Systems and methods for analyzing a sample

Abstract

Systems and methods for analyzing a sample are provided. In some embodiments, a mass spectrometer may include a source configured to output one or more ions, a plurality of chambers having different pressures, a detector configured to detect the one or more ions, and a particle guide. The plurality of chambers may include at least a first chamber having a first pressure less than atmospheric pressure and a second chamber having a second pressure less than the first pressure. In some embodiments, the particle guide may include a conduit through which one or more ions may travel the entire length of the particle guide. A conduit may be disposed within at least the first chamber and the second chamber, and a vent may be provided to define a passage between the chambers and the conduit.

Description

Technical Field

[0001] The present disclosure relates to systems and methods for analyzing a sample. More particularly, the present disclosure relates to an improved mass spectrometry apparatus, components thereof, and methods of using the same. Background Art

[0002] Mass spectrometry is an analytical technique that can be used to analyze a sample. Among other applications, mass spectrometry can be used to analyze the composition of a sample. A mass spectrometer can be operated by applying energy to a sample, causing the sample to emit ions. The ions can travel through an electric field, and their collisions with a detector can be measured. The location where the particles are detected or the time it takes for the ions to reach the detector can vary with the mass of the ions. Thus, by measuring these parameters, the mass of the ions can be determined, and the composition of the sample can be inferred.

[0003] A time-of-flight mass spectrometer operates by measuring the time it takes for ions to travel to a detector. A time-of-flight mass spectrometer can include a particle guide that directs ions to the detector. Certain particle guides known as quadrupoles can include a section having four electrodes that are collectively disposed around a central channel through which ions can travel. A mass spectrometer typically has multiple chambers at different pressures, which traditionally has created a need for multiple particle guides. Particle guides are complex electrical devices, and the need for multiple particle guides can significantly increase cost and manufacturing difficulty. There can also be a risk that multiple quadrupoles will not be properly aligned or synchronized, which can degrade performance.

[0004] Accordingly, there is a need for systems and methods for accurately analyzing sample composition with improved reliability and at lower cost. In addition, there is a need for a mass spectrometer having an improved particle guide that can extend through multiple chambers at different pressures, allowing a single particle guide to provide an ion path through multiple chambers of the mass spectrometer. Summary of the Invention

[0005] The following description presents a simplified overview in order to provide a basic understanding of some aspects described herein. This overview is not an extensive overview of the claimed subject matter. It is neither intended to identify key or critical elements of the claimed subject matter nor to delineate its scope.

[0006] In some embodiments, a mass spectrometer may be provided. In some embodiments, the mass spectrometer may include a source configured to output one or more ions, a plurality of chambers having different pressures, a detector configured to detect the one or more ions, and a particle guide. The plurality of chambers may include at least a first chamber having a first pressure less than atmospheric pressure and a second chamber having a second pressure less than the first pressure. In some embodiments, the particle guide may include a conduit through which the one or more ions can travel the entire length of the particle guide. The conduit may be disposed at least within the first chamber and the second chamber. The particle guide may further include a housing surrounding the conduit. In some embodiments, the housing may include: a first open section including a first vent that defines a passage between the first chamber and the conduit; a second open section including a second vent that defines a passage between the second chamber and the conduit; and a closed section disposed between the first open section and the second open section, at least a portion of the closed section being disposed at the junction of the first chamber and the second chamber. The one or more ions may be configured to travel from the source, through at least the first chamber, the second chamber, and the particle guide, and to the detector.

[0007] In some embodiments, the conduit may include a quadrupole. In some embodiments, the quadrupole may include a plurality of quadrupole segments, each quadrupole segment being configured to generate an electric field that can be controlled independently of the other quadrupole segments. The plurality of quadrupole segments may be collectively configured to reduce the kinetic energy of the one or more ions as the one or more ions traverse the length of the particle guide.

[0008] In some embodiments, the quadrupole may include at least four linear components axially disposed along the length of the conduit. A central channel may extend between the four linear components, and the central channel may be open such that the one or more ions can traverse the length of the conduit by traveling through the central channel. The passage defined by the first vent may extend between two of the four linear components to the central channel.

[0009] In some embodiments, the particle guide may have a fluid conductivity defined by the open cross-sectional area of the conduit and the length of the closed section, the fluid conductivity being less than one liter per second.

[0010] In some embodiments, a seal ring may be provided between the closed section of the housing and the junction between the first chamber and the second chamber. In some embodiments, the third chamber may have a third pressure that is less than the second pressure of the second chamber. In some embodiments, the particle deflector may terminate at a lens gate disposed at the junction between the second chamber and the third chamber, and the lens gate may be configured to selectively permit the one or more ions to enter the third chamber.

