Atmospheric pressure ion source interface

Abstract

Interface (20) for receiving ions in a carrier gas from an atmospheric pressure ion source at a spectrometer configured to analyze the received ions at a lower pressure, wherein the interface (20) comprises: an interface vacuum chamber (22) which has a downstream opening (80); a support arrangement (45) defining an axial bore (30) arranged such that a removable capillary tube extends through it, wherein ions from the atmospheric pressure ion source are received through the capillary tube and directed towards the downstream opening (80); and a jet jammer (40) positioned downstream of the axial bore (30) and configured to interrupt the gas flow between the axial bore (30) and the downstream opening (80) only when the capillary tube is not fully inserted through the axial bore (30), characterized in that the interface (20) further comprises a sealing valve located along the axial bore (30) and configured to seal the axial bore (30) when the capillary tube is removed.

Description

Technical field of the disclosure

[0001] The disclosure relates to an interface for receiving ions in a carrier gas from an atmospheric pressure ion source at a spectrometer (e.g., a mass spectrometer or ion mobility spectrometer) configured to analyze the received ions at a lower pressure, and to a spectrometer including such an interface. Background of the Revelation

[0002] Mass spectrometers can be used to analyze samples to determine the mass-to-charge ratio (m / z) of the sample's ions. The sample is often ionized in an atmospheric pressure ion source. In atmospheric pressure ion sources, the sample ions are generated at a pressure close to atmospheric pressure, although the pressure range may differ somewhat from that of the surrounding atmosphere depending on the design of the ion source. This class of ion sources can include: an electrospray ionization (ESI) source; an atmospheric pressure chemical ionization (APCI) source; an atmospheric pressure matrix-assisted laser desorption / ionization (AP-MALDI) source; and an atmospheric pressure photoionization (APPI) source.The ESI source can also be a heated electrospray ionization (HESI) source.

[0003] Mass spectrometers typically involve the ionization of a sample from a gas or liquid phase, which may be provided, for example, through a nozzle and / or a needle. Ionization of the sample from a liquid phase can produce a spray, preferably of uncharged or charged droplets. Ions are typically introduced via a conductivity-restricting capillary into an interface of the mass spectrometer, which includes an interface vacuum chamber. The ions are then transferred to a higher vacuum, which has a lower pressure, through stages of differential pumping. Since the capillary becomes contaminated over time, it is preferred that it be replaceable without breaking the instrument's vacuum.Protecting the instrument from vacuum loss during this process is important to avoid having to restore the vacuum after the instrument has been baked out, which would normally take a day during which the instrument could not be used for measurements.

[0004] A common method for protecting the vacuum is to install a small shutoff valve upstream of the capillary, which can be manually closed before removing the capillary. This method is used on commercial instruments, including a "6545 Q-TOF" sold by Agilent Technologies, Inc. Installing such valves can be expensive, the valve can be bulky, and it can increase the complexity of the capillary exchange procedure and impair the performance of the mass spectrometer.

[0005] Another protection method is to ensure that sufficient conductivity restriction remains in the interface when the capillary is removed and pumped to tolerate the additional gas load for short periods. This can also affect performance due to the position of the conductivity-restricting parts, which may include parts upstream of the capillary. This can further increase the risk of the capillary bore being left open by the user for extended periods. Additionally, some restrictions on the radius of the capillary can be introduced to keep the surrounding bore small. Alternatively, excess pumping capacity may be required, which is expensive.

[0006] An improvement is described in US Patent Nos. 6,667,474 B1 and 8,242,440 B2, in which a ball valve is provided in a support assembly for the capillary, which presses against the body of the capillary such that the valve automatically closes and seals the atmospheric interface when the capillary is removed and opens when the capillary is inserted. This approach has been found to work well, but that vacuum protection remains suboptimal during capillary removal. In this condition, a gas jet could reach a vacuum chamber downstream of the interface vacuum chamber (i.e., the chamber into which the capillary projects). Accordingly, excess pumping capacity must be provided to this downstream vacuum chamber, which the gas jet may inadvertently reach.Improving vacuum protection without significantly increasing instrument cost and complexity is therefore highly desirable. Summary of Revelation

[0007] Against this background, an interface is provided for receiving ions in a carrier gas from an atmospheric pressure ion source at a spectrometer (for example, a mass spectrometer or ion mobility spectrometer) configured to analyze the received ions at a lower pressure according to claim 1 and at a spectrometer (mass spectrometer or ion mobility spectrometer) according to claim 14. Further features of the disclosure are set forth in the dependent claims and explained herein.

