Laser ablation electrospray-moderated barrier discharge combined ionization source mass spectrometry imaging device

Abstract

The application belongs to the technical field of mass spectrometers, and discloses a laser ablation electrospray-moderate barrier discharge composite ionization source mass spectrometry imaging device. The mass spectrometry imaging device comprises a sample carrier, a laser emitter, an electrospray module and a moderate barrier discharge module. The sample carrier is used for carrying a sample to be analyzed. The laser emitter is used for emitting laser towards the sample to be analyzed. The electrospray module is used for spraying charged droplets towards the top of the sample to be analyzed. The moderate barrier discharge module has a discharge cavity. The discharge inlet of the discharge cavity is correspondingly arranged in correspondence with the spray outlet of the electrospray module. The discharge outlet of the discharge cavity is in communication with the ion transmission tube of the mass spectrometer. The mass spectrometry imaging device generates gasified samples by laser ablation of the surface of the sample, extracts charged droplets by electrospray, ionizes polar molecules after the droplets are desolvated, and secondarily ionizes the remaining weak / non-polar molecules by moderate barrier discharge plasma, thereby improving ionization efficiency and realizing high-coverage and high-sensitivity metabolite mass spectrometry imaging.

Description

Technical Field

[0001] This invention relates to the field of mass spectrometry equipment, and more particularly to a laser ablation electrospray-dielectric barrier discharge composite ionization source mass spectrometry imaging device. Background Technology

[0002] Mass spectrometry imaging, with its unique advantages such as label-free, non-targeted detection, high sensitivity and high spatial resolution, has become an important tool for visualizing the spatial distribution of elements and molecules in complex samples. As the core component of this technology, the ionization source is particularly crucial for obtaining high-quality mass spectrometry images.

[0003] Current mainstream imaging mass spectrometry ionization techniques mainly include desorption electrospray ionization (DESI) and matrix-assisted laser desorption / ionization (MALDI). The former enables chemical composition analysis of sample surfaces in an open environment, visualizing the spatial distribution of molecules, while the latter achieves chemical analysis and spatial distribution acquisition in a vacuum environment with the assistance of a matrix. Both techniques can achieve in-situ analysis of tissue samples, but both require pretreatment steps such as frozen sectioning, and cannot achieve direct in-situ analysis of living organisms or raw samples (such as leaves).

[0004] Electrospray ionization (LAESI) is a direct ionization technique that combines mid-infrared laser ablation and secondary electrospray ionization. It can be used on a wide range of samples, including plants, tissues, cells, and even untreated biological tissues and liquid samples. This technique first uses atmospheric pressure infrared laser to activate the biological water in aqueous biological samples, performing micro-area ablation and vaporizing the sample to generate a plume of neutral particles. Then, electrospray ionization extracts and ionizes the neutral molecules, which are then analyzed by mass spectrometry. This technique is in-situ and label-free, requiring no complex pretreatment. It can be used to analyze live cells, tissue sections, plants, microorganisms, and even meat samples. Furthermore, by positioning the laser spot, it supports spatial metabolomics imaging, revealing the distribution of molecules in tissues. Therefore, it plays an important role in direct sample analysis and imaging, such as the molecular distribution in plant leaves. However, because the ionization method is based on the principle of electrospray ionization, it exhibits a significant ionization bias and selectivity, responding strongly to polar molecules and weakly to weakly / nonpolar molecules. Therefore, mass spectrometry analysis and imaging based on LAESI technology do not provide comprehensive information and cannot obtain high-sensitivity mass spectrometry imaging results of the full spectrum of metabolites. Summary of the Invention

[0005] The purpose of this invention is to provide a laser ablation electrospray-dielectric barrier discharge composite ionization source mass spectrometry imaging device. This mass spectrometry imaging device uses laser ablation of the sample surface to generate a vaporized sample, electrospray extraction to generate charged droplets, and after the droplets are desolvated, polar molecules are ionized. The remaining weak / nonpolar molecules are ionized a second time by dielectric barrier discharge plasma. The two ionizations achieve simultaneous coverage of polar and weak / nonpolar molecules, improve ionization efficiency, and realize high coverage and high sensitivity metabolic mass spectrometry imaging.

