阅读说明：本技术 适于质谱仪的抽真空系统 (Vacuum pumping system suitable for mass spectrometer ) 是由 李向广 尚元贺 韩乐乐 曹洁茹 蔡克亚 于 2021-03-10 设计创作，主要内容包括：本发明公开了一种适于质谱仪的抽真空系统,包括第一抽气单元和第二抽气单元,第一抽气单元包括连通设置的分子泵和机械泵,且分子泵的抽气口与质谱仪的真空腔室相连通；第二抽气单元包括真空气路、进气阀和预抽阀,真空气路的一端与质谱仪的过渡腔室连通,真空气路的另一端分为两路,第一路通过进气阀与外界大气连通而其第二路通过预抽阀与真空腔室连通。本发明利用预抽阀实现了真空腔室和过渡腔室的连通,在抽真空时分子泵可通过真空腔室对过渡腔室间接抽取真空,实现了过渡腔室的快速预抽,大大缩短了样品了进样等待时间,提高了检测效率。(The invention discloses a vacuum pumping system suitable for a mass spectrometer, which comprises a first pumping unit and a second pumping unit, wherein the first pumping unit comprises a molecular pump and a mechanical pump which are communicated, and a pumping opening of the molecular pump is communicated with a vacuum chamber of the mass spectrometer; the second air extraction unit comprises a vacuum air path, an air inlet valve and a pre-extraction valve, one end of the vacuum air path is communicated with the transition cavity of the mass spectrometer, the other end of the vacuum air path is divided into two paths, the first path is communicated with the external atmosphere through the air inlet valve, and the second path is communicated with the vacuum cavity through the pre-extraction valve. The invention realizes the communication between the vacuum chamber and the transition chamber by utilizing the pre-pumping valve, and the molecular pump can indirectly pump the transition chamber to be vacuumized through the vacuum chamber during the vacuumizing, thereby realizing the rapid pre-pumping of the transition chamber, greatly shortening the sample introduction waiting time and improving the detection efficiency.)

1. An evacuation system for a mass spectrometer, characterized by: the mass spectrometer comprises a first air extraction unit and a second air extraction unit, wherein the first air extraction unit comprises a molecular pump and a mechanical pump which are communicated, and an air extraction opening of the molecular pump is communicated with a vacuum chamber of the mass spectrometer; the second air extraction unit comprises a vacuum air path, an air inlet valve and a pre-extraction valve, one end of the vacuum air path is communicated with the transition cavity of the mass spectrometer, the other end of the vacuum air path is divided into two paths, the first path is communicated with the external atmosphere through the air inlet valve, and the second path is communicated with the vacuum cavity through the pre-extraction valve.

2. The evacuation system for a mass spectrometer of claim 1, wherein: the vacuum pumping system further comprises a vacuum detection component for detecting the vacuum degree of the transition chamber, and the vacuum detection component is arranged on the vacuum path between the pre-pumping valve and the transition chamber.

3. The evacuation system for a mass spectrometer of claim 2, wherein: the vacuum detection component is a vacuum gauge.

4. The evacuation system for a mass spectrometer of claim 2, wherein: the vacuum pumping system further comprises a valve body manifold block arranged on the outer wall of the vacuum chamber, and the air inlet valve and the pre-pumping valve are installed on the valve body manifold block.

5. The evacuation system for a mass spectrometer of claim 4, wherein: the vacuum gas circuit comprises a first connecting hole and a second connecting hole which are vertically formed in the valve body manifold block, and a first connecting channel and a second connecting channel which are horizontally arranged on the valve body manifold block, wherein one end of the first connecting channel is communicated with the transition chamber, and the other end of the first connecting channel is communicated with the first connecting hole; one end of the second connecting passage communicates with the vacuum chamber and the other end thereof communicates with the second connecting hole;

the vacuum gas circuit also comprises a first channel and a second channel which are horizontally arranged on the valve body manifold block, one end of the first channel is communicated with the first connecting hole, the other end of the first channel is communicated with the first interface of the gas inlet valve, one end of the second channel is communicated with the second interface of the gas inlet valve, and the other end of the second channel is communicated with the outside atmosphere;

the vacuum gas circuit also comprises a third channel and a fourth channel which are horizontally arranged on the valve body manifold block, one end of the third channel is communicated with the first connecting hole, the other end of the third channel is communicated with the first interface of the pre-pumping valve, one end of the fourth channel is communicated with the second interface of the pre-pumping valve, and the other end of the fourth channel is communicated with the second connecting hole.