[0008] The inventors have found that vacuum protection at the interface in existing approaches is not ideal because, even with an automatic vacuum protection valve, such as a ball valve, under certain circumstances an ion beam can still flow into the interface vacuum chamber (i.e., the beam can flow downstream to the support assembly) when the capillary is inserted or removed. This beam can disrupt the ion transfer optics and introduce additional gas load into downstream pumping regions via the downstream opening. Therefore, the disclosure provides a device for blocking the gas beam, a beam disruptor. This device is applied only during the vulnerable time of retraction and / or insertion of the capillary (i.e.,However, this device (which interrupts the gas flow) is not applied during normal operation (or is advantageously removed) when the capillary tube is fully inserted through the axial bore. The jet disruptor can close the downstream end of the capillary once the capillary movement begins.

[0009] The approach disclosed here reduces the risk of vacuum disturbance during capillary movement. It is simple and cost-effective to implement and does not affect device performance during operation.

[0010] The beam disruptor is preferably retractable from a position in which it interrupts the gas flow when the capillary tube is not fully inserted, to a position in which it does not interrupt the gas flow when the capillary tube is fully inserted. For example, the beam disruptor may remain in a position to interrupt the gas flow and be elastically biased against displacement upon insertion of the capillary, for example by means of a spring or other elastic mechanism or by means of an automatic (for example, electronic) control. The beam disruptor may be electrically conductive, for example comprising a sheet metal strip that can effectively interrupt the gas flow. For example, one end of the metal strip may be attached to the support assembly so that a distal portion interrupts the gas flow when the capillary tube is not fully inserted through the axial bore.This distal section can be pushed or displaced when the capillary tube is fully inserted through the axial bore to avoid interrupting the gas flow. The distal section can be connected to the fixed end by a movable joint and / or the distal section can be shaped (e.g., bent relative to the fixed section) to better interrupt the flow. One end of the axial bore can be chamfered. Then, the sheet metal strip of the jet disruptor can lie flat over the chamfered end of the axial bore when the capillary tube is not fully inserted through the axial bore. Optionally, the jet disruptor can be elastic up to a temperature of at least 200°C.

[0011] The jet disruptor is provided in addition to a sealing valve that seals the interface when the capillary tube is removed. For example, the sealing valve can be a ball valve or an electronically controlled valve. The sealing valve can be arranged along the axial bore so that the jet disruptor is located between the sealing valve and the downstream opening. Optionally, in some embodiments, the sealing valve can be combined with the jet disruptor. Then, the combined jet disruptor and sealing valve can be located at the end of the axial bore closest to the downstream opening.

[0012] As explained below, beam disruptors for protecting open interfaces (i.e., without a sealing valve) are known, where the capillary opens directly opposite a downstream opening. In preferred embodiments according to the disclosure, the interface is arranged such that the tube opening (i.e., the bore receiving the tube) is offset from the downstream opening. This limits the line of sight for the gas load and unwanted material such as droplets that can cause contamination of the ion optics. The beam disruptor of the present disclosure therefore provides additional protection for the vacuum.

[0013] The interface may include additional components, such as: an ion funnel to direct the ion flow toward the downstream orifice; and a heated block that is integrated into or forms the support assembly and extends around the bore that accommodates the capillary.

[0014] The interface vacuum chamber is desirably maintained at a pressure below atmospheric pressure, for example by means of a vacuum pumping arrangement.

[0015] According to the disclosure, a spectrometer (in particular an ion spectrometer, for example a mass spectrometer or an ion mobility spectrometer) comprising an interface disclosed herein is also provided. The spectrometer advantageously further comprises an atmospheric pressure ion source, for example one or more of: an electrospray ionization (ESI) source; an atmospheric pressure chemical ionization (APCI) source; an atmospheric pressure matrix-assisted laser desorption / ionization (AP-MALDI) source; an atmospheric pressure photoionization (APPI) source; and a hot electrospray ionization (HESI) source.Typically, the mass spectrometer further comprises a mass analyzer downstream of the interface, for example, one or more of: a time-of-flight (TOF) analyzer; a quadrupole mass analyzer; a Fourier transform mass spectrometry (FTMS) analyzer; an ion trap mass analyzer; a magnetic sector mass analyzer; and a hybrid mass analyzer. In preferred embodiments, the spectrometer is differentially pumped, for example, such that a pressure in a chamber downstream of the interface vacuum chamber (for example, where the mass analyzer is located) is lower than the pressure in the interface vacuum chamber. Brief description of the drawings

