An online reaction mass spectrometry ion source

Abstract

The application discloses an online reaction mass spectrum ion source, belongs to the technical field of mass spectrum analysis, and solves the problems of incapability of online reaction with low-polarity reactants, short and unstable spray duration, insufficient reaction efficiency and single optimization parameter in the prior art. The ion source comprises a base module, an ultrasonic spray module and an electrospray module arranged on the base module; the ultrasonic spray module is used for preparing droplets of low-polarity reactants and comprises an injection pump, a first capillary and an ultrasonic atomization sheet; the liquid inlet of the first capillary is connected with the injection pump, and the liquid outlet of the first capillary faces the ultrasonic atomization sheet; the electrospray module is used for preparing droplets of high-polarity reactants and comprises a second capillary and an electrode; the electrode is inserted into the high-polarity reactant solution of the second capillary; the droplets of the ultrasonic spray module and the droplets of the electrospray module have coincidence on a motion path. The ion source can be used for mass spectrum analysis.

Description

Technical Field

[0001] This invention belongs to the field of mass spectrometry analysis technology, and particularly relates to an online reaction mass spectrometry ion source. Background Technology

[0002] Mass spectrometry, as a widely used analytical technique, can provide a wealth of information about the structure of substances. A mass spectrometer typically consists of an ion source, a mass analyzer, and a detector. The ion source, as an important component of the mass spectrometer, is used to ionize the atoms or molecules to be measured and to extract an ion current from the sample for subsequent devices. The successful ionization of the analyte molecules is crucial for the smooth execution of mass spectrometry detection.

[0003] Nano-ionization (NIE) technology is a soft ionization technique characterized by its simple structure and low sample requirements. It is widely used for the characterization of systems such as peptides, proteins, metal clusters, and metal complexes.

[0004] The specific method of nano-electrospray ionization (NOE) technology is as follows: A solution containing ionic or polar analyte molecules is added to a capillary. A high-voltage electric field is set at the micron-sized outlet of the capillary. Under the action of Coulomb force, the analyte solution is atomized into charged microdroplets at the outlet. The gradually desolvated charged microdroplets then enter the mass spectrometer under the influence of the electric field for subsequent analysis.

[0005] The ionization efficiency of the analyte significantly affects the detection performance of mass spectrometry. When using traditional nano-electrospray ionization (NEL) for online reactions, the solutions containing reactants are typically directly mixed and loaded into the capillary. This requires the reactants to possess a certain polarity to ensure ionization efficiency, but this greatly limits the application scope of NEL. NEL optimization parameters are limited, typically only allowing optimization of parameters such as voltage and relative position to the mass spectrometer inlet. Changing the reactant ratio often requires re-preparing the solution and loading it into a new capillary. Even slight variations in capillary specifications between batches can affect ionization efficiency, introducing greater experimental errors. Furthermore, the open design of the NEL nozzle means that if highly volatile solvents are used, the spray can only be maintained for a few minutes, and the reactant concentration gradually increases over time due to the small solution volume, which is detrimental to online reaction experiments. Summary of the Invention

[0006] Based on the above analysis, the present invention aims to provide an online reaction mass spectrometry ion source that solves the problems of existing technologies, such as inability to react with low-polarity reactants online, short and unstable spray duration, insufficient reaction efficiency, and limited optimization parameters.

[0007] The objective of this invention is mainly achieved through the following technical solutions:

[0008] This invention provides an online reactive mass spectrometry ion source, including a base module and an ultrasonic spray module and an electrospray module disposed on the base module; the ultrasonic spray module is used for the preparation of droplets of low-polarity reactants, and includes an injection pump, a first capillary, and an ultrasonic atomizing plate, with the inlet of the first capillary connected to the injection pump and the outlet of the first capillary facing the ultrasonic atomizing plate; the electrospray module is used for the preparation of droplets of high-polarity reactants, and includes a second capillary and an electrode, with the electrode inserted into the high-polarity reactant solution in the second capillary; the droplets of the ultrasonic spray module and the droplets of the electrospray module overlap in their movement paths.

[0009] Furthermore, the droplets in the ultrasonic spray module move in a direction perpendicular to the inlet axis of the mass spectrometer, while the droplets in the electrospray module move towards the inlet of the mass spectrometer.

[0010] Furthermore, the first capillary includes a first pipe, a reducing straight section, and a second pipe connected sequentially along the direction from the inlet to the outlet, wherein the inner diameter of the first pipe is smaller than the inner diameter of the second pipe.

