Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
  • H01J49/00—Particle spectrometers or separator tubes
  • H01J49/02—Details
  • H01J49/06—Electron- or ion-optical arrangements
  • H01J49/062—Ion guides

Definitions

• the present disclosure relates generally to ion extraction and transmission systems used in the fields of ion mobility spectrometry (IMS) and mass spectrometry (MS). More specifically, the present disclosure relates to systems and methods for extracting ions from a gas flow, e.g., using ion manipulation systems such as Structures for Lossless Ion Manipulation (SLIM) to extract ions from a low-pressure gas mixture and focus the extracted ions through an aperture into an adjoining vacuum chamber.
• SLIM Structures for Lossless Ion Manipulation
• Mass spectrometry and ion mobility systems can utilize one or more inlet ion optics to couple an ionization source, e.g., an electrospray ion source, with an analyzer device, e.g., a mass spectrometer, or ion manipulation optics, e.g., an ion mobility separation (IMS) device, for example.
• an ionization source e.g., an electrospray ion source
• an analyzer device e.g., a mass spectrometer
• ion manipulation optics e.g., an ion mobility separation (IMS) device
• IMS ion mobility separation
• such inlet ion optics are configured to receive ions from the ionization source, which can be discharged from the ionization source and into the inlet ion optics through a capillary or skimmer, focus the received ions, and transfer the ions to an adjoining vacuum region that differs in pressure
• This adjoining vacuum region can contain an analyzer that separates or filters the incoming ions based on their gas phase mobility or mass to charge ratio.
• the capillary can discharge the ions into the inlet ion optics within a low-pressure, high-flow gas stream.
• ion funnel such as a stacked ring ion funnel.
• Stacked ring ion funnels can include a series of stacked ring electrodes that are spaced apart and extend from an entrance to an exit, and define an interior chamber.
• the entrance can receive the capillary, e.g., from an electrospray ion source, which discharges ions into the interior chamber of the stacked ring ion funnel.
• ion funnels often require a multitude of high-precision components arranged into a complex and costly assembly, a relatively large form factor to operate properly, and time consuming and complicated computational fluid dynamics and ion trajectory simulations for design optimization.
• Inlet ion optics can also be expensive and complex devices that require substantial design effort to ensure compatibility with the ionization source and analyzer to which they are intended to be coupled. In some instances, this can also require modification of the ionization source and/or device hardware. Moreover, since in some instances prior art inlet ion optics are designed to be coupled to a specific ionization source and analyzer, additional or alternative inlet ion optics cannot be utilized in the same system without substantial and expensive modifications.
• the present disclosure relates to systems and methods for extracting ions from a gas flow, e.g., using an ion manipulation path to extract the ions from a low-pressure gas flow and transmit the extracted ions into an adjoining vacuum region for analysis.
• a system for extracting ions from a gas flow includes a housing, an ion manipulation path, and a pump.
• the housing includes an entrance port, an exit port, and a vacuum pump port.
• the entrance port is configured to receive a gas flow comprising ions and gas.
• the ion manipulation path includes a first surface having a first plurality of electrodes and a second surface having a second plurality of electrodes.
• the ion manipulation path is positioned within the housing and is configured to receive the gas flow.
• the ion manipulation path is also configured to extract at least a portion of the ions from the gas flow, and transmit the ions extracted from the gas flow toward the exit port of the housing.
• the pump is in fluidic communication with the vacuum pump port, and is configured to extract the gas from the housing through the vacuum pump port.
• the vacuum pump port can prevent the gas from exiting the housing through the exit port.
• the system can include an analyzer region positioned adjacent the exit port.
• the analyzer region can have a pressure greater than a pressure of the housing to prevent the gas from exiting the housing through the exit port and entering the analyzer region.
• the ion manipulation path can include one or more printed circuit boards having the first plurality of electrodes and the second plurality of electrodes. While in other aspects, the exit port can be configured to be mounted adjacent an analyzer. In such aspects, the analyzer region can include one or more of an ion mobility separation device, a Structure for Lossless Ion Manipulation (SLIM), and a mass spectrometer.
• SLIM Structure for Lossless Ion Manipulation
• the entrance port can be positioned in a first side of the housing and the exit port can be positioned in a second side of the housing opposite the first side of the housing.
• the vacuum pump port can be positioned in a third side of the housing between the entrance port and the exit port.
• the vacuum pump port can be positioned in the second side of the housing aligned with the entrance port, and the exit port can be offset from the vacuum pump port.
• the ion manipulation path can include an inlet region, a diverter region, and an exit region. The diverter region can be configured to guide the ions in a direction different than a direction of the gas flow.
• the entrance port can be positioned in a first side of the housing and the vacuum pump port can be positioned in a second side of the housing opposite the first side of the housing such that the vacuum pump port is aligned with the entrance port.
• the exit port can be positioned in a third side of the housing between the entrance port and the vacuum port.
• the system can include a gas diverter positioned within the housing between the entrance port and the exit port.
• the gas diverter can be configured to block the gas flow from accessing the exit port.
• the ion manipulation path can include an inlet region, a diverter region, and an outlet region.
• the diverter region can extend partially around the gas diverter toward the vacuum pump port.
• the diverter region can form an open area, and the gas diverter can be positioned within the open area.
• the gas diverter can include a curved face aligned with the entrance port, and the curved face can be concave and curve generally from the entrance port to the vacuum pump port.
• the ion manipulation path can include a tapered funnel region configured to capture and focus ions from the gas flow, and to permit the gas of the gas flow to expand and dissipate.
• a method of extracting ions from a gas flow includes discharging a gas flow comprising ions and gas into a housing of an ion extraction system that includes an entrance port, an exit port, and a vacuum pump port. The method further involves receiving the gas flow, extracting at least a portion of the ions from the gas flow, and transmitting the ions extracted from the gas flow toward the exit port of the housing, by an ion manipulation path of the ion extraction system, which is positioned within the housing and includes a first surface having a first plurality of electrodes and a second surface having a second plurality of electrodes. The method further involves extracting, with a pump, the gas from the housing through the vacuum pump port.
• the method can include the step of preventing the gas from exiting the housing through the exit port with the vacuum pump port.