[0016] The disclosure may be put into practice in various ways and preferred embodiments will now be described by way of example only with reference to the accompanying drawings in which: Fig. 1 schematically shows an interface for receiving ions from an atmospheric pressure ion source at a mass spectrometer according to an embodiment of the disclosure; Fig. 2 a perspective view of a part of an interface according to Fig. 1, comprising a beam disruptor in (a) an active position and (b) a retracted position; Fig. 3 a cross-sectional view of a part of an interface according to Fig. 1, comprising a beam disruptor in (a) an active position and (b) a retracted position; and Fig. Figure 4 shows pressure versus time plots during insertion and removal of a capillary at a mass spectrometer interface (a) without a beam disruptor and (b) with a beam disruptor. Detailed description of preferred embodiments

[0017] A basic embodiment comprises a known interface for receiving ions from an atmospheric pressure ion source to a mass spectrometer with the addition of a beam disruptor that interrupts the gas flow only when the capillary is not fully inserted into the interface. Advantageously, the beam disruptor is retracted from the ion path when the capillary is fully inserted. When the capillary is retracted, the beam disruptor can move down into the gas flow path to break the beam and limit the amount of gas that propagates to the next vacuum region. During normal operation, the beam disruptor advantageously does not interact with gas flows or ion transfer.

[0018] As mentioned above, beam disruptors are known, for example, in US Patent No. 6,583,408 B2. This describes a fixed beam disruptor located within an electrodynamic ion funnel, blocking the line of sight between the inlet capillary and the opening to the next vacuum stage. This is intended to assist in the separation of desolvated ions from droplets and carrier gas, as well as to reduce the gas load in downstream vacuum stages. This device also blocks the line of sight for ion transmission. The beam disruptor can also increase the risk of contamination and charging, as well as overall complexity and cost. In addition, the capillary (or rather, the axial bore into which the capillary is inserted) is usually slightly offset from the next downstream opening. This limits the line of sight for the gas load and unwanted material such as droplets, which can cause contamination of the ion optics.In this case, a beam disruptor of the type described in US Patent No. US 6 583 408 B2 is of little use.

[0019] The advantage of a beam disruptor according to the disclosure, in which the gas flow is only interrupted when the capillary is not fully inserted into the interface, but advantageously is not interrupted when the capillary is fully inserted, is that the vacuum is significantly better protected. Preventing an ion beam from flowing into the interface vacuum chamber when the capillary is not fully inserted or removed reduces both the disturbance to the ion transmission optics and the gas load into the downstream pumping regions. These advantages apply when no other form of vacuum protection is provided, but are even greater when a sealing valve is provided to seal the bore into which the capillary is inserted and / or the bore and downstream opening are offset from each other.

[0020] In a generalized sense, an interface for receiving ions in a carrier gas from an atmospheric pressure ion source at a spectrometer (typically a mass spectrometer or an ion mobility spectrometer) can be considered. The spectrometer is configured to analyze the received ions at a lower pressure. The interface includes: an interface vacuum chamber having a downstream port; a support assembly defining an axial bore arranged to have a removable capillary tube extending therethrough; and a beam disruptor positioned downstream of the axial bore and configured to interrupt gas flow between the axial bore and the downstream port only when the capillary tube is not fully inserted through the axial bore.Ions are advantageously collected from the atmospheric-pressure ion source through the capillary tube and directed toward the downstream orifice. Advantageously, the beam disruptor is configured so that it does not interrupt the gas flow between the axial bore and the downstream orifice when the capillary tube is fully inserted through the axial bore.

[0021] In a further generalized aspect, a spectrometer may be considered, comprising: an atmospheric pressure ion source; and an interface for receiving ions in a carrier gas from the atmospheric pressure ion source according to any such interface disclosed herein. The downstream opening of the interface separates the interface chamber from a downstream chamber. One or more further ion optical devices may be provided in the downstream chamber. The mass spectrometer may further comprise a mass analyzer downstream of the interface.

