Small liquid phase mass spectrometer based on high-precision voltage measurement

Abstract

The invention relates to the technical field of liquid phase mass spectrometers, in particular to a small liquid phase mass spectrometer based on high-precision voltage measurement, which comprises a box body, a box shell is mounted at the top end of the box body through bolts, a first-stage cavity, a second-stage cavity and a placement area are arranged in the box shell, and the first-stage cavity, the second-stage cavity and the placement area are distributed in an up-and-down structure; an ion funnel is arranged in the first-stage cavity, and a taper hole plate is mounted at the top of the inner wall of the second-stage cavity through a bolt; the linear ion trap is a double-potential-well plane, collection of entering ions and controllable cooling and throwing of confined ions can be achieved respectively, and compared with a single-potential-well plane ion trap, the linear ion trap is more sufficient in ion collection and focusing and higher in ion concentration efficiency. Meanwhile, the work cycle, the ion flux and the thrown ions of the double-potential-well plane ion trap all meet the work requirements of the multi-reflection time-of-flight mass analyzer, the double-potential-well plane ion trap can be coupled with the multi-reflection time-of-flight mass analyzer, introduced ions with high flux and concentrated states are provided for the multi-reflection time-of-flight mass analyzer, and the detection accuracy and precision of the liquid phase mass spectrometer are greatly improved.

Description

Technical Field

[0001] The invention relates to the technical field of liquid phase mass spectrometers, in particular to a small liquid phase mass spectrometer based on high-precision voltage measurement. Background Art

[0002] Liquid chromatography-mass spectrometry, abbreviated as LC-MS, is an instrument that combines liquid chromatography with mass spectrometry. It combines the liquid chromatography's ability to effectively separate thermally unstable and high-boiling point compounds with the mass spectrometer's strong component identification capabilities. It is an effective means of separating and analyzing complex organic mixtures.

[0003] The Chinese patent with publication number CN112420479B provides a miniature mass spectrometer, comprising: an ionization source, which is used to convert sample molecules into gas-phase ions in a region substantially at atmospheric pressure; a capture device, which is used to capture and store ions; a discontinuous atmospheric pressure interface device, which is used to transfer ions from the region substantially at atmospheric pressure to at least one other region with reduced pressure, wherein the atmospheric pressure interface device includes a valve for controlling ions to enter or stop entering the capture device, and by opening the valve multiple times, ions are transferred to the capture device in a discontinuous manner to capture and enrich ions; it also includes a mass analyzer, a detector, a circuit, a vacuum chamber, a vacuum pump, a barometer and a computer; the present invention provides a miniature mass spectrometer that can improve sensitivity and ion detection limit, and improve ion intensity stability.

[0004] It can be found from the above patents and existing liquid mass spectrometers that the existing liquid mass spectrometers have the following deficiencies: the linear ion trap in the traditional liquid mass spectrometer is a single potential well plane, and its collection and focusing of ions are insufficient, resulting in the liquid mass spectrometer being unable to accurately detect the composition of the substance to be detected, affecting the detection accuracy of the liquid mass spectrometer. Therefore, it is urgent to develop a small liquid mass spectrometer based on high-precision voltage measurement. Summary of the invention

[0005] The present invention is proposed in view of the problems existing in an existing small liquid phase mass spectrometer based on high-precision voltage measurement.

[0006] Therefore, the purpose of the present invention is to provide a small liquid mass spectrometer based on high-precision voltage measurement, which solves the problem that the linear ion trap in the traditional liquid mass spectrometer is a single potential well plane, which is insufficient in collecting and focusing ions, resulting in the liquid mass spectrometer being unable to accurately detect the components of the substance to be detected, affecting the detection accuracy of the liquid mass spectrometer. Therefore, it is urgently necessary to develop a small liquid mass spectrometer based on high-precision voltage measurement.

