Vacuum pressure detection device of liquid chromatography tandem mass spectrometer

Abstract

The invention discloses a vacuum pressure detection device of a liquid chromatogram tandem mass spectrometer, and belongs to the technical field of liquid chromatogram tandem mass spectrometers. Comprising a mass analyzer, an analysis cavity is formed in the mass analyzer, a pressure detection mechanism is arranged on the outer wall of the mass analyzer, and the pressure detection mechanism comprises a box body which is arranged on the outer wall of the mass analyzer and internally divided into a detection cavity and an adjusting cavity through a partition plate; one end of the corrugated pipe is communicated with the analysis cavity, and the other end of the corrugated pipe is closed and is provided with a sliding plate; one end of the pointer penetrates through the box body and is in sliding connection with the surface of the box body. According to the invention, when the vacuum degree in the analysis cavity is changed, a worker can visually know the vacuum degree in the analysis cavity only by observing the position of the pointer on the scale line through the transparent glass cover, and the vacuum degree in the analysis cavity can be adjusted by arranging the adjusting mechanism, so that the performance of the mass spectrometer is guaranteed, and the working efficiency is improved. And the reliability of an analysis result is improved.

Description

Technical Field

[0001] The invention relates to a vacuum pressure detection device of a liquid chromatography tandem mass spectrometer, belonging to the technical field of liquid chromatography tandem mass spectrometers. Background Art

[0002] Liquid chromatography-tandem mass spectrometry is a highly advanced analytical instrument that cleverly combines liquid chromatography (LC) and tandem mass spectrometry (MS / MS) to achieve efficient and sensitive analysis and identification of compounds in complex mixtures.

[0003] Among them, the mass spectrometer identifies the structure and composition of a compound by analyzing the mass-to-charge ratio (m / z). This process needs to be carried out in a high vacuum environment to reduce the collision and fragmentation of ions during transmission, ensuring that the ions can fly along the predetermined path and accurately reach the detector, thereby improving the accuracy and sensitivity of the analysis.

[0004] However, at present, due to reasons such as equipment sealing and material outgassing, a small amount of gas still exists in the cavity of the mass analyzer in the mass spectrometer, which makes it impossible for staff to detect and eliminate these gases in time, further causing the performance of the mass spectrometer to decline and reducing the reliability of the analysis results.

[0005] Therefore, a new solution needs to be proposed to solve this problem. Summary of the invention

[0006] The technical problem to be solved by the present invention is to provide a vacuum pressure detection device for a liquid chromatography-tandem mass spectrometer, which solves the problem in the prior art that due to equipment sealing, material outgassing, etc., a small amount of gas still exists in the cavity of a mass analyzer in the mass spectrometer, resulting in the staff being unable to remove the gas from the detection box in time, further resulting in a decrease in the performance of the mass spectrometer and a reduction in the reliability of the analysis results.

[0007] The technical problem to be solved by the present invention is achieved by adopting the following technical scheme: A vacuum pressure detection device for a liquid chromatography tandem mass spectrometer comprises a mass analyzer, an analysis chamber is provided inside the mass analyzer, and a pressure detection mechanism is provided on the outer wall of the mass analyzer, the pressure detection mechanism comprises: The box body is arranged on the outer wall of the mass analyzer and the interior of the box body is divided by a partition to form a detection cavity and an adjustment cavity; The bellows is arranged in the detection cavity, one end of which is connected with the analysis cavity, and the other end is closed and provided with a slide plate; An indicator needle is arranged on the slide plate and one end of the indicator needle penetrates through the box body and is slidably connected to the surface of the box body; The surface of the box is provided with a slide groove for the end of the indicator needle to slide, and the box is provided with a number of scale lines corresponding to the slide groove position; An adjusting mechanism is arranged inside the adjusting cavity, which is driven by bellows expansion and contraction to adjust the vacuum degree in the analysis cavity.