• the method can include the step of preventing the gas from exiting the housing through the exit port and entering an analyzer region positioned adjacent the exit port by adjusting a pressure of the housing to a first pressure value and adjusting a pressure of an analyzer region to a second pressure value greater than the first pressure value
• the ion manipulation path includes one or more printed circuit boards having the first plurality of electrodes and the second plurality of electrodes.
• the exit port can be configured to be mounted adjacent an analyzer region that can include one or more of an ion mobility separation device, a Structure for Lossless Ion Manipulation (SLIM), and a mass spectrometer.
• an analyzer region can include one or more of an ion mobility separation device, a Structure for Lossless Ion Manipulation (SLIM), and a mass spectrometer.
• SLIM Structure for Lossless Ion Manipulation
• the entrance port can be positioned in a first side of the housing and the exit port can be positioned in a second side of the housing opposite the first side of the housing.
• the vacuum pump port can be positioned in a third side of the housing between the entrance port and the exit port.
• the vacuum pump port can be positioned in the second side of the housing aligned with the entrance port, and the exit port can be offset from the vacuum pump port.
• the ion manipulation path can include an inlet region, a diverter region, and an exit region. The diverter region can be configured to guide the ions in a direction different than a direction of the gas flow.
• the entrance port can be positioned in a first side of the housing and the vacuum pump port can be positioned in a second side of the housing opposite the first side of the housing such that the vacuum pump port is aligned with the entrance port.
• the exit port can be positioned in a third side of the housing between the entrance port and the vacuum port.
• the method can include blocking the gas of the gas flow from accessing the exit port of the housing with a diverter of the ion extraction system positioned between the entrance port and the exit port.
• the ion manipulation path can include an inlet region, a diverter region, and an outlet region.
• the diverter region can extend partially around the gas diverter toward the vacuum pump port.
• the diverter region can form an open area, and the gas diverter can be positioned within the open area.
• the gas diverter can include a curved face aligned with the entrance port. In such aspects, the curved face can be concave and curve generally from the entrance port to the vacuum pump port.
• the method can include capturing and focusing ions from the gas flow with a tapered funnel region of the ion manipulation path, causing the gas of the gas flow to expand and dissipate.
• FIG. 1 is a first schematic diagram of an exemplary ion mobility separation (IMS) system incorporating an exemplary ion extraction system of the present disclosure
• FIG. 2 is a second schematic diagram of the IMS system of FIG. 1 showing details of the ion extraction system and an IMS device of the present disclosure
• FIG. 3 is a detailed schematic diagram of the ion extraction system of FIGS. 1 and 2;
• FIG. 4 is a diagrammatic view of a portion of the ion extraction system and the IMS device of the ion mobility separation system of FIGS. 1 and 2;
• FIG. 5 is a schematic diagram illustrating an exemplary arrangement of electrodes for implementation with the ion extraction system and the IMS device of FIGS. 1 and 2;
• FIG. 6 is a detailed schematic diagram of the ion extraction system of FIG. 3 showing an exemplary flow path of ions and exemplary flow path of gas;
• FIG. 7 is a perspective view of an exemplary ion extraction apparatus for use with the ion extraction system of the present disclosure
• FIG. 8 is a side elevational view of the exemplary ion extraction apparatus of FIG. 7 ;
• FIG. 9 is a sectional view of the exemplary ion extraction apparatus taken along line 9-9 of FIG. 8;
• FIG. 10 is a detailed schematic diagram of a second ion extraction system of the present disclosure.
• FIG. 11 is a detailed schematic diagram of a third ion extraction system of the present disclosure.
• FIG. 12 is a detailed schematic diagram of a fourth ion extraction system of the present disclosure.
• FIG. 13 is a diagram illustrating hardware and software components capable of being utilized to implement embodiments of the system of the present disclosure.
• the present disclosure relates to systems and methods for extracting ions from a gas flow, e.g., using ion manipulation systems, as described in detail below in connection with FIGS. 1-13.
• FIG. 1 is a first schematic diagram of an exemplary ion analysis system 100 in accordance with the present disclosure.
• the ion analysis system 100 includes an ionization source 102, an ion extraction system 104, an analyzer region 106 (e.g., an IMS system and/or a mass spectrometer such as a time of flight (TOF) mass spectrometer), a vacuum system 110, a controller 114, a computer system 116, and a power source 118.
• an IMS system and/or a mass spectrometer such as a time of flight (TOF) mass spectrometer
• TOF time of flight
• the ionization source 102 generates ions (e.g., ions having varying mobility and mass-to- charge-ratios) and passes the ions into the ion extraction system 104 through a capillary 120 (see FIG. 3).
• the ionization source 102 can be an electrospray ion source and the capillary 120 can be a heated capillary to aid in desolvation of the ions.
• the capillary 120 discharges a gas jet stream mixture (herein referred to as a gas flow, gas jet, and/or gas stream), which can be a mixture of low abundance ions and high abundance neutral molecules. Accordingly, the ions exiting the capillary 120 are entrained in a gas flow that controls movement of the ions as they enter the ion extraction system 104.
• the ion extraction system 104 is configured to transmit the ions to the analyzer region 106, and is described in more detail in connection with FIGS. 2 and 5.
• the ion extraction system 104 is in fluidic communication with the vacuum system 110 which regulates the pressure within the ion extraction system 104 and removes gas therefrom.
• the vacuum system 110 can include a vacuum pump 122 and a pressure gauge 124, as shown and described in connection with FIG. 2.
• the analyzer region 106 can be any device known in the art used for analyzing, e.g., transporting, accumulating, storing, separating, or detecting, ions, or a combination of multiple devices provided sequentially.
• the analyzer region 106 can be an ion mobility spectrometry (IMS) device configured to separate the ions based on their mobility. Mobility separation can be achieved, for example, by applying one or more potential waveforms (e.g., traveling potential waveforms, direct current (DC) gradient, or both) on the ions.
• the analyzer region 106 can be a SLIM device that performs IMS based mobility separation by systematically applying traveling and/or DC potential waveforms to a collection of ions.
• the analyzer region 106 can be configured and operated in accordance with the SLIM devices disclosed and described in U.S. Patent No. 8,835,839 entitled “Method and Apparatus for Ion Mobility Separations Utilizing Alternating Current Waveforms” and U.S. Patent No. 10,317,364 entitled “Ion Manipulation Device,” both of which are incorporated herein by reference in their entirety.