[0007] To solve the above technical problems, according to one aspect of the present invention, the present invention provides the following technical solutions: A small liquid phase mass spectrometer based on high-precision voltage measurement, a small liquid phase mass spectrometer based on high-precision voltage measurement, comprising a box body, a box shell is installed on the top of the box body by bolts, a primary cavity, a secondary cavity and a placement area are arranged inside the box shell, and the primary cavity, the secondary cavity and the placement area are distributed in an upper and lower structure, an ion funnel is arranged inside the primary cavity, a cone plate is installed on the top of the inner wall of the secondary cavity by bolts, and the top of the cone plate extends into the first cavity, an electron multiplier is arranged inside the secondary cavity, a linear ion trap is arranged inside the secondary cavity, and Two DC lenses located at both ends of the linear ion trap are arranged inside the secondary cavity. Molecular pumps and mechanical pumps are respectively installed on both sides of the bottom of the inner wall of the placement area by bolts, and the molecular pump is connected with the mechanical pump through a pipeline. A connecting pipe 2 is arranged at one end of the molecular pump, and the other end of the connecting pipe 2 extends to the inside of the secondary cavity. A connecting pipe 1 is arranged at one end of the mechanical pump, and one end of the connecting pipe 1 extends to the inside of the primary cavity. An ultraviolet lamp is installed on the outer wall of one side of the box by bolts, and the ultraviolet lamp extends into the inside of the primary cavity. The linear ion trap is composed of two planar electrode groups placed in parallel.

[0008] As a preferred solution of the small liquid mass spectrometer based on high-precision voltage measurement described in the present invention, a gas-permeable grid is embedded in the outer wall of one side of the box body through bolts, and grooves are provided on the outer walls of both sides of the box body.

[0009] As a preferred solution of the small liquid mass spectrometer based on high-precision voltage measurement described in the present invention, one end of the mechanical pump is threadedly connected to a threaded cover, and a filter element is provided inside the threaded cover.

[0010] As a preferred solution of the small liquid mass spectrometer based on high-precision voltage measurement described in the present invention, a microcomputer module is installed on one side of the inner wall of the box shell by bolts, and the microcomputer module is electrically connected to the mechanical pump and the molecular pump through wires.

[0011] As a preferred solution of the small liquid mass spectrometer based on high-precision voltage measurement described in the present invention, a box cover is installed on the outer wall on one side of the top of the box shell through a hinge, and a handle groove is opened on the outer wall on one side of the top of the box cover.

[0012] As a preferred solution of the small liquid mass spectrometer based on high-precision voltage measurement described in the present invention, a feeding assembly is provided on the outer wall on one side of the top of the box body, and the feeding assembly is located inside the box shell.

[0013] As a preferred solution of a small liquid mass spectrometer based on high-precision voltage measurement described in the present invention, the feeding assembly includes a liquid storage cylinder, and a liquid storage cavity and a water storage cavity are respectively provided inside the liquid storage cylinder.

[0014] As a preferred solution of a small liquid mass spectrometer based on high-precision voltage measurement described in the present invention, the outer walls on both sides of the top of the liquid storage cylinder are threadedly connected with threaded plugs, and the two threaded plugs extend into the liquid storage cavity and the water storage cavity respectively.

[0015] As a preferred solution of a small liquid mass spectrometer based on high-precision voltage measurement described in the present invention, wherein: the outer wall on one side of the bottom of the liquid storage cylinder is threadedly connected to a pump body, and the top of the pump body extends into the liquid storage cavity, and the discharge end of the pump body is threadedly connected to a sampling tube, and the sampling tube extends into the interior of the primary cavity.

[0016] As a preferred solution of the small liquid mass spectrometer based on high-precision voltage measurement described in the present invention, wherein: an electromagnetic valve is threadedly connected to the outer wall on one side of the bottom of the liquid storage cylinder, and the top of the electromagnetic valve extends into the water storage cavity, a water pipe is provided at one end of the solenoid valve, and the other end of the water pipe is connected to the pump body.