[0011] In some embodiments, a particle deflector configured to be disposed in a mass spectrometer may be provided. The particle deflector may be configured to be disposed in a mass spectrometer that includes a plurality of chambers having different pressures, the plurality of chambers including at least a first chamber having a first pressure less than atmospheric pressure and a second chamber having a second pressure less than the first pressure. In some embodiments, the particle deflector may include a conduit through which the one or more ions can travel the entire length of the particle deflector. The conduit may be configured to be disposed within at least the first chamber and the second chamber. The particle deflector may further include a housing surrounding the conduit. In some embodiments, the housing may include: a first open section including a first vent configured to define a passage between the first chamber and the conduit when the first open section is disposed in the first chamber. The housing may further include a second open section including a second vent configured to define a passage between the second chamber and the conduit when the second open section is disposed in the second chamber. The housing may further include a closed section disposed between the first open section and the second open section. At least a portion of the closed section may be configured to be disposed at the junction between the first chamber and the second chamber.

[0012] In some embodiments, the particle deflector may include a quadrupole. The quadrupole may include a plurality of quadrupole sections, each quadrupole section being configured to generate an electric field that can be controlled independently of the other quadrupole sections. The plurality of quadrupole sections may be collectively configured to reduce the kinetic energy of the one or more ions as the one or more ions traverse the length of the particle deflector.

[0013] In some embodiments, the quadrupole may include four linear members axially disposed along the length of the particle deflector. A central channel may extend between the four linear members, the central channel being open such that the one or more ions can traverse the length of the particle deflector by traveling through the central channel. The passage defined by the first vent may extend between two of the four linear members to the central channel. In some embodiments, the closed section may have a fluid conductivity defined by the open cross-sectional area of the central channel and the length of the closed section, the fluid conductivity being less than one liter per second.

[0014] In some embodiments, a seal ring may be provided between the enclosed section of the housing and the junction between the first chamber and the second chamber.

[0015] In some embodiments, a particle deflector may terminate at a lens gate configured to be disposed at the junction between the second chamber and the third chamber of a mass spectrometer. The third chamber may have a third pressure that is less than the second pressure of the second chamber. The lens gate may be configured to selectively permit the one or more ions to enter the third chamber.

[0016] In some embodiments, a method for analyzing a sample may be provided. In some embodiments, the method may be performed using a mass spectrometer including a plurality of chambers having different pressures, the plurality of chambers including at least a first chamber having a first pressure less than atmospheric pressure and a second chamber having a second pressure less than the first pressure. In some embodiments, the method may include applying energy to the sample to generate one or more ions, passing the one or more ions through a particle deflector disposed at least partially in the first chamber and the second chamber of the mass spectrometer, and detecting the arrival of the one or more ions at a detector. In some embodiments, the particle deflector may include a conduit and a housing surrounding the conduit, and the one or more ions may travel through the conduit the entire length of the particle deflector. In some embodiments, the housing may include a first open section including a first vent configured to define a passage between the first chamber and the conduit. The housing may further include a second open section including a second vent configured to define a passage between the second chamber and the conduit. The housing may further include an enclosed section disposed between the first open section and the second open section, at least a portion of the enclosed section being disposed at the junction between the first chamber and the second chamber.

[0017] Further variations included within the systems and methods are described in the detailed description of the invention below. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 A schematic diagram of an exemplary mass spectrometer is shown.

[0019] Figure 2 A perspective view of certain components of the mass spectrometer is shown.

[0020] Figure 3 An exemplary particle deflector is shown.

[0021] Figure 4A and Figure 4B shows Figure 3 an additional view of the particle deflector shown in

[0022] Figure 5 shows Figure 3 a longitudinal cross - section of the particle guide shown in

[0023] Figure 6 shows an exemplary skimmer arrangement for receiving ions.

[0024] Figure 7 shows an exemplary method for analyzing a sample. Detailed Description

[0025] While aspects of the subject matter of this disclosure may be embodied in various forms, the following description and the drawings are only intended to disclose some of these forms as specific examples of the subject matter. Accordingly, the subject matter of this disclosure is not intended to be limited to the forms or embodiments so described and shown.

[0026] Figure 1 shows a schematic diagram of an exemplary mass spectrometer 100. In some embodiments, the mass spectrometer 100 can include a plurality of chambers 110a, 110b, 110c, 110d, each of which can have a different pressure. For example, chamber 110a can have a pressure less than atmospheric pressure, and each of chambers 110b, 110c, 110d can have a gradually decreasing pressure such that chamber 110d has a low enough pressure that air molecules do not affect (or minimally affect) the ion flow through chamber 110d to the detector 118. In an exemplary embodiment, chamber 110a can have a pressure between 0.1 and 10 Torr, or preferably about 1 Torr. Chamber 110b can have a pressure between 0.001 and 0.1 Torr, or preferably about 0.01 Torr. The pressure of chamber 110c can be between 10 -5 and 10 -3 Torr, or preferably about 10 -4 Torr. Chamber 110d can have a pressure between 10 -8 and 10 -5 Torr, or preferably about 10 -7 Torr. In some embodiments, a greater or lesser number of chambers can optionally be provided, and the pressure in each chamber can optionally be different from the values described herein.