[0006] To achieve this objective, the present invention adopts the following technical solution: This invention discloses a laser ablation electrospray-dielectric barrier discharge composite ionization source mass spectrometry imaging device, comprising: a sample stage for supporting a sample to be analyzed; a laser emitter located above the sample stage for emitting laser light toward the sample to be analyzed; an electrospray module located on one side of the sample stage for spraying charged droplets toward the sample to be analyzed; and a dielectric barrier discharge module located on the other side of the sample stage, the dielectric barrier discharge module having a discharge cavity, the discharge inlet of the discharge cavity corresponding to the outlet of the electrospray module, and the discharge outlet of the discharge cavity connected to the ion transmission tube of the mass spectrometer.

[0007] In some embodiments, the electrospray module includes: an electrospray capillary with the spray outlet formed at one end and the other end open; an electrospray electrode inserted into the electrospray capillary from the open end; and a DC high-voltage power supply connected to the electrospray electrode.

[0008] In some alternative embodiments, the electrospray module includes: an electrospray capillary with the spray outlet at one end and an open end; an encapsulation structure, at least a portion of which is a conductive material; a DC high-voltage power supply connected to the encapsulation structure; and an infusion pump that passes through the encapsulation structure and is used to input liquid into the electrospray capillary.

[0009] In some alternative embodiments, the end of the electrospray capillary that forms the nozzle has a tapered portion with a gradually decreasing diameter, and the smaller end of the tapered portion forms the nozzle.

[0010] In some embodiments, the dielectric barrier discharge module includes: an inner electrode, which is a tubular structure and one end of the inner electrode forms the discharge inlet; a discharge capillary, one end of which is sleeved on the end of the inner electrode away from the discharge inlet and is sealed to the inner electrode, and the other end of the discharge capillary forms the discharge outlet; an outer electrode, which is sleeved on the discharge capillary; and an AC high-voltage power supply, which is electrically connected to the inner electrode and the outer electrode.

[0011] In some specific embodiments, the discharge capillary and the inner electrode are sealed together by a sealant.

[0012] In some specific embodiments, the dielectric barrier discharge module further includes: a connecting conduit, both ends of which are open, and one end is connected to the end of the discharge capillary that forms the discharge outlet; and a sealing cap, which is connected to the end of the connecting conduit away from the discharge outlet, and has a sealing communication port connected to the ion transport tube.

[0013] In some specific embodiments, the inner diameter of the inner electrode is 0.6mm-1mm, the outer diameter of the inner electrode is 0.8mm-1.2mm, and the length of the inner electrode is 2cm-4cm; and / or: The discharge capillary has an inner diameter of 1.3mm-1.7mm, an outer diameter of 1.8mm-2.2mm, and a length of 1cm-2cm.

[0014] In some specific embodiments, the external electrode is a conductive foil wrapped around the outer wall of the discharge capillary.

[0015] In some embodiments, the sample stage includes: a base having a receiving groove; and a stage installed in the receiving groove.

[0016] The beneficial effects of the laser ablation electrospray-dielectric barrier discharge composite ionization source mass spectrometry imaging device of the present invention are as follows: In actual operation, the sample to be analyzed is placed on the sample stage, and the laser emitter can emit laser towards the sample to be analyzed, thereby generating an upward-sprayed vaporized sample plume. The charged droplets generated by the electrospray module converge with the vaporized sample plume, extracting sample molecules and initially ionizing polar molecules. Then, the sample enters the dielectric barrier discharge module, where the plasma excited by the AC high-voltage electric field performs secondary ionization on the sample to be analyzed. Finally, the ionized sample enters the mass spectrometer for analysis through the ion transmission tube. Therefore, the mass spectrometry imaging device of the present invention uses laser ablation to ablate the surface of the sample to be analyzed, generating a vaporized sample. The vaporized sample is further extracted by electrospray to generate charged droplets. During the flight, the charged droplets gradually lose solvent and ionize the polar molecules therein. The ionized polar molecules, unionized weak / nonpolar molecules, and some charged droplets then enter the discharge chamber. The discharge chamber generates plasma under the action of AC high voltage electric field, and performs secondary ionization on the weak / nonpolar molecules. Through the two ionization processes, both polar and weak / nonpolar molecules can be covered at the same time, and the ionization efficiency is significantly improved, thereby realizing high coverage and high sensitivity metabolic mass spectrometry imaging.