[0017] Compared with existing technologies: The linear ion trap designed in the present invention is a double-potential well planar ion trap, which can respectively realize the collection of incoming ions and the controllable cooling and ejection of confined ions. Compared with the single-potential well planar ion trap, the linear ion trap can collect and focus ions more fully. At the same time, the working cycle, ion flux, and ejected ions of the double-potential well planar ion trap all meet the working requirements of the multiple reflection time-of-flight mass analyzer, and can be coupled with it to provide it with high-flux, state-concentrated introduced ions, which greatly improves the detection accuracy and precision of the liquid mass spectrometer.

[0018] The feeding assembly designed by the present invention can operate the solenoid valve to start when the liquid mass spectrometer analysis is completed, so that the pump body draws clean water inside the water storage chamber into the sampling tube, and then the clean water repeats the flow stroke of the material to be detected, thereby cleaning the internal structures of the primary cavity and the secondary cavity, thereby achieving the purpose of automatic cleaning of the liquid mass spectrometer.

[0019] The threaded cover and filter element designed in the present invention, when the mechanical pump starts to balance the pressure inside the primary cavity and the secondary cavity, the extracted gas will be filtered and discharged through the filter element, thereby filtering the extracted gas and preventing the discharged gas from polluting the surrounding air environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 A schematic diagram of the overall structure provided by the present invention; Figure 2 A schematic diagram of the back structure of the box body and the box shell provided by the present invention; Figure 3 A schematic diagram of the planar structure of the box body and the box shell provided by the present invention; Figure 4 This is a schematic diagram of the structure of the feeding assembly provided by the present invention.

[0021] Explanation of the reference numerals: 1. box body; 2. box shell; 3. air-permeable grille; 4. box cover; 5. handle groove; 6. microcomputer module; 7. placement area; 8. molecular pump; 9. mechanical pump; 10. threaded cover; 11. filter element; 12. connecting pipe one; 13. secondary cavity; 14. linear ion trap; 15. electron multiplier; 16. connecting pipe two; 17. DC lens; 18. conical orifice plate; 19. primary cavity; 20. ion funnel; 21. ultraviolet lamp; 22. feeding assembly; 23. liquid storage cylinder; 24. threaded plug; 25. liquid storage cavity; 26. water storage cavity; 27. solenoid valve; 28. water pipe; 29. ​​pump body; 30. injection tube; 31. groove. DETAILED DESCRIPTION