• the analyzer region 106 can be configured to transfer ions, accumulate ions, store ions, and/or separate ions, depending on the desired functionality and waveforms applied thereto by the controller 114.
• the analyzer region 106 need not be a SLIM device, but can be a different type of IMS device known in the art, such as a drift tube, a trapped ion mobility spectrometry (TIMS) device, or a field asymmetric ion mobility spectrometer (FAIMS), etc.
• the analyzer region 106 could be a mass spectrometer or other analytical device known in the art, including ion detection devices and downstream ion optics.
• the analyzer region 106 could include more than one device arranged sequentially.
• the analyzer region 106 could include a SLIM device and a mass spectrometer, where the SLIM device is configured to receive ions from the ion extraction system 104 and provide the ions separated based on mobility to the mass spectrometer for detection.
• the vacuum system 110 can be in fluidic communication with the analyzer region 106 and regulate the gas pressure within the analyzer region 106. Specifically, the vacuum system 110 can provide nitrogen to the analyzer region 106 while maintaining the pressure therein at a consistent level.
• the controller 114 can receive power from the power source 118, which can be, for example, a DC power source that provides DC voltage to the controller 114, and can be in communication with and control operation of the ionization source 102, the ion extraction system 104, the analyzer region 106, and the vacuum system 110.
• the power source 118 can be, for example, a DC power source that provides DC voltage to the controller 114, and can be in communication with and control operation of the ionization source 102, the ion extraction system 104, the analyzer region 106, and the vacuum system 110.
• the controller 114 can control the rate of injection of ions into the ion extraction system 104 by the ionization source 102, a target mobility of the analyzer region 106 (e.g., when the analyzer region 106 includes a SLIM device), the pump 122 of the vacuum system 110, the pressure within the ion extraction system 104 (e.g., through control of the vacuum system 110), the pressure within the analyzer region 106 (e.g., through control of the vacuum system 110), and ion detection by the analyzer region 106 (e.g., when the analyzer region 106 includes an ion detection device).
• a target mobility of the analyzer region 106 e.g., when the analyzer region 106 includes a SLIM device
• the pump 122 of the vacuum system 110 e.g., the pressure within the ion extraction system 104 (e.g., through control of the vacuum system 110)
• the pressure within the analyzer region 106 e.g., through control of the vacuum system 110
• the controller 114 can control the characteristics and motion of potential waveforms (e.g., amplitude, shape, frequency, etc.) generated by the analyzer region 106 (e.g., by applying RF/AC/DC potentials to the electrodes of the analyzer region 106) in order to transfer, accumulate, store, and/or separate ions.
• potential waveforms e.g., amplitude, shape, frequency, etc.
• the controller 114 can be communicatively coupled to a computer system 116.
• the computer system 116 can provide operating parameters of the ion analysis system 100 via a control signal to the master control circuit.
• a user can provide the computer system 116 (e.g., via a user interface) with the operating parameters.
• the master control circuit can control the operation of control circuits (e.g., RF, AC, and DC control circuits) associated with the ion extraction system 104 and/or the analyzer region 106, which in turn can dictate the operation thereof.
• the control circuits can be physically distributed over the ion analysis system 100.
• one or more of the control circuits can be located in the ion analysis system 100, and the various control circuits can operate based on power from the power source 118.
• FIG. 2 is a second schematic diagram of the IMS system 100 of FIG. 1 showing details of the ion extraction system 104 of the present disclosure, and an exemplary analyzer region 106 illustrated as a SLIM device.
• the ion extraction system 104 includes a vacuum chamber housing 126, an ion manipulation path 128 (e.g., a SLIM path), and a gas diverter 130.
• the vacuum chamber housing 126 includes a vacuum pump port 132, an entrance port 134, and an exit port 136, and forms a vacuum chamber 138 in which the SLIM path 128 and gas diverter 130 are positioned.
• the entrance port 134 is configured to be coupled to the ionization source 102, which can include a desolvation chamber 140, and receive the capillary 120, which can extend through the entrance port 134 and into the vacuum chamber 138 so as to discharge the gas jet/flow into the SLIM path 128.
• the exit port 136 is positioned generally opposite to the entrance port 134 and configured to be coupled to the analyzer region 106.
• a conductance limit orifice plate 142 can be positioned at the exit port 136 between the vacuum chamber housing 126 and the analyzer region 106.
• the vacuum pump port 132 extends from the vacuum chamber housing 126 to the vacuum pump 122, placing the vacuum pump 122 in fluidic communication with the vacuum chamber 138.
• the pressure gauge 124 is in fluidic communication with the vacuum chamber 138 and provides a reading of the pressure within the vacuum chamber 138 to the controller 114, which can control the vacuum pump 122 to adjust the pressure within the vacuum chamber 138.
• the system 100 can include a separate flow controller that meters in gas, e.g., nitrogen gas, to adjust the pressure.
• the ion extraction system 104 is discussed in greater detail in connection with FIGS. 3 and 6.
• the exemplary analyzer region 106 shown in FIG. 2 can include an IMS housing 144, an ion mobility separation path 146, and an outlet conductance limit orifice plate 148 between the ion mobility separation path 146 and a downstream device, such as a mass spectrometer.
• the ion mobility separation path 146 includes an inlet region 150, an ion separation path 152, and an outlet region 154.
• the ion separation path 152 extends from the inlet region 150 to the outlet region 154 and can be serpentine in shape to maximize the length thereof.
• the inlet region 150 is positioned adjacent the exit port 136 of the vacuum chamber housing 126 and the conductance limit orifice plate 142 so as to receive ions from the SLIM path 128 of the ion extraction system 104 through the conductance limit orifice plate 142.
• the outlet region 154 is positioned adjacent the outlet conductance limit orifice plate 148 and configured to output ions there through into the downstream device.
• the analyzer region 106 could have various other configurations than that shown in FIG. 2, or could be one or more different devices, such as a different IMS device, ion optics, an analytical device, an ion detection device, etc.
• the vacuum system 110 is in fluidic communication with the analyzer region 106 and regulates the gas pressure within the analyzer region 106.
• the vacuum system 110 can include a gas pressure controller 156 and a pressure gauge 158, in addition to the vacuum pump 122 and a pressure gauge 124.