[0017] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of the laser ablation electrospray-dielectric barrier discharge composite ionization source mass spectrometry imaging device according to Embodiment 1 of the present invention; Figure 2 This is the laser ablation electrospray-dielectric barrier discharge composite ionization source mass spectrometry imaging device of Embodiment 2 of the present invention; Figure label: 100. Sample stage; 110. Base; 120. Stage; 200. Laser emitter; 300. Electrospray module; 301. Spray outlet; 310. Electrospray capillary; 311. Taper section; 320. Electrospray electrode; 330. DC high voltage power supply; 340. Encapsulation structure; 350. Infusion pump; 400, Dielectric barrier discharge module; 401, Discharge chamber; 402, Discharge inlet; 403, Discharge outlet; 410, Inner electrode; 420, Discharge capillary; 430, Outer electrode; 440, AC high voltage power supply; 450, Connecting conduit; 460, Sealing cap; 500. Mass spectrometer; 510. Ion transmission tube. Detailed Implementation

[0019] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.

[0020] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0021] In the description of this embodiment, the terms "upper," "lower," "left," "right," "front," and "rear," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first" and "second" are used only for distinction in description and have no special meaning.

[0022] Example 1: This invention discloses a laser ablation electrospray-dielectric barrier discharge composite ionization source mass spectrometry imaging device (hereinafter referred to as mass spectrometry imaging device for ease of description), reference Figure 1As shown, the mass spectrometry imaging device includes a sample stage 100, a laser emitter 200, an electrospray module 300, and a dielectric barrier discharge module 400. The sample stage 100 is used to hold the sample to be analyzed. The laser emitter 200 is located above the sample stage 100 and is used to emit laser light toward the sample to be analyzed. The electrospray module 300 is located on one side of the sample stage 100 and is used to spray charged droplets toward the sample to be analyzed. The dielectric barrier discharge module 400 is located on the other side of the sample stage 100. The dielectric barrier discharge module 400 has a discharge cavity 401. The discharge inlet 402 of the discharge cavity 401 is correspondingly set to the outlet 301 of the electrospray module 300. The discharge outlet 403 of the discharge cavity 401 is connected to the ion transmission tube 510 of the mass spectrometer 500. Understandably, in actual operation, the sample to be analyzed is placed on the sample stage 100, and the laser emitter 200 emits a laser towards the sample to be analyzed, thereby generating an upward-sprayed vaporized sample plume. The charged droplets generated by the electrospray module 300 converge with the vaporized sample plume, extracting sample molecules and initially ionizing polar molecules. Subsequently, the sample enters the dielectric barrier discharge module 400, where the plasma excited by the AC high-voltage electric field performs secondary ionization of the sample to be analyzed. Finally, the ionized sample enters the mass spectrometer 500 for analysis via the ion transmission tube 510. Therefore, the mass spectrometry imaging device of the present invention uses laser ablation to ablate the surface of the sample to be analyzed, generating a vaporized sample. The vaporized sample is further extracted by electrospray to generate charged droplets. During the flight, the charged droplets gradually lose solvent and ionize the polar molecules therein. The ionized polar molecules, unionized weak / nonpolar molecules, and some charged droplets then enter the discharge chamber 401. The discharge chamber 401 generates plasma under the action of AC high voltage electric field, and performs secondary ionization on the weak / nonpolar molecules. Through the two ionization processes, polar and weak / nonpolar molecules can be covered simultaneously, and the ionization efficiency is significantly improved, thereby realizing high coverage and high sensitivity metabolic mass spectrometry imaging.

