analytical instrument

Abstract

Analytical instruments, such as liquid chromatography (LC) stacks, include: a rack; and an analyzer, such as a mass spectrometer (MS), configured to be mounted within the main body of the rack. The analyzer has one or more vacuum chambers, and the instrument further includes a vacuum tube configured to provide a vacuum connection between the analyzer's vacuum chamber and a vacuum pump. The analyzer and rack are configured such that the analyzer is slidably movable between a first position, in which the analyzer is mounted within the main body of the rack, and in a second position, in which the analyzer is at least partially removed from the main body of the rack. The vacuum tube is configured such that the vacuum connection between the analyzer's vacuum chamber and the vacuum pump can be maintained when the analyzer is in the first position, when the analyzer is in the second position, and when the analyzer is between the first and second positions.

Description

Technical Field

[0001] This invention relates to analytical instruments, and more particularly to liquid chromatography-mass spectrometry (LC-MS) systems. Background Technology

[0002] Liquid chromatography (LC) is a widely used separation technique in analytical chemistry that involves separating mixtures based on the interaction between the mixture and the stationary and mobile phases.

[0003] One objective of liquid chromatography is to separate analytes of interest from samples that are typically embedded in complex matrices. A non-limiting example of such LC separation is the detection of metabolites of a target analyte in plasma.

[0004] LC separation can improve the reliability of analytical chemistry analysis because, in addition to the specific detection of target analytes by a quality analyzer, chromatographic retention time provides an independent property for confirming the identity of the target analyte.

[0005] A typical liquid chromatography instrument comprises several components, including a solvent delivery system, an injector, a chromatographic column, and an analyzer. These components are typically arranged together in a "stacked" configuration, forming what is known as a liquid chromatography stack. Several types of analyzers are used in a liquid chromatography stack, including UV detectors and fluorescence detectors.

[0006] While interface connections between liquid chromatography (LC) instruments and mass spectrometers are common, they are typically performed with the mass spectrometer remaining separate from the LC stack. However, smaller mass spectrometers have recently been developed for use as analyzers within LC stacks. Mass spectrometers require vacuum conditions and are usually connected to one or more vacuum pumps during operation.

[0007] It is believed that there is still room for improvement in the analytical instruments. Summary of the Invention

[0008] The first aspect provides an analytical instrument, which includes: frame; An analyzer having one or more vacuum chambers, wherein the analyzer is configured to be mounted within the main body of a rack; and A vacuum tube configured to provide a vacuum connection between the analyzer's vacuum chamber and the vacuum pump; The analyzer and the rack are configured such that the analyzer is slidably movable between a first position, in which the analyzer is mounted within the main body of the rack, and in the second position, the analyzer is at least partially removed from the main body of the rack; and The vacuum tube is configured to maintain a vacuum connection between the analyzer's vacuum chamber and the vacuum pump when the analyzer is in the first position, when the analyzer is in the second position, and when the analyzer is between the first and second positions.

[0009] An embodiment provides an analytical instrument (such as a liquid chromatography (LC) instrument) comprising (e.g., a housing) a frame, an analyzer (such as a mass spectrometer) having one or more vacuum chambers, and vacuum tubing for connecting the vacuum chamber of the analyzer to a vacuum pump. The instrument is designed to allow the analyzer to be at least partially (or completely) removed from the body of the frame (e.g., from the body of the housing) while maintaining a vacuum connection between the vacuum chamber and the vacuum pump.

[0010] In a particular embodiment, the analyzer and rack are configured such that the analyzer can slide between a fully mounted (first) position and a second position within the rack body, in which the analyzer is at least partially (or completely) removed from the rack body. In other words, the analyzer and rack can be configured such that the analyzer can slidably move from a closed arrangement (first position) in which the analyzer is mounted within the body to an open arrangement (second position) in which the analyzer is removed from the rack body. The analyzer can be positioned in the first position during use and can be moved to the second position, for example, for maintenance. The vacuum tube is designed to maintain a vacuum during this sliding movement, for example, by means of a flexible tube (i.e., a hose) and / or a telescopic arrangement of a first rigid tube and a second rigid tube. In other words, the vacuum tube is configured such that a vacuum connection between the analyzer's vacuum chamber and the vacuum pump can be maintained when the analyzer is positioned in the closed arrangement, when the analyzer is positioned in the open arrangement, and when the analyzer is in any position between the closed and open arrangements.