• the gas pressure controller 156 is connected to a gas, e.g., nitrogen source, and configured to discharge gas into the IMS housing 144 based on a reading of the pressure gauge 158, which monitors the pressure within the IMS housing 144.
• the pressure gauge 158 can provide the pressure reading directly to the gas pressure controller 156, or to controller 114, which can in turn control the gas pressure controller 156.
• the gas pressure controller 156 can be a valve that can be manipulated by the controller 114. Additionally, it should be understood that the components of the vacuum system 110, namely, the vacuum pump 122, the pressure gauge 124, the gas pressure controller 156, and the pressure gauge 158, can be controlled in concert and as a singular unit. For example, the pressure within the ion extraction system 104 and the analyzer region 106 can be controlled based on the characteristics of each other and the respective pressures, among other considerations. Accordingly, the vacuum system 110 can be an integrated vacuum system that considers the ion analysis system 100 holistically.
• FIG. 3 is a detailed schematic diagram of the ion extraction system 104 of FIGS. 1 and 2.
• the SLIM path 128 is positioned within the vacuum chamber 138 of the vacuum chamber housing 126 and extends from the entrance port 134 to the exit port 136, which are positioned generally on opposite sides of the vacuum chamber 138.
• the SLIM path 128 generally includes an inlet region 160, a diverter region 162, and an outlet region 164, which are in sequence.
• the inlet region 160 is positioned adjacent the capillary 120 with a small space between the end of the capillary 120 and the edge of the inlet region 160.
• the diverter region 162 is subsequent the inlet region 160 and generally curves toward the vacuum pump port 132, which can be positioned in the middle of the vacuum chamber housing 126, e.g., at a central point between the entrance port 134 and the exit port 136, and can extend perpendicularly from the vacuum chamber housing 126. That is, the central axis of the vacuum pump port 132 can be perpendicular to a line drawn connecting the entrance port 134 and the exit port 136.
• the outlet region 164 is subsequent the diverter region 162 and extends to the exit port 136 and the inlet conductance limit orifice plate 148 with a small gap between the end of the outlet region 164 and the inlet conductance limit orifice plate 148.
• the SLIM path 128 has a serpentine configuration with a bend, e.g., the diverter region 162, that bring the SLIM path 128 closer to the vacuum pump port 132 to assist in removal of gas, as discussed in greater detail below.
• the SLIM path 128 is configured to transport the ions discharged from the capillary 120 to the ion mobility separation path 146 of the analyzer region 106.
• the gas diverter 130 includes a body 166 and a curved diverter face 168 that can be concave and semi-circular in shape.
• the gas diverter 130 is mounted within the vacuum chamber housing 126, and positioned between the capillary 120 and the exit port 136 within an open area 170 created by the bend of the diverter region 162 of the SLIM path 128. Additionally, the gas diverter 130 is positioned in front of the capillary 120 with the curved diverter face 168 directly in the line-of-sight of the capillary 120, e.g., in the discharge trajectory of the capillary 120, and the entrance port 134, e.g., aligned with the entrance port 134.
• the curved diverter face 168 curves from the entrance port 134 toward the vacuum pump port 132 so that the outlet of the curved diverter face 168 is inline or parallel to the central axis of the vacuum pump port 132. That is, a tangent line to the end of the curved diverter face 168 would extend substantially toward the vacuum pump port 132. Accordingly, the gas diverter 130 directs the gas stream/flow discharged by the capillary 120 off axis toward the vacuum pump port 132 and away from the exit port 136, thus preventing the gas stream/flow from traveling through the exit port 136 and into the analyzer region 106.
• FIG. 4 is a diagrammatic view of an area A-A of the SLIM path 128 of FIG. 3.
• the SLIM path 128 can be configured and operated in accordance with the SLIM devices disclosed and described in U.S. Patent No. 8,835,839 entitled “Method and Apparatus for Ion Mobility Separations Utilizing Alternating Current Waveforms” and U.S. Patent No. 10,317,364 entitled “Ion Manipulation Device,” both of which are incorporated herein by reference in their entirety.
• the SLIM path 128 need not be a SLIM device, but can be any ion manipulation path/device that transfers ions without the use of gas or pressure for ion motion.
• the SLIM path 128 can include a first surface 172a and a second surface 172b.
• the first and second surfaces 172a, 172b can be arranged (e.g., parallel to one another) to define one or more ion channels there between.
• the capillary 120 is configured to discharge the neutral/ion mixed gas stream/flow between the first and second surfaces 172a, 172b.
• the first and second surfaces 172a, 172b can include electrodes 174, 176a-f, 178a-e, 180a-h (see FIG. 5), e.g., arranged as arrays of electrodes on the surfaces facing the ion channel.
• the electrodes 174, 176a-f, 178a-e, 180a-h on the first and second surfaces 172a, 172b can be electrically coupled to the controller 114 and receive voltage (or current) signals or waveforms therefrom.
• the first surface 172a and second surface 172b can include a backplane that includes multiple conductive channels that allow for electrical connection between the controller 114 and the electrodes 174, 176a-f, 178a-e, 180a-h on the first surface 172a and second surface 172b.
• the number of conductive channels can be fewer than the number of electrodes 174, 176a-f, 178a-e, 180a-h.
• multiple electrodes 174, 176a-f, 178a-e, 180a-h can be connected to a single electrical channel.
• a given voltage (or current) signal can be transmitted to multiple electrodes 174, 176a-f, 178a-e, 180a-h simultaneously.
• the electrodes 174, 176a-f, 178a-e, 180a-h can generate one or more potentials (e.g., a superposition of various potentials) that can confine, drive, and/or separate ions along the SLIM path 128.
• FIG. 3 is a schematic diagram of the first and second surfaces 172a, 172b of the SLIM path 128 illustrating the arrangement of electrodes 174, 176a-f, 178a-e, 180a-h thereon.
• the first and second surfaces 172a, 172b can be substantially mirror images relative to a parallel plane, and thus it should be understood that the description of the first surface 172a applies equally to the second surface 172b, thus the second surface 172b can include electrodes with similar electrode arrangement to the first surface 172a.
• the electrodes 174, 176a-f, 178a-e, 180a-h can be arranged and configured in accordance with U.S. Patent Nos. 8,835,839 and 10,317,364.
• the first and second surfaces 172a, 172b can include guard electrodes 174, a plurality of RF electrodes 176a-f, and a plurality of segmented electrode arrays 178a-e.