[0008] By adopting the above technical solution and arranging a retractable bellows, when the vacuum degree in the analysis chamber changes, that is, when gas exists in the analysis chamber, the bellows is extended by the change of the air pressure in the analysis chamber, thereby driving the slide plate to slide, and then causing the indicator needle to slide on the surface of the box body. At this time, the staff only needs to observe the position of the indicator needle on the scale line through the transparent glass cover to intuitively understand the vacuum degree in the analysis chamber. By arranging an adjustment mechanism, the vacuum degree in the analysis chamber can be adjusted by the telescopic movement of the bellows, thereby ensuring the performance of the mass spectrometer and improving the reliability of the analysis results.

[0009] The present invention is further configured as follows: the adjustment mechanism comprises: An adjusting tube is fixed on the partition plate and one end of the adjusting tube passes through the slide plate and extends into the interior of the bellows. An end plate is provided at the end of the adjusting tube extending into the interior of the bellows. The piston slides inside the regulating tube and is hinged with a driving rod on one side away from the analysis chamber, and forms an air extraction chamber between the other side and the end plate; Among them, a plurality of one-way valves are arranged on the end plate and the piston. Specifically, one one-way valve is arranged at the center of the end plate, and two one-way valves are arranged at the positions of the piston on both sides of the driving rod. The one-way valve located at the center of the end plate is used to unidirectionally restrict the gas in the pumping chamber from entering the analysis chamber and allow the gas in the analysis chamber to enter the pumping chamber, and the one-way valve located on the piston is used to unidirectionally restrict the gas in the regulating tube from entering the pumping chamber and allow the gas in the pumping chamber to enter the regulating tube and be discharged; A driving mechanism is also provided on the partition, one side of the driving mechanism is connected to the slide plate, and the other side is connected to the driving rod, which is used to synchronously drive the piston to reciprocate when the bellows is extended or retracted.

[0010] By adopting the above technical solution, when the piston is away from the end plate, the gas in the analysis chamber can be drawn into the vacuum chamber through the one-way valve at the end plate position, and when the piston is reset, the air pressure in the vacuum chamber increases, thereby discharging the gas from the one-way valve on the piston to the inside of the regulating tube, and so on, thereby completing the operation of the regulating mechanism to adjust the vacuum degree in the analysis chamber.

[0011] The present invention is further configured as follows: the driving mechanism includes a fixing frame fixed on the side of the partition away from the bellows, a rotating shaft is rotatably connected at the center of the fixing frame, a ratchet and a driving wheel are respectively fixed on the rotating shaft, and the driving wheel is located at the axial direction of the adjusting tube, and the end of the driving rod away from the piston is hinged at the eccentricity of the driving wheel, and a pawl for limiting the rotation of the ratchet is also slidably connected inside the box body, and an elastic member for storing energy to drive the rotating shaft to rotate is also provided inside one end of the fixing frame. In this embodiment, the elastic member is a coil spring, one end of the coil spring is fixed on the rotating shaft, and the other end is fixed inside the fixing frame, and the slide plate is connected to the rotating shaft through a transmission structure. When the bellows is extended or retracted, the slide plate slides and drives the rotating shaft to rotate through the transmission structure; the transmission structure includes a transmission tube fixed on the slide plate, a transmission sleeve is rotatably connected to the partition, the transmission tube is arranged inside the transmission sleeve, and a driving block is arranged on the outer peripheral wall of the transmission tube, and a driving groove for the driving block to be clamped in the inner peripheral wall of the transmission sleeve is opened along the spiral direction, and one side of the transmission sleeve passes through the partition and a bevel gear 1 is fixed on the partition, and a bevel gear 2 meshing with the bevel gear 1 is fixed on the rotating shaft.

[0012] By adopting the above technical solution, under the elastic force of the elastic member, the rotating shaft will rotate in the opposite direction and continue to drive the rotating shaft and the driving wheel to move. On the one hand, the driving wheel will drive the piston to continue to reciprocate in the adjusting tube, thereby extracting and discharging the gas in the analysis chamber. On the other hand, under the guiding action of the reverse rotating driving groove, the transmission tube will move axially in the opposite direction and drive the bellows to contract accordingly, thereby squeezing the gas in the analysis chamber, so that the gas can enter the exhaust chamber through the one-way valve at the end plate position and be discharged by the piston, thereby greatly improving the efficiency of the piston in extracting gas, and making it more convenient for the staff to adjust the vacuum degree in the analysis chamber.