[0027] In some embodiments, the mass spectrometer 100 may include a source 102 configured to output one or more ions. In some embodiments, the source 102 may include a chamber in which a sample may be accommodated. The source 102 may also include means for applying energy to molecules in the sample and ionizing them. In some embodiments, the source may use capillary electrophoresis and / or electrospray ionization. In some embodiments, ions may flow from the source 102 to the tube 104. The ions may flow from the tube 104 to the deflector 106 and then to the skimmer 108. The skimmer 108 may allow ions on the intended path to travel into the particle guide 120. Ions that deviate from the intended path may be blocked by the skimmer and may be prevented from entering the particle guide 120. The following describes an exemplary skimmer arrangement in more detail with respect to Figure 6 More detailed description of the exemplary skimmer arrangement.

[0028] In some embodiments, the particle guide 120 may include quadrupoles, as described in more detail below with respect to Figures 3 - 5 The particle guide may include a plurality of segments 122 that may apply an electric field to guide and manipulate the ion flow through the length of the particle guide. Figure 1 An exemplary particle guide having thirteen quadrupole segments is shown. The particle guide may optionally have more or fewer segments than shown in this embodiment. The particle guide may terminate at a lens gate 112, which may selectively allow ions to enter the chamber 110d. In some embodiments, the lens gate 112 may be attached to or integrated with the particle guide 120. In other embodiments, the lens gate 112 may be adjacent to the particle guide 120. The lens gate 112 may have a first state in which it is open for the passage of ions from the particle guide 120 to the chamber 110d, and may have a second state in which it blocks the flow of ions from the particle guide 120 to the chamber 110d. The lens gate 112 may be configured to selectively switch between the first state and the second state based on a signal provided by a controller.

[0029] In some embodiments, mass spectrometer 100 may include a pusher 114, a reflector 116, and a detector 118. The pusher 114 may include a plurality of conductive elements (e.g., stacked plates electrically isolated from each other) that may be selectively charged at different voltages. Ions may be configured to travel from lens gate 112 into a channel within pusher 114, and pusher 114 may generate an electric field gradient that causes the ions to accelerate through the pusher channel toward reflector 116. The reflector 116 may include a plurality of conductive rings or other elements that may be selectively charged at different voltages to generate an electric field gradient that is configured to reflect the ions toward detector 118. The detector 118 may be configured to detect the arrival of each ion that contacts detector 118 and record the precise time of each arrival. In some embodiments, detector 118 may be a microchannel plate that may be configured to detect individual ions.

[0030] In use, a sample may be placed in source 102 and energized to generate ions. The ions may flow from source 102 to tube 104, to deflector 106, and through skimmer 108 to particle guide 120. The ions may then travel through particle guide 120, which may restrict the travel of the ions and, in some embodiments, reduce their kinetic energy. The ions may then travel through lens gate 112 and reach pusher 114. The ions may be accelerated by the pusher toward reflector 116 and then reflected toward detector 118, where their arrival times may be recorded.

[0031] The time of flight of the ions from pusher 114 to detector 118 may vary based on the mass and charge of the ions. For example, ions with a larger mass may be accelerated more slowly at pusher 114 and reflector 116, resulting in a longer time of flight to detector 118. Conversely, a greater charge may produce a higher acceleration, resulting in a shorter time of flight to detector 118. By precisely measuring the time when the ions are accelerated at pusher 114 and when those ions reach detector 118, the mass and charge of the ions may be inferred, and the composition of the sample at source 102 may be analyzed.

[0032] Figure 2 A perspective view of certain components of a mass spectrometer is shown. As described above, in Figure 1 the schematic diagram shown, Figure 2 particle guide 120, lens gate 112, pusher 114, reflector 116, and detector 118 are shown.

