility spectrometry - H01J 49/0031: {Step by step routines describing the use of the apparatus (H01J49/0081 takes precedence)} - H01J 49/0431: {for liquid samples (interfaces to liquid chromatographs G01N30/7233)} - G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q) - H01J: ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS (spark-gaps H01T; electric arc lamps H05B31/00; particle accelerators H05H) ## Abstract In general, a liquid phase ion mobility spectrometer is described in which ions in a drift chamber are pushed against an increasing retarding electric field by means of liquid flow. In some examples, a method comprises ionizing an analyte to generate ions; introducing the ions into a separation region of a drift chamber; directing, at a velocity, a liquid flow through the separation region to apply first forces to the ions within the separation region of the drift chamber; using an electric field with a non-zero gradient, applying second forces to the ions within a separation region of a drift chamber, the second forces counter the first forces; modifying at least one of the velocity or the electric field; and after modifying at least one of the velocity or the electric field, detecting the ions at an ion detector to generate a signal. ## Claims ### Claim 1 An ion mobility spectrometer comprising: an ionization source configured to generate ions from an analyte; a drift chamber with a separation region configured to receive the ions; a flow controller configured to direct, at a velocity, a liquid flow of a separation media comprising a non-polar liquid through the separation region to apply first forces to the ions within the separation region of the drift chamber; an electric field controller configured to use an electric field with a non-zero gradient to apply second forces to the ions within the separation region of the drift chamber, the second forces counter the first forces; a computing device configured to modify one or more of (1) the velocity of the liquid flow by directing the flow controller to modify the velocity of the liquid flow, or (2) the electric field by directing the electric field controller to modify the electric field; and an ion detector configured to detect, after the modification of the one or more of the velocity of the liquid flow or the electric field, the ions to generate a signal. ### Claim 2 (depends on 1) The ion mobility spectrometer of claim 1, wherein the electric field comprises a retarding DC electric field to retard movement of the ions within the separation region, the movement of the ions responsive to the first forces. ### Claim 3 (depends on 1) The ion mobility spectrometer of claim 1, wherein the ions comprise first ions and second ions, wherein the first forces applied by the liquid flow and the second forces applied by the electric field cause the first ions to reach equilibrium at a first position in the separation region, wherein the first forces applied by the liquid flow and the second forces applied by the electric field cause the second ions to reach equilibrium at a second position in the separation region, the first position different than the second position. ### Claim 4 (depends on 3) The ion mobility spectrometer of claim 3, wherein, after the modification of the at least one of the velocity of the liquid flow or the electric field, the first ions strike the detector before the second ions because the first position is nearer to the ion detector than the second position. ### Claim 5 (depends on 3) The ion mobility spectrometer of claim 3, wherein, after the drift chamber receives the ions, the computing device waits a configurable amount of time to enable the first ions to the reach equilibrium and the second ions to reach equilibrium before modifying the at least one of the velocity of the liquid flow or the electric field. ### Claim 6 (depends on 1) The ion mobility spectrometer of claim 1, wherein the electric field has a first electric field profile to apply the second forces and the modified electric field has a second electric field to apply third forces to the ions, the second electric field profile having lower magnitudes than the first electric field profile across at least a portion of the separation region. ### Claim 7 (depends on 1) The ion mobility spectrometer of claim 1, wherein the electric field has a first electric field profile to apply the second forces and the modified electric field has a second electric field to apply third forces to the ions, the second electric field profile having higher magnitudes than the first electric field profile across at least a portion of the separation region. ### Claim 8 (depends on 1) The ion mobility spectrometer of claim 1, wherein a liquid of the liquid flow has a Reynolds number sufficient to create a velocity flow profile for the liquid flow within the separation region, the velocity flow profile having a parabolic shape with a flat central section having a uniform velocity to provide a nearly uniform force on ions at different radial positions in the flat central section. ### Claim 9 (depends on 1) The ion mobility spectrometer of claim 1, wherein the velocity of the liquid flow is toward the ion detector. ### Claim 10 (depends on 1) The ion mobility spectrometer of claim 1, wherein the drift chamber is configured to receive the ions at an inlet, and wherein the velocity of the liquid flow is toward the inlet. ### Claim 11 (depends on 1) The ion mobility spectrometer of claim 1, wherein the ions within the separation region are in liquid phase. ### Claim 12 (depends on 1) The ion mobility spectrometer of claim 1, where the liquid flow is a gravity-fed flow. ### Claim 13 (depends on 1) The ion mobility spectrometer of claim 1, wherein the ions comprise enantiomers, and wherein the liquid flow comprises chiral substances for chiral separation of enantiomers within the separation region. ### Claim 14 (depends on 1) The ion mobility spectrometer of claim 1, where the liquid flow has a Reynolds number of less than 2300. ### Claim 15 (depends on 1) The ion mobility spectrometer of claim 1, where the liquid flow has a Reynolds number between: a lower limit of 2300; and an upper limit of 4000. ### Claim 16 (depends on 1) The ion mobility spectrometer of claim 1, wherein the electric field is generated within the drift chamber by one or more of a plurality of electrodes, a shape of a charged surface, and a direct current (DC) current through a liquid medium used to generate the liquid flow. ### Claim 17 (depends on 1) The ion mobility spectrometer of claim 1, wherein the electric field and the liquid flow separate the ions laterally along the center axis of the drift chamber. ### Claim 18 A method comprising: ionizing an analyte to generate ions; introducing the ions into a separation region of a drift chamber; directing, at a velocity, a liquid flow of a separation media comprising a non-polar liquid through the separation region to apply first forces to the ions within the separation region of the drift chamber; using an electric field with a non-zero gradient, applying second forces to the ions within a separation region of a drift chamber, the second forces counter the first forces; modifying at least one of the velocity or the electric field; and after modifying the at least one of the velocity or the electric field, detecting the ions at an ion detector to generate a signal. ### Claim 19 (depends on 18) The method of claim 18, wherein the ions comprise first ions and second ions, wherein the first forces applied by the liquid flow and the second forces applied by the electric field cause the first ions to reach equilibrium at a first position in the separation region, wherein the first forces applied by the liquid flow and the second forces applied by the electric field cause the second ions to reach equilibrium at a second position in the separation region, the first position different than the second position. ### Claim 20 A non-transitory computer-readable medium comprising instructions for causing processing circuitry to perform, using an ion mobility spectrometer, operations comprising: ionizing an analyte to generate ions; introducing the ions into a separation region of a drift chamber; directing, at a velocity, a liquid flow of a separation media comprising a non-polar liquid through the separation region to apply first forces to the ions within the separation region of the drift chamber; using an electric field with a non-zero gradient, applying second forces to the ions within a separation region of a drift chamber, the second forces counter the first forces; modifying at least one of the velocity or the electric field; and after modifying the at least one of the velocity or the electric field, detecting the ions at an ion detector to generate a signal. ### Claim 21 (depends on 1) The ion mobility spectrometer of claim 1, wherein the separation media comprises at least one polar additive.