[0022] A method for manufacturing and / or operating an interface for a spectrometer and / or a spectrometer comprising steps corresponding to the effects of the specific features or components described herein may additionally be considered. Additional generalized aspects, including preferred and / or optional features, are described below. Specific embodiments are described first.

[0023] With reference to Fig. Figure 1 schematically shows an exemplary interface for receiving ions from an atmospheric pressure ion source at a mass spectrometer. The interface 20 includes: an interface vacuum chamber 22 having a downstream port 80; a support assembly 45 comprising an axial bore 30 for receiving a transport capillary 35 and a heated block 60; a retractable beam disruptor 40; a ball valve 50; and an ion funnel 70. In this embodiment, the ion sample 10 is provided to an atmospheric pressure electrospray ionization (ESI) needle 12, and the resulting spray 15 flows through the capillary 35. The interface 20 is maintained at a sub-atmospheric pressure by vacuum pumps 25.

[0024] In the Fig. In the position shown in Figure 1, the beam disruptor is retracted and does not interrupt the gas flow. Furthermore, insertion of the capillary opens the ball valve 50, so this also does not provide an interruption. The ions flow through the capillary 35, the ion funnel 70, and the downstream orifice 80 (or exit orifice) to capture ions across a vacuum region and transfer them to the downstream ion optics 90 (such as a quadrupole ion guide). The downstream ion optics 90 are located in a separate chamber from the interface vacuum chamber 22 of the interface 20 and are maintained by vacuum pumps 85 at a lower pressure than in the interface 20. In other words, the vacuum chamber is differentially pumped.

[0025] The heated block (which in this embodiment uses resistive electrical heating) assists in the desolvation of ions from water droplets within the transfer capillary 35. The capillary 35 is supported in the support assembly 45, which includes the ball valve 50 to seal the inlet during capillary removal. The support assembly 45 also supports the beam disruptor 40, which rests on the capillary by a bent end portion 41 and moves downward in front of the capillary as the capillary is retracted. The beam disruptor 40 typically interrupts the ion beam when more than 20% of the length of the capillary 35 is retracted from the axial bore 30, more preferably when more than 10% of the length of the capillary 35 has been retracted, and especially when more than 5% of the length of the capillary 35 has been retracted.Therefore, the beam disruptor 40 can begin to affect the gas flow even when only a small portion of the capillary 35 has been retracted. Typically, the beam disruptor interrupts the ion beam when more than 5 mm of the capillary 35 has been retracted, more preferably when more than 2 mm of the capillary 35 has been retracted, and especially when more than 1 mm of the capillary 35 has been retracted.

[0026] With reference to Fig. 2 is a perspective view of a portion of an interface according to Fig. 1, which includes a beam disruptor in (a) an active position and (b) a retracted position. It is also Fig. 3, which shows a cross-sectional view of the Fig. 2 shown sections, although in Fig. 3(b) the capillary 35 is not removed. The same reference numbers as in Fig. 1. These drawings are an example of a capillary housing (in this case including the heated block 60) incorporating the jet disruptor 40 according to the disclosure. In this specification, the jet disruptor 40 is a thin strip of cut sheet metal, one end 42 of which (distal of the bent end 41) is attached to the support assembly 45, specifically the heated block 60. The jet disruptor 40 is advantageously made of spring steel. The end of the axial bore 30 (or rather, the part of the heated block where the axial bore ends) is chamfered so that the end face of the axial bore is inclined. The end of the capillary 35 is typically not chamfered.

[0027] The beam disruptor 40a hangs down in front of the retracted capillary in the active position. When the capillary 35 is inserted, it pushes the beam disruptor 40b up into the retracted position and out of the gas path. The sheet metal of the beam disruptor 40 is bolted to the heated block 60, which surrounds the capillary body 35 and also serves as an electrical contact between the two. The beam disruptor 40 includes a relatively long straight section that is generally parallel to the (beveled) side of the heated block 60. The long straight section of the beam disruptor 40 includes the bolted end of the sheet metal. The other end of the beam disruptor 40 includes a bent section that is angled away from the side of the heated block 60 with respect to the long straight section.