[0033] Figure 3An exemplary particle guide 120 is shown. The particle guide 120 may include a housing 123, which may encapsulate electrical components and provide a rigid support by which the particle guide 120 may be fixed within a mass spectrometer. A plurality of quadrupole segments 122 may be disposed within the housing 123. As Figure 4A and 4B shown in more detail in

[0034] each quadrupole segment 122 may include four conductive members 128, which may be disposed around a central channel 130. The conductive members 128 may be selectively charged such that the conductive members of the quadrupole segment in combination with other quadrupole segments of the particle guide may direct and manipulate an ion stream passing through the central channel 130 of the particle guide. The central channel 130 may extend along the entire length of the particle guide. Figure 1 and Figure 6 described above with reference to

[0035] The particle guide 120 may include segments 111a, 111b, 111c. In some embodiments, segment 111a may be an open segment including a vent 124a that provides a passage from the exterior of segment 111a to the central channel 130. For example, the passage defined by the vent 124a may extend between two of the four conductors 128 of one or more quadrupole segments 122 in segment 111a.

[0036] Segment 111c may also be an open segment. Segment 111c may include a vent 124b that provides a passage from the exterior of segment 111c to the central channel 130. For example, the passage defined by the vent 124b may extend between two of the four conductors 128 of one or more quadrupole segments 122 in segment 111c. Segment 111b may preferably be a closed segment that does not include a vent hole. Additional open or closed segments may optionally be provided.

[0037] The particle guide 120 including segments 111a, 111b, 111c may be disposed within a mass spectrometer having a plurality of chambers at different pressures. Segment 111a may be disposed, for example, in a first chamber having a first pressure (such as the chamber 110b in Figure 1 ), and segment 111c may be disposed, for example, in a second chamber (such as Figure 1in chamber 110c). The vent 124a can provide a passage from the first chamber to the central channel, and the vent 124b can provide a passage from the second chamber to the central channel. Thus, the portion of the central channel near the vent 124a can be equal to or approximately equal to the pressure in the first chamber, and the portion of the central channel near the vent 124b can be equal to or approximately equal to the pressure in the second chamber.

[0038] A pressure difference can exist along the portion of the central channel spanning from the first vent 124a to the second vent 124b. The flow of air molecules can be restricted by the fluid conductivity of the closed section 111b. For example, the fluid conductivity of the closed section 111b can be determined by the cross-sectional area of the opening in the channel 130 and the length of the closed section. By making the fluid conductivity low enough (e.g., because the cross-sectional area is small enough and the length of the closed section is large enough), the air flow from the higher-pressure chamber to the lower-pressure chamber can be reduced to a level that can be counteracted by a vacuum pump or other device, thereby maintaining the pressure difference in a desired state. In some embodiments, the length of the closed section can be at least 1 cm, at least 40 cm, or more preferably at least 4 cm. In some embodiments, the cross-sectional area of the opening of the channel 130 can be less than 0.05 cm 2 , less than 5 cm 2 , or more preferably less than 0.3 cm 2 . In some embodiments, the fluid conductivity of the closed section can be less than 0.01 liters per second, less than 10 liters per second, or more preferably less than 1 liter per second. As Figure 1 illustrated, one or more vacuum pumps 113a, 113b, 113c, 113d can be arranged to remove air molecules from chambers 110a, 110b, 110c, 110d, respectively. One or more vacuum pumps can be directly fixed to the housing of the mass spectrometer 100, or they can be coupled to the chambers via hoses. In some embodiments, the vacuum pump can be a rough pump, such as a rotary vane or scroll, or a turbomolecular pump. In some embodiments, compared with chamber 110a, chambers 110b, 110c, and / or 110d can use pumps with higher power. For example, a rotary vane can be connected to chamber 110a, and a three-stage turbopump can be connected to chambers 110b, 110c, and 110d. Other pumping devices can be used.

[0039] When arranged in such as Figure 1When in the mass spectrometer shown, the opening section 111a can be arranged in chamber 110b, the opening section 111c can be arranged in chamber 110c, and the closed section 111b can be arranged across the junction between chambers 110a and 110b. In this way, a single particle guide can be arranged across multiple chambers at different pressures without generating an unacceptable level of air flow across the chambers. This can advantageously reduce the number of separate particle guides that need to be provided and installed in the mass spectrometer, thereby reducing the cost of the mass spectrometer and improving the consistency and reliability of the performance of the device.

[0040] The particle guide 120 can include one or more circumferential rings 121a, 121b, which can be configured to receive electrical contacts for controlling the electric field in the particle guide. In some embodiments, the rings 121a, 121b can alternatively or additionally be used to provide mechanical support against which the particle guide 120 can be fixed within the mass spectrometer. In some embodiments, the rings 121a, 121b can be replaced with mechanical supports having different geometries. For example, the support can be a protrusion that extends less than the entire circumference of the housing, or have a flat outer surface (e.g., triangular, rectangular, pentagonal, or hexagonal protrusion).

