Patent Application
20230187194
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, as well as IMS devices having curved regions and ion manipulation paths.
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. In particular, 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 or flow characteristics. 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. For example, the capillary can discharge the ions into the inlet ion optics within a low-pressure, high-flow gas stream.
One type of inlet ion optics is an 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. However, 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.
An additional issue that can result from the low-pressure, high-flow gas stream being discharged into the inlet ion optics is that a portion of the discharged gas can enter the adjoining vacuum region. In many ion analysis systems this adjoining vacuum region houses analyzers which require well controlled pressure and flow conditions to operate properly. This analyzer region can be at a lower or higher pressure than that of the inlet optics region. In either case, the incoming gas flow from the ion source may be transmitted to the analyzer region, e.g., if the inlet extraction optics are not designed with significant care to ensure proper and adequate removal of the gas. This can result in the contamination or disruption of the analyzer region, which can be detrimental to the device's intended ion manipulation function, e.g., due to the gas flow and/or composition. To fully remove gas jet effects from the exit of the inlet ion optics, complicated designs, such as dual ion funnels, orthogonal capillary inlet configurations, etc., are necessary, which can add to the overall cost, size, and complexity of the system.
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.
In addition to the foregoing, prior art SLIM devices include turn regions that are formed from multiple paths interfacing at 90 degree angles, and which utilize perpendicular intersections or junctions of electrodes, e.g., RF electrodes and traveling wave electrodes, in order to change the direction of travel for ions. Thus, in prior art turn regions, ions are discharged from one path into another perpendicular path to cause the ions' direction of travel to change. However, this configuration results in some different phase RF electrodes being in close proximity at interface regions of the turn, e.g., where a first path transitions or intersects with a second path. This can result in mis-aligned RF signals that can have negative impacts on performance, including, for example: unintentional trapping of ions, ion heating and fragmentation, loss of large or small ions at the edges of the core transmission range, and reduction of ion mobility resolution due to differential ion transmission through the junction. Additionally, the turn regions of the prior art SLIM devices generally permit ions to travel in a single direction through the turn, as they must be discharged perpendicularly from the first path to the second path, which is disposed perpendicularly thereto, and this perpendicular discharge is unidirectional.
Accordingly, there is a need for systems for ion extraction and guidance that prevent neutral gas molecules from contaminating or disrupting an associated ion analysis region and address the above-identified challenges, as well as improved turn regions for SLIM devices that address the above-identified challenges.
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.
In accordance with embodiments of the present disclosure, 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.
In some aspects, the vacuum pump port can prevent the gas from exiting the housing through the exit port.
In some aspects, 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.
In some aspects, 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.
In some other aspects, 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. In these aspects, the vacuum pump port can be positioned in a third side of the housing between the entrance port and the exit port. Alternatively, 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. In such aspects, 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.
In other aspects, 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. In these aspects, the exit port can be positioned in a third side of the housing between the entrance port and the vacuum port.
In still other aspects, 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. In such aspects, 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. In such aspects, the diverter region can form an open area, and the gas diverter can be positioned within the open area. In other such aspects, 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.
In further aspects, 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.
In accordance with embodiments of the present disclosure, 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.
In some aspects, the method can include the step of preventing the gas from exiting the housing through the exit port with the vacuum pump port.
In some aspects, 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
In other aspects, the ion manipulation path includes 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 region that can include one or more of an ion mobility separation device, a Structure for Lossless Ion Manipulation (SLIM), and a mass spectrometer.
In some other aspects, 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. In these aspects, the vacuum pump port can be positioned in a third side of the housing between the entrance port and the exit port. Alternatively, 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. In such aspects, 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.
In other aspects, 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. In these aspects, the exit port can be positioned in a third side of the housing between the entrance port and the vacuum port.
In some aspects, 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. In such aspects, 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. In such aspects, the diverter region can form an open area, and the gas diverter can be positioned within the open area. In other aspects, 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.
In further aspects, 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.
In accordance with the present disclosure, an apparatus for ion manipulations includes an inlet, and outlet, an ion manipulation path, at least one continuous electrode, and a plurality of segmented electrodes. The inlet is configured to receive ions and the outlet is configured to have ions discharged therefrom. The ion manipulation path extends between the inlet and the outlet, and includes a first region extending in a first direction, a second region extending in a second direction, and a curved region extending between the first region and the second region. The at least one continuous electrode is configured to receive a first RF voltage signal and extends through the first region, the curved region, and the second region. The plurality of segmented electrodes are arranged along the ion manipulation path in the first region, the curved region, and the second region, and are configured to receive a second voltage signal and generate a traveling wave field based on the second voltage signal. The traveling wave field is configured to cause the ions received at the inlet to travel through the first region, the curved region, and the second region.