[0022] The following will be combined with the attached Figure 1-4 The present invention is described in detail, and the technical solutions in the embodiments of the present invention are clearly and completely described. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0023] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which the present invention belongs. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0024] The present invention provides a small liquid phase mass spectrometer based on high-precision voltage measurement through improvement, such as Figure 1-Figure 4As shown, it includes a box body 1, a box shell 2 is installed on the top of the box body 1 by bolts, a primary cavity 19, a secondary cavity 13 and a placement area 7 are arranged inside the box shell 2, and the primary cavity 19, the secondary cavity 13 and the placement area 7 are distributed in an upper and lower structure, an ion funnel 20 is arranged inside the primary cavity 19, and the ion funnel 20 is composed of 27 annular metal electrode sheets, with a total length of about 35 mm, an electrode thickness of 0.3 mm, and an electrode sheet aperture gradually decreasing from 8.8 mm to 1 mm, a conical plate 18 is installed on the top of the inner wall of the secondary cavity 13 by bolts, and the top of the conical plate 18 extends into the first cavity 19, an electron multiplier 15 is arranged inside the secondary cavity 13, a linear ion trap 14 is arranged inside the secondary cavity 13, and two The DC lens 17 located at both ends of the linear ion trap 14 is a planar metal electrode with a thickness of 1 mm and a central aperture of 0.3 mm. The distance from the cone hole and the front plate of the ion trap is 3 mm. In the positive ion mode, a -30 V voltage is applied. A molecular pump 8 and a mechanical pump 9 are respectively installed on both sides of the bottom of the inner wall of the placement area 7 by bolts. The molecular pump 8 is preferably a AGILENT Twis Torr 704FS magnetic levitation molecular pump, and the mechanical pump 9 is preferably a AD5KEEDB12 / 24SV. During normal operation, the air pressure of the first-stage cavity 19 is maintained in the range of 130-1300 Pa, and the air pressure of the second-stage cavity 13 is maintained at about 0.27 Pa. The molecular pump 8 is interconnected with the mechanical pump 9 through a pipeline. A connecting pipe 16 is provided at one end of the pump 8, and the other end of the connecting pipe 16 extends to the inside of the secondary cavity 13. A connecting pipe 12 is provided at one end of the mechanical pump 9, and one end of the connecting pipe 12 extends to the inside of the primary cavity 19. An ultraviolet lamp 21 is installed on the outer wall of one side of the box body 1 by bolts. The model of the ultraviolet lamp 21 is preferably LUYOR-2130L, and the ultraviolet lamp 21 extends into the inside of the primary cavity 19. The linear ion trap 14 is composed of two parallel planar electrode groups, with a spacing of 4.2 mm, a field radius of 4 mm, and a length of 40 mm. The linear ion trap 14 adopts sinusoidal frequency scanning drive, quadrupole enhanced dipole resonance excitation ion technology, and operates the microcomputer module 6, so that the ion funnel inside the primary cavity 19 and the secondary cavity 13 20, the ultraviolet lamp 21, the electron multiplier 15, and the linear ion trap 14 are started, and then the pump body 29 is operated to start, so that the material to be detected in the liquid storage chamber 25 flows into the ion funnel 20 through the sampling tube 30, and then flows into the DC lens 17 and the linear ion trap 14 in the secondary chamber 13 through the conical hole plate 18, and cooperates with the started electron multiplier 15 to realize the detection of the material to be detected. During the detection process, since the linear ion trap 14 is a double potential well plane, it can respectively realize the collection of incoming ions and the controllable cooling and ejection of constrained ions, which meets the working needs of the multiple reflection flight time mass analyzer, and can be coupled with it to provide it with high-flux, state-concentrated introduced ions, which greatly improves the detection accuracy and precision of the liquid mass spectrometer.

[0025] Furthermore, an air-permeable grille 3 is embedded in the outer wall of one side of the box body 1 by bolts, and grooves 31 are provided on the outer walls of both sides of the box body 1. A threaded cover 10 is threadedly connected to one end of the mechanical pump 9, and a filter element 11 is provided inside the threaded cover 10. The filter element 11 is activated carbon. When the mechanical pump 9 starts to balance the pressure inside the primary cavity 19 and the secondary cavity 13, the extracted gas will be filtered and discharged through the filter element 11, and then discharged into the air from the air-permeable grille 3, thereby filtering the extracted gas and preventing the discharged gas from polluting the surrounding air environment.

[0026] Furthermore, a microcomputer module 6 is installed on one side of the inner wall of the box shell 2 by bolts. The microcomputer module 6 is an industrial tablet computer. Operating the microcomputer module 6 can control the startup of the electronic equipment on the device, and the microcomputer module 6 is electrically connected to the mechanical pump 9 and the molecular pump 8 through wires. A box cover 4 is installed on the outer wall of one side of the top of the box shell 2 by hinges, and a handle groove 5 is opened on the outer wall of one side of the top of the box cover 4, and the box cover 4 can be pulled open through the handle groove 5.