[0013] The present invention is further configured as follows: a through hole is opened on the outer wall of the box body, one end of the ratchet is hinged with a connecting rod for inserting into the through hole and passing through the box body, a screw sleeve is rotatably connected to the outer peripheral wall of the connecting rod, an external thread structure is arranged on the outer peripheral wall of the screw sleeve, an embedding groove for inserting the screw sleeve is opened on the inner peripheral wall of the through hole, an internal thread structure matching the external thread structure is arranged in the embedding groove, and a handle is also arranged on the screw sleeve.

[0014] By adopting the above technical solution, when the pawl needs to be removed, it is only necessary to rotate the handle to drive the screw sleeve to rotate, and then gradually drive the connecting rod to move axially, thereby driving the pawl to disengage from the ratchet to release the limit on the ratchet. The operation is convenient, and when installing, the screw sleeve can be rotated in the opposite direction.

[0015] The present invention is further configured as follows: a plurality of slide bars are fixed between the partition plate and the outer wall of the mass analyzer, and a plurality of slide holes for the slide bars to slide are provided on the slide plate.

[0016] By adopting the above technical solution, the sliding plate slides along the axial direction of the sliding rod, thereby making the sliding of the sliding plate more stable and smooth.

[0017] The present invention is further configured such that ventilation holes are arranged on the side walls of both sides of the regulating cavity.

[0018] By adopting the above technical solution, the gas extracted through the piston can be discharged in time to avoid affecting the movement of the driving wheel.

[0019] The beneficial effect of the present invention is that by arranging a retractable bellows, when the vacuum degree in the analysis chamber changes, that is, when gas exists in the analysis chamber, the bellows is extended by the change of the air pressure in the analysis chamber, thereby driving the slide plate to slide, and then causing the indicator needle to slide on the surface of the box body. At this time, the staff only needs to observe the position of the indicator needle on the scale line through the transparent glass cover to intuitively understand the vacuum degree in the analysis chamber. By arranging an adjustment mechanism, the vacuum degree in the analysis chamber can be adjusted by the telescopic movement of the bellows, thereby ensuring the performance of the mass spectrometer and improving the reliability of the analysis results. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a structural schematic diagram of the present invention; Figure 2 It is a partial cross-sectional view of the present invention; Figure 3 for Figure 2 A schematic diagram of the enlarged structure at A in the middle; Figure 4 A half-section diagram of the present invention; Figure 5 for Figure 4 A schematic diagram of the enlarged structure at B in the middle; Figure 6 It is a schematic diagram of the exploded structure of the bellows, the regulating mechanism and the driving mechanism in the present invention; Figure 7 It is a schematic diagram of the structure of the bellows in the present invention; Figure 8 It is a schematic diagram of the structure of the driving mechanism and the piston in the present invention.

[0021] In the figure: 1, mass analyzer; 11, analysis chamber; 2, pressure detection mechanism; 21, box; 211, partition; 2111, slide rod; 212, detection chamber; 213, adjustment chamber; 214, slide groove; 215, scale line; 216, transparent glass cover; 217, through hole; 218, embedded groove; 2181, internal thread structure; 219, vent; 22, bellows; 221, slide plate; 222, indicator needle; 223, connecting rod; 224, slide hole; 23, adjustment mechanism; 231, adjustment tube; 2311, end plate; 2 32. Piston; 233. Drive rod; 234. Pumping chamber; 235. One-way valve; 24. Drive mechanism; 241. Fixed frame; 242. Rotating shaft; 243. Ratchet; 244. Drive wheel; 245. Ratchet; 2451. Connecting rod; 2452. Screw sleeve; 2453. External thread structure; 2454. Handle; 246. Elastic member; 247. Transmission structure; 2471. Transmission pipe; 2472. Transmission sleeve; 2473. Drive block; 2474. Drive groove; 2475. Bevel gear one; 2476. Bevel gear two. DETAILED DESCRIPTION

[0022] In order to make the technical means, creative features, objectives and effects of the present invention easier to understand, the present invention is further described below with reference to specific illustrations.