[0023] Optionally, the laser emitter 200 can be a commercial platform or a custom-built system, where the laser uses an infrared laser with a wavelength of 2.94 μm to excite the hydrogen-oxygen bonds of water molecules in the sample.

[0024] Optional, see reference Figure 1As shown, the electrospray module 300 includes an electrospray capillary 310, an electrospray electrode 320, and a DC high-voltage power supply 330. One end of the electrospray capillary 310 has a spray outlet 301, while the other end is open. The electrospray electrode 320 is inserted into the electrospray capillary 310 from its open end. The DC high-voltage power supply 330 is connected to the electrospray electrode 320. Understandably, in actual operation, the electrospray capillary 310 absorbs the desorption solvent (98% acetonitrile or 98% methanol, or other solvents as needed), then it is horizontally fixed on the experimental platform. The electrospray electrode 320 is connected to the DC high-voltage power supply 330 and then inserted into the electrospray capillary 310. Due to the small diameter of the electrospray capillary 310, the desorption solvent can be stably maintained within the capillary 310 and will not flow freely. The electrospray module 300 consists of only three parts: an electrospray capillary 310, an electrospray electrode 320, and a DC high-voltage power supply 330. Its simple structure makes it easy to assemble, thus facilitating the use of mass spectrometry imaging devices.

[0025] Further optional, see reference Figure 1 As shown, the electrospray capillary 310 has a tapered portion 311 with a gradually decreasing diameter at one end forming the nozzle 301, and the smaller end of the tapered portion 311 forms the nozzle 301. It can be understood that the tapered structure of the tapered portion 311 at one end of the electrospray capillary 310 forming the nozzle 301 facilitates droplet ejection and ensures that the ejected liquid forms a fan-shaped area, facilitating stable contact between the charged droplets and the vaporized sample plume.

[0026] Alternatively, the DC high-voltage power supply 330 can output a voltage with an amplitude of -3.5kV to +3.5kV, which, when connected to the electrospray electrode 320, allows for the observation of stable electrospray generation at the outlet of the electrospray capillary 310.

[0027] Alternatively, the electrospray capillary 310 has an inner diameter of 0.86 mm, an outer diameter of 1.5 mm, a length of 5 cm, and is made of glass. Of course, the size and material of the electrospray capillary 310 can be selected according to actual needs.

[0028] Optional, see reference Figure 1As shown, the dielectric barrier discharge module 400 includes an inner electrode 410, a discharge capillary 420, an outer electrode 430, and an AC high-voltage power supply 440. The inner electrode 410 has a tubular structure, with one end forming a discharge inlet 402. One end of the discharge capillary 420 is fitted onto the end of the inner electrode 410 opposite to the discharge inlet 402 and is sealed to the inner electrode 410. The other end of the discharge capillary 420 forms a discharge outlet 403. The outer electrode 430 is fitted onto the discharge capillary 420. The AC high-voltage power supply 440 is electrically connected to the inner electrode 410 and the outer electrode 430. It can be understood that in the actual assembly process, it is only necessary to insert the inner electrode 410 into the discharge capillary 420, then fit the outer electrode 430 onto the discharge capillary 420, and then electrically connect the AC high-voltage power supply 440 to the inner electrode 410 and the outer electrode 430. The structure of this dielectric barrier discharge module 400 is very simple and easy to assemble, thus facilitating the use of the mass spectrometry imaging device.

[0029] Alternatively, the inner electrode 410 may be a stainless steel tube.

[0030] Alternatively, the discharge capillary 420 and the inner electrode 410 can be sealed together with sealant. This allows for a simple and convenient sealed connection between the discharge capillary 420 and the inner electrode 410, preventing the sample to be analyzed from entering the discharge chamber 401 through the gap between the discharge capillary 420 and the inner electrode 410.

[0031] Alternatively, the inner electrode 410 and the outer electrode 430 are connected to an AC high-voltage power supply 440 via a high-voltage connection cable, and the connection points are insulated with high-voltage resistant insulating tape. This prevents leakage.