In some aspects, the at least one continuous electrode can curve along the curved region in a single continuous curve, while in other aspects the at least one continuous electrode can curve along the curved region in a plurality of angularly connected sequential straight sections.
In further aspects, the second direction can be different than the first direction, while in other aspects the second direction can be the same as the first direction and the second region can be laterally offset from the first region.
In still other aspects, the curved region can curve between 0° to 180° from the first region to the second region, can include at least two sequential turns, and/or can be configured to change a direction of travel of the ions.
In some aspects, the at least one continuous electrode can include a first continuous electrode and a second continuous electrode, and the plurality of segmented electrodes can be positioned between the first continuous electrode and the second continuous electrode. In such aspects, a second plurality of segmented electrodes can be arranged along the ion manipulation path in the first region, the curved region, and the second region. Additionally, the at least one continuous electrode can include a third continuous electrode and the second plurality of segmented electrodes can be positioned between the second continuous electrode and the third continuous electrode. The plurality of segmented electrodes can also include a first number of individual electrodes in the curved region and the second plurality of segmented electrodes can include a second number of individual electrodes in the curved region. In this regard, the second number of individual electrodes can be greater than the first number of individual electrodes. Additionally, in such aspects, the second voltage signal can be an AC voltage signal that is applied to adjacent electrodes within a sequential set of the plurality of segmented electrodes and phase shifted on the adjacent electrodes of the plurality of segmented electrodes by a first value between 1° and 359°. The second plurality of segmented electrodes can also be configured to receive the AC voltage signal, which can be applied to adjacent electrodes within a sequential set of the second plurality of segmented electrodes and phase shifted on the adjacent electrodes of the second plurality of segmented electrodes by a second value between 1° and 359°, which can be different than the first value.
In some aspects, the plurality of segmented electrodes can be curved electrodes, rectangular electrodes, or a combination of curved electrodes and rectangular electrodes.
In still other aspects, the at least one continuous electrode and the plurality of segmented electrodes can be arranged on the same surface.
In accordance with the present disclosure, a curved ion manipulation path includes an inlet, an outlet, a curved region extending between the inlet and the outlet, at least one continuous electrode, and a plurality of segmented electrodes. The inlet is configured to receive ions in a first direction and the outlet is configured to discharge ions in a second direction. The at least one continuous electrode extends through the curved region from the inlet to the outlet, and is configured to receive a first RF voltage signal. The plurality of segmented electrodes are arranged along the curved region from the inlet to the outlet, and are configured to receive a second voltage signal and generate a traveling wave field based on the second voltage signal. The traveling wave field is configured to cause the ions received at the inlet to travel through the curved region and to be discharged from the outlet in the second direction.
In some aspects, the at least one continuous electrode can curve along the curved region in a single continuous curve, while in other aspects the at least one continuous electrode can curve along the curved region in a plurality of angularly connected sequential straight sections.
In further aspects, the second direction can be different than the first direction, while in other aspects the second direction can be the same as the first direction and the inlet can be laterally offset from the outlet.
In still other aspects, the curved region can curve between 0° to 180° from the inlet to the outlet, can include at least two sequential turns, and/or can be configured to change a direction of travel of the ions.
In some aspects, the at least one continuous electrode can include a first continuous electrode and a second continuous electrode, and the plurality of segmented electrodes can be positioned between the first continuous electrode and the second continuous electrode. In such aspects, a second plurality of segmented electrodes can be arranged along the curved region from the inlet to the outlet. Additionally, the at least one continuous electrode can include a third continuous electrode and the second plurality of segmented electrodes can be positioned between the second continuous electrode and the third continuous electrode. The plurality of segmented electrodes can also include a first number of individual electrodes in the curved region and the second plurality of segmented electrodes can include a second number of individual electrodes in the curved region. In this regard, the second number of individual electrodes can be greater than the first number of individual electrodes. Additionally, in such aspects, the second voltage signal can be an AC voltage signal that is applied to adjacent electrodes within a sequential set of the plurality of segmented electrodes and phase shifted on the adjacent electrodes of the plurality of segmented electrodes by a first value between 1° and 359°. The second plurality of segmented electrodes can also be configured to receive the AC voltage signal, which can be applied to adjacent electrodes within a sequential set of the second plurality of segmented electrodes and phase shifted on the adjacent electrodes of the second plurality of segmented electrodes by a second value between 1° and 359°, which can be different than the first value.
In some aspects, the plurality of segmented electrodes can be curved electrodes, rectangular electrodes, or a combination of curved electrodes and rectangular electrodes.