6. The evacuation system for a mass spectrometer of claim 5, wherein: the vacuum gas circuit also comprises a vacuum detection channel vertically arranged on the valve body manifold block, one end of the vacuum detection channel is communicated with the first connecting hole, the other end of the vacuum detection channel is provided with a counter bore, and the detection part of the vacuum detection component is inserted in the counter bore.

7. The evacuation system for a mass spectrometer of claim 5, wherein: a silencer is arranged at one end part of the second channel communicated with the outside atmosphere.

8. The evacuation system for a mass spectrometer of claim 4, wherein: the upper part or the lower part of one side surface of the valve body manifold block protrudes outwards to form a mounting table surface, and the mounting table surface is arranged on the outer wall of the vacuum chamber in a sealing mode.

9. An evacuation system for a mass spectrometer according to claim 1 or 2, wherein: the vacuum pumping system further comprises a negative pressure cache unit, the negative pressure cache unit comprises a cache cavity and a cache valve, a first interface of the cache cavity is communicated with the air pumping port of the mechanical pump, and a second interface of the cache cavity is communicated with the transition cavity through the cache valve.

10. An evacuation system for a mass spectrometer according to claim 1 or 2, wherein: the vacuumizing system further comprises a negative pressure cache unit, the negative pressure cache unit further comprises a cache cavity and a buffer valve, a first interface of the cache cavity is communicated with the vacuum cavity through the pre-vacuumizing valve, and a second interface of the cache cavity is communicated with the transition cavity through the buffer valve.

Technical Field

The invention relates to a mass spectrometer, in particular to an evacuation system suitable for the mass spectrometer.

Background

The matrix-assisted laser desorption ionization time-of-flight mass spectrometer (MALDI-TOF-MS, hereinafter referred to as mass spectrometer) needs to perform sample analysis in a vacuum state, namely, a sample is placed in a vacuum chamber of the mass spectrometer to sample and dissociate the sample. As shown in fig. 1, conventionally, a vacuum chamber 2.1 (surrounded by a case 2.4 and a lid 2.3) is often evacuated by a molecular pump to ensure the vacuum degree of the vacuum chamber; meanwhile, in order to protect the molecular pump 1.1, a front-stage mechanical pump is also arranged at the front end of the molecular pump.

The vacuum chamber 2.1 of mass spectrograph is great, and the evacuation time of vacuum chamber is longer, if realize getting of sample through supplementing the air repeatedly and evacuating to the vacuum chamber and put, has seriously reduced the detection efficiency of mass spectrograph. For this reason, most of the existing mass spectrometers have a transition chamber 2.2 (a fetching and placing port is opened on a cover plate 2.3 of the vacuum chamber, and the transition chamber is enclosed by a sample target groove F abutting against the bottom of the fetching and placing port and a sealing cover M covering the fetching and placing port), as shown in fig. 1. During operation, the transition cavity is vacuumized and pre-pumped to achieve the sample taking and placing operation, and therefore the detection efficiency is improved.

The pre-pumping mode of the existing transition chamber is to utilize a mechanical pump of a mass spectrometer, when the vacuum degree of the transition chamber reaches the preset vacuum degree, the sample target slot descends to preset height, and the transition chamber and the vacuum chamber are communicated to form a whole, so that stable sample introduction is realized. However, the pre-pumping time of the mechanical pump is relatively long, so that the waiting time of the sample is long, and the requirement of rapid detection of high-throughput samples cannot be met.

For this reason, the pre-pumping time of the transition chamber is usually shortened by using a high-power mechanical pump, and the high-power mechanical pump is relatively larger in volume and relatively more expensive as the power of the mechanical pump is larger, so that the high-power mechanical pump is often larger in volume and higher in cost along with the mass spectrometer. Therefore, how to design an evacuation system capable of realizing rapid pre-evacuation of the transition chamber is an important technical problem to be solved by the industry.

Disclosure of Invention

The invention aims to provide a vacuum pumping system suitable for a mass spectrometer, wherein a transition chamber and a vacuum chamber of the vacuum pumping system are communicated through a pre-pumping valve, and the transition chamber can be pre-pumped through the vacuum chamber, so that the transition chamber can be quickly pre-pumped, and the sample introduction waiting time of a sample is shortened.

In order to achieve the purpose, the invention adopts the following technical scheme:

the vacuum pumping system suitable for the mass spectrometer comprises a first pumping unit and a second pumping unit, wherein the first pumping unit comprises a molecular pump and a mechanical pump which are communicated, and a pumping opening of the molecular pump is communicated with a vacuum chamber of the mass spectrometer; the second air extraction unit comprises a vacuum air path, an air inlet valve and a pre-extraction valve, one end of the vacuum air path is communicated with the transition cavity of the mass spectrometer, the other end of the vacuum air path is divided into two paths, the first path is communicated with the external atmosphere through the air inlet valve, and the second path is communicated with the vacuum cavity through the pre-extraction valve.