[0028] In this embodiment, the beam disruptor 40 therefore comprises a metal object at the end of a spring device (in this case, a consequence of the use of spring steel for the beam disruptor 40) that can exert an (elastic bias) force when the capillary tube 35 is retracted. The force to retract the beam disruptor is applied by the capillary 35 during its insertion. The beam disruptor 40 is extended over the heater block 60 to interrupt the gas flow at the beginning of the movement of the capillary 35. As shown, the upper end 41 of the beam disruptor 40 is bent toward, but parallel to, the outer surface of the capillary tube 35.

[0029] Therefore, the beam disruptor 40 shown in this embodiment does not seal the atmospheric interface. Fig. 2 and Fig. The configuration shown in Figure 3 covers the axial bore 30, but without the force or sealing members required to prevent complete gas flow. Fig. Figure 3(a) shows how partial insertion or removal of capillary 35 does not necessarily result in a stoppage of the gas flow, since ball valve 50 may not yet seal axial bore 30. Nevertheless, a reduction in gas flow can be seen. The reduced gas flow flows around the end section 41 of the jet disruptor 40, which is arranged downstream.

[0030] The choice of metal for the beam deflector 40 is not limited to a specific composition (although spring steels may be advantageous), but in a preferred embodiment, Duratherm (RTM) 600 hard (sold by VACUUMSCHMELZE GmbH & Co. KG), Inconel (RTM) 718 hard (sold by Special Metals Corporation), or Inconel (RTM) 750 (sold by Special Metals Corporation), which are thermally resilient, can be used. This is discussed further below.

[0031] A number of preferred and / or optional features relating to the generalized aspect discussed above will now be described. For example, the configuration of the jet disruptor such that gas flow is interrupted only when the capillary tube is not fully inserted may be a result of one or more of the shape; the dimensions; the movement (particularly with respect to the capillary); and the position of the jet disruptor. Preferably, the jet disruptor is configured to retract from a position to interrupt gas flow between the axial bore and the downstream orifice when the capillary tube is fully inserted through the axial bore.In other words, the jet disruptor may be in an interrupted position when the capillary tube is not fully inserted through the axial bore and is retracted from this interrupted position when the capillary tube is fully inserted through the axial bore. Additionally or alternatively, the jet disruptor may be arranged to rest in an interrupted position to interrupt the gas flow between the axial bore and the downstream opening and may be elastically biased against displacement from this position upon insertion of the capillary tube through the axial bore. Such elastic bias may be provided by a spring device or equivalent.Inserting the capillary tube through the axial bore may subsequently cause displacement away from the interruption position, with advantageously no interruption being provided when the capillary tube is fully inserted through the axial bore.

[0032] In preferred embodiments, the beam disruptor comprises (or consists of) a sheet metal strip. For example, a first end of the sheet metal strip of the beam disruptor may be attached to the support assembly (e.g., a heated block of the support assembly, as discussed below). In this way, a portion of the sheet metal strip distal to the first end may be configured to interrupt gas flow if the capillary tube is not fully inserted through the axial bore. The portion of the sheet metal strip distal to the first end is advantageously pushed or displaced when the capillary tube is fully inserted through the axial bore. In embodiments, one end of the axial bore may be chamfered (or, equivalently, a portion of the support structure defining the axial bore may be shaped such that the end of the axial bore is chamfered).Then, the sheet metal strip of the beam disruptor is optionally arranged so that it lies flat over the beveled end of the axial bore when the capillary tube is not fully inserted through the axial bore. This can improve the interruption of gas flow when the capillary tube is not fully inserted. The beam disruptor can be resistant to a temperature of at least 200°C and optionally to a temperature of at least 250°C, 300°C, 400°C, 500°C, 550°C, or 600°C. The materials described above for the beam disruptor can be resistant to temperatures between 370°C and 550°C. Stability at temperatures above 400°C may be preferred for use in the ion source interface, as the inlet capillary (or axial bore) can reach this temperature.

[0033] Advantageously, the support arrangement comprises a heated block extending around (and / or defining) the axial bore.

[0034] In preferred embodiments, the interface further comprises: a sealing valve disposed along the axial bore and configured to seal the axial bore when the capillary tube is removed. In embodiments, the sealing valve is provided along the axial bore upstream of the jet disruptor (or equivalently, the jet disruptor is located between the sealing valve and the downstream orifice). Optionally, the sealing valve comprises (or is) a ball valve or an electronically controlled valve.