[0023] like Figure 1-5 As shown in , 7, a vacuum pressure detection device for a liquid chromatography tandem mass spectrometer includes a mass analyzer 1, an analysis chamber 11 is provided inside the mass analyzer 1, and a pressure detection mechanism 2 connected to the analysis chamber 11 is provided on the outer wall of the mass analyzer 1, and the pressure detection mechanism 2 includes: The box body 21 is arranged on the outer wall of the mass analyzer 1 and is divided into a detection chamber 212 and an adjustment chamber 213 by a partition 211, wherein the detection chamber 212 is on the side facing the mass analyzer 1; A retractable bellows 22 is disposed in the detection cavity 212, with one end connected to the analysis cavity 11 and the other end closed and provided with a slide plate 221; The indicator needle 222 is arranged on the slide plate 221 through a connecting rod 223 and one end of the indicator needle 222 passes through the box body 21 and is slidably connected to the surface of the box body 21; The surface of the box body 21 is provided with a slide groove 214 for the end of the indicator needle 222 to slide. The box body 21 is provided with a scale line 215 engraved with a vacuum degree in the reaction analysis chamber 11 at a position corresponding to the slide groove 214. A transparent glass cover 216 is also provided on the box body 21 at a position corresponding to the scale line 215. In addition, an adjusting mechanism 23 is provided inside the adjusting chamber 213 , which is driven by the bellows 22 to adjust the vacuum degree in the analysis chamber 11 .

[0024] By providing a retractable bellows 22, when the vacuum degree in the analysis chamber 11 changes, that is, when gas exists in the analysis chamber 11, the change in the air pressure in the analysis chamber 11 drives the bellows 22 to extend, thereby driving the slide plate 221 to slide, and then causing the indicator needle 222 to slide on the surface of the box body 21. At this time, the staff only needs to observe the position of the indicator needle 222 at the scale line 215 through the transparent glass cover 216 to intuitively understand the vacuum degree in the analysis chamber 11. By providing an adjustment mechanism 23, the vacuum degree in the analysis chamber 11 can be adjusted by the telescopic movement of the bellows 22, thereby ensuring the performance of the mass spectrometer and improving the reliability of the analysis results.

[0025] like Figure 5 and Figure 6 As shown, the adjustment mechanism 23 includes: The regulating tube 231 is fixed on the partition plate 211 and one end of the regulating tube 231 passes through the slide plate 221 and extends into the interior of the bellows 22. The end of the regulating tube 231 extending into the interior of the bellows 22 is provided with an end plate 2311. The piston 232 slides inside the regulating tube 231 and is hinged with a driving rod 233 on one side away from the analysis chamber 11, and forms an air extraction chamber 234 between the other side and the end plate 2311; Among them, a plurality of one-way valves 235 (not shown in the figure) are arranged on the end plate 2311 and the piston 232. Specifically, one one-way valve 235 is arranged at the center of the end plate 2311, and two one-way valves 235 (not shown in the figure) are arranged at the positions on both sides of the driving rod 233 of the piston 232. The one-way valve 235 (not shown in the figure) located at the center of the end plate 2311 is used to unidirectionally restrict the gas in the pumping chamber 234 from entering the analysis chamber 11 and allow the gas in the analysis chamber 11 to enter the pumping chamber 234. The one-way valve 235 (not shown in the figure) located on the piston 232 is used to unidirectionally restrict the gas in the regulating tube 231 from entering the pumping chamber 234 and allow the gas in the pumping chamber 234 to enter the regulating tube 231 and be discharged. A driving mechanism 24 is also provided on the partition plate 211 . One side of the driving mechanism 24 is connected to the slide plate 221 , and the other side is connected to the driving rod 233 . The driving mechanism 24 is used to synchronously drive the piston 232 to reciprocate when the bellows 22 is extended or retracted.

[0026] When the bellows 22 is extended, it will synchronously drive the slide plate 221 to slide in the direction of the partition 211. Under the drive of the driving mechanism 24, when the bellows 22 is extended, it can synchronously drive the piston 232 to reciprocate in the regulating tube 231. When the piston 232 is away from the end plate 2311, the gas in the analysis chamber 11 can be drawn into the exhaust chamber 234 through the one-way valve 235 (not shown in the figure) at the position of the end plate 2311. When the piston 232 is reset, the air pressure in the exhaust chamber 234 increases, thereby discharging the gas from the one-way valve 235 (not shown in the figure) on the piston 232 to the inside of the regulating tube 231, and thus completing the operation of the regulating mechanism 23 to adjust the vacuum degree in the analysis chamber 11.