In a preferred embodiment of the present invention, the vacuum pumping system further includes a vacuum detection component for detecting a vacuum degree of the transition chamber, and the vacuum detection component is disposed on the vacuum path between the pre-pumping valve and the transition chamber. More preferably, the vacuum detection component is a vacuum gauge.

In a preferred embodiment of the present invention, the vacuum pumping system further comprises a valve body manifold block provided on an outer wall of the vacuum chamber, the intake valve and the pre-pump valve being mounted on the valve body manifold block.

In a preferred embodiment of the present invention, the vacuum air path includes a first connection hole and a second connection hole vertically opened on the valve body manifold block, and a first connection channel and a second connection channel horizontally opened on the valve body manifold block, one end of the first connection channel communicates with the transition chamber and the other end thereof communicates with the first connection hole; one end of the second connecting passage communicates with the vacuum chamber and the other end thereof communicates with the second connecting hole;

the vacuum gas circuit also comprises a first channel and a second channel which are horizontally arranged on the valve body manifold block, one end of the first channel is communicated with the first connecting hole, the other end of the first channel is communicated with the first interface of the gas inlet valve, one port of the second channel is communicated with the second interface of the gas inlet valve, and the other end of the second channel is communicated with the outside atmosphere;

the vacuum gas circuit also comprises a third channel and a fourth channel which are horizontally arranged on the valve body manifold block, one end of the third channel is communicated with the first connecting hole, the other end of the third channel is communicated with the first interface of the pre-pumping valve, one end of the fourth channel is communicated with the second interface of the pre-pumping valve, and the other end of the fourth channel is communicated with the second connecting hole.

In another preferred embodiment of the present invention, the vacuum gas circuit further includes a vacuum detection channel vertically opened on the valve body manifold block, one end of the vacuum detection channel is communicated with the first connection hole, and the other end of the vacuum detection channel has a counter bore, and the detection portion of the vacuum detection component is inserted into the counter bore.

In another preferred embodiment of the present invention, one end of the second passage communicating with the outside atmosphere is provided with a silencer (with a sieve).

In another preferred embodiment of the present invention, the vacuum pumping system further comprises a buffer chamber and a buffer valve, the first port of the buffer chamber is communicated with the pumping port of the mechanical pump, and the second port of the buffer chamber is communicated with the transition chamber through the buffer valve.

In a preferred embodiment of the present invention, an upper portion or a lower portion of one side surface of the valve body manifold protrudes outward to form a mounting table, and the mounting table is hermetically disposed on the outer wall of the vacuum chamber, so as to effectively reduce a contact area between the side surface of the valve body manifold and the outer wall.

In another preferred embodiment of the present invention, the vacuum pumping system further includes a negative pressure buffer unit, the negative pressure buffer unit includes a buffer cavity and a buffer valve, the first port of the buffer cavity is communicated with the pumping port of the mechanical pump, and the second port of the buffer cavity is communicated with the transition chamber through the buffer valve.

In another preferred embodiment of the present invention, the vacuum pumping system further includes a negative pressure buffer unit, the negative pressure buffer unit further includes a buffer chamber and a buffer valve, the first interface of the buffer chamber is communicated with the vacuum chamber through the pre-pumping valve, and the second interface of the buffer chamber is communicated with the transition chamber through the buffer valve.

The invention realizes the communication between the vacuum chamber and the transition chamber by utilizing the pre-pumping valve, and the molecular pump can indirectly pump the transition chamber to be vacuumized through the vacuum chamber during the vacuumizing, thereby realizing the rapid pre-pumping of the transition chamber, greatly shortening the sample introduction waiting time and improving the detection efficiency.

The valve body manifold block is hermetically arranged on the cover plate of the vacuum chamber, and the pre-pumping valve, the vacuum gauge and the air inlet valve can be integrally arranged on the valve body manifold block, so that the air passage structure is reduced, the mass spectrometer is cleaner and tidier, and the faults caused by drawing the air passage or air passage friction and the like are effectively reduced. Meanwhile, the vacuum gauge can detect the vacuum degree of the transition chamber, the pre-vacuumizing degree of the transition chamber is ensured to be within a preset range when each sample is detected, and when the vacuum degree of the transition chamber is difficult to pre-vacuumize within the preset range, a control system of the mass spectrometer sends an error-reporting prompt.

The vacuum system further comprises a buffer cavity, the transition cavity can be pre-pumped through the buffer cavity, then the pre-pumping of the transition cavity is realized by the vacuum cavity, or the quick pre-pumping of the transition cavity is realized by the aid of the negative pressure of the buffer cavity in one step, the negative pressure can be cached by the buffer cavity, the quick descending of the transition cavity can be realized, the pre-pumping time of the transition cavity is shortened, and the detection efficiency is improved.