[0011] Furthermore, it also includes an ultrasonic spray base plate, an atomizing plate base, and an ultrasonic spray support rod mounted on the base plate module. The ultrasonic spray base plate and the base module are provided with mutually cooperating slide rails and slide grooves. One end of the ultrasonic spray support rod is fixedly connected to the ultrasonic spray base plate, and the atomizing plate base and the ultrasonic spray support rod are slidably fixedly connected.

[0012] Furthermore, it also includes an ultrasonic spray limiting assembly; the ultrasonic spray limiting assembly includes an ultrasonic spray limiting ring and an ultrasonic spray limiting screw, the ultrasonic spray limiting ring is sleeved on the outer wall of the ultrasonic spray support rod and located below the atomizing plate base, and the ultrasonic spray limiting screw passes through the ultrasonic spray limiting ring and abuts against the outer wall of the ultrasonic spray support rod.

[0013] Furthermore, the middle part of the ultrasonic atomizing plate protrudes upward, forming a groove on the lower end face of the middle part.

[0014] Furthermore, the outlet of the first capillary is machined into an inclined surface; the base module includes a base plate, a first base support rod, a second base support rod, and a third base support rod. The first base support rod is arranged vertically, while the second and third base support rods are arranged horizontally. The lower end of the first base support rod is fixedly connected to the base plate, and the upper end of the first base support rod is rotatably and slidably fixedly connected to one end of the second base support rod. The other end of the second base support rod is rotatably and fixedly connected to one end of the third base support rod. The first capillary is located at the other end of the third base support rod.

[0015] Furthermore, the electrospray module also includes a T-shaped tee and an auxiliary air line; the T-shaped tee has a first branch, a second branch and a third branch, the first branch and the second branch are coaxially arranged, the third branch is perpendicular to the first branch and the second branch respectively, the electrode and the second capillary are mounted in the pipeline formed by the first branch and the second branch, and the auxiliary air line is located in the third branch.

[0016] Furthermore, the electrospray module also includes a first threaded cap and a first fixing ring fitted onto the outer wall of the electrode and fixedly connected to the electrode. The first threaded cap is fastened to the end of the first branch away from the second branch, and the first fixing ring is located between the inner end wall of the first threaded cap and the outer end wall of the first branch. It also includes a second threaded cap fastened to the end of the second branch away from the first branch and a fixing piece located between the inner end wall of the second threaded cap and the inner end wall of the second branch. The second capillary is inserted into the fixing piece.

[0017] Furthermore, it also includes a displacement module mounted on the base plate module. The displacement module is used to support the electrospray module, adjust the distance between the electrospray module and the mass spectrometer inlet, the vertical position of the electrospray module, and the angle between the axis of the electrospray module and the mass spectrometer inlet.

[0018] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0019] A) The online reactive mass spectrometry ion source provided by this invention uses ultrasonic spraying to prepare droplets of low-polarity reactants and electrospraying to prepare droplets of high-polarity reactants. This ensures the online reaction of low-polarity and high-polarity reactants, guarantees the preparation efficiency of reaction droplets, and effectively reduces the amount of low-polarity and high-polarity reactants used. In practical applications, the volume of low-polarity reactant solution is 450-550 μL, and the volume of high-polarity reactant solution is 10-20 μL, which can achieve mass spectrometry analysis in 10-15 minutes. Meanwhile, since the droplets in the ultrasonic spray module move vertically downwards, while the droplets in the electrospray module move horizontally towards the mass spectrometer inlet, the droplets of low-polarity reactants collide and react with the horizontally moving droplets of high-polarity reactants during their downward movement. The products and unreacted droplets of high-polarity reactants are then introduced into the mass spectrometer by the electric field for analysis. The unreacted droplets of low-polarity reactants continue to move downwards, ensuring that the amount of unreacted reactants entering the mass spectrometer is minimized, reducing residues and thus ensuring the cleanliness of the working environment of the mass spectrometer.

[0020] B) The online reactive mass spectrometry ion source provided by this invention has a first capillary inlet connected to an injection pump, an outlet of the first capillary facing an ultrasonic atomizing plate, and an electrode inserted into a highly polar reactant solution in a second capillary, so that the entire system can be basically in a closed state, effectively reducing the volatilization of low-polarity and high-polarity reactant solutions. Compared with traditional nanoliter electrospraying, the spraying time can be increased several times and is more stable.