[0011] In some embodiments, the first rigid tube and the second rigid tube are configured to move relative to each other along a common axis, thereby allowing the vacuum tube to be compressed or extended. The inner diameter of the first rigid tube may be larger than the outer diameter of the second rigid tube, and the second rigid tube may be arranged at least partially within the first rigid tube in a coaxial manner. This telescopic arrangement allows the vacuum tube to be compressed when the analyzer is fully mounted in the body of the rack, and allows the vacuum tube to be extended when the analyzer is at least partially (or completely) removed from the body of the rack.

[0012] In some embodiments, the first and second tubes are connected (i.e. sealed) by a pneumatic or hydraulic rod seal.

[0013] In some embodiments, the first and second tubes are connected (i.e., sealed) by a flexible tube. Both the first and second rigid tubes may have corresponding inlets and outlets, and the flexible tube connects the outlet of the first rigid tube to the inlet of the second rigid tube. The flexible tube extends from the outlet of the first rigid tube against the inner wall of the first rigid tube, then turns at a bend, extending against the outer wall of the second rigid tube to or near its outlet. In this way, most of the flexible tube can be supported by the inner wall of the first rigid tube and / or the outer wall of the second rigid tube, with only the bend of the flexible tube not supported by either rigid tube.

[0014] The vacuum tube can be configured such that when the first rigid tube and the second rigid tube move between a compressed state and an extended state (and / or when the analyzer moves between a first position and a second position), the length of the portion of the tube supported by the first and second tubes changes, while the length of the unsupported inflection point remains substantially constant. A portion of the flexible tube can be rolled from the inner wall of the first rigid tube to the outer wall of the second rigid tube (or from the outer wall of the second rigid tube to the inner wall of the first rigid tube).

[0015] In some embodiments, the flexible tube may have a constant inner diameter corresponding to the outer diameter of the first rigid tube, and the flexible tube may be connected to the outlet of the first rigid tube and to a connector disposed on or near the outlet of the second rigid tube. The connector may have a radially undulating profile such that its circumference corresponds to the inner diameter of the flexible tube. For example, the connector may be shaped like a gear with round teeth.

[0016] In some embodiments, the instrument includes a vacuum pump connected to a vacuum tube and responsible for maintaining the analyzer's vacuum chamber under vacuum. The vacuum tube is specifically designed to ensure that the vacuum connection is maintained even when the analyzer is partially (or completely) removed from the main body of the rack.

[0017] In some embodiments, the instrument further includes a forestage vacuum pump and a turbomolecular pump. One or more vacuum chambers may comprise a series of two or more vacuum chambers, including a forestage vacuum chamber and one or more additional vacuum chambers. The turbomolecular pump may be configured to pump one or more additional vacuum chambers, and the forestage vacuum pump may be configured to pump the forestage vacuum chamber and the output of the turbomolecular pump.

[0018] The vacuum tube is configured such that when the analyzer is in the first position, when the analyzer is in the second position, and when the analyzer is between the first and second positions, the forestage vacuum pump and the turbomolecular pump can work together to keep the analyzer's vacuum chamber under vacuum.

[0019] The turbomolecular pump is slidably movable together with the analyzer between a first position and a second position. The vacuum tube can be configured to provide a vacuum connection between (i) the forestage vacuum chamber of the turbomolecular pump and / or the analyzer and (ii) the forestage vacuum pump.

[0020] Generally, the instrument can be a chromatographic instrument, such as a liquid chromatography (LC) stack, a gas chromatography (GC) stack, an ion chromatography (IC) stack, or similar instruments. The analyzer can be a mass spectrometer, such as a mass spectrometer that includes an electrostatic ion trap mass analyzer. The instrument may further include one or more additional analyzers, such as any and more of a UV detector, a fluorescence detector, or an electrofogging detector.