Drawings

Fig. 1 is a schematic diagram of a prior art mass spectrometer (with the mechanical pump omitted).

Fig. 2 is a diagram showing a state of mounting the first embodiment of the present invention on a mass spectrometer.

FIG. 3 is a view of the mounting of the intake and pre-extraction valves of the present invention on the valve block manifold.

Fig. 4 is a front view of the valve block manifold of fig. 3.

Fig. 5 is a schematic sectional view along line D-D of fig. 4.

Fig. 6 is a right side view of the valve block manifold of fig. 3.

Fig. 7 is a left side view of the valve block manifold of fig. 3.

Fig. 8 is a schematic sectional view along line B-B of fig. 7.

Fig. 9 is a schematic sectional view along line C-C of fig. 7.

Fig. 10 is a bottom view of the valve body manifold block of fig. 3.

Fig. 11 is a diagram of a vacuum evacuation gas circuit according to the second embodiment.

Fig. 12 is a diagram of a vacuum evacuation circuit according to the third embodiment.

Detailed Description

The following describes embodiments of the present invention in detail with reference to the drawings, which are implemented on the premise of the technical solution of the present invention, and detailed embodiments and specific operation procedures are provided, but the scope of the present invention is not limited to the following embodiments.

It should be noted that all the directional indicators (such as up, down, left, right, front, and back … …) in the embodiment of the present invention are only used to explain the relative position relationship between the components, the motion situation, etc. in a specific posture, if the specific posture is changed, the directional indicator is changed accordingly.

It should also be noted that the description herein as relating to "first", "second", etc. is for descriptive purposes only and is not to be construed as indicating or implying any relative importance or implicit indication of the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature.

Implementation mode one

As shown in fig. 1 to 3, the vacuum pumping system for a mass spectrometer according to this embodiment includes a first pumping unit and a second pumping unit, where the first pumping unit includes a molecular pump 1.1 and a mechanical pump 1.2 (operating pressure is 10) which are arranged in communication with each other^-2 Pa or less), the pumping hole of the molecular pump 1.1 is communicated with the vacuum chamber 2.1 of the mass spectrometer; before detection (i.e. detection of a sample by a mass spectrometer), the molecular pump 1.1 is pre-pumped by the mechanical pump 1.2, and then the molecular pump 1.1 is started again to utilize moleculesThe pump 1.1 pumps a negative pressure into the vacuum chamber 2.1 (the mechanical pump 1.2 is continuously operated) to maintain the negative pressure in the vacuum chamber 2.1 at a high vacuum level (about 10 degrees f) required for the sample^-6 mbar）；

The second air extraction unit comprises a vacuum air path, an air inlet valve 3 and a pre-extraction valve 4, one end of the vacuum air path is communicated with a transition chamber 2.2 (enclosed by a sealing cover M and a sample target groove F in the vacuum chamber) of the mass spectrometer, the other end of the vacuum air path is divided into two paths, the first path is communicated with the outside atmosphere through the air inlet valve 3, and the second path is communicated with the vacuum chamber 2.1 through the pre-extraction valve 4;

when a sample is taken and placed, the sample target groove F of the vacuum chamber 2.1 moves to the position below the taking and placing port of the vacuum chamber 2.1, then is lifted upwards and abuts against the bottom edge of the taking and placing port, the sample target groove F and a sealing cover M at the taking and placing port enclose a transition chamber 2.2, at the moment, an air inlet valve 3 replenishes air into the transition chamber 2.2, and when the pressure in the transition chamber 2.2 is consistent with the external pressure, the sealing cover M at the taking and placing port is opened, and the sample is placed in a limiting groove of the sample target groove F;

then, a sealing cover M is covered, the air inlet valve 3 is closed, the pre-pumping valve 4 is opened (in order to avoid instant transition of vacuum degree caused by communication between the transition chamber and the vacuum chamber before the transition chamber is impacted and further to stop working, the opening mode of the pre-pumping valve 4 can adopt high-frequency opening and closing or small-flow opening), the transition chamber 2.2 and the vacuum chamber 2.1 are in an intermittent communication state, and the molecular pump 1.1 can directly pump negative pressure to the transition chamber 2.2 through the vacuum chamber 2.1. Compared with the traditional method of pumping the negative pressure of the transition chamber 2.2 by using the mechanical pump 1.2, the method greatly shortens the pre-pumping time (controllable within 3 s) of the transition chamber 2.2, further shortens the sample introduction waiting time of each sample, improves the detection efficiency, and effectively meets the requirement of high-throughput samples.