[0035] Preferably, the axial bore defines an axis that is offset from an axis through the downstream opening that is perpendicular to a plane of the downstream opening. The axes are advantageously offset in a direction perpendicular to the axis of the axial bore and / or the axis through the downstream opening. Preferably, the axes are parallel.

[0036] Optionally, the interface further comprises an ion funnel arranged between the axial bore and the downstream opening (in particular in the interface vacuum chamber). The ion funnel is preferably configured to direct the ion flow toward the downstream opening of the interface vacuum chamber.

[0037] In embodiments, the interface further comprises a vacuum pumping arrangement arranged such that a pressure between the axial bore and the downstream opening is lower than atmospheric pressure. The vacuum pumping arrangement may additionally or alternatively be arranged to cause a first pressure in the interface vacuum chamber below atmospheric pressure and a second pressure in a chamber downstream of the interface below the first pressure. In other words, the interface and the downstream chamber may be differentially pumped. An ion optical device, such as an ion guide, an ion trap, an ion filter, or a mass selection device, may be provided in the downstream chamber. The ion optical device may be a quadrupole device. Further generalized and / or specific features are discussed below.

[0038] With reference to Fig. Figure 4 shows pressure versus time plots during the insertion and removal of a capillary at a mass spectrometer interface (a) without a beam disruptor and (b) with a beam disruptor. These plots illustrate the pressure changes experimentally measured in differentially pumped vacuum regions downstream of the downstream opening of the interface vacuum chamber during capillary insertion and removal before and after application of the beam disruptor according to this disclosure. It can be seen that without the beam disruptor (a), pressure spikes occur at levels that may require vacuum restoration, but with the beam disruptor installed (b), these spikes were effectively eliminated.

[0039] It is understood that changes may be made to the above embodiment, which, however, still fall within the scope of the disclosure. For example, an alternative to the Fig. 1 shown jet disruptor 40 may consist of a valve such as the one in Fig. 1, to the downstream end of the axial bore 30, thereby minimizing the time the capillary can retract before the valve closes. In other words, the functions of the sealing valve and the jet disruptor could be combined to close the opening and simultaneously interrupt the jet. This is less preferred because, according to Fig. 1 may be significantly more expensive than the beam disruptor 40 and may pose mechanical space constraints (since the size and position of the sealing valve and beam disruptor combination may not be efficiently fitted at the downstream end of the axial bore 30). It may also require the capillary 35 to move into a suboptimal position for ion transfer to accommodate the combined sealing valve and beam disruptor in the limited space of the support assembly.

[0040] As discussed herein, in accordance with generalized embodiments of the disclosure, the jet disruptor may be considered part of a sealing valve. In such embodiments, the combined jet disruptor and sealing valve may be located toward (or at) the end of the axial bore closest to the downstream port.

[0041] Other alternatives to Fig. The beam disruptors 40 shown in Figure 1 may also be considered by those skilled in the art. For example, these alternatives may be a suspended object or include a suspended object that can be moved between the capillary and the downstream opening (exit opening) when the capillary is not fully inserted into the axial bore of the support assembly. The suspended object may be motorized and moved manually or even automatically via a sensor that records the capillary position. Alternatively to spring devices, the weight of the beam disruptor may exert a force on the beam disruptor through gravity. When the capillary tube is reinserted, a force against the weight of the disruptor is provided either by the capillary tube or by an additional mechanism.

[0042] Variants of a beam disruptor consisting of a metal strip (e.g., cut from a metal sheet) or a similar material and / or structure may also be considered. For example, the bent end of such a beam disruptor may be connected to the longer straight section of the beam disruptor via a movable joint. In this case, the bent section may be shaped to serve as a closure for quickly closing the end of the capillary tube when the capillary tube is retracted. In this regard, or in another way, shaping one or more parts of the beam disruptor to correspond to a shape of the end of the capillary tube may be considered. For example, the bent section of the beam disruptor may be shaped to fit over the capillary tube (particularly its end).A particular example may be when the end of the capillary tube is tapered or angled so that the bent end of the beam disruptor fits better over the end of the capillary tube. In some embodiments, the beam disruptor need not have a bent end or may be bent differently than shown in the embodiments described above. The material for the beam disruptor may be varied, for example, to include spring steel and / or other materials (particularly those that may exhibit resistance to deformation and / or high temperature, as discussed above).