[0027] Furthermore, a feeding assembly 22 is provided on the outer wall of one side of the top of the box body 1, and the feeding assembly 22 is located inside the box shell 2, and the feeding assembly 22 includes a liquid storage cylinder 23, and the liquid storage cylinder 23 is respectively provided with a liquid storage chamber 25 and a water storage chamber 26, and the outer walls on both sides of the top of the liquid storage cylinder 23 are threadedly connected with threaded plugs 24, and the two threaded plugs 24 are unscrewed, and then the prepared materials to be tested and clean water are sent into the liquid storage chamber 25 and the water storage chamber 26, which is convenient for subsequent detection, and the two threaded plugs 24 extend into the liquid storage chamber 25 and the water storage chamber 26, respectively, and the outer wall on one side of the bottom of the liquid storage cylinder 23 is threadedly connected with a pump body 29, and the model of the pump body 29 is preferably Kamoer Kamoer 2L large flow, high pressure and small volume diaphragm liquid pump KLLP1000, and the top of the pump body 29 extends into the liquid storage chamber 25, and the pump body 2 9 The discharge end is threadedly connected with a sampling tube 30, which is a capillary metal tube with a length of 10 cm and an inner diameter of 0.38 mm, and the sampling tube 30 extends into the first-level cavity 19. The outer wall on one side of the bottom of the liquid storage cylinder 23 is threadedly connected with a solenoid valve 27, and the top of the solenoid valve 27 extends into the water storage cavity 26. A water pipe 28 is provided at one end of the solenoid valve 27. After the detection is completed, the solenoid valve 27 can be operated to start, so that the pump body 29 draws the clean water inside the water storage cavity 26 into the sampling tube 30 through the water pipe 28, and then the clean water repeats the flow stroke of the material to be detected, thereby realizing the cleaning of the internal structure of the first-level cavity 19 and the second-level cavity 13, avoiding the problem of cross contamination in subsequent detection, and achieving the purpose of automatic cleaning of the liquid mass spectrometer, and the other end of the water pipe 28 is connected to the pump body 29.

[0028] Working principle: When using the liquid phase mass spectrometer to detect the material to be detected, the worker can open the box cover 4 through the handle slot 5, and then unscrew the two threaded plugs 24, and then send the prepared material to be detected and clean water into the liquid storage chamber 25 and the water storage chamber 26, and then cover the box cover 4, and then operate the microcomputer module 6 to start the ion funnel 20, ultraviolet lamp 21, electron multiplier 15, and linear ion trap 14 in the primary cavity 19 and the secondary cavity 13, and then operate the pump body 29 to start, so that the material to be detected in the liquid storage chamber 25 flows into the ion funnel 20 through the sampling tube 30, and then flows into the DC lens 17 and linear ion trap 14 in the secondary cavity 13 through the conical hole plate 18, and cooperates with the started electron multiplier 15 to realize the detection of the material to be detected. During the detection process, since the linear ion trap 14 is a double potential well plane, it can respectively realize the collection of incoming ions and the controllable cooling and ejection of constrained ions. It meets the working needs of the multiple reflection time-of-flight mass analyzer and can be coupled with it to provide it with high-flux and concentrated state introduced ions, which greatly improves the detection accuracy and precision of the liquid mass spectrometer. At the same time, the molecular pump 8 and the mechanical pump 9 will be started in the process to adjust the internal pressure of the primary cavity 19 and the secondary cavity 13, and when the mechanical pump 9 starts to balance the pressure inside the primary cavity 19 and the secondary cavity 13, the extracted gas will be filtered and discharged through the filter element 11 to filter the extracted gas and avoid the discharged gas from polluting the surrounding air environment. After the subsequent detection is completed, the solenoid valve 27 can be operated to start, so that the pump body 29 draws the clean water inside the water storage cavity 26 into the sampling tube 30, and then the clean water repeats the flow stroke of the material to be detected, so as to clean the internal structure of the primary cavity 19 and the secondary cavity 13, avoid the problem of cross contamination in subsequent detection, and achieve the purpose of automatic cleaning of the liquid mass spectrometer.