• the guard electrodes 174 can receive a DC voltage from the controller 114, which retains the ions laterally and prevents the ions from exiting the SLIM path 128 through the sides thereof.
• Each of the plurality of RF electrodes 176a-f can receive voltage (or current) signals, or can be connected to ground potential, and can generate a pseudopotential that can prevent or inhibit ions from approaching the first and second surfaces 172a, 172b.
• the RF electrodes 176a-f can receive RF signals from the controller 114.
• the RF voltages applied to the RF electrodes 176a-f can be phase shifted with respect to adjacent RF electrodes 176a-f, e.g., adjacent RF electrodes 176a-f can receive the same RF signal, but phase shifted by 180 degrees.
• the foregoing functionality retains the ions between the first and second surfaces 172a, 172b and prevents the ions from contacting the first and second surfaces 172a, 172b.
• the plurality of RF electrodes 176a-f can be separated from each other along a lateral direction, which can be perpendicular to the direction of propagation.
• Each of the plurality of segmented electrode arrays 178a-e can be placed between two RF electrodes 176a-f, and includes a plurality of individual electrodes 180a-h, e.g., eight electrodes, sixteen electrodes, twenty-four electrodes, etc., that are arranged along a direction of ion motion.
• the plurality of RF electrodes 176a-f and the plurality of segmented electrode arrays 178a-e can be arranged in alternating fashion on the first and second surfaces 172a, 172b between the DC guard electrodes 174.
• the plurality of segmented electrode arrays 178a-e can receive a second voltage signal and generate a drive potential that can drive/transmit ions along the central axis of the SLIM path 128.
• the segmented electrodes 178a-e can be traveling wave (TW) electrodes such that each of the individual electrodes 180a-h of each segmented electrode array 178a-e receives a voltage signal that is simultaneously applied to all individual electrodes 180a-h, but phase shifted between adjacent electrodes 180a-h along the z-axis.
• TW traveling wave
• the voltage signal applied to the individual electrodes 180a-h can be a sinusoidal waveform (e.g., an AC voltage waveform), a rectangular waveform, a DC square waveform, a sawtooth waveform, a biased sinusoidal waveform, a pulsed current waveform, etc., and the amplitude of the signal provided to the individual electrodes 180a-h can be determined based on the voltage waveform applied, e.g., in view of the phase shifting referenced above. Accordingly, the segmented electrodes 178a-e are configured to transmit the received ions along the SLIM path 128.
• a sinusoidal waveform e.g., an AC voltage waveform
• a rectangular waveform e.g., a DC square waveform
• a sawtooth waveform e.g., a biased sinusoidal waveform
• a pulsed current waveform e.g., a pulsed current waveform
• the SLIM path 128 functions as a conduit for the ions as the electrode configuration creates an ion trap that retains the ions along its length. More specifically and as previously described in detail, the RF electrodes 176a-f on the first and second surfaces 172a, 172b retain the ions between the first and second surfaces 172a, 172b, e.g., along the x-axis shown in FIG. 4, while the DC guard electrodes 174 retain the ions laterally, e.g., along the y-axis shown in FIGS. 4 and 5, and prevent the ions from exiting the SLIM path 128 through the sides thereof.
• the ions are permitted to travel only along the length of the SLIM path 128, e.g., along the z-axis shown in FIGS. 4 and 5, in accordance with the travelling wave applied to the individual electrodes 180a-h of each segmented electrode array 178a-e, which propels the ions along the SLIM path 128 toward the exit port 136.
• the arrangement of electrodes 174, 176a-f, 178a-e, 180a-h of the SLIM path 128 allows for flexibility in design of the SLIM path 128.
• the SLIM path 128 can be designed with a non-linear configuration, such as that shown in FIGS. 2 and 3, be either curving the electrode arrangement, as shown in FIGS. 9-11, or by orienting different segments of the SLIM path 128 at an angle with respect to one another, e.g., at right angles.
• the SLIM path 128 can be designed to go around the gas diverter 130 or transmit ions in a direction that is different than the discharge trajectory of the capillary 120 in order to extract the ions from the discharged gas.
• FIG. 6 is a detailed schematic diagram of the ion extraction system 104 of FIG. 5 showing an exemplary flow path of ions 182 and an exemplary flow path of gas 184 within the ion extraction system 104.
• the capillary 120 discharges a gas jet/flow into the SLIM path 128, e.g., between the first and second surfaces 172a, 172b and between the guard electrodes 174 (see FIGS. 4 and 5).
• the gas jet/flow is a mixture of ions 182 and high pressure gas 184.
• the ions 182 of the mixture are retained within the SLIM path 128, transferred along the SLIM path 128 to the exit port 136, and passed through the conductance limit orifice plate 142 and into the ion mobility separation path 146 of the analyzer region 106 where they can undergo ion mobility separation.
• voltage applied to the guard electrodes 174 (see FIG.
• the RF voltage applied to the RF electrodes 176a-f retains the ions 182 between the first and second surfaces 172a, 172b, and the electrical signal applied to the plurality of segmented electrode arrays 178a-e transmits the ions 182 along the SLIM path 128.
• the gas 184 of the gas jet/flow is not influenced by the electrical signals of the guard electrodes 174, the RF electrodes 176a-f, or the plurality of segmented electrode arrays 178a- e. Accordingly, the gas flow 184 contacts the gas diverter 130, e.g., the curved diverter face 168, and is diverted off of the original trajectory and directed toward the vacuum pump port 132.
• the vacuum pump 122 creates a suction effect at the vacuum pump port 132, which draws the gas flow 184 toward the vacuum pump port 132 and suctions the gas flow 184 out from the vacuum chamber housing 126 through the vacuum pump port 132, thus removing the gas from the vacuum chamber housing 126 and preventing the gas from entering the analyzer region 106 and preventing contamination of the analyzer region 106.
• the analyzer 106 can be maintained at a greater pressure than the vacuum chamber housing 126 to assist with preventing gas from entering the analyzer region 106 and control contamination thereof.
• the ion extraction system 104 extracts the ions from the gas jet/flow by diverting the gas into the vacuum pump port 132 and guiding the ions away from gas using the SLIM path 128.
• the SLIM path 128 further transmits the extracted ions to the analyzer region 106.