[0021] It should be understood that this analytical instrument provides a user-friendly and easy-to-maintain solution. The telescopic arrangement of the vacuum tubes allows the analyzer to be easily removed from the rack body without disrupting the vacuum connection, and the design of the vacuum tubes supports the necessary movement and flexibility. Attached Figure Description

[0022] Various embodiments will now be described in more detail with reference to the accompanying drawings, in which: Figure 1A schematically illustrates a liquid chromatography stack according to an embodiment, and Figure 1B schematically illustrates a liquid chromatography stack according to an embodiment; Figure 2A An external view of a vacuum tube in its retracted state, according to an embodiment, is shown schematically. Figure 2B The cross-section of a vacuum tube in its retracted state, according to an embodiment, is schematically shown. Figure 2C A cross-section of a vacuum tube in an extended state according to an embodiment is schematically shown; Figure 3A The details of the membrane connection of the vacuum tube according to an embodiment are schematically shown, and Figure 3B Details of the membrane in the vacuum tube according to an embodiment are schematically shown; Figure 4 An analytical instrument according to an embodiment is illustrated schematically; Figure 5 Figure A shows a perspective view of the analytical instrument in the closed position according to an embodiment. Figure 5 Figure B shows a perspective view of the analytical instrument in the open position according to an embodiment. Figure 5 Figure C shows a side view of the analytical instrument in the closed position according to an embodiment, and Figure 5 Figure D shows a side view of the analytical instrument in the open position according to an embodiment; and Figure 6 A perspective view of the analytical instrument according to an embodiment is shown. Detailed Implementation

[0023] A liquid chromatography stack is a combination of various components used for liquid chromatography analysis. These various components are arranged together in a "stacked" configuration in a rack and / or housing, forming what is known as a liquid chromatography stack.

[0024] Figures 1A and 1B schematically illustrate a liquid chromatography stack according to an embodiment. As shown in Figures 1A and 1B, the stack includes a solvent delivery system 10 responsible for pumping and delivering the mobile phase or solvent to the column 30. This system may include a solvent reservoir, a pump, and a mixing chamber to ensure consistent and controlled flow of the mobile phase.

[0025] The stack also includes an injector 20 for introducing samples into the chromatographic system. The injector allows for precise and repeatable sample injection, ensuring accurate separation and detection.

[0026] The stack also includes a chromatographic column 30. The column may be filled with a stationary phase that interacts with the sample components to separate them based on their affinity for the sample components and their interaction with the stationary phase. Depending on the separation requirements, the column can be of various types, such as reversed-phase, normal-phase, ion-exchange, or size exclusion.

[0027] Finally, the stack includes an analyzer 40 for detecting and quantifying separated sample components.

[0028] In addition to the core components shown, the liquid chromatography stack may also include other components and accessories, such as a degasser for removing dissolved gases from the mobile phase, a column oven for controlling the column temperature, a data acquisition system and / or a control system, etc.

[0029] In this embodiment, the analyzer 40 is configured as a "miniature" mass spectrometer mounted within an LC stack. The mass spectrometer can have any suitable design. In a particular embodiment, the mass spectrometer includes an electrostatic ion trap mass analyzer, such as an Orbitrap. TM Mass analyzer. The mass spectrometer requires high vacuum conditions during operation, and is therefore connected to the vacuum pump 50 via vacuum tube 60.

[0030] As shown in Figures 1A and 1B, the analyzer 40 and the rack are configured such that the analyzer can be at least partially slidably removed from the rack body, for example, for maintenance. Figure 1A shows the analyzer 40 fully mounted within the rack, and Figure 1B shows the analyzer 40 slid out of the rack. It is preferable to keep the analyzer 40 under vacuum conditions both when mounted within the rack and when slid out of the rack. This reduces instrument downtime, for example, by reducing or eliminating the time required to evacuate the analyzer to a suitable high vacuum after maintenance. Therefore, the embodiment requires the two points of the vacuum tube to be connected in a fully sealed and flexible manner with a variable axial distance.

[0031] For this purpose, flexible tubing connections, such as vacuum hoses, can be used. The vacuum hoses can be long enough to allow the vacuum pump 50 to remain connected to the analyzer 40 even when the analyzer has slid out of the main housing to its maximum extent. When the analyzer 40 is mounted in the rack, the hose can be coiled or otherwise stored, for example, within the housing of the vacuum pump. When the analyzer 40 slides out of the main housing of the LC stack, the vacuum hose can be pulled into the main housing of the LC stack. While this solution is relatively simple, it also has the disadvantage of requiring additional space and guiding mechanisms to accommodate the additional number of tubes.

[0032] Another solution is to provide a coaxial arrangement of two tubes with different diameters, where the larger tube is sealed to the smaller tube. The seal can be formed from, for example, one or more O-rings, one or more shaft seals, packing seals, pneumatic or hydraulic rod seals, etc. The disadvantage of this solution is that all these types of seals are contact-type, which generates friction during axial movement. Furthermore, these types of seals may require fairly precise positioning of the two coaxial tubes relative to each other and are prone to frictional wear.