As shown in fig. 2-3, the vacuum pumping system of this embodiment further includes a vacuum detection component (preferably, a vacuum gauge 5, a signal output end of the vacuum gauge 5 is connected to a control system of the mass spectrometer), the vacuum gauge 5 is disposed on a vacuum gas path between the pre-pumping valve 4 and the transition chamber 2.2, and can detect a vacuum degree of the transition chamber 2.2, the vacuum gauge 5 can transmit the detected vacuum degree to the control system, and when the vacuum gauge 5 detects that the vacuum degree in the transition chamber 2.2 cannot reach the preset vacuum degree all the time in the pre-pumping process, the control system reports an error prompt to ensure normal sample introduction of each sample, thereby realizing accurate detection of the sample.

As shown in fig. 2, the vacuum pumping system of the present embodiment further includes a valve body manifold block 6 disposed outside the vacuum chamber 2.1, and the air intake valve 3, the pre-pumping valve 4 (the air intake valve 3 and the pre-pumping valve 4 are preferably two-position two-way solenoid valves) and the vacuum gauge 5 can be integrally mounted on the valve body manifold block 6, so that the ventilation and the rapid pre-pumping of the transition chamber 2.2 can be realized without an external pipeline in the whole structure, and the whole structure of the mass spectrometer is simpler. Specifically, the method comprises the following steps:

as shown in fig. 7, the upper portion of the rear side surface of the valve block manifold 6 is provided with a mounting table surface protruding backward, the upper portion of the valve block manifold 6 is horizontally provided with a pair of mounting holes 6.1 along the front-rear direction, the bolts penetrating through each mounting hole 6.1 fix the valve block manifold 6 on the cover plate 2.3 of the vacuum chamber 2.1 (and ensure that the mounting table surface is sealed and attached on the cover plate 2.3), and the contact area between the valve block manifold 6 and the vacuum chamber 2.1 is reduced;

the cover plate 2.3 is provided with first through holes communicated with the transition chamber 2.2 and second through holes communicated with the vacuum chamber 2.1 at intervals, the first through holes are communicated with a first connecting channel 6.4 which is described later, the second through holes are communicated with a second connecting channel 6.5 which is described later, and the valve body manifold block 6 is communicated with the vacuum chamber 2.1 and the transition chamber 2.2;

as shown in fig. 3-5, the vacuum gas circuit includes a first connecting hole 6.2 and a second connecting hole 6.3 vertically opened on the valve body manifold block 6, and a first connecting channel 6.4 and a second connecting channel 6.5 horizontally opened on the valve body manifold block 6, the first connecting hole 6.2 and the second connecting hole 6.3 are process holes vertically opened downwards from the top surface of the valve body manifold block 6, and the upper parts of the first connecting hole 6.2 and the second connecting hole 6.3 are sealed and inserted with plugging pieces (i.e. plugging heads) to prevent the first connecting hole 6.2 and the second connecting hole 6.3 from leaking gas; the first connecting channel 6.4 is communicated with the transition chamber 2.2 through the first through hole, and the other end of the first connecting channel is communicated with the first connecting hole 6.2, so that the first connecting hole 6.2 is communicated with the transition chamber 2.2; one end of the second connecting channel 6.5 is communicated with the vacuum chamber 2.1 through the second through hole, and the other end is communicated with the second connecting hole 6.3, so that the second connecting hole 6.3 is communicated with the vacuum chamber 2.1;

as shown in fig. 7 to 9, the intake valve 3 is fixedly mounted on the left side surface of the valve body manifold 6 by screws; the vacuum air path further comprises a first channel 6.6 (a blind hole) and a second channel 6.7 (a through hole) which are horizontally arranged from the left side surface of the valve body manifold block 6 to the right, the right end of the first channel 6.6 is communicated with the first connecting hole 6.2, the left end of the first channel is communicated with the first interface of the air inlet valve 3, the left end of the second channel 6.7 is communicated with the second interface of the air inlet valve 3, a silencer H (with a filter screen) communicated with the outside atmosphere is inserted into the right end of the second channel 6.7, and outside air sequentially passes through the second channel 6.7 → the air inlet valve 3 → the first channel 6.6 → the first connecting hole 6.2 → the first connecting channel 6.4 → the first through hole to enter the transition chamber 2.2, so that the sealing cover M is opened to place a sample; the silencer H can reduce the squeaking caused by too fast air inlet speed;