[0041] In some embodiments, the particle guide 120 can further include one or more sealing rings 126a, 126b. The sealing rings 126a, 126b can be made of a deformable material such as rubber or elastomeric polymer so that a sealed connection can be formed when the sealing ring contacts a surface. In some embodiments, when the particle guide 120 is installed in the mass spectrometer, the sealing rings 126a, 126b can be aligned with and contact the wall between adjacent chambers. For example, referring to Figure 1 , the sealing ring 126a can be arranged such that it contacts the inner surface of the hole in the wall between chambers 110b and 110c. The sealing ring 126b can be arranged such that it contacts the inner surface of the orifice in the wall between chambers 110c and 110d.

[0042] Figure 4A and Figure 4B shows Figure 3 a cross-sectional view of the particle guide 120 shown in

[0043] Figure 4A shows the opening section 111a of the particle guide 120. The particle guide 120 can include one or more quadrupole sections 122, each of the quadrupole sections 122 can include four conductive members 128 to which a voltage can be applied. In Figure 4AFour quadrupole segments can be seen in the cross-section of the particle deflector shown. The quadrupole segment 122 can be arranged around the central channel 130, which can define a path through which ions can flow along the length of the particle deflector. The vent 124a can form a channel from the exterior of the particle deflector to the interior of the particle deflector 120, and more specifically, to the central channel 130.

[0044] Figure 4B A closed cross-section 111b of the particle deflector 120 is shown. In Figure 4B the opening cross-sectional area of the central channel 130 can be seen. By increasing or decreasing this cross-sectional area, the fluid conductivity of the closed segment can be changed.

[0045] Figure 5 A longitudinal cross-sectional view of the particle deflector 120 as installed in the Figure 1 mass spectrometer shown is presented. As Figure 5 shown, the mount 132 can be fixed to the wall disposed between the chambers 110b and 110c by bolts or other fixing means. The mount 132 can be press-fitted or otherwise coupled to the housing 123 of the particle deflector. A sealing ring 126 can be provided between the mount 132 and the housing 123 to provide an airtight seal between these components. The same or similar structure can be provided at other locations where the particle deflector 120 is fixed to other parts of the mass spectrometer. For example, the same or similar structure can be provided at the distal end of the particle deflector 120 (e.g., around the sealing ring 126b), where the particle deflector 120 can be fixed to the wall between the chambers 110c and 110d.

[0046] Figure 6 An exemplary skimmer arrangement for receiving ions is shown. The skimmer device can include a first surface 141, a second surface 142, and a third surface 143. The first surface 11 can be disposed at a non-zero angle relative to the second surface 143, and the third surface 143 can be disposed at a non-zero angle relative to the second surface 143. In some embodiments, the first surface 141 and the third surface 143 can be parallel to each other or within 5 degrees of being parallel to each other. The second surface 142 can be disposed at an angle parallel to the central axis of the tube 104. Optionally, the second surface can be disposed at an angle closer to being parallel to the central axis of the tube 104 than the surface 141 or the surface 143.

[0047] As described above with respect to Figure 1 the particles can generally flow from the source through the tube 104. In some embodiments, the tube 104 can be a capillary 104. A series of particles with different charge-to-mass ratios can enter the flow path, in which they can be deflected by the voltage on the deflector 106. Additionally, minor changes in the particle trajectories can be observed. Figure 6Two exemplary, simplified flow paths are shown in dashed lines. In the case of the first particle path, the particles can be repelled by the deflector 106 and guided through the holes between the surfaces 141 or between the surfaces 141 and 142 of the skimmer 108 and into the particle guide 120. The second particle may not be redirected or may be minimally redirected by the deflector (e.g., due to a low charge-to-mass ratio or misalignment), and may travel through the hole and contact a surface 143 that is spaced a certain distance from the hole. By means of the inclined surface 142 as shown in Figure 6 , particles that are not redirected by the deflector or are minimally redirected by the deflector will tend to travel a distance away from the hole before contacting the skimmer. In some embodiments, at least 50%, at least 75%, at least 85%, at least 90%, at least 95%, at least 97%, at least 99% or at least 99.5% of the uncharged particles traveling through the tube can be deposited at least a certain distance from the hole. In some embodiments, this distance can be at least 500 microns, at least 1 mm, at least 3 mm, at least 5 mm, at least 10 mm, at least 20 mm, at least 50 mm, at least 100 mm or at least 200 mm. This can beneficially reduce the rate at which misaligned particles contact and deposit on or around the hole, where they may potentially become displaced and enter the particle guide during future measurements. It is noted that the contamination problem is most frequently caused by neutral substances, heavy particles and droplets, which are not redirected by the deflector 106 or are only minimally redirected by the deflector 106. Therefore, these particles can reliably travel from the hole to the surface 143, where they pose little risk of contaminating future measurements. Therefore, Figure 6 the skimmer arrangement shown can reduce the risk of deposited particle contamination of future measurements, thereby improving the accuracy and reliability of the mass spectrometer.