[0033] Another solution is to use a rolling bellows linear compensator, such as... Figures 2A to 2C As shown. This solution addresses the issue of high space requirements and avoids the need for contact seals. In these embodiments, two rigid tubes 61 and 62 of different diameters are arranged coaxially to save space, while a flexible membrane 63 replaces the contact seal. This membrane can be made of flexible materials such as ethylene propylene diene monomer (EPDM) rubber, nitrile rubber (NBR), natural rubber (NR), or similar materials, and can be reinforced with a fabric structure to withstand forces caused by fluid pressure. The membrane 63 can be connected to the outlet of the large tube 61 and the inlet of the small tube 62.

[0034] To further describe the arrangement of the components, and referring to... Figure 2A and Figure 2B Assume that vacuum tube 60 is in its compressed or contracted state, thus having the shortest possible length. Assume that the fluid flow direction is from left to right or from the inlet of large tube 61 to the outlet of small tube 62.

[0035] from Figure 2B As can be seen, under this compressed state, the flexible membrane 63 extends from the outlet of the larger tube 61 against the flow direction until approximately half the length of the larger tube 61, while simultaneously extending suspended against the inner wall of the larger tube 61 to the inflection point. At this inflection point, its direction changes to the flow direction, and it gains support against the outer wall of the inner tube 62. Then, it extends upward to a point near the outlet of the inner tube 62.

[0036] When the system is in use, a vacuum is applied to the inlet of the larger tube 61 and the outlet of the smaller tube 62, thus creating a pressure difference that is applied to the membrane 63. This pressure causes the membrane 63 to be pushed against the inner wall of the larger outer tube 61 and simultaneously against the outer wall of the inner tube 62. Therefore, the tube walls support the membrane 63 and prevent it from collapsing.

[0037] The only part of membrane 63 that must support itself against the pressure difference between the environment and the vacuum is the transition point where membrane 63 changes from being supported by the outer tube 61 to being supported by the inner tube 62. This part of membrane 63 forms a curved single bellows that transitions from the inner wall of the outer tube 61 to the outer wall of the inner tube 62.

[0038] As the vacuum tube 60 moves, relative motion occurs between the outer and inner tubes, causing a portion of the membrane 63 to transfer from the outer tube to the inner tube (and vice versa), depending on the direction of the vacuum tube's movement. It is advantageous that there are no rigid parts moving relative to each other during contact, as this relative movement would generate friction; in this case, such forces can be avoided by using the membrane 63. The movement between the membrane 63 and the tube is rolling; as the vacuum tube 60 extends, the membrane 63 rolls off the inner wall of the larger tube 61 and onto the outer wall of the inner tube 62 (and vice versa).

[0039] Figure 2C The vacuum tube 60 is shown in its fully extended position.

[0040] It should be understood that the embodiments provide reduced space requirements and virtually frictionless movement, while remaining unaffected by misalignment.

[0041] Although various specific embodiments have been described above, various alternative embodiments are possible.

[0042] For example, vacuum tube 60 may further include a guiding arrangement to restrict relative movement of the first tube and the second tube in the axial direction. Vacuum tube 60 may further include a locking mechanism to prevent unwanted movement of the vacuum tube due to pressure.

[0043] Since membrane 63 is connected to two tubes of different diameters at each end, it can have a specific shape to accommodate the two diameters. For example, the membrane can be a custom-made conical membrane.

[0044] However, it is best to use a standard hose-type membrane with a constant diameter. The inner diameter of this hose can be adapted to the outer diameter of the smaller tube 62, in which case the hose should be stretched to fit the larger tube 61.

[0045] Alternatively, the hose may have an inner diameter that matches the outer diameter of the larger tube 61. In this case, since the inner diameter of the hose now selected is equal to the outer diameter of the larger tube 61, it would seem impossible to connect it to the smaller tube 62.

[0046] To overcome this problem, a connector can be introduced to the outlet end of the inner tube 62. This connector may include a ring 64 shaped like a gear with round teeth. A hose can then be fitted onto this ring 64 while another ring 65, having a similar shape on its interior, presses against it. This allows a corrugated shape to be applied to the hose to reduce its circumference while maintaining its circumference, enabling a seal to the inner tube.