as shown in fig. 6 and fig. 8-9, the pre-pump valve 4 is fixedly mounted on the right side of the valve body manifold block 6 by screws; the vacuum gas circuit further comprises a third channel 6.8 and a fourth channel 6.9 (the third channel 6.8 and the fourth channel 6.9 are both blind holes) which are horizontally arranged towards the left from the right side surface of the valve body manifold block 6, the left end of the third channel 6.8 is communicated with the first connecting hole 6.2, the right end of the third channel is communicated with the first interface of the pre-pumping valve 4, the right end of the fourth channel 6.9 is communicated with the second interface of the pre-pumping valve 4, and the left end of the fourth channel is communicated with the second connecting hole 6.3. The specific communication path is as follows: the transition chamber 2.2 → the first through hole → the first connecting channel 6.4 → the first connecting hole 6.2 → the third channel 6.8 → the pre-pumping valve 4 → the fourth channel 6.9 → the second connecting hole 6.3 → the second through hole → the vacuum chamber 2.1, and the communication between the pre-pumping valve 4 and the vacuum chamber 2.1 and the transition chamber 2.2 is realized.

During actual installation, the pre-pumping valve 4 and the air inlet valve 3 both adopt two-position two-way electromagnetic valves, and a control system of a mass spectrometer is used for controlling the automatic opening and closing of the pre-pumping valve 4 and the air inlet valve 3, so that the automatic pre-pumping and air inlet of the transition chamber 2.2 are realized, and the sample taking and placing requirements are further met; meanwhile, the opening mode of the pre-pumping valve 4 can be a small-flow opening mode or a multi-frequency opening and closing mode, so that the pre-pumping time of the transition chamber 2.2 can be controlled, the shutdown of the molecular pump caused by the sudden reduction of the vacuum degree of the vacuum chamber can be prevented, and the operation stability is improved.

As shown in fig. 8 and 10, the vacuum gas path further includes a vacuum detection channel 6.10 vertically and upwardly opened from the bottom surface of the valve body manifold block 6, the upper end of the vacuum detection channel 6.10 is communicated with the first connection hole 6.2, and the lower end thereof has a counterbore 6.11, the detection portion of the vacuum detection component is inserted in the counterbore 6.11 for detecting the vacuum degree of the first connection hole 6.2, because the transition chamber 2.2 is communicated with the first connection hole 6.2 through the first through hole and the first connection channel 6.4, the vacuum degree of the first connection hole 6.2 is the same as the vacuum degree in the transition chamber 2.2, and the monitoring of the vacuum degree in the transition chamber 2.2 can be realized by monitoring the vacuum degree of the first connection hole 6.2.

The working process of the vacuum system according to the present embodiment is as follows:

before detection, the mass spectrometer is started, the mechanical pump 1.2 is used for pre-pumping the molecular pump 1.1, and then the molecular pump 1.1 is used for pumping negative pressure to the vacuum chamber 2.1 (the mechanical pump 1.2 is continuously operated), so that the negative pressure of the vacuum chamber 2.1 reaches the high vacuum degree (about 10) required by sample detection^-6 mbar）；

When a sample is taken and placed, the sample target groove F of the vacuum chamber 2.1 moves to the position below the taking and placing port, then is lifted upwards and abuts against the bottom edge of the taking and placing port, the sealing cover M and the sample target groove F which are covered at the taking and placing port enclose a transition chamber 2.2, the air inlet valve 3 is opened, outside air sequentially passes through the second channel 6.7 → the air inlet valve 3 → the first channel 6.6 → the first connecting hole 6.2 → the first connecting channel 6.4 → the first through hole to enter the transition chamber 2.2, so that the pressure in the transition chamber 2.2 is restored to normal pressure, and the sealing cover M is opened to place a new sample to be detected; after the sample is placed, the sealing cover M is covered, the pre-pumping valve 4 is opened (high-frequency opening and closing or small-flow opening) to pre-pump the transition chamber 2.2, and the negative pressure path is as follows: the vacuum chamber 2.1 → the second through hole → the second connecting hole 6.3 → the fourth channel 6.9 → the pre-pumping valve 4 → the third channel 6.8 → the first connecting hole 6.2 → the first connecting channel 6.4 → the transition chamber 2.2, so that the vacuum chamber 2.1 and the transition chamber 2.2 are in a communicated state, the high vacuum degree of the vacuum chamber 2.1 enables the transition chamber 2.2 to quickly reach a preset vacuum degree, the vacuum chamber 2.1 and the molecular pump 1.1 are in a communicated state, which is equivalent to the molecular pump 1.1 pumping vacuum to the transition chamber 2.2 through the vacuum chamber 2.1, thereby realizing the quick pre-pumping of the transition chamber 2.2, shortening the waiting time of a sample, and improving the detection efficiency; when the vacuum degree of the transition chamber 2.2 reaches a preset vacuum degree, moving the sample target groove F to an ion source of the vacuum chamber 2.1 for sample dissociation detection; the dissociation detection of a plurality of samples can be realized by repeating the operation.