In still other aspects, the at least one continuous electrode and the plurality of segmented electrodes can be arranged on the same surface.
Other features will become apparent from the following detailed description considered in conjunction with the accompanying drawings. It is to be understood, however, that the drawings are designed as an illustration only and not as a definition of the limits of the invention.
The foregoing features of the present disclosure will be apparent from the following Detailed Description of the Invention, taken in connection with the accompanying drawings, in which:
The present disclosure relates to systems and methods for extracting ions from a gas flow, e.g., using ion manipulation systems, as well as improved turn regions for IMS devices, as described in detail below in connection with
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
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
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. For example, 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. In this exemplary configuration, 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. For example, the analyzer region 106 can be configured and operated in accordance with the SLIM devices disclosed and described in U.S. Pat. No. 8,835,839 entitled “Method and Apparatus for Ion Mobility Separations Utilizing Alternating Current Waveforms” and U.S. Pat. No. 10,317,364 entitled “Ion Manipulation Device,” both of which are incorporated herein by reference in their entirety. Moreover, 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. However, it should be understood that 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. Alternatively, 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. Moreover, as previously noted, the analyzer region 106 could include more than one device arranged sequentially. For example, 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. For example, 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). In some aspects, e.g., when the analyzer region 106 includes a SLIM device or the ion extraction system 104 includes a SLIM path, 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.
The controller 114 can be communicatively coupled to a computer system 116. For example, the computer system 116 can provide operating parameters of the ion analysis system 100 via a control signal to the master control circuit. In some implementations, a user can provide the computer system 116 (e.g., via a user interface) with the operating parameters. Based on the operating parameters received via the control signal, 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. In some implementations, the control circuits can be physically distributed over the ion analysis system 100. For example, 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.
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. Alternatively, 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
The exemplary analyzer region 106 shown in
As previously noted, 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. In some aspects, 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.
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. In this regard, 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.
In particular, 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. In this regard, 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
In particular, 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. In particular, 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 degree. 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. In particular, 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. 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.
Accordingly, 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
Moreover, 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. For example, since the RF electrodes 176a-f retain the ions between the first and second surfaces 172a, 172b and the DC guard electrodes 174 retain the ions laterally, the SLIM path 128 can be designed with a non-linear configuration, such as that shown in
As shown in
However, 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. Additionally, 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. Additionally, 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.
Accordingly, 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.
It should be understood that 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. For example, 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. It is also contemplated by the present disclosure that the 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
However, contrary to the ion extraction system 104 shown and described in connection with
More specifically, 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. As such, 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.
Additionally, it should be understood that 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. Thus, the outlet region 164a functions as an ion diverter as it diverts and extracts the ions from the gas flow.
Furthermore, it should be understood that the ion diverter region 162a can have a turn angle less than or greater than 90 degrees if desired. For example, it may be advantageous for the ion diverter region 162a to turn less than 90 degrees, e.g., 30 or 45 degrees, to avoid a stronger cross-flow force from the gas flow, which can assist with the diversion and extraction of ions from the gas flow. The ion diverter region 162a can also include a series of smaller incremental turns, if desired. Similarly, where the ion diverter region 162a is omitted, and 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.
Accordingly, in view of the foregoing, 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.
However, contrary to the ion extraction system 104 shown and described in connection with
More specifically, 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. As such, 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.
Additionally, it should be understood that instead of having a curved design, 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. In this configuration, 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.
Furthermore, it should be understood that the ion diverter region 162b can have turn angles less than or greater than the two 90 degree turns noted above, if desired. For example, it may be advantageous for the ion diverter region 162b to have turn angles less than 90 degrees, e.g., 30 or 45 degrees, to avoid a stronger cross-flow force from the gas flow, which can assist with the diversion and extraction of ions from the gas flow. The ion diverter region 162b can also include a series of smaller incremental turns if desired. Similarly, where 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.
Accordingly, 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.
However, contrary to the ion extraction system 104 shown and described in connection with
More specifically, 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. As one example, 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, and 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. Additionally, 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.
In view of this configuration, and because the SLIM path 128c is provided on spaced apart first and second surfaces 172a, 172b having open lateral sides, 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
Accordingly, 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.
It is also contemplated by the present disclosure that 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. Thus, the present disclosure allows for the replacement of complex assemblies with a much simpler assembly. For example, 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.
Additionally, 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. Moreover, 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.
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 modern computers, such as dynamic RAM (DRAM), etc.