[0047] Figure 3A A gear-shaped inner ring 64 with a hose and a clamping ring 65 are shown, the clamping ring having an inverted shape to clamp the hose to the tube 62 from the outside. Figure 3B A flexible membrane 63 with applied pleats is shown to reduce its outer diameter while maintaining its circumference.

[0048] While specific embodiments involve integrating an analyzer such as a mass spectrometer (MS) into a liquid chromatography (LC) system, the analytical instrument can also be a gas chromatography (GC) system, an ion chromatography (IC) system, or a similar device stack.

[0049] As shown in Figure 1, although the instrument may include several components arranged within a rack, in general, the instrument may include two or more components arranged within a rack. That is, the instrument may include at least two housings arranged in a stacked configuration.

[0050] Vacuum pumps can be configured in any suitable manner. In some embodiments, a single vacuum pump is provided and used to pump the analyzer. Alternatively, for example, where a high vacuum is required, the instrument may include a first vacuum pump, such as a forestage vacuum pump (i.e., a roughing vacuum pump), and a second vacuum pump, such as a turbomolecular pump (and the instrument may optionally include one or more additional vacuum pumps). In these embodiments, one or more vacuum chambers may comprise a series of two or more vacuum chambers, including a forestage vacuum chamber and one or more additional vacuum chambers, wherein the turbomolecular pump is configured to pump one or more additional vacuum chambers, and the forestage vacuum pump is configured to pump the forestage vacuum chamber and serve as a post-pump for the turbomolecular pump (i.e., pumping the output of the turbomolecular pump), as described, for example, as in U.S. Patent Application No. 2015 / 056060, the contents of which are incorporated herein by reference. In these embodiments, the series of vacuum chambers may be maintained at a gradually decreasing pressure, wherein the mass analyzer is arranged in the last vacuum chamber of the series (at the lowest pressure).

[0051] As shown in Figure 1, although the vacuum pumps may be disposed separately from the rack (“stack”) (but connected to the rack), they may also be disposed within the rack (i.e., within the “stack”). In the case of two or more vacuum pumps, one or more or each of the vacuum pumps may be disposed separately from the rack (“stack”) (but connected to the rack), and / or one or more or each of the vacuum pumps may be disposed within the rack (i.e., within the “stack”).

[0052] Figure 4 An embodiment in which the instrument comprises two housings 1 and 2 is shown. Housing 1 houses a fore-vacuum pump 51, and housing 2 houses an analyzer 40 and a turbomolecular pump 52. The turbomolecular pump 52 is disposed adjacent to the analyzer 40 within the same housing 2, while the fore-vacuum pump 51 is disposed within a separate housing 1 within a rack. The analyzer housing 2 can be mounted directly above (top of) the fore-vacuum pump housing 1. The fore-vacuum pump 51 maintains the pumping speed required to keep the analyzer 40 under vacuum. A flexible vacuum hose 60 connects the fore-vacuum pump 51 to the fore-vacuum chamber of the analyzer 40 and / or to the turbomolecular pump 52.

[0053] In this embodiment, the turbomolecular pump 52 is slidably movable together with the analyzer 40 between a first position and a second position (while the foreground vacuum pump 51 is not slidably movable). In other words, the analyzer 40 can be moved horizontally / ejected from its stack housing / box for servicing operations (such as repair, maintenance, etc.) while the turbomolecular pump 52 remains operational to ensure uninterrupted vacuum within the analyzer 40. To maintain the turbomolecular pump 52, its connection to the foreground vacuum pump 51 should be maintained when the analyzer 40 is moved horizontally / ejected from its stack housing / box. For this purpose, the vacuum tube 60 can follow the analyzer module when it ejects from its stack housing / box.

[0054] Therefore, vacuum tube 60 is configured to provide a vacuum connection between (i) the forestage vacuum chamber of turbomolecular pump 52 and / or analyzer 40 and (ii) forestage vacuum pump 51. Vacuum tube 60 is configured such that the vacuum connection can be maintained when analyzer 40 and turbomolecular pump 52 are in a first position, when analyzer 40 and turbomolecular pump 52 are in a second position, and when analyzer 40 and turbomolecular pump 52 move between the first and second positions.