[0027] like Figure 6 and Figure 8 As shown, the driving mechanism 24 includes a fixing frame 241 fixed on the side of the partition 211 away from the bellows 22, and a rotating shaft 242 is rotatably connected at the center of the fixing frame 241. A ratchet 243 and a driving wheel 244 are respectively fixed on the rotating shaft 242, and the driving wheel 244 is located at the axial direction of the adjusting tube 231. One end of the driving rod 233 away from the piston 232 is hinged at the eccentric point of the driving wheel 244. A pawl 245 for limiting the rotation of the ratchet 243 is also slidably connected inside the box body 21. An elastic member 246 for storing energy to drive the rotating shaft 242 to rotate is also provided inside one end of the fixing frame 241. In this embodiment, the elastic member 246 is a coil spring, one end of the coil spring is fixed on the rotating shaft 242, and the other end is fixed inside the fixing frame 241. The slide plate 221 is connected to the rotating shaft 242 through a transmission structure 247. When the bellows 22 is extended or retracted, the slide plate 221 slides and drives the rotating shaft 242 to rotate through the transmission structure 247.

[0028] Specifically, the transmission structure 247 includes a transmission tube 2471 fixed on the slide plate 221, a transmission sleeve 2472 is rotatably connected to the partition 211, the transmission tube 2471 is arranged inside the transmission sleeve 2472 and a driving block 2473 is arranged on the outer peripheral wall of the transmission tube 2471, and a driving groove 2474 for the driving block 2473 to be inserted is opened on the inner peripheral wall of the transmission sleeve 2472 along the spiral direction, one side of the transmission sleeve 2472 passes through the partition 211 and a bevel gear 1 2475 is fixed on the partition 211, and a bevel gear 2 2476 meshing with the bevel gear 1 2475 is fixed on the rotating shaft 242.

[0029] When the air pressure in the analysis chamber 11 increases, the bellows 22 drives the slide plate 221 to extend, thereby driving the transmission tube 2471 to slide axially toward the inside of the transmission sleeve 2472. Under the guidance of the spiral driving groove 2474, the movement energy of the driving block 2473 drives the transmission sleeve 2472 to rotate, thereby driving the bevel gear 1 2475 and the bevel gear 2476 to rotate. Driven by the bevel gear 2476, the shaft 242 rotates accordingly, which, on the one hand, drives the ratchet 243 and the driving wheel 244 to rotate and causes the driving wheel 244 to drive the piston 232 to reciprocate. On the other hand, it drives the elastic member 246 to contract and generate an elastic force to restore the original state. The ratchet 243 cannot rotate in the opposite direction under the action of the elastic force and drive the shaft 242 to move in the opposite direction through the limiting of the pawl 245. During the process of the piston 232 extracting the gas in the analysis chamber 11, the gas pressure in the analysis chamber 11 changes accordingly, and the bellows 22 will also slow down its extension speed and eventually stop extending. However, under the limit of the pawl 245, the bellows 22 cannot shrink. Specifically, when the bellows 22 is extended, the shaft 242 and the ratchet 243 are driven to rotate, and the elastic member 246 is deformed accordingly. When the elastic force provided by the deformation of the elastic member 246 to limit the rotation of the shaft 242 is greater than or equal to the force provided by the bellows 22 during the extension process to drive the shaft 242 to rotate, the ratchet 243 cannot rotate, that is, the shaft 242 cannot rotate. After extracting gas several times, the piston 232 and the bellows 22 both stop moving. At this time, a small amount of gas still remains in the analysis chamber 11 and has not been exhausted, that is, the slide plate 221 is still a distance away from the initial position of the vacuum state. At this time, the staff can observe the reading of the indicator needle 222 on the surface of the box body 21, and then slide the ratchet 245 to release the limit of the ratchet 245 on the ratchet 243. At this time, the elastic member Under the elastic force of 246, the rotating shaft 242 will rotate in the opposite direction and continue to drive the rotating shaft 242 and the driving wheel 244 to move. On the one hand, the driving wheel 244 will drive the piston 232 to continue to reciprocate in the adjusting tube 231, thereby extracting and discharging the gas in the analysis chamber 11. On the other hand, under the guiding action of the reverse rotating driving groove 2474, the transmission tube 2471 will move axially in the opposite direction and drive the bellows 22 to contract accordingly, thereby squeezing the gas in the analysis chamber 11, so that the gas can enter the exhaust chamber 234 through the one-way valve 235 (not shown in the figure) at the position of the end plate 2311 and be discharged by the piston 232, thereby greatly improving the efficiency of the piston 232 in extracting gas, and making it more convenient for the staff to adjust the vacuum degree in the analysis chamber 11.