Second embodiment

The evacuation system according to the present embodiment is different from the first embodiment in that: the vacuum pumping system also comprises a negative pressure buffer unit. Specifically, the method comprises the following steps: as shown in fig. 11, the negative pressure buffer unit includes a buffer cavity 7.1 and a buffer valve 7.2, a first interface of the buffer cavity 7.1 is communicated with the air suction port of the mechanical pump 1.2 through a first pipeline, a second interface of the buffer cavity 7.1 is communicated with the transition cavity 2.2 through a second pipeline, the other end of the second pipeline is hermetically inserted into a connecting port on the sealing cover M plate at the corresponding position of the transition cavity 2.2, and the buffer valve 7.2 (preferably, two-position two-way electric valve) is communicated and disposed on the second pipeline.

During actual installation, the buffer valve 7.2 can be integrally installed on the valve body manifold block 6, only a fifth channel communicated with the first connecting hole 6.2 needs to be formed in the front side face of the valve body manifold block 6, the buffer valve 7.2 is installed on the front side face of the valve body manifold block 6, one interface of the buffer valve 7.2 is ensured to be communicated with the fifth channel, the other interface of the buffer valve 7.2 is ensured to be connected with the second pipeline, and when the buffer valve 7.2 is opened, the buffer cavity 7.1 is ensured to be in a communicated state with the fifth channel through the buffer valve 7.2.

The working process of the vacuum system according to the present embodiment is as follows:

before sample detection, the mass spectrometer is started, the mechanical pump 1.2 of the mass spectrometer pre-pumps the molecular pump 1.1, then the molecular pump 1.1 is started again, and the molecular pump 1.1 pumps negative pressure to the vacuum chamber 2.1 (the mechanical pump 1.2 continuously works), so that the negative pressure of the vacuum chamber 2.1 reaches the high vacuum degree (about 10) required by sample detection^-6mbar); in the process, the buffer valve 7.2 is in a closed state, and the mechanical pump 1.2 can simultaneously control the air outlet of the molecular pump 1.1And the buffer cavity 7.1 extracts negative pressure to make the buffer cavity 7.1 in a constant negative pressure state;

when a sample is taken and placed, the sample target groove F of the vacuum chamber 2.1 moves to the position below the taking and placing port, then is lifted upwards and abuts against the bottom edge of the taking and placing port, the sealing cover M and the sample target groove F which are covered at the taking and placing port enclose a transition chamber 2.2, the air inlet valve 3 is opened, outside air sequentially passes through the second channel 6.7 → the air inlet valve 3 → the first channel 6.6 → the first connecting hole 6.2 → the first connecting channel 6.4 → the first through hole to enter the transition chamber 2.2, so that the pressure in the transition chamber 2.2 is restored to normal pressure, and the sealing cover M is opened to place a new sample to be detected; after placing the sample in sample target groove F, cover sealed lid M and enclose into transition cavity 2.2, open buffer valve 7.2 earlier and utilize buffer memory chamber 7.1 to take out in advance transition cavity 2.2, take out the negative pressure route and be: the buffer cavity 7.1 ← buffer valve 7.2 ← fifth channel ← first connection hole 6.2 ← first connection channel 6.4 ← transition chamber 2.2, the transition chamber 2.2 and the buffer cavity 7.1 are in a communicated state, the transition chamber 2.2 rapidly reaches equilibrium under the negative pressure effect of the buffer cavity 7.1, and pre-pumping of the transition chamber 2.2 is realized; then closing the buffer valve 7.2, opening the pre-pumping valve 4 (high-frequency opening and closing or small-flow opening), continuously pumping vacuum to the buffer chamber by utilizing the high vacuum of the vacuum chamber 2.1, rapidly reducing the vacuum degree of the transition chamber 2.2, closing the pre-pumping valve 4 when the vacuum degree detected by the vacuum gauge 5 reaches a sample introduction condition, moving the sample target groove F in the vacuum chamber 2.1 downwards by a preset height, forming the transition chamber 2.2 and the vacuum chamber 2.1 into a whole, and then moving the sample target groove F to the lower part of the ion source for sample dissociation detection.