• the waveforms applied to the electrodes 174, 176a-f, 178a-e, 180a-h of the SLIM path 128 can be adjusted based on the velocity and pressure of the gas jet/flow, as well as the pressure generated by the vacuum pump 122.
• the DC voltage applied to the guard electrodes 174 can be increased in the diverter region 162 of the SLIM path 128 in order to ensure that the ions are retained on the SLIM path 128 and not pushed off of the SLIM path 128 by the gas.
• gas diverter 130, entrance port 134, exit port 136, and vacuum port 132 could be provided in a different form, position, configuration, arrangement, or size, so long as the ion extraction system 104 sufficiently directs the gas flow away from the exit port 136 and toward the vacuum pump port 132, and extracts the ions.
• Exemplary alternative configurations contemplated by the present disclosure are shown and described in connection with FIGS. 10-12.
• FIGS. 7-9 illustrate an exemplary ion extraction apparatus 186 of the present disclosure that can be implemented in the ion extraction system 104.
• FIG. 7 is a perspective view of the exemplary ion extraction apparatus 186
• FIG. 8 is a side elevational view of the exemplary ion extraction apparatus 186
• FIG. 9 is a sectional view of the exemplary ion extraction apparatus 186 taken along line 9-9 of FIG. 8.
• the ion extraction apparatus 186 can include the first and second surfaces 172a, 172b, which can be printed circuit boards, and the gas diverter 130.
• the first and second surfaces 172, 172b can contain the SLIM path 128 which includes electrodes 174, 176a-c, 178a-b, as discussed in connection with FIGS. 4 and 5, which trap and transfer the ions there along.
• the SLIM path 128 of the ion extraction apparatus 186 of FIGS. 7-9 includes only three rows of RF electrodes 176a-c (instead of six as shown in the configuration of FIG. 5) and two rows of segmented electrodes 178a-b (instead of five as shown in the configuration of FIG. 5). Additionally, the RF electrodes 176a-c of FIGS. 7-9 are segmented instead of continuous, but nonetheless function as described in connection with FIGS. 4 and 5.
• FIG. 10 is a detailed schematic diagram of a second ion extraction system 104a of the present disclosure.
• the second ion extraction system 104a is similar in operation to the ion extraction system 104 shown and described in connection with FIGS. 2 and 3, but includes an alternative configuration. Similar to the ion extraction system 104 shown and described in connection with FIGS. 2 and 3, the second ion extraction system 104a includes a vacuum chamber housing 126a and an ion manipulation path 128a (e.g., a SLIM path).
• the vacuum chamber housing 126a includes a vacuum pump port 132a, an entrance port 134a, and an exit port 136a, and forms a vacuum chamber 138a in which the SLIM path 128a is positioned.
• the SLIM path 128a can have the same electrode configuration as that shown and described in connection with FIGS. 4, 5, and 8.
• the vacuum pump port 132a extends from the vacuum chamber housing 126a to a vacuum pump 122a, placing the vacuum pump 122a in fluidic communication with the vacuum chamber 138a.
• the ion extraction system 104a can also include a pressure gauge 124a that is in fluidic communication with the vacuum chamber 138a, and provides a reading of the pressure within the vacuum chamber 138a to the controller 114, which can control a vacuum pump 122a to adjust the pressure within the vacuum chamber 138a.
• the pressure within the vacuum chamber 138a can be controlled by a separate flow controller that meters in gas, e.g., nitrogen gas.
• the second ion extraction system 104a does not include a gas diverter 130 to redirect the flow of gas. Instead, the vacuum pump port 132a is positioned directly opposite the entrance port 134a such that it is aligned therewith, and the SLIM path 128a curves 90 degrees toward the exit port 136a.
• the SLIM path 128a generally extends from the entrance port 134a to the exit port 136a, which can be positioned in orthogonal walls of the vacuum chamber housing 126a.
• the SLIM path 128a includes an inlet region 160a, an ion diverter region 162a (e.g., a curved region), and an outlet region 164a.
• the inlet region 160a is positioned adjacent the capillary 120, which extends through the entrance port 134a.
• the ion diverter region 162a is subsequent the inlet region 160a and generally curves or turns 90 degrees toward the exit port 136a, which can extend perpendicularly from the vacuum chamber housing 126a, is configured to be coupled to the analyzer region 106, and can have a conductance limit orifice plate 142a positioned adjacent thereto. That is, the central axis of the exit port 136a can be perpendicular to a line drawn connecting the entrance port 134a and the vacuum pump port 132a.
• the outlet region 164a is subsequent the ion diverter region 162a, and extends to the exit port 136a and the conductance limit orifice plate 148a. The outlet region 164a can extend perpendicularly to the inlet region 160a.
• the SLIM path 128a has a curved configuration with a bend, e.g., the ion diverter region 162a, that extracts the ions from the gas stream/flow and causes the ions to travel perpendicular to the original direction of travel and in a direction different than the gas stream/flow.
• the SLIM path 128a is configured to transport the ions discharged from the capillary 120 to the analyzer region 106.
• the SLIM path 128a need not include the ion diverter region 162a, but instead the inlet region 160a and the outlet region 164a can directly intersect at a right angle such that they are positioned orthogonally. In this configuration, the ions would travel to the end of the inlet region 160a and turn 90 degrees at the interface with the outlet region 164a, at which point they would enter the outlet region 164a and be transferred to the exit port 136a.
• the outlet region 164a functions as an ion diverter as it diverts and extracts the ions from the gas flow.
• the ion diverter region 162a can have a turn angle less than or greater than 90 degrees if desired.
• the ion diverter region 162a can also include a series of smaller incremental turns, if desired.
• the outlet region 164a intersects directly with the inlet region 160a, such intersection can be at an angle less than or greater than 90 degrees.
• the second ion extraction system 104a utilizes the ion manipulation path 128a to trap, transfer, and extract the ions from the gas stream/flow, and a vacuum pump 122a to extract the gas through the vacuum pump port 132a so that the gas does not reach the exit port 136a. Additionally, due to the configuration of the entrance port 134a and the vacuum pump port 132a, the gas stream/flow generally flows toward the vacuum pump port 132a, thus eliminating the need for a gas diverter.
• FIG. 11 is a detailed schematic diagram of a third ion extraction system 104b of the present disclosure.