[0030] like Figure 3 and Figure 8As shown, the pawl 245 is arranged perpendicular to the horizontal plane under the action of gravity, a through hole 217 is opened on the outer wall of the box body 21, and one end of the pawl 245 is hinged with a connecting rod 2451 for inserting into the through hole 217 and passing through the box body 21, and a screw sleeve 2452 is rotatably connected to the outer peripheral wall of the connecting rod 2451, and an external thread structure 2453 is arranged on the outer peripheral wall of the screw sleeve 2452, and an embedding groove 218 for inserting the screw sleeve 2452 is opened on the inner peripheral wall of the through hole 217, and an internal thread structure 2181 matching the external thread structure 2453 is arranged in the embedding groove 218, and a handle 2454 is also arranged on the screw sleeve 2452.

[0031] When the pawl 245 needs to be removed, the handle 2454 is turned to drive the screw sleeve 2452 to rotate, and the connecting rod 2451 can be gradually driven to move axially, thereby driving the pawl 245 to disengage from the ratchet 243 to release the limit on the ratchet 243. The operation is convenient. When installing, the screw sleeve 2452 can be rotated in the opposite direction.

[0032] like Figure 6 As shown, a plurality of slide bars 2111 are fixed between the partition plate 211 and the outer wall of the mass analyzer 1, and a plurality of slide holes 224 for the slide bars 2111 to slide are provided on the slide plate 221. The slide plate 221 slides along the axial direction of the slide bar 2111, so that the slide plate 221 slides more stably and smoothly.

[0033] like Figure 1 and Figure 2 As shown, the box body 21 is provided with vents 219 on both side walls of the regulating chamber 213. Thus, the gas drawn out by the piston 232 can be discharged in time to avoid affecting the movement of the driving wheel 244.

[0034] The above shows and describes the basic principles, main features and advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention. The scope of the present invention is defined by the attached claims and their equivalents.

Claims

1. A vacuum pressure detection device for a liquid chromatography tandem mass spectrometer, comprising a mass analyzer (1), wherein an analysis chamber (11) is provided inside the mass analyzer (1), and characterized in that: A pressure detection mechanism (2) is provided on the outer wall of the mass analyzer (1), and the pressure detection mechanism (2) comprises: A box body (21) is arranged on the outer wall of the mass analyzer (1) and has an interior divided by a partition (211) to form a detection cavity (212) and an adjustment cavity (213); A bellows (22) is disposed in the detection cavity (212), one end of which is in communication with the analysis cavity (11), and the other end of which is closed and provided with a slide plate (221); An indicating needle (222) is disposed on the slide plate (221) and one end of which penetrates through the box body (21) and is slidably connected to the surface of the box body (21); The surface of the box body (21) is provided with a slide groove (214) for the end of the indicating needle (222) to slide, and the box body (21) is provided with a plurality of scale lines (215) at positions corresponding to the slide groove (214); An adjusting mechanism (23) is arranged inside the adjusting chamber (213) and is driven by the bellows (22) to adjust the vacuum degree in the analysis chamber (11).