The SLIM path 1500 with curved regions 1501, 1502 has improved ion transmission over the prior art turn region 1400, including faster ion transmission, less ion loss, wider mass-to-charge ratio (m/z) transmission, reduced ion heating, improved IM resolution, and minimized number of RF electrode vias. Furthermore, the curved regions 1501, 1502 also permit for bi-directional ion transmission. For example, ions can travel through the SLIM path 1500 from a first end 1503 to a second end 1504, or, alternatively, ions can travel through the SLIM path 1500 in the opposite direction, that is, from the second end 1504 to the first end 1503.
As shown in
In the curved turn region 1601, each of the individual electrodes of the segmented electrode arrays 1678a-e can be curved electrodes that follow the curvature of the curved turn region 1601, and the number of electrodes in the curved turn region 1601 for each segmented electrode array 1678a-e can be individually tailored depending on the positioning. In particular, the first segmented electrode array 1678a traverses less distance across the curved turn region 1601 than the fifth segmented electrode array 1678e. For example, the first electrode array 1678a, which is positioned as the inner row of the curved turn region 1601, can have two individual electrodes in the curved turn region 1601, the second electrode array 1678b can have four individual electrodes in the curved turn region 1601, the third electrode array 1678c can have eight individual electrodes in the curved turn region 1601, the fourth electrode array 1678d can have eight individual electrodes in the curved turn region 1601, and the fifth electrode array 1678e can have sixteen individual electrodes in the curved turn region 1601. The number of individual electrodes or electrode segments in each array 1678a-e can also vary independently of the other arrays 1678a-e. For example, the number of individual electrodes in any given array 1678a-e can be 1, 2, 3, 4, etc. Additionally, it is noted that the size, e.g., length and width, of each individual electrode can vary with respect to other individual electrodes within the same array 1678a-e or with respect to individual electrodes of other arrays 1678a-e. That is to say, the individual electrodes need not be uniform in dimensions across the electrode arrays 1678a-e.
The plurality of segmented electrode arrays 1678a-e can receive a voltage signal and generate a drive potential that can drive/transmit ions along the direction of the SLIM path 1600, e.g., in the direction of arrows A and B. In particular, the segmented electrodes 1678a-e can be traveling wave (TW) electrodes such that each of the individual electrodes of each segmented electrode array 1678a-e receives a voltage signal that is simultaneously applied to all individual electrodes, but phase shifted between adjacent electrodes along the curved direction of arrow A or B. Accordingly, each of the individual electrodes is labeled in
Thus, in the curved turn region 1601, the phase shift between the two adjacent individual electrodes for the first segmented electrode array 1678a can be 180 degree, e.g., the first individual electrode (4) would receive the 135° phase of the traveling wave voltage signal and the second individual electrode (8) would receive the 315° phase of the traveling wave voltage signal. For the second segmented electrode array 1678, the phase shift between adjacent electrodes of the four individual electrodes in the curved turn region 1601 can be 90 degrees, e.g., the first individual electrode (2) would receive the 45° phase of the traveling wave voltage signal, the second individual electrode (4) would receive the 135° phase of the traveling wave voltage signal, the third individual electrode (6) would receive the 225° phase of the traveling wave voltage signal, and the fourth individual electrode (8) would receive the 315° phase of the traveling wave voltage signal. For the remaining three segmented electrode arrays 1678c. 1678d, 1678e, the phase shift between adjacent individual electrodes in the curved turn region can be 45 degrees, e.g., the first individual electrodes (1) would receive the 0° phase of the traveling wave voltage signal, the second individual electrodes (2) would receive the 45° phase of the traveling wave voltage signal, the third individual electrodes (3) would receive the 90° phase of the traveling wave voltage signal, the fourth individual electrodes (4) would receive the 135° phase of the traveling wave voltage signal, the fifth individual electrodes (5) would receive the 180° phase of the traveling wave voltage signal, the sixth individual electrodes (6) would receive the 225° phase of the traveling wave voltage signal, the seventh individual electrodes (7) would receive the 270° phase of the traveling wave voltage signal, and the eighth individual electrodes (8) would receive the 315° phase of the traveling wave voltage signal. It is noted that the fifth segmented electrode array 1678e includes two groups of eight individual electrodes in the curved turn region 1601. The voltage signal applied to the individual electrodes of each segmented electrode array 1678a-e 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 can be determined based on the voltage waveform applied, e.g., in view of the phase shifting referenced above. Accordingly, the segmented electrodes 1678a-e are configured to transmit the received ions along the SLIM path 1600.