[0021] C) The online reaction mass spectrometry ion source provided by this invention, since the inlet of the first capillary is connected to the injection pump, can realize the online reaction of low-polarity reactant microdroplets of different concentrations with polar reactant microdroplets of constant concentration by changing the flow rate of the injection pump. Moreover, during the reaction process, online reaction experiments with different concentration gradients can be realized using only one capillary, which can save capillary consumption and reduce systematic errors introduced by the differences between different capillary replacements.

[0022] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the written description and the accompanying drawings. Attached Figure Description

[0023] The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Throughout the drawings, the same reference numerals denote the same parts.

[0024] Figure 1 This is a schematic diagram of the structure of the online reaction mass spectrometry ion source provided in Embodiment 1 of the present invention;

[0025] Figure 2 This is a schematic diagram of the base module in the online reactive mass spectrometry ion source provided in Embodiment 1 of the present invention;

[0026] Figure 3 This is a schematic diagram of the displacement module in the online reaction mass spectrometry ion source provided in Embodiment 1 of the present invention;

[0027] Figure 4 This is a schematic diagram of the ultrasonic spray module in the online reactive mass spectrometry ion source provided in Embodiment 1 of the present invention;

[0028] Figure 5 This is a cross-sectional schematic diagram of the electrospray module in the online reactive mass spectrometry ion source provided in Embodiment 1 of the present invention.

[0029] Figure label:

[0030] 1-Base module; 101-Slide rail; 102-Base base plate; 103-First base support rod; 104-Second base support rod; 105-Third base support rod; 106-First cross-shaped fixing clip; 107-Second cross-shaped fixing clip; 108-Third cross-shaped fixing clip; 109-Base limiting ring; 110-Base limiting screw; 2-Ultrasonic spray module; 201-Injection pump; 202-First capillary tube; 2021-First pipeline; 2022-Reducing straight-through tube; 2023-Second pipeline; 203-Ultrasonic atomizing plate; 204-Ultrasonic spray base plate; 205-Atomizing plate base; 206-Ultrasonic spray support rod; 207-Ultrasonic spray chute; 208-Ultrasonic spray limiting ring; 209- 210-Ultrasonic spray limiting screw; 3-Electro-spray module; 301-Second capillary tube; 302-Electrode; 303-T-type tee; 304-Auxiliary air line; 305-First threaded cap; 306-First fixing ring; 307-Electrode soft ring; 308-Capillary soft ring; 309-Second threaded cap; 310-Fixing plate; 311-Third threaded cap; 312-Second fixing ring; 313-Filter element; 4-Displacement module; 401-Displacement base plate; 402-Rotating table; 403-Fixing component; 404-Displacement support rod; 405-Displacement slide groove; 406-Displacement limiting ring; 407-Displacement limiting screw; 408-Displacement rotating screw; 409-Displacement sliding screw. Detailed Implementation

[0031] Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which form part of the present invention and, together with the embodiments of the present invention, serve to illustrate the principles of the present invention.

[0032] Example 1

[0033] This embodiment provides an online reactive mass spectrometry ion source; see [link to documentation]. Figures 1 to 5The device includes a base module 1 and an ultrasonic spray module 2 and an electro-spray module 3 disposed on the base module 1. The droplets of the ultrasonic spray module 2 move in a direction perpendicular to the inlet axis of the mass spectrometer (e.g., vertically downward), while the droplets of the electro-spray module 3 move in a direction toward the inlet of the mass spectrometer. The droplets of the ultrasonic spray module 2 and the droplets of the electro-spray module 3 overlap in their movement paths. The ultrasonic spray module 2 is used to prepare droplets of low-polarity reactants. It includes an injection pump 201, a first capillary tube 202, and an ultrasonic atomizing plate 203. The inlet of the first capillary tube 202 is connected to the injection pump 201, and the outlet of the first capillary tube 202 faces the ultrasonic atomizing plate 203. The electrospray module 3 is used to prepare droplets of high-polarity reactants. It includes a second capillary tube 301 and an electrode 302. The second capillary tube 301 is filled with a high-polarity reactant solution, and the electrode 302 is inserted into the high-polarity reactant solution in the second capillary tube 301. One end of the second capillary tube 301 is a micron-level outlet, and the two ends of the electrode 302 are an electrode wire and a high-voltage power supply needle, respectively.