[0048] Figure 7 An exemplary method 700 for analyzing a sample is shown. The method 700 can be performed using a mass spectrometer having a particle guide generally described as above with respect to Figures 1 to 5 . For example, the method 700 can be performed using a mass spectrometer having multiple chambers with different pressures, the multiple chambers including at least a first chamber having a first pressure less than atmospheric pressure and a second chamber having a second pressure less than the first pressure. The mass spectrometer can include a particle guide that includes a conduit and a housing surrounding the conduit, and one or more ions can travel through the conduit the entire length of the particle guide. The housing can define a first open section including a first vent, a second open section including a second vent, and a closed section disposed between the first open section and the second open section, the first vent being configured to define a passage between the first chamber and the conduit, and the second vent being configured to define a passage between the second chamber and the conduit.

[0049] In step 702, energy can be applied to the sample to generate one or more ions. For example, capillary electrophoresis and / or electrospray ionization can be used to generate ions. The ions can then optionally flow from the sample to the particle guide via one or more of a capillary, a deflector, and / or a skimmer. In step 704, the ions can travel through the length of the particle guide. The particle guide can be arranged across multiple chambers of the mass spectrometer at different pressures. In some embodiments, the particle guide can have a first vent defining a channel leading to a first chamber of the mass spectrometer and a second vent defining a channel leading to a second chamber of the mass spectrometer. To reduce the flow of air molecules along the pressure difference between the chambers, the vents can be spaced apart by a closed section having a cross-sectional area and length selected to provide a sufficiently low fluid conductivity. To maintain the desired pressure conditions, the chambers of the mass spectrometer can additionally be evacuated continuously or intermittently using a vacuum pump.

[0050] In step 706, the detector can detect the arrival of the ions at the detector. In some embodiments, the detector can be configured to detect the arrival of each ion contacting the detector and record the exact time of each arrival. In some embodiments, the detector can be a microchannel plate. In some embodiments, the time between when the pusher starts to accelerate the ions and when those ions reach the detector can be analyzed to determine the composition of the sample.

[0051] Numbered examples

[0052] Exemplary embodiments of the systems and methods disclosed herein are described in the numbered paragraphs below.

[0053] A1. A mass spectrometer, the mass spectrometer comprising:

[0054] A source configured to output one or more ions;

[0055] Multiple chambers having different pressures, the multiple chambers at least including a first chamber having a first pressure less than atmospheric pressure and a second chamber having a second pressure less than the first pressure;

[0056] A detector configured to detect the one or more ions; and

[0057] A particle guide, the particle guide including:

[0058] A conduit through which the one or more ions can travel the entire length of the particle guide, the conduit being disposed at least within the first chamber and the second chamber; and

[0059] A housing surrounding the conduit, the housing at least including:

[0060] ​

[0061] A first opening section including a first vent opening that defines a passage between the first chamber and the conduit;

[0062] A second opening section including a second vent opening that defines a passage between the second chamber and the conduit; and

[0063] A closed section disposed between the first opening section and the second opening section, with at least a portion of the closed section disposed at the junction between the first chamber and the second chamber;

[0064] wherein the one or more ions are configured to travel from the source, through at least the first chamber, the second chamber, and the particle guide, and reach the detector.

[0065] A2. The mass spectrometer according to embodiment A1, wherein the conduit comprises a quadrupole.

[0066] A3. The mass spectrometer according to embodiment A2, wherein the quadrupole comprises a plurality of quadrupole sections, each quadrupole section being configured to generate an electric field that can be controlled independently of other quadrupole sections, and the plurality of quadrupole sections being jointly configured to reduce the kinetic energy of the one or more ions as they pass through the length of the particle guide.

[0067] A4. The mass spectrometer according to embodiment A2, further wherein:

[0068] the quadrupole comprises four linear components axially disposed along the length of the conduit;

[0069] a central channel that extends between the four linear components, the central channel being open such that the one or more ions can pass through the central channel to traverse the length of the conduit; and

[0070] the passage defined by the first vent opening extends between two of the four linear components to the central channel.

[0071] A5. The mass spectrometer according to embodiment A4, wherein at least a portion of the particle guide has a fluid conductance defined by the cross-sectional area of the opening of the conduit and the length of the closed section, and the fluid conductance is less than one liter per second.

[0072] A6. The mass spectrometer according to any one of embodiments A1 - A5, wherein a sealing ring is disposed between the closed section of the housing and the junction between the first chamber and the second chamber.

[0073] A7. The mass spectrometer according to any one of embodiments A1 - A6 further includes a third chamber having a third pressure less than the second pressure of the second chamber;

[0074] wherein the particle guide terminates at a lens gate disposed at the junction between the second chamber and the third chamber, and the lens gate is configured to selectively allow the one or more ions to enter the third chamber.