[0029] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A small liquid phase mass spectrometer based on high-precision voltage measurement, comprising a housing (1), characterized in that: A box shell (2) is installed at the top of the box body (1) by means of bolts, a primary cavity (19), a secondary cavity (13) and a placement area (7) are provided inside the box shell (2), and the primary cavity (19), the secondary cavity (13) and the placement area (7) are arranged in an upper and lower structure, an ion funnel (20) is provided inside the primary cavity (19), a conical plate (18) is installed at the top of the inner wall of the secondary cavity (13) by means of bolts, and the top of the conical plate (18) extends into the primary cavity (19), an electron multiplier (15) is provided inside the secondary cavity (13), a linear ion trap (14) is provided inside the secondary cavity (13), and two ion funnels (20) are provided inside the linear ion trap (14) A direct current lens (17) is provided at both ends; a molecular pump (8) and a mechanical pump (9) are respectively installed on both sides of the bottom of the inner wall of the placement area (7) by means of bolts, and the molecular pump (8) is connected to the mechanical pump (9) by means of a pipeline; a connecting pipe (16) is provided at one end of the molecular pump (8), and the other end of the connecting pipe (16) extends into the interior of the secondary cavity (13); a connecting pipe (12) is provided at one end of the mechanical pump (9), and one end of the connecting pipe (12) extends into the interior of the primary cavity (19); an ultraviolet lamp (21) is installed on the outer wall of one side of the box body (1) by means of bolts, and the ultraviolet lamp (21) extends into the interior of the primary cavity (19); and the linear ion trap (14) is composed of two parallel planar electrode groups.

2. A small liquid phase mass spectrometer based on high-precision voltage measurement according to claim 1, characterized in that: An air-permeable grille (3) is embedded in an outer wall of one side of the box body (1) by means of bolts, and grooves (31) are provided on the outer walls of both sides of the box body (1).

3. A small liquid phase mass spectrometer based on high-precision voltage measurement according to claim 1, characterized in that: One end of the mechanical pump (9) is threadedly connected to a threaded cover (10), and a filter element (11) is provided inside the threaded cover (10).

4. A small liquid phase mass spectrometer based on high-precision voltage measurement according to claim 1, characterized in that: A microcomputer module (6) is installed on one side of the inner wall of the box shell (2) by means of bolts, and the microcomputer module (6) is electrically connected to the mechanical pump (9) and the molecular pump (8) respectively through wires.

5. A small liquid phase mass spectrometer based on high-precision voltage measurement according to claim 1, characterized in that: A box cover (4) is mounted on an outer wall on one side of the top of the box shell (2) via a hinge, and a handle groove (5) is provided on an outer wall on one side of the top of the box cover (4).

6. A small liquid phase mass spectrometer based on high-precision voltage measurement according to claim 1, characterized in that: A feeding assembly (22) is provided on an outer wall on one side of the top of the box body (1), and the feeding assembly (22) is located inside the box shell (2).

7. A small liquid phase mass spectrometer based on high-precision voltage measurement according to claim 1, characterized in that: The feeding assembly (22) comprises a liquid storage cylinder (23), wherein a liquid storage cavity (25) and a water storage cavity (26) are respectively provided inside the liquid storage cylinder (23).

8. A small liquid phase mass spectrometer based on high-precision voltage measurement according to claim 1, characterized in that: The outer walls on both sides of the top of the liquid storage cylinder (23) are both threadedly connected with threaded plugs (24), and the two threaded plugs (24) extend into the liquid storage cavity (25) and the water storage cavity (26) respectively.

9. A small liquid phase mass spectrometer based on high-precision voltage measurement according to claim 1, characterized in that: A pump body (29) is threadedly connected to an outer wall of one side of the bottom of the liquid storage cylinder (23), and the top end of the pump body (29) extends into the liquid storage cavity (25). A sample injection tube (30) is threadedly connected to an outlet end of the pump body (29), and the sample injection tube (30) extends into the interior of the primary cavity (19).

10. A small liquid phase mass spectrometer based on high-precision voltage measurement according to claim 1, characterized in that: A solenoid valve (27) is threadedly connected to the outer wall of one side of the bottom of the liquid storage cylinder (23), and the top end of the solenoid valve (27) extends into the water storage chamber (26). A water delivery pipe (28) is provided at one end of the solenoid valve (27), and the other end of the water delivery pipe (28) is connected to the pump body (29).

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