[0043] Some specific points should be considered for atmospheric pressure ion sources. As mentioned above, the pressure range may differ somewhat from that of the surrounding atmosphere depending on the design of the ion source. Within this class of ion sources, this range can typically deviate from the ambient atmospheric pressure by a degree close to 1×10 5 Pa (the exact standard value at an altitude of 0 m or sea level is 1,013.25 hPa). For example, the pressure of the ion source can be in the range of 1×10 4 Pa to 1×10 6 Pa. Preferably, the range deviates by less than one power of atmospheric pressure, for example, so that the pressure is in the range of 3×10 4 Pa up to 3×10 5 Pa. Typically, the pressure at which ions are generated in an atmospheric pressure source can be in the range of 3×10 4 Pa to 1×10 6 Pa lie.

[0044] Although an ESI source in Fig. As shown in Figure 1, in principle, any ion source that can be coupled to a mass spectrometer via an atmospheric interface could be used. The most important such ion sources include an electrospray ionization (ESI) source; an atmospheric pressure chemical ionization (APCI) source; an atmospheric pressure matrix-assisted laser desorption / ionization (AP-MALDI) source; an atmospheric pressure photoionization (APPI) source; and a hot electrospray ionization (HESI) source. Other, more niche types of ion sources, such as a desorption electrospray ionization (DESI) or paper spray ionization source, can also be used.

[0045] A ball valve is a simple, well-known automatic valve that acts as a sealing valve. However, one skilled in the art could alternatively consider any electronically controlled valve whose activation is linked to the presence of the capillary, such as a solenoid valve.

[0046] The ion funnel can be replaced or supplemented by an ion-optical device in the vacuum region to move ions out of the gas beam during normal operation, especially when the beam disruptor is retracted. Alternatives can be an S-lens or a base deflector.

[0047] The beam disruptor according to the disclosure can be used with mass spectrometers using a wide range of mass analyzers. For example, those skilled in the art will consider: a time-of-flight (TOF) analyzer; a quadrupole mass analyzer; a Fourier transform mass spectrometry (FTMS) analyzer; an ion trap mass analyzer; a magnetic section mass analyzer; and a hybrid mass analyzer.

[0048] In addition to mass spectrometers, an interface according to the disclosure may also be applied to ion mobility spectrometers (where a drift tube or the like may be provided in a downstream chamber or as a downstream chamber). Other ion-based spectrometry analyzers may also be considered. The specific manufacturing details of the interface and / or mass spectrometer and the associated uses, while potentially advantageous (particularly in view of known manufacturing limitations and capabilities), may be varied considerably to achieve devices with similar or identical operation. Any feature disclosed in the patent specification may, unless otherwise stated, be replaced by alternative features serving the same, equivalent, or similar purpose.Thus, each feature disclosed is merely an example of a general series of equivalent or similar features, unless otherwise indicated.

[0049] As used in this specification, including in the claims, singular forms of terms in this specification are to be construed to include the plural form and vice versa, unless the context suggests otherwise. For example, throughout this specification, including in the claims, a reference to the singular, such as "a" or "an" (such as an analog-to-digital converter), means "one or more" (for example, one or more analog-to-digital converters), unless the context suggests otherwise. Throughout the description and claims of the present disclosure, the words "comprise," "include," "have," and "contain," and variations of these words, such as "comprising" and "comprises," or the like, mean "including without limitation" and are not intended to exclude (and do not exclude) further components.

[0050] The use of any and all examples or exemplary language provided herein ("for example," "such as," "for example," and the like) is intended only to better illustrate the disclosure and does not imply any limitation on the scope of the disclosure unless otherwise claimed. Language in the specification should not be construed to indicate any unclaimed element as essential to the practice of the disclosure.

[0051] All steps described in this patent specification may be performed in any order or simultaneously, unless otherwise indicated or the context dictates otherwise.

[0052] All aspects and / or features disclosed in this specification may be combined in any combination, except for combinations where at least some such features and / or steps are mutually exclusive. As described herein, there may be certain combinations of aspects that are further advantageous, for example, with respect to the jet disruptor in conjunction with a sealing valve and / or an offset of the axial bore and the downstream opening. In particular, the preferred features of the disclosure apply to all aspects of the disclosure and may be used in any combination. Likewise, features described in non-essential combinations may be used separately (not combined with each other).