[0034] It should be noted that the terms "highly polar reactant" and "lowly polar reactant" are relative definitions. That is, a highly polar reactant is more polar than a lowly polar reactant. Generally, a highly polar reactant refers to a reactant with greater polarity suitable for electrospraying, while a lowly polar reactant refers to a reactant with less polarity that is not suitable for electrospraying. For example, a highly polar reactant has a dielectric constant greater than 20, while a lowly polar reactant has a dielectric constant less than 5.

[0035] Compared with existing technologies, the online reactive mass spectrometry ion source provided in this embodiment uses ultrasonic spraying to prepare droplets of low-polarity reactants and electrospraying to prepare droplets of high-polarity reactants. This ensures the online reaction of low-polarity and high-polarity reactants respectively, guarantees the preparation efficiency of reaction droplets, and effectively reduces the amount of low-polarity and high-polarity reactants used. In practical applications, the volume of low-polarity reactant solution is 450-550 μL, and the volume of high-polarity reactant solution is 10-20 μL, which can achieve mass spectrometry analysis in 10-15 minutes. Meanwhile, since the droplets in the ultrasonic spray module 2 move vertically downwards, while the droplets in the electrospray module 3 move horizontally towards the mass spectrometer inlet, the droplets of low-polarity reactants collide and react with the horizontally moving droplets of high-polarity reactants during their downward movement. The products and the droplets of unreacted high-polarity reactants are then introduced into the mass spectrometer by the electric field for analysis. The droplets of unreacted low-polarity reactants continue to move downwards, which ensures that the amount of unreacted reactants entering the mass spectrometer is minimized, reducing residues and thus ensuring the cleanliness of the working environment of the mass spectrometer.

[0036] Furthermore, in the aforementioned online reactive mass spectrometry ion source, the inlet of the first capillary 202 is connected to the syringe pump 201, the outlet of the first capillary 202 faces the ultrasonic atomizing plate 203, and the electrode 302 is inserted into the highly polar reactant solution of the second capillary 301, so that the entire system can be basically in a closed state, effectively reducing the volatilization of low-polarity reactant solutions and high-polarity reactant solutions. Compared with traditional nanoliter electrospraying, the spraying time can be increased several times and is more stable.

[0037] Furthermore, since the inlet of the first capillary 202 is connected to the syringe pump 201, online reactions of low-polarity reactant microdroplets of different concentrations with polar reactant microdroplets of constant concentration can be achieved by changing the flow rate of the syringe pump 201. During the reaction, online reaction experiments with different concentration gradients can be conducted using only one capillary, thus saving capillary consumption and reducing systematic errors introduced by differences between different capillary tubes. For example, the flow rate of the syringe pump 201 is 500–2000 μL / h (e.g., 500 μL / h, 1000 μL / h, 1500 μL / h, or 2000 μL / h).

[0038] Specifically, regarding the structure of the atomizing plate, the ultrasonic atomizing plate 203 includes a piezoelectric ceramic and a metal sheet with a microporous area in the center, which is wrapped with a silicone ring on the outside and can be driven by a circuit board to generate high-frequency vibration.

[0039] Specifically, the structure of the first capillary 202 includes a first conduit 2021, a reducing straight section 2022, and a second conduit 2023 connected sequentially from the inlet to the outlet. The inner diameter of the first conduit 2021 is smaller than that of the second conduit 2023. On one hand, choosing a smaller inner diameter for the first conduit 2021 reduces the dead volume of the conduit, saves on the amount of low-polarity reactant solution used, and improves the accuracy of mass spectrometry analysis. On the other hand, the larger inner diameter of the second conduit 2023 facilitates the flow of the low-polarity reactant solution, allowing it to uniformly and stably wet the central raised area of ​​the ultrasonic nebulizer 203.

[0040] Considering that as the solution in the low-polarity reactant droplets evaporates continuously along the direction gradually moving away from the ultrasonic atomizing plate 203, the droplet size and density of the ultrasonic spray gradually decrease. Furthermore, the distance between the ultrasonic spray module 2 and the mass spectrometer inlet also affects the reaction efficiency of the low-polarity and high-polarity reactants, as well as the accuracy of the mass spectrometry analysis. Therefore, the ultrasonic spray module 2 further includes an ultrasonic spray base plate 204, an atomizing plate base 205, and an ultrasonic spray support rod 206 mounted on the base plate module. The atomizing plate base 205 has mounting holes for accommodating the ultrasonic atomizing plate 203. The outer silicone ring contacts the mounting hole to install the ultrasonic atomizing plate 203. A sliding rail 101 and a sliding groove are provided between the ultrasonic spray base plate 204 and the base module 1. For example, the sliding rail 101 is provided on the side of the base module 1 facing the ultrasonic spray base plate 204, and an ultrasonic spray groove 207 is provided on the side of the ultrasonic spray base plate 204 facing the base module 1. One end of the ultrasonic spray support rod 206 is fixedly connected to the ultrasonic spray base plate 204. The atomizing plate base 205 is fixedly connected to the ultrasonic spray support rod 206 and can slide along the axis of the ultrasonic spray support rod 206. Thus, the ultrasonic spray module 2 can adjust the distance between the ultrasonic spray module 2 and the mass spectrometer inlet by moving on the sliding rail 101 of the base module 1, and the vertical position of the ultrasonic spray module 2 can be adjusted by sliding the atomizing plate base plate along the axis of the ultrasonic spray support rod 206.