[0032] Alternatively, the AC high-voltage power supply 440 can provide a voltage of 1kV-3kV and a frequency of 15kHz-40kHz, which facilitates flexible adjustment of the operating parameters of the dielectric barrier discharge module 400. After the dielectric barrier discharge module 400 is powered on, a distinct, uniform and stable purple plasma flame is generated in the discharge chamber 401.

[0033] Further optional, see reference Figure 1As shown, the dielectric barrier discharge module 400 also includes a connecting conduit 450 and a sealing cap 460. The two ends of the connecting conduit 450 are open, and one end is connected to the end of the discharge capillary 420 to form a discharge outlet 403. The sealing cap 460 is connected to the end of the connecting conduit 450 away from the discharge outlet 403, and the sealing cap 460 has a sealed communication port connected to the ion transport tube 510. Understandably, the connecting conduit 450 is connected to the discharge capillary 420 via sealant, and the sealing cap 460 is also connected to the connecting conduit 450 via sealant. The ion transmission tube 510 can be directly inserted into the sealed connection port to complete the connection between the dielectric barrier discharge module 400 and the mass spectrometer 500. If the direct connection of the discharge capillary 420 is adopted, one end of the discharge capillary 420 needs to be manufactured to fit the shape of the ion transmission tube 510. This would not only increase the structural complexity of the discharge capillary 420, but also cause the dielectric barrier discharge module 400 to be incompatible with different models and types of mass spectrometers 500. In this embodiment, the added connecting conduit 450 and sealing cap 460 can be replaced according to the position of the mass spectrometer 500 and the size of the ion transmission tube 510, thereby improving the mass spectrometry imaging device.

[0034] Optionally, the inner diameter of the inner electrode 410 is 0.6mm-1mm, and the outer diameter of the inner electrode 410 is 0.8mm-1.2mm. Specifically, the inner diameter of the inner electrode 410 can be 0.6mm, 0.7mm, 0.8mm, 0.9mm, or 1mm, and the outer diameter of the inner electrode 410 can be 0.8mm, 0.9mm, 1mm, 1.1mm, or 1.2mm. Of course, the inner diameter of the inner electrode 410 can also be other values ​​within the range of 0.6mm-1mm, and is not limited to the examples mentioned above. Similarly, the outer diameter of the inner electrode 410 can also be other values ​​within the range of 0.8mm-1.2mm, and is not limited to the examples mentioned above. Understandably, if the inner and outer diameters of the inner electrode 410 are too small, it will be difficult for the sample to be analyzed to enter the discharge chamber 401. If the inner and outer diameters of the inner electrode 410 are too large, it will be inconvenient to connect with the discharge capillary 420. In this embodiment, the inner diameter of the inner electrode 410 is set to 0.6mm-1mm and the outer diameter of the inner electrode 410 is set to 0.8mm-1.2mm, which is both conducive to the sample to be analyzed entering the discharge chamber 401 and convenient to connect with the discharge capillary 420.

[0035] Optionally, the length of the inner electrode 410 is 2cm-4cm. Specifically, the length of the inner electrode 410 can be 2cm, 2.1cm, 2.2cm, 2.3cm, 2.4cm, 2.5cm, 2.6cm, 2.7cm, 2.8cm, 2.9cm, 3cm, 3.1cm, 3.2cm, 3.3cm, 3.4cm, 3.5cm, 3.6cm, 3.7cm, 3.8cm, or 3.9cm, or other values ​​within the range of 2cm-4cm. If the length of the inner electrode 410 is too long, it occupies too much space; if the length of the inner electrode 410 is too short, it is not conducive to the sample to be analyzed entering the discharge chamber 401. In this embodiment, the length of the inner electrode 410 is set to 2cm-4cm, which can control the size of the inner electrode 410 and facilitate the sample to be analyzed entering the discharge chamber 401.

[0036] Optionally, the inner diameter of the discharge capillary 420 is 1.3mm-1.7mm, and the outer diameter is 1.8mm-2.2mm. Specifically, the inner diameter