Third embodiment

The vacuum system according to the present embodiment is different from the second embodiment in that the negative pressure buffer unit is different. Specifically, the method comprises the following steps: as shown in fig. 12, the negative pressure buffer unit includes a buffer chamber 7.1 and a buffer valve 7.2 (the buffer valve 7.2 is preferably a two-position two-way solenoid valve), a first interface of the buffer chamber 7.1 is communicated with the vacuum chamber 2.1 through the pre-pumping valve 4, and a second interface of the buffer chamber 7.1 is communicated with the transition chamber 2.2 through the buffer valve 7.2;

one interface of the pre-pumping valve 4 is communicated with the fourth channel 6.9, so that the pre-pumping valve is communicated with the vacuum chamber 2.1 through the fourth channel 6.9, the second connecting hole 6.3 and the second connecting channel 6.5; the other interface of the pre-pumping valve 4 is communicated with the cache cavity 7.1 through a connecting pipe, and the other interface of the cache cavity 7.1 is communicated with a third channel 6.8 through a connecting pipe;

the buffer valve 7.2 is installed on the connecting pipe between the buffer cavity 7.1 and the pre-pumping valve 4, and of course, it can also be installed on the valve body manifold block 6 integrally, that is, the third channel 6.8 is opened on the front side surface of the valve body manifold block 6 along the horizontal direction, the buffer valve 7.2 is installed on the front side surface of the valve body manifold block 6 integrally and ensures that one interface of the buffer valve 7.2 is connected with the valve body manifold block 6 and the other interface is connected with the buffer cavity 7.1 through the connecting pipe. The negative pressure extraction path of the transition chamber 2.2 in this embodiment is: vacuum chamber 2.1 ← second connection channel 6.5 ← second connection channel 6.3 ← fourth channel 6.9 ← pre-pumping valve 4 ← buffer chamber 7.1 ← third channel 6.8 ← first connection channel 6.2 ← first connection channel 6.4 ← transition chamber 2.2.

In actual work, the opening mode of the buffer valve 7.2 can be opened with small flow or opened and closed in multiple frequency, so that the vacuum degree balance time of the transition chamber 2.2 and the buffer cavity 7.1 is effectively controlled, and the probability of vibration is reduced. Meanwhile, in order to further avoid the rapid flow of the cushion valve 7.2 from generating the squealing noise, a silencer is arranged at one end part of the cushion valve 7.2 communicated with the transition chamber 2.2.

The specific working process of the embodiment is as follows:

before the sample detection, firstly, the mechanical pump 1.2 is started to pre-pump for a certain time, then the molecular pump 1.1 is started again, the molecular pump 1.1 is utilized to pump negative pressure to the vacuum chamber 2.1 (the mechanical pump 1.2 continuously works), so that the pressure in the vacuum chamber 2.1 reaches the high vacuum degree (about 10) required by the sample detection^-6mbar); the pre-pumping valve 4 can be opened (high-frequency opening or small-flow opening) in the vacuum pumping process, the air inlet valve 3 and the buffer valve 7.2 are closed, the vacuum chamber 2.1 and the buffer chamber 7.1 are in a communicated state, the molecular pump 1.1 is utilized to pump negative pressure to the buffer chamber 7.1, the vacuum degree in the buffer chamber 7.1 is close to the vacuum chamber 2.1, and the basis is established for realizing the quick pre-pumping of the vacuum degree of the transition chamber 2.2;

when a sample needs to be taken and placed in the detection process, the sample target groove F of the vacuum chamber 2.1 moves to the position below the taking and placing port, then is lifted upwards and abuts against the bottom edge of the taking and placing port, the sealing cover M and the sample target groove F which are covered on the taking and placing port enclose a transition chamber 2.2, the air inlet valve 3 is opened, outside air sequentially passes through the second channel 6.7 → the air inlet valve 3 → the first channel 6.6 → the first connecting hole 6.2 → the first connecting channel 6.4 → the first through hole to enter the transition chamber 2.2, and the pressure in the transition chamber 2.2 is recovered to the normal pressure, so that the sealing cover M is opened to place a new sample to be detected;

after a sample is placed in the sample target groove F, the transition chamber 2.2 is enclosed by the sealing cover M, the pre-pumping valve 4 and the air inlet valve 3 are closed, the buffer valve 7.2 is opened, the transition chamber 2.2 and the buffer chamber 7.1 are in a communicated state, the transition chamber 2.2 rapidly descends under the action of the buffer chamber 7.1 due to the fact that the vacuum degree in the buffer chamber 7.1 is close to the vacuum chamber 2.1, the sample introduction requirement is met, then the buffer valve 7.2 is closed, the sample target groove F in the vacuum chamber 2.1 is moved downwards by the preset height, the transition chamber 2.2 and the vacuum chamber 2.1 form a whole, and then the sample target groove F is moved to the position below an ion source to carry out sample dissociation detection.

It should be emphasized that the above-described embodiments are merely exemplary embodiments of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily conceive various equivalent modifications, substitutions, improvements, etc. within the technical scope of the present invention, and these modifications and improvements should be covered by the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.