[0041] In order to limit the vertical displacement between the ultrasonic spray base plate 204 and the base module 1, the cross-sectional shape of the ultrasonic spray groove 207 is an inverted trapezoid. Correspondingly, the cross-sectional shape of the slide rail 101 is also an inverted trapezoid. In this way, the side of the slide rail 101 can be limited by the groove wall of the ultrasonic spray groove 207.

[0042] In practical applications, to avoid the vertical position change of the nebulizer base plate affecting the accuracy of the analysis during mass spectrometry analysis, the ultrasonic spray module 2 also includes an ultrasonic spray limiting component for limiting the vertical relative position of the nebulizer base 205 and the ultrasonic spray support rod 206. Specifically, the ultrasonic spray limiting component includes an ultrasonic spray limiting ring 208 and an ultrasonic spray limiting screw 209. The ultrasonic spray limiting ring 208 is sleeved on the outer wall of the ultrasonic spray support rod 206 and located below the nebulizer base 205. The ultrasonic spray limiting screw 209 passes through the ultrasonic spray limiting ring 208 and abuts against the outer wall of the ultrasonic spray support rod 206.

[0043] In order to ensure that the relative position of the electrospray module 3 remains unchanged during the mass spectrometry analysis and to ensure the stability of the analysis, the ultrasonic spray module 2 also includes an ultrasonic spray sliding screw 210, which passes through the ultrasonic spray base plate 204 and abuts against the slide rail 101.

[0044] In order to ensure that the low-polarity reactive droplets generated by the ultrasonic atomizing plate 203 move downward, the middle part of the ultrasonic atomizing plate 203 protrudes upward, so that the lower end face of the middle part forms a groove. Accordingly, the middle side of the ultrasonic atomizing plate 203 needs to be tilted.

[0045] In practical applications, to ensure that the low-polarity reactant solution flowing from the first capillary 202 uniformly and continuously wets the central area of ​​the ultrasonic atomizing plate 203, on the one hand, the outlet of the first capillary 202 is required to be processed into an inclined surface. This reduces the surface tension of the low-polarity reactant solution, ensuring its uniform and continuous flow without dripping. On the other hand, the outlet of the first capillary 202 needs to be aligned with the central side of the ultrasonic atomizing plate 203. Therefore, the aforementioned base module 1 includes a base plate 102, a first base support rod 103, a second base support rod 104, and a third base support rod 105. The first base support rod 103 is vertically arranged, and the second and third base support rods... The first base support rod 103 is horizontally positioned, with its lower end fixedly connected to the base plate 102. The upper end of the first base support rod 103 is rotatably and slidably fixedly connected to one end of the second base support rod 104. The other end of the second base support rod 104 is rotatably and fixedly connected to one end of the third base support rod 105. The first capillary tube 202 is located at the other end of the third base support rod 105. Thus, by adjusting the relative positions and angles between the first base support rod 103, the second base support rod 104, and the third base support rod 105, the first capillary tube 202 can be positioned in any vertical or horizontal position, making it easy for the liquid outlet of the first capillary tube 202 to be aligned with the middle side of the ultrasonic atomizing plate 203.

[0046] To reduce the overall weight of the base module 1, the first base support rod 103, the second base support rod 104, and the third base support rod 105 are all hollow structures, which can reduce the relative displacement that occurs after the three are fixed.

[0047] For example, the first base support rod 103 can be connected to the second base support rod 104 through the first cross-shaped fixing clip 106. Similarly, the second base support rod 104 can be connected to the third base support rod 105 through the second cross-shaped fixing clip 107. The third base support rod 105 is connected to the first capillary tube 202 through the third cross-shaped fixing clip 108.