Claims

[1] An interface (20) for receiving ions in a carrier gas from an atmospheric pressure ion source to a spectrometer configured to analyze the received ions at a lower pressure, the interface (20) comprising: an interface vacuum chamber (22) having a downstream opening (80); a support assembly (45) defining an axial bore (30) arranged to have a removable capillary tube extending therethrough, wherein ions from the atmospheric pressure ion source are received by the capillary tube and directed toward the downstream aperture (80); and a jet disruptor (40) positioned downstream of the axial bore (30) and configured to interrupt the gas flow between the axial bore (30) and the downstream opening (80) only when the capillary tube is not fully inserted through the axial bore (30),characterized by that the interface (20) further comprises a sealing valve located along the axial bore (30) and configured to seal the axial bore (30) when the capillary tube is removed. [2] The interface (20) of claim 1, wherein the jet disruptor (40) is configured to retract from a position to interrupt gas flow between the axial bore (30) and the downstream orifice (80) when the capillary tube is fully inserted through the axial bore (30). [3] The interface (20) of claim 1 or claim 2, wherein the jet disruptor (40) is arranged to rest in a position to interrupt the flow of gas between the axial bore (30) and the downstream orifice (80) and is resiliently biased against displacement from the position upon insertion of the capillary tube through the axial bore (30). [4] Interface (20) according to one of the preceding claims, wherein the beam disruptor (40) comprises a sheet metal strip. [5] The interface (20) of claim 4, wherein a first end of the sheet metal strip of the beam disruptor (40) is attached to the support assembly (45) such that a portion of the sheet metal strip distal to the first end is configured to interrupt gas flow when the capillary tube is not fully inserted through the axial bore (30). [6] The interface (20) of claim 5, wherein the portion of the sheet metal strip distal from the first end is connected to the first end by a movable connection. [7] Interface (20) according to one of claims 4 to 6, wherein one end of the axial bore (30) is chamfered and the sheet metal strip of the beam disruptor (40) is arranged to lie flat over the chamfered end of the axial bore (30) when the capillary tube is not fully inserted through the axial bore (30). [8] Interface (20) according to one of the preceding claims, wherein the beam disruptor (40) is resistant to a temperature of at least 200 °C. [9] Interface (20) according to one of the preceding claims, wherein the sealing valve comprises a ball valve (50) or an electronically controlled valve. [10] Interface (20) according to any one of the preceding claims, wherein the axial bore (30) defines an axis offset from an axis through the downstream opening (80). [11] Interface (20) according to one of the preceding claims, further comprising: an ion funnel (70) arranged between the axial bore (30) and the downstream opening (80) in the interface vacuum chamber (22) to direct the ion flow towards the downstream opening (80). [12] Interface (20) according to any one of the preceding claims, wherein the support arrangement comprises a heated block around the axial bore (30). [13] Interface (20) according to one of the preceding claims, further comprising: a vacuum pump arrangement (25) arranged such that a pressure between the axial bore (30) and the downstream opening (80) in the interface vacuum chamber (22) is lower than atmospheric pressure. [14] Spectrometer comprising: an atmospheric pressure ion source; an interface (20) for receiving ions in a carrier gas from the atmospheric pressure ion source according to claim 1; and a mass analyzer or an ion mobility analyzer connected downstream of the interface. [15] The spectrometer of claim 14, wherein the atmospheric pressure ion source comprises one or more of the following components: an electrospray ionization (ESI) source; an atmospheric pressure chemical ionization (APCI) source; an atmospheric pressure matrix-assisted laser desorption / ionization (AP-MALDI) source; an atmospheric pressure photoionization (APPI) source; and a heated electrospray ionization (HESI) source. [16] A spectrometer according to claim 14 or claim 15, wherein the spectrometer is a mass spectrometer and the mass analyzer comprises: a time-of-flight (TOF) analyzer; a quadrupole mass analyzer; a Fourier transform mass spectrometry (FTMS) analyzer; an ion trap mass analyzer; a magnetic section mass analyzer; and a hybrid mass analyzer. [17] A spectrometer according to any one of claims 14 to 16, further comprising: a vacuum pumping arrangement (25) arranged to cause a first pressure in the interface vacuum chamber (22) below atmospheric pressure and a second pressure in a chamber downstream of the interface vacuum chamber (22) below the first pressure.

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