[0055] This arrangement allows most servicing operations to be performed while the analyzer 40 is kept under vacuum. Servicing operations may include, for example, repairing or replacing electronic components (not required to keep the instrument under vacuum). A typical mass spectrometer includes several electronic devices that can be serviced or maintained according to embodiments. These may include, but are not limited to: an internal computing system for controlling the mass detector, a digital control subsystem, a data acquisition subsystem, ion optical drive electronics (such as DC or RF voltage power supplies), electronics for driving the mass detection subsystem (such as a high-voltage power supply for driving the electrostatic ion trap), electronics supporting ion generation (such as electronics for providing high voltage for electrospray and for controlling the gas required to support electrospray ionization), one or more heaters (such as a heater for heating the vacuum manifold, a heater for supporting heated electrospray ionization, or a heater for heating the ion transport tube), etc.

[0056] Figure 5 Details of an embodiment are shown, comprising two housings arranged in a stacked configuration, with the housing of the mass spectrometer (MS) positioned above the housing of the forestage vacuum pump. The instrument can operate in two different configurations while the analyzer's vacuum remains undisturbed.

[0057] like Figure 5 A and Figure 5 As shown in Figure C, in the first configuration, the MS module is located within its enclosure. This configuration represents the standard operating scenario in which the system can perform measurements.

[0058] like Figure 5 B and Figure 5 As shown in Figure D, in the second configuration, the MS module is ejected from the housing. This configuration is suitable for maintenance or repair scenarios. During such maintenance operations, the foreground vacuum pump continues to evacuate the foreground vacuum chamber of the MS module, enabling the turbomolecular pump to operate and maintain the vacuum within the MS system. After the maintenance intervention is complete, the MS module can be slid back into the housing. This allows the system to quickly return to its operating configuration and resume measurements.

[0059] MS modules can be connected to their housing using rails (such as horizontally mounted rails) to enable pop-up and slide-in functionality.

[0060] exist Figure 5 In the illustrated embodiment, the vacuum tube is designed to be flexible, allowing it to move with the MS module as it ejects or slides back into the housing. Despite this movement, the vacuum tube maintains the vacuum connection between the MS system and the backing vacuum pump. Figure 5In diagram D, the curved arrow indicates that the flexible vacuum hose rotates about a fixed pivot at the backing vacuum pump. When the MS system is removed from the enclosure, the connection point of the flexible vacuum hose on the MS system side moves horizontally out, while the length of the vacuum hose remains unchanged. The vacuum tube can be connected to the MS system via the side or back of the enclosure, providing flexibility in system design.

[0061] When the MS unit is pulled out, the backing vacuum pump itself does not need to move. The weight of the backing vacuum pump (typically >25kg) can be used to balance the change in the center of gravity of the stack when the MS unit slides out. The backing vacuum pump can be oriented along or perpendicular to the ejection or sliding direction of the MS module.

[0062] This system is not limited to Figure 4 and Figure 5 The configuration can be a dual-chamber setup (but is not limited to the four-chamber setup shown in Figure 1). For example, the location of the mass spectrometer chamber is not limited to directly above the backstage vacuum pump chamber. Depending on the design requirements, one or more additional chambers can be positioned between them.

[0063] Generally, the instrument's stackable configuration offers the flexibility to accommodate additional modules, thus adding more functionality to the entire instrument. These modules can include any suitable components, such as alternative detection methods, sample preparation functions, etc. Furthermore, the instrument can support the integration of two different MS units, each with different analytical characteristics, such as different quality analyzers or injection systems. This versatility allows the instrument to be customized and tailored to specific analytical requirements.

[0064] Figure 6 An embodiment comprising a vertically stacked array of four housings is illustrated. This housing stack may include one or more LC detectors, samplers, and / or binary pumps. When the MS housing is slidably removed from the stack, the other housings remain in place. Therefore, the alignment of the other housings and their connections (such as power supplies, solvent tubing, etc.) do not require replacement or relocation when the MS housing slides in / out.

[0065] While the above embodiments include a single analyzer in the form of a quality analyzer, a stack may also include more than one analyzer, such as another quality analyzer and / or one or more analyzers of different types. For example, a stack may include any or more of a UV detector, a fluorescence detector, an electrofogging detector, etc.

[0066] Although the invention has been described with reference to various embodiments, it should be understood that various changes may be made without departing from the scope of the invention as set forth in the appended claims.