[0075] B1. A particle guide configured to be arranged in a mass spectrometer including a plurality of chambers having different pressures, the plurality of chambers including at least a first chamber having a first pressure less than atmospheric pressure and a second chamber having a second pressure less than the first pressure, the particle guide comprising:

[0076] a conduit through which the one or more ions can travel the entire length of the particle guide, the conduit being configured to be arranged in at least the first chamber and the second chamber; and

[0077] a housing surrounding the conduit, the housing including at least:

[0078] a first opening section including a first vent configured to define a passage between the first chamber and the conduit when the first opening section is disposed in the first chamber;

[0079] a second opening section including a second vent configured to define a passage between the second chamber and the conduit when the second opening section is disposed in the second chamber; and

[0080] a closed section disposed between the first opening section and the second opening section, at least a portion of the closed section being configured to be disposed at the junction between the first chamber and the second chamber.

[0081] B2. The particle guide according to embodiment B1, wherein the particle guide includes a quadrupole.

[0082] B3. The particle guide according to embodiment B2, wherein the quadrupole includes a plurality of quadrupole sections, each quadrupole section being configured to generate an electric field that can be controlled independently of the other quadrupole sections, and the plurality of quadrupole sections being collectively configured to reduce the kinetic energy of the one or more ions as the one or more ions travel through the length of the particle guide.

[0083] B4. The particle guide according to embodiment B2, further wherein:

[0084] The quadrupole includes four linear components arranged axially along the length of the particle guide;

[0085] A central channel that extends between the four linear components, the central channel being open such that the one or more ions can pass through the length of the particle guide by traveling through the central channel; and

[0086] A channel defined by a first vent hole extends between two of the four linear components into the central channel.

[0087] B5. The particle guide according to embodiment B4, wherein the closed section has a fluid conductance defined by the open cross-sectional area of the central channel and the length of the closed section, the fluid conductance being less than one liter per second.

[0088] B6. The particle guide according to any one of embodiments B1 - B5, wherein a sealing ring is provided between the closed section of the housing and the junctions between the first chamber and the second chamber.

[0089] B7. The particle guide according to any one of embodiments B1 - B6, wherein the particle guide terminates at a lens gate configured to be disposed at the junction between the second chamber and the third chamber of the mass spectrometer, the third chamber having a third pressure less than the second pressure of the second chamber, the lens gate being configured to selectively allow the one or more ions to enter the third chamber.

[0090] C1. A method of analyzing a sample using a mass spectrometer, the mass spectrometer including a plurality of chambers having different pressures, the plurality of chambers including at least a first chamber having a first pressure less than atmospheric pressure and a second chamber having a second pressure less than the first pressure, the method comprising:

[0091] Applying energy to the sample to generate one or more ions;

[0092] Passing the one or more ions through a particle guide disposed at least partially in the first chamber and the second chamber of the mass spectrometer, wherein the particle guide includes:

[0093] A conduit through which the one or more ions can travel the entire length of the particle guide; and

[0094] A housing surrounding the conduit, the housing including at least:

[0095] A first open section including a first vent hole configured to define a channel between the first chamber and the conduit;

[0096] A second opening section, including a second ventilation opening configured to define a passage between the second chamber and the conduit; and

[0097] A closed section disposed between the first opening section and the second opening section, at least a portion of the closed section being disposed at the junction of the first chamber and the second chamber; and

[0098] Detecting the arrival of the one or more ions at the detector.

[0099] Although the subject matter of the present disclosure has been described and illustrated in considerable detail with reference to certain illustrative embodiments including various combinations and sub - combinations of features, those skilled in the art will readily understand other embodiments and variations and modifications included within the scope of the present disclosure. Further, the description of such embodiments, combinations, and sub - combinations is not intended to convey that the claimed subject matter requires features or combinations of features other than those expressly recited in the claims. Accordingly, the scope of the present disclosure is intended to include all modifications and variations that fall within the spirit and scope of the following appended claims.

Claims

1. A mass spectrometer, the mass spectrometer comprising: a source configured to output one or more ions; a plurality of chambers having different pressures, the plurality of chambers including at least a first chamber having a first pressure less than atmospheric pressure and a second chamber having a second pressure less than the first pressure; a detector configured to detect the one or more ions; and a particle guide, the particle guide comprising: a duct through which the one or more ions can travel the entire length of the particle guide, the duct being disposed at least within the first chamber and the second chamber; and a housing surrounding the duct, the housing including at least: a first opening section including a first vent, the first vent defining a passage between the first chamber and the duct; a second opening section including a second vent, the second vent defining a passage between the second chamber and the duct; and a closed section disposed between the first opening section and the second opening section, at least a portion of the closed section being disposed at the junction of the first chamber and the second chamber; wherein the one or more ions are configured to travel from the source, through at least the first chamber, the second chamber, and the particle guide, and to reach the detector.