During operation, ions can travel into the inlet region 1805 of the first SLIM path 1820, enter the curved turn region 1801 traveling in the direction of arrow C, turn 90 degrees as they traverse the curved turn region 1801, enter the outlet region 1807, travel through the straight transmission region 1840, enter the inlet region 1806 of the second SLIM path 1830, enter the curved turn region 1802 traveling in the direction of arrow C, turn 90 degrees as they traverse the curved turn region 1802, and finally enter the outlet region 1808 where they can be transferred out to a subsequent SLIM path. Alternatively, since the curved turn regions 1801, 1802 permit for bi-directional ion transmission, ions can alternatively be guided through the SLIM path 1800 in the opposite direction, e.g., entering at the outlet region 1808 of the second SLIM path 1830 and exiting at the inlet region 1805 of the first SLIM path 1820. In this configuration, the ions would travel in the direction of arrow D.
As shown in
In the curved turn region 1901, each of the individual electrodes of the segmented electrode arrays 1978a-e can be curved electrodes that follow the curvature of the curved turn region 1901, and the number of electrodes in the curved turn region 1901 for each segmented electrode array 1978a-e can be individually tailored depending on the positioning. In particular, the first segmented electrode array 1978a traverses less distance across the curved turn region 1901 than the fifth segmented electrode array 1978e. For example, the first electrode array 1978a, which is positioned as the inner row of the curved turn region 1901, can have eight individual electrodes in the curved turn region 1901, while each of the second, third, fourth, and fifth electrode arrays 1978b, c, d, e can have sixteen individual electrodes in the curved turn region 1901. As previously noted, the number of individual electrodes in each electrode array 1978a-e can be more or less than described herein.
As discussed in connection with
However, the electrode configuration illustrated in
However, the electrode configuration illustrated in
However, the electrode configuration illustrated in
However, the electrode configuration illustrated in
However, the electrode configuration illustrated in
During operation, ions can travel into the inlet region 2505 of the first SLIM path 2520, enter the curved turn region 2501 traveling in the direction of arrow G, turn 90 degrees as they traverse the first curved turn region 2501, enter the outlet region 2507, travel through the straight transmission region 2540, enter the inlet region 2506 of the second SLIM path 2530, enter the second curved turn region 2502 continuing to travel along the path of arrow G, turn 90 degrees as they traverse the curved turn region 2502, and finally enter the outlet region 2508 where they can be transferred out to a subsequent SLIM path. Alternatively, since the curved turn regions 2501, 2502 permit for bi-directional ion transmission, ions can alternatively be guided through the SLIM path 2500 in the opposite direction, e.g., entering at the outlet region 2508 of the second SLIM path 2530 and exiting from the inlet region 2505 of the first SLIM path 2520. In this configuration, the ions would travel along the path denoted by arrow H.
During operation, ions can travel along the path denoted by arrow L. Accordingly, during operation, ions can travel into the inlet region 2605 of the SLIM path 2600, enter the first curved turn region 2601, turn 90 degrees as they traverse the first curved turn region 2601, enter the second curved turn region 2502 continuing to travel along the path of arrow L, turn 90 degrees as they traverse the second curved turn region 2502, and finally enter the outlet region 2606 where they can be transferred to a subsequent SLIM path. Alternatively, since the complex curved turn region 2603 permits for bi-directional ion transmission, ions can be guided through the SLIM path 2600 in the opposite direction, e.g., entering at the outlet region 2606 and exiting from the inlet region 2605. In this configuration, the ions would travel along the path denoted by arrow K.
It should be understood that while the curved turn regions 1501, 1601, 1701, 1801, 1802, 1901, 2001, 2101, 2201, 2301, 2401, 2501, 2502, 2601, 2602 of the present disclosure are illustrated as smooth curves with curved electrodes, these regions could be formed from a series of segmented lines using, for example, square, rectangular, trapezoidal, bent, or otherwise angled electrodes in the rounded turn regions, such that a bent ion path is formed. One exemplary configuration is shown in
As shown in
Additionally, it should be understood that while
It should be understood that while
Having thus described the system and method in detail, it is to be understood that the foregoing description is not intended to limit the spirit or scope thereof. It will be understood that the embodiments of the present disclosure described herein are merely exemplary and that a person skilled in the art may make any variations and modification without departing from the spirit and scope of the disclosure. All such variations and modifications, including those discussed above, are intended to be included within the scope of the disclosure.
The present application is a continuation-in-part of International Application No. PCT/US2021/065617, filed Dec. 30, 2021, which claims the benefit of priority to U.S. Provisional Patent Application Ser. No. 63/132,876, filed on Dec. 31, 2020, both of which are herein incorporated by reference in their entirety.
| Number | Date | Country | |
|---|---|---|---|
| 63132876 | Dec 2020 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/US2021/065617 | Dec 2021 | US |
| Child | 18105083 | US |