[0048] In practical applications, to avoid the vertical position change of the first capillary 202 affecting the accuracy of the analysis during mass spectrometry analysis, the aforementioned base module 1 also includes a base limiting component for defining the vertical relative position of the first base support rod 103 and the second base support rod 104. Specifically, the base limiting component includes a base limiting ring 109 and a base limiting screw 110. The base limiting ring 109 is sleeved on the outer wall of the first base support rod 103 and located below the second base support rod 104. The base limiting screw 110 passes through the base limiting ring 109 and abuts against the outer wall of the first base support rod 103. At the same time, the base limiting component can also serve as a height marker to facilitate experimental implementation.

[0049] In order to achieve stable installation of the second capillary tube 301 and the electrode 302, the electrospray module 3, for example, further includes a T-shaped tee 303 and an auxiliary air pipe 304. The T-shaped tee 303 has a first branch, a second branch and a third branch, wherein the first branch and the second branch are coaxially arranged, and the third branch is perpendicular to the first branch and the second branch respectively. The electrode 302 and the second capillary tube 301 are mounted in the pipe formed by the first branch and the second branch, and the auxiliary air pipe 304 is located in the third branch. In this way, the electrode 302 and the second capillary 301 can be placed in the first and second branches, which not only achieves stable installation of the two but also protects them. By setting up the auxiliary gas pipeline 304 and placing it in the third pipeline, the auxiliary gas provided by the auxiliary gas pipeline 304 can be ejected from the gas outlets of the first and second branches. The auxiliary gas ejected from the second branch can further ensure that the highly polar reactant droplets move towards the mass spectrometer, help the microdroplets desolvate, make the reactants better ionized, and at the same time disturb the collisions between microdroplets, increase the collision probability, and improve the reaction efficiency.

[0050] To further improve the installation stability of electrode 302 in the first branch, the electrospray module 3 further includes a first threaded cap 305 and a first fixing ring 306 sleeved on the outer wall of electrode 302 and fixedly connected to electrode 302. The first threaded cap 305 is fastened to the end of the first branch away from the second branch, and the first fixing ring 306 is located between the inner end wall of the first threaded cap 305 and the outer end wall of the first branch. In this way, the radial movement of electrode 302 can be limited by the first threaded cap 305 and the first fixing ring 306, and the first fixing ring 306 can be axially limited by the first threaded cap 305 and the end of the first branch, thereby axially limiting electrode 302.

[0051] In order to further seal the second capillary 301 and reduce the volatilization of the highly polar reactant solution, the electrospray module 3 also includes an electrode soft ring 307. The electrode wire of the electrode 302 is supported on the inner wall of the first branch through the electrode soft ring 307. The outer wall of the electrode soft ring 307 is in contact with the inner wall of the first branch, and the inner wall of the electrode soft ring 307 is in contact with the electrode wire of the electrode 302.

[0052] Similarly, the electrospray module 3 also includes a capillary soft ring 308, which is located at the liquid inlet of the second capillary 301. The electrode wire of the electrode 302 passes through the capillary soft ring 308 and is inserted into the second capillary 301. In this way, the capillary soft ring 308 can seal the second capillary 301, effectively reducing the evaporation of solvent in the highly polar reactant solution and extending the spraying time. At the same time, the concentration of the highly polar reactant solution is more stable than that of traditional nano-liter electrospraying, making the spraying more stable.

[0053] To further improve the installation stability of the second capillary 301 in the second branch, the electrospray module 3 further includes a second threaded cap 309 fastened to the end of the second branch away from the first branch and a fixing piece 310 located between the inner end wall of the second threaded cap 309 and the inner end wall of the second branch. The second capillary 301 is inserted into the fixing piece 310. In this way, the fixing piece 310 can be radially and axially limited by the first threaded cap 305 and the end of the second branch, thereby radially and axially limiting the second capillary 301.

[0054] In order to further improve the installation stability of the auxiliary air line 304 in the third branch, the above-mentioned electro-spray module 3 also includes a third threaded cap 311 fastened to the end of the third branch away from the first and second branches, and a second fixing ring 312 located between the inner end wall of the third threaded cap 311 and the inner end wall of the third branch. The auxiliary air line 304 is inserted into the second fixing ring 312. In this way, the second fixing ring 312 can be radially and axially limited by the third threaded cap 311 and the end of the third branch, thereby enabling the auxiliary air line 304 to be radially and axially limited.