2. The mass spectrometer according to claim 1, wherein the duct comprises a quadrupole.

3. The mass spectrometer according to claim 2, wherein the quadrupole comprises a plurality of quadrupole segments, each quadrupole segment being configured to generate an electric field that can be controlled independently of the other quadrupole segments, the plurality of quadrupole segments being collectively configured to reduce the kinetic energy of the one or more ions as the one or more ions traverse the length of the particle guide.

4. The mass spectrometer according to claim 2, further wherein: the quadrupole comprises four linear members axially disposed along the length of the duct; a central channel extending between the four linear members, the central channel being open such that the one or more ions can travel through the central channel to traverse the length of the duct; and the passage defined by the first vent extends between two of the four linear members to the central channel.

5. The mass spectrometer according to claim 4, wherein at least a portion of the particle guide has a fluid conductivity defined by the open cross-sectional area of the duct and the length of the closed section, the fluid conductivity being less than one liter per second.

6. The mass spectrometer according to claim 1, wherein a sealing ring is disposed between the closed section of the housing and the junction between the first chamber and the second chamber.

7. The mass spectrometer according to claim 1, further comprising a third chamber having a third pressure less than the second pressure of the second chamber; wherein the particle guide terminates at a lens gate disposed at the junction between the second chamber and the third chamber, the lens gate being configured to selectively allow the one or more ions to enter the third chamber.

8. A particle guide configured to be arranged in a mass spectrometer, the mass spectrometer including a plurality of chambers having different pressures, the plurality of chambers including at least a first chamber having a first pressure less than atmospheric pressure and a second chamber having a second pressure less than the first pressure, the particle guide comprising: a conduit through which the one or more ions can travel the entire length of the particle guide, the conduit being configured to be disposed in at least the first chamber and the second chamber; and a housing surrounding the conduit, the housing including at least: a first opening section including a first vent configured to define a passage between the first chamber and the conduit when the first opening section is disposed in the first chamber; a second opening section including a second vent configured to define a passage between the second chamber and the conduit when the second opening section is disposed in the second chamber; and a closed section disposed between the first opening section and the second opening section, at least a portion of the closed section being configured to be disposed at the junction between the first chamber and the second chamber.

9. The particle guide according to claim 8, wherein the particle guide includes a quadrupole.

10. The particle guide according to claim 9, wherein the quadrupole includes a plurality of quadrupole segments, each quadrupole segment being configured to generate an electric field that can be controlled independently of the other quadrupole segments, the plurality of quadrupole segments being jointly configured to reduce the kinetic energy of the one or more ions as the one or more ions travel through the length of the particle guide.

11. The particle guide according to claim 9, further wherein: the quadrupole includes four linear components axially disposed along the length of the particle guide; a central channel extending between the four linear components, the central channel being open such that the one or more ions can travel through the central channel to pass through the length of the particle guide; and the passage defined by the first vent extends between two of the four linear components to the central channel.

12. The particle guide according to claim 11, wherein the closed section has a fluid conductivity defined by the open cross-sectional area of the central channel and the length of the closed section, the fluid conductivity being less than one liter per second.

13. The particle guide according to claim 8, wherein a sealing ring is disposed between the closed section of the housing and the junction between the first chamber and the second chamber.

14. The particle guide according to claim 8, wherein the particle guide terminates in a lens gate configured to be disposed at the junction between the second chamber and a third chamber of the mass spectrometer, the third chamber having a third pressure less than the second pressure of the second chamber, the lens gate being configured to selectively allow the one or more ions to enter the third chamber.

15. A method for analyzing a sample using a mass spectrometer, the mass spectrometer comprising a plurality of chambers having different pressures, the plurality of chambers including at least a first chamber having a first pressure less than atmospheric pressure and a second chamber having a second pressure less than the first pressure, the method comprising: applying energy to the sample to generate one or more ions; passing the one or more ions through a particle guide disposed at least partially in the first chamber and the second chamber of the mass spectrometer, wherein the particle guide comprises: a conduit through which the one or more ions can travel the entire length of the particle guide; and a housing surrounding the conduit, the housing including at least: a first opening section including a first vent configured to define a passage between the first chamber and the conduit; a second opening section including a second vent configured to define a passage between the second chamber and the conduit; and a closed section disposed between the first opening section and the second opening section, at least a portion of the closed section being disposed at the junction of the first chamber and the second chamber; and detecting the arrival of the one or more ions at a detector.

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