2. The vacuum pressure detection device for a liquid chromatography tandem mass spectrometer according to claim 1, characterized in that: The regulating mechanism (23) comprises: An adjusting tube (231) is fixed on the partition plate (211) and one end of which passes through the slide plate (221) and extends into the interior of the bellows (22); an end plate (2311) is provided at the end of the adjusting tube (231) extending into the interior of the bellows (22); A piston (232) slides inside the regulating tube (231) and is hingedly connected to a driving rod (233) on one side, and forms an air extraction cavity (234) between the other side and the end plate (2311); Wherein, a plurality of one-way valves (235) are provided on the end plate (2311) and the piston (232), and the plurality of one-way valves (235) are respectively used to restrict the gas in the air extraction chamber (234) from entering the analysis chamber (11) and to restrict the gas in the regulating tube (231) from entering the air extraction chamber (234); A driving mechanism (24) is also provided on the partition plate (211), and the driving mechanism (24) is used to be connected to the driving rod (233) so as to synchronously drive the piston (232) to perform reciprocating motion when the bellows (22) is extended or retracted.

3. The vacuum pressure detection device for a liquid chromatography tandem mass spectrometer according to claim 2, characterized in that: The driving mechanism (24) comprises a fixing frame (241) arranged on a side of the partition (211) away from the bellows (22); a rotating shaft (242) is rotatably connected to the fixing frame (241); a ratchet (243) and a driving wheel (244) are respectively fixed to the rotating shaft (242); one end of the driving rod (233) away from the piston (232) is hinged to an eccentric position of the driving wheel (244); a ratchet (245) for limiting the rotation of the ratchet (243) is slidably connected inside the box (21); an elastic member (246) for storing energy to drive the rotating shaft (242) to rotate is also provided inside one end of the fixing frame (241); the slide plate (221) is connected to the rotating shaft (242) via a transmission structure (247); when the bellows (22) is extended or retracted, the slide plate (221) slides and drives the rotating shaft (242) to rotate via the transmission structure (247).

4. The vacuum pressure detection device for a liquid chromatography tandem mass spectrometer according to claim 3, characterized in that: The transmission structure (247) comprises a transmission tube (2471) fixed on the slide plate (221); a transmission sleeve (2472) is rotatably connected to the partition plate (211); the transmission tube (2471) is arranged inside the transmission sleeve (2472) and a driving block (2473) is arranged on the outer peripheral wall of the transmission tube (2471); a driving groove (2474) for the driving block (2473) to be inserted is provided on the inner peripheral wall of the transmission sleeve (2472) along a spiral direction; one side of the transmission sleeve (2472) passes through the partition plate (211) and is fixed with a bevel gear 1 (2475); and a bevel gear 2 (2476) meshing with the bevel gear 1 (2475) is fixed on the rotating shaft (242).

5. The vacuum pressure detection device for a liquid chromatography tandem mass spectrometer according to claim 3, characterized in that: A through hole (217) is provided on the outer wall of the box body (21), and a connecting rod (2451) is hingedly connected to one end of the ratchet (245) for being inserted into the through hole (217) and passing through the box body (21).

6. The vacuum pressure detection device for a liquid chromatography tandem mass spectrometer according to claim 1, characterized in that: A plurality of sliding rods (2111) are fixed between the partition plate (211) and the outer wall of the mass analyzer (1), and a plurality of sliding holes (224) for the sliding rods (2111) to slide are provided on the slide plate (221).

7. The vacuum pressure detection device for a liquid chromatography tandem mass spectrometer according to claim 5, characterized in that: A screw sleeve (2452) is rotatably connected to the outer peripheral wall of the connecting rod (2451), an external thread structure (2453) is provided on the outer peripheral wall of the screw sleeve (2452), an embedding groove (218) for the screw sleeve (2452) to be inserted is provided on the inner peripheral wall of the through hole (217), and an internal thread structure (2181) matching the external thread structure (2453) is provided in the embedding groove (218).

8. The vacuum pressure detection device for a liquid chromatography tandem mass spectrometer according to claim 1, characterized in that: A transparent glass cover (216) is also provided on the box body (21) at a position corresponding to the scale line (215).

9. The vacuum pressure detection device for a liquid chromatography tandem mass spectrometer according to claim 1, characterized in that: The box body (21) is provided with ventilation holes (219) at positions on the side walls on both sides of the adjustment cavity (213).

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