• the third ion extraction system 104b is similar in operation to the ion extraction system 104 shown and described in connection with FIGS. 2 and 3, and the second ion extraction system 104a shown and described in connection with FIG. 10, but includes another alternative configuration.
• the third ion extraction system 104b includes a vacuum chamber housing 126b and an ion manipulation path 128b (e.g., a SLIM path).
• the vacuum chamber housing 126b includes a vacuum pump port 132b, an entrance port 134b, and an exit port 136b, and forms a vacuum chamber 138b in which the SLIM path 128b is positioned.
• the SLIM path 128b can have the same electrode configuration as that shown and described in connection with FIGS. 4, 5, and 8.
• the vacuum pump port 132b extends from the vacuum chamber housing 126b to a vacuum pump 122b, placing the vacuum pump 122b in fluidic communication with the vacuum chamber 138b.
• the ion extraction system 104b can also include a pressure gauge 124b that is in fluidic communication with the vacuum chamber 138b, and provides a reading of the pressure within the vacuum chamber 138b to the controller 114, which can control a vacuum pump 122b to adjust the pressure within the vacuum chamber 138b.
• the pressure within the vacuum chamber 138b can be controlled by a separate flow controller that meters in gas, e.g., nitrogen gas.
• the third ion extraction system 104b does not include a gas diverter 130 to redirect the flow of gas. Instead, the vacuum pump port 132b is positioned directly opposite the entrance port 134b such that it is aligned therewith, and the SLIM path 128b make two 90 degrees turns toward the exit port 136b. This is similar to the SLIM path 128a of the second ion extraction system 104a, but instead of a single 90 degree turn, the SLIM path 128b makes two 90 degree turns so that the exit port 136b is positioned in the same wall of the vacuum chamber housing 126b as the vacuum pump port 132b. Thus, the SLIM path 128b has a serpentine shape.
• the SLIM path 128b generally extends from the entrance port 134b to the exit port 136b, which can be positioned in opposite walls of the vacuum chamber housing 126b.
• the SLIM path 128b includes an inlet region 160b, an ion diverter region 162b (e.g., a curved/serpentine region), and an outlet region 164b.
• the inlet region 160b is positioned adjacent the capillary 120, which extends through the entrance port 134b.
• the ion diverter region 162b is subsequent the inlet region 160b and makes two counter- acting 90 degree curves or turns toward the exit port 136b, which can extend perpendicularly from the vacuum chamber housing 126b, is configured to be coupled to the analyzer region 106, and can have a conductance limit orifice plate 142b positioned adjacent thereto. That is, the central axis of the exit port 136b can be parallel to a line drawn connecting the entrance port 134b and the vacuum pump port 132b.
• the outlet region 164b is subsequent the ion diverter region 162b, and extends to the exit port 136b and the conductance limit orifice plate 148b.
• the outlet region 164b can extend parallel to the inlet region 160b, but is laterally offset therefrom, e.g., due to the ion diverter region 162b.
• the SLIM path 128b has a curved/serpentine configuration with a bend, e.g., the ion diverter region 162b, that extracts the ions from the gas stream/flow and causes the ions to travel first in a direction different than the gas stream/flow and then parallel to the original direction of travel but separate from the gas stream/flow.
• the SLIM path 128b is configured to transport the ions discharged from the capillary 120 to the analyzer region 106.
• the ion diverter region 162b of the SLIM path 128b could be a straight section that is positioned at a right angle with respect to the inlet region 160b and/or the outlet region 164b, e.g., the ion diverter region 162b can directly intersect the inlet region 160b and/or the outlet region 164b at a right angle such that they are positioned orthogonally.
• the ions would travel to the end of the inlet region 160b, turn 90 degrees at the interface with the ion diverter region 164b, enter the ion diverter region 164b, travel to the end of the ion diverter region 164b, and turn 90 degrees at the interface with the outlet region 164b, at which point they would enter the outlet region 164b and be transferred to the exit port 136b.
• the ion diverter region 162b can have turn angles less than or greater than the two 90 degree turns noted above, if desired.
• the ion diverter region 162b can also include a series of smaller incremental turns if desired.
• the ion diverter region 162a is a straight section that directly intersects with the inlet region 160b and/or the outlet region 164b at an angle, such intersections can be at an angle less than or greater than 90 degrees.
• the third ion extraction system 104b utilizes the ion manipulation path 128b to trap, transfer, and extract the ions from the gas stream/flow, and a vacuum pump 122b to extract the gas through the vacuum pump port 132b so that the gas does not reach the exit port 136b. Additionally, due to the configuration of the entrance port 134b and the vacuum pump port 132b, the gas stream/flow generally flows toward the vacuum pump port 132b, thus eliminating the need for a gas diverter.
• FIG. 12 is a detailed schematic diagram of a fourth ion extraction system 104c of the present disclosure.
• the fourth ion extraction system 104c includes a vacuum chamber housing 126c and an ion manipulation path 128c (e.g., a SLIM path).
• the vacuum chamber housing 126c includes a vacuum pump port 132c, an entrance port 134c, and an exit port 136c, and forms a vacuum chamber 138c in which the SLIM path 128c is positioned.
• the SLIM path 128c can have the same electrode configuration as that shown and described in connection with FIGS. 4, 5, and 8.
• the vacuum pump port 132c extends from the vacuum chamber housing 126c to a vacuum pump 122c, placing the vacuum pump 122c in fluidic communication with the vacuum chamber 138c.
• the ion extraction system 104c can also include a pressure gauge 124c that is in fluidic communication with the vacuum chamber 138c, and provides a reading of the pressure within the vacuum chamber 138c to the controller 114, which can control a vacuum pump 122c to adjust the pressure within the vacuum chamber 138c.
• the fourth ion extraction system 104c does not include a gas diverter 130 to redirect the flow of gas. Instead, the fourth ion extraction system 104c utilizes a flat SLIM funnel inlet region 160c, which can have a tapered design, to capture and focus ions from a gas jet/flow 188 that is discharged from the capillary 120 while permitting the gas jet/flow 188 to expand and dissipate reducing drag forces on the ions.
• the SLIM path 128c generally extends from the entrance port 134c to the exit port 136c, which can be positioned in opposite walls of the vacuum chamber housing 126c.
• the SLIM path 128c includes the flat SLIM funnel inlet region 160c and an outlet region 164c.