Claims

1. An analytical instrument, the analytical instrument comprising: frame; An analyzer having one or more vacuum chambers, wherein the analyzer is configured to be mounted in the main body of the rack; and A vacuum tube configured to provide a vacuum connection between the vacuum chamber of the analyzer and a vacuum pump; The analyzer and the rack are configured such that the analyzer is slidably movable between a first position and a second position, in the first position the analyzer is mounted within the body of the rack, and in the second position the analyzer is at least partially removed from the body of the rack; and The vacuum tube is configured such that when the analyzer is in the first position, when the analyzer is in the second position, and when the analyzer is between the first and second positions, the vacuum connection between the vacuum chamber of the analyzer and the vacuum pump can be maintained.

2. The apparatus of claim 1, wherein, The vacuum tube includes: Telescopic arrangement, the telescopic arrangement comprising a first rigid tube and a second rigid tube; and / or Flexible pipe.

3. The instrument according to claim 2, characterized in that, The inner diameter of the first rigid tube is larger than the outer diameter of the second rigid tube; The second rigid tube is arranged at least partially within the first rigid tube in a substantially coaxial manner having a common axis; and The first rigid tube and the second rigid tube are movable relative to each other along a common axis between a compressed state and an extended state. In the compressed state, most or all of the second rigid tube is arranged inside the first rigid tube, and in the extended state, most or all of the second rigid tube is arranged outside the first rigid tube.

4. The apparatus of claim 3, wherein, The analytical instrument is configured such that when the analyzer is in the first position, the vacuum tube is arranged in its compressed state, and when the analyzer is in the second position, the vacuum tube is arranged in its extended state.

5. An apparatus according to any one of claims 2 to 4, characterised in that, The instrument includes a seal between the first rigid tube and the second rigid tube.

6. An apparatus according to any one of claims 2 to 5, characterised in that, The vacuum tube is configured such that the flexible tube extends from the outlet of the first rigid tube against the inner wall of the first rigid tube to the turning point, and then against the outer wall of the second rigid tube to or near the outlet of the second rigid tube.

7. The apparatus of claim 6, wherein, The vacuum tube is configured such that only the inflection point of the flexible tube is not supported by the first rigid tube and / or the second rigid tube.

8. Apparatus according to claim 7 when dependent on claim 3, characterised in that, The vacuum tube is configured such that, when the first rigid tube and the second rigid tube change from the compressed state to the extended state and / or when the analyzer moves from the first position to the second position: The length of the portion of the flexible tube supported by the inner wall of the first rigid tube is reduced; The length of the portion of the flexible tube supported by the outer wall of the second rigid tube increases; and The length of the unsupported turning point of the flexible tube remains basically the same.

9. The instrument according to any one of claims 2 to 8, characterized in that, The flexible tube has a constant inner diameter, which corresponds to the outer diameter of the first rigid tube; The flexible tube is connected to the outlet of the first rigid tube and to a connector disposed on or near the outlet of the second rigid tube; and The joint has a radially undulating profile such that its circumference corresponds to the inner diameter of the flexible tube.

10. The apparatus of claim 9, wherein, The connector is shaped like a gear with round teeth.

11. An apparatus according to any one of the preceding claims, characterised in that, The instrument further includes: A vacuum pump connected to the vacuum tube, wherein the vacuum pump is configured to maintain the vacuum chamber of the analyzer under vacuum; The vacuum tube is configured such that the vacuum pump can maintain the vacuum chamber of the analyzer under vacuum when the analyzer is in the first position, when the analyzer is in the second position, and when the analyzer is between the first and second positions.

12. An apparatus according to any one of the preceding claims, characterised in that, The instrument further includes: Foreboard vacuum pump; and turbomolecular pump; The vacuum tube is configured such that when the analyzer is in the first position, when the analyzer is in the second position, and when the analyzer is between the first and second positions, the forestage vacuum pump and the turbomolecular pump can together maintain the vacuum chamber of the analyzer under vacuum.

13. The instrument according to claim 12, characterized in that, The turbomolecular pump is slidably movable together with the analyzer between the first position and the second position; and The vacuum tube is configured to provide a vacuum connection between (i) the turbomolecular pump and / or the analyzer and (ii) the forestage vacuum pump.

14. An apparatus according to any one of the preceding claims, characterised in that, The instrument is a chromatography instrument, such as a liquid chromatography stack, a gas chromatography stack, or an ion chromatography stack.

15. An apparatus according to any one of the preceding claims, characterised in that, The analyzer is a mass spectrometer.

16. The apparatus of claim 15, wherein, The mass spectrometer includes an electrostatic ion trap mass analyzer.

17. An apparatus according to any one of the preceding claims, characterised in that, The instrument further includes one or more additional analyzers.

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