[0055] Considering that the stability of the auxiliary gas supply may affect the accuracy of mass spectrometry analysis, a filter element 313 is provided at the outlet of the auxiliary gas pipeline 304 in the third branch. The filter element 313 is made of a rigid porous material, allowing the auxiliary gas to pass through. In this way, the auxiliary gas can be stabilized through the filter element 313, thereby ensuring the accuracy of mass spectrometry analysis. The auxiliary gas passes through the auxiliary gas pipeline 304 and the filter element 313 in sequence, reaching the middle of the T-shaped tee 303, and finally forming an auxiliary gas coaxial with the second capillary 301.

[0056] In order to adjust the peak value of unreacted highly polar reactants on the mass spectrometry analysis spectrum and avoid them from excessively affecting the peak value of the reaction products, the above-mentioned online reaction mass spectrometry ion source also includes a displacement module 4 on the base plate module. The displacement module 4 is used to support the electrospray module 3, adjust the distance between the electrospray module 3 and the mass spectrometer inlet, the vertical position of the electrospray module, and the angle between the axis of the electrospray module 3 and the mass spectrometer inlet.

[0057] Specifically, the displacement module 4 includes a displacement base plate 401, a rotating platform 402, a fixing member 403, and a displacement support rod 404. The displacement base plate 401 and the base module 1 are provided with a sliding rail 101 and a sliding groove that cooperate with each other. For example, the sliding rail 101 is provided on the side of the base module 1 facing the displacement base plate 401, and the displacement base plate 401 is provided on the side facing the base module 1. One end of the displacement support rod 404 is fixedly connected to the displacement base plate 401. The rotating platform 402 is fixedly connected to the displacement support rod 404. The rotating platform 402 can rotate around the axial direction of the displacement support rod 404 and slide along the axis of the displacement support rod 404. The fixing frame is fixed on the rotating platform 402, and the fixing clamp 403 clamps the electro-spray module 3. In this way, the displacement module 4 can adjust the distance between the electrospray module 3 and the mass spectrometer inlet by moving on the slide rail 101 of the base module 1, the angle between the axis of the electrospray module 3 and the mass spectrometer inlet can be adjusted by rotating the rotary table 402 around the axis of the displacement support rod 404, and the vertical position of the electrospray module 3 can be adjusted by sliding the rotary table 402 along the axis of the displacement support rod 404.

[0058] For example, the droplet movement direction of the electrospray module 3 is deflected upward by 1 to 1.5 mm relative to the axis of the mass spectrometer inlet. This is because the droplets of the electrospray module 3 will deflect downward after colliding with the droplets of the ultrasonic spray. By adjusting the droplet movement direction of the electrospray module 3 to deflect upward relative to the axis of the mass spectrometer inlet, the downward deflection caused by the collision with the droplets of the ultrasonic spray can be compensated, ensuring that the product droplets after the reaction can accurately enter the mass spectrometer.

[0059] In order to limit the vertical displacement between the displacement base plate 401 and the base module 1, the cross-sectional shape of the aforementioned groove is an inverted trapezoid. Correspondingly, the cross-sectional shape of the slide rail 101 is also an inverted trapezoid. In this way, the side of the slide rail 101 can be limited by the groove wall of the displacement groove 405.

[0060] In practical applications, to prevent the rotary table 402 from rotating axially around the displacement support rod 404, its vertical position is usually required to remain unchanged. Therefore, the displacement module 4 also includes a displacement limiting component for limiting the vertical relative position of the rotary table 402 and the displacement support rod 404. Specifically, the displacement limiting component includes a displacement limiting ring 406 and a displacement limiting screw 407. The displacement limiting ring 406 is sleeved on the outer wall of the displacement support rod 404 and located below the rotary table 402. The displacement limiting screw 407 passes through the displacement limiting ring 406 and abuts against the outer wall of the displacement support rod 404. It should be noted that when the second capillary tube 301 needs to be replaced, the displacement rotation screw 408 is loosened, the rotary table 402 is rotated axially around the displacement support rod 404, the second capillary tube 301 is replaced, the rotary table 402 is returned to its original position, and the displacement rotation screw 408 is tightened.

[0061] To ensure that the relative position of the electrospray module 3 remains unchanged during mass spectrometry analysis and to guarantee the stability of the analysis, the displacement module 4 further includes a displacement rotating screw 408 and / or a displacement sliding screw 409. The displacement rotating screw 408 passes through the rotary table 402 and abuts against the outer wall of the displacement support rod 404, while the displacement sliding screw 409 passes through the displacement base plate 401 and abuts against the slide rail 101.

[0062] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. An online reaction mass spectrometry ion source, characterized in that, Includes a base module and an ultrasonic spray module and an electro-spray module mounted on the base module; The ultrasonic spray module is used to prepare droplets of low-polarity reactants. The ultrasonic spray module includes an injection pump, a first capillary tube, and an ultrasonic atomizing plate. The inlet of the first capillary tube is connected to the injection pump, and the outlet of the first capillary tube faces the ultrasonic atomizing plate. The electrospray module is used for the preparation of droplets of highly polar reactants. The electrospray module includes a second capillary and an electrode, with the electrode inserted into the highly polar reactant solution in the second capillary. The droplets from the ultrasonic spray module and the droplets from the electro-spray module overlap in their movement paths; The droplets in the ultrasonic spray module move in a direction perpendicular to the inlet axis of the mass spectrometer, while the droplets in the electrospray module move towards the inlet of the mass spectrometer.

2. The online reactive mass spectrometry ion source according to claim 1, characterized in that, The first capillary includes a first pipe, a reducing straight section, and a second pipe connected sequentially along the direction from the inlet to the outlet, wherein the inner diameter of the first pipe is smaller than the inner diameter of the second pipe.

3. The online reactive mass spectrometry ion source according to claim 1, characterized in that, It also includes an ultrasonic spray base plate, an atomizing plate base, and an ultrasonic spray support rod mounted on the base plate module. The ultrasonic spray base plate and the base module are provided with mutually cooperating slide rails and slide grooves. One end of the ultrasonic spray support rod is fixedly connected to the ultrasonic spray base plate, and the atomizing plate base is slidably fixedly connected to the ultrasonic spray support rod.

4. The online reactive mass spectrometry ion source according to claim 3, characterized in that, It also includes an ultrasonic spray limiting component; The ultrasonic spray limiting assembly includes an ultrasonic spray limiting ring and an ultrasonic spray limiting screw. The ultrasonic spray limiting ring is sleeved on the outer wall of the ultrasonic spray support rod and located below the atomizing plate base. The ultrasonic spray limiting screw passes through the ultrasonic spray limiting ring and abuts against the outer wall of the ultrasonic spray support rod.

5. The online reactive mass spectrometry ion source according to claim 1, characterized in that, The ultrasonic atomizing plate protrudes upward in the middle, forming a groove on the lower end face of the middle section.

6. The online reactive mass spectrometry ion source according to claim 5, characterized in that, The outlet of the first capillary is machined into an inclined surface; The base module includes a base plate, a first base support rod, a second base support rod, and a third base support rod. The first base support rod is vertically arranged, while the second and third base support rods are horizontally arranged. The lower end of the first base support rod is fixedly connected to the base plate, and the upper end of the first base support rod is rotatably and slidably fixedly connected to one end of the second base support rod. The other end of the second base support rod is rotatably and fixedly connected to one end of the third base support rod. The first capillary tube is located at the other end of the third base support rod.

7. The online reactive mass spectrometry ion source according to claim 1, characterized in that, The electro-spray module also includes a T-shaped tee and an auxiliary air pipeline; The T-shaped tee has a first branch, a second branch, and a third branch. The first branch and the second branch are coaxially arranged, and the third branch is perpendicular to the first branch and the second branch. The electrode and the second capillary are installed in the pipeline formed by the first branch and the second branch, and the auxiliary gas pipeline is located in the third branch.

8. The online reactive mass spectrometry ion source according to claim 1, characterized in that, The electrospray module further includes a first threaded cap and a first fixing ring sleeved on the outer wall of the electrode and fixedly connected to the electrode. The first threaded cap is fastened at the end of the first branch away from the second branch, and the first fixing ring is located between the inner end wall of the first threaded cap and the outer end wall of the first branch. It also includes a second threaded cap fastened to the end of the second branch away from the first branch and a fixing piece located between the inner end wall of the second threaded cap and the inner end wall of the second branch, with the second capillary inserted into the fixing piece.

9. The online reactive mass spectrometry ion source according to any one of claims 1 to 8, characterized in that, It also includes a displacement module mounted on the base plate module, which is used to support the electrospray module, adjust the distance between the electrospray module and the mass spectrometer inlet, the vertical position of the electrospray module, and the angle between the axis of the electrospray module and the mass spectrometer inlet.

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