• the flat SLIM funnel inlet region 160c is positioned adjacent the capillary 120, which extends through the entrance port 134c, and includes a funnel shape with the number of rows of electrodes decreasing along a length thereof.
• a first column of electrodes 190a closest to the capillary 120 can include fifteen rows of electrodes that alternate between RF electrodes and travelling wave electrodes
• a second column of electrodes 190b can include thirteen rows of electrodes that similarly alternate
• a third column of electrodes 190c can include eleven rows of electrodes that similarly alternate
• a fourth column of electrodes 190d can include eleven rows of electrodes that similarly alternate
• a fifth column of electrodes 190e can include nine rows of electrodes that similarly alternate
• a sixth column of electrodes 190f can include seven rows of electrodes that similarly alternate
• a seventh column of electrodes 190g can include seven rows of electrodes that similarly alternate
• an eighth column of electrodes 190h can include five rows of electrodes that similarly alternate and correspond with the five rows of electrodes of the outlet region 164c.
• the DC guard electrodes 174 of the flat SLIM funnel inlet region 160c can be angled to follow the reduction in electrode rows and form the funnel shape.
• the outlet region 164c is subsequent the flat SLIM funnel inlet region 160c, and extends to the exit port 136c and the conductance limit orifice plate 148c.
• the SLIM path 128c is configured to transport the ions discharged from the capillary 120 to the analyzer region 106.
• the gas jet/flow 188 is permitted to expand as it discharges into the flat SLIM funnel inlet region 160c, and laterally exit the SLIM path 128c. That is, the gas jet/flow 188 expands, which causes it to lose velocity and dissipate, and is extracted by the vacuum pump 122c through the vacuum pump port 132c so that the gas does not reach the exit port 136c. Additionally, this configuration permits the exit port 136c to be positioned opposite to and aligned with the entrance port 134c
• the fourth ion extraction system 104c utilizes the flat SLIM funnel inlet region 160c of the ion manipulation path 128c to focus, capture, and extract the ions from the gas jet/flow 188 while permitting the gas jet/flow to expand 188, and a vacuum pump 122c to extract the gas through the vacuum pump port 132c so that the gas does not reach the exit port 136c.
• the ion extraction systems 104, 104a- c are modular components that can be swapped in or out for existing/conventional systems while retaining the mechanical and electrical components of the associated ion optics, e.g., IMS device, mass spectrometer, etc., or other related components. Additionally, the ion extraction systems 104, 104a-c of the present disclosure can be combined with each other in order to further enhance their performance.
• the foregoing configuration e.g., utilization of a gas diverter 130 and/or SLIM technology for the SLIM paths 128, 128a-c, provides for an ion extraction system that can be smaller in size, cheaper to manufacture, easier to assembly, and easier to clean than conventional inlet ion optics such as ion funnels.
• the present disclosure allows for the replacement of complex assemblies with a much simpler assembly.
• a prior art ion funnel that requires over one hundred etched metal electrodes to be soldered into an assembly of multiple printed circuit boards, a process that can take hours to complete, can be replaced with an ion extraction system 104, 104a-c of the present disclosure that in some instances requires only two circuit boards, spacers, and an optional gas diverter. Moreover, this allows for multiple prototypes to be built and tested quickly and inexpensively.
• the ion extraction systems 104, 104a-c are a more robust alternative to capillary-ion optics interfaces of existing instruments, and can be quicker to assemble and easier to interface with additional ion optics equipment, such as IMS systems, commercial mass spectrometers, etc.
• the ion extraction system 104 is easier to optimize through computational simulations than some other systems, which reduces the design time needed and allows for more accurate simulations and designs to be realized. The foregoing benefits also allow for faster prototyping.
• FIG. 13 is a diagram 192 showing hardware and software components of the computer system 116 on which aspects of the present disclosure can be implemented.
• the computer system 116 can include a storage device 194, computer software code 196, a network interface 198, a communications bus 200, a central processing unit (CPU) (microprocessor) 202, random access memory (RAM) 204, and one or more input devices 206, such as a keyboard, mouse, etc.
• CPU central processing unit
• RAM random access memory
• input devices 206 such as a keyboard, mouse, etc.
• the CPU 202 could also include, or be configured as, one or more graphics processing units (GPUs).
• the computer system 116 could also include a display (e.g., liquid crystal display (LCD), cathode ray tube (CRT), and the like).
• LCD liquid crystal display
• CRT cathode ray tube
• the storage device 194 could comprise any suitable computer- readable storage medium, such as a disk, non-volatile memory (e.g., read-only memory (ROM), erasable programmable ROM (EPROM), electrically-erasable programmable ROM (EEPROM), flash memory, field-programmable gate array (FPGA), and the like).
• the computer system 116 could be a networked computer system, a personal computer, a server, a smart phone, tablet computer, etc.
• the functionality provided by the present disclosure could be provided by the computer software code 196, which each could be embodied as computer-readable program code (e.g., algorithm) stored on the storage device 194 and executed by the computer system 116 using any suitable, high or low level computing language, such as Python, Java, C, C++, C#, .NET, MATLAB, etc.
• a network interface 198 could include an Ethernet network interface device, a wireless network interface device, or any other suitable device which permits the computer system 116 to communicate via a network.
• the CPU 202 could include any suitable single-core or multiple-core microprocessor of any suitable architecture that is capable of implementing and running the computer software code 196 (e.g., Intel processor).
• the random access memory 204 could include any suitable, high-speed, random access memory typical of most modem computers, such as dynamic RAM (DRAM), etc.

Landscapes

• Chemical & Material Sciences (AREA)
• Analytical Chemistry (AREA)
• Other Investigation Or Analysis Of Materials By Electrical Means (AREA)
• Electron Tubes For Measurement (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=82259749

Family Applications (1)

Country Status (3)

Families Citing this family (3)

Family Cites Families (6)

• 2021
  • 2021-12-30 EP EP21916461.3A patent/EP4271747A1/de active Pending
  • 2021-12-30 WO PCT/US2021/065617 patent/WO2022147201A1/en unknown
• 2023
  • 2023-02-02 US US18/105,083 patent/US20230187194A1/en active Pending
• 2024
  • 2024-02-01 WO PCT/US2024/014012 patent/WO2024163746A2/en unknown

Also Published As

Similar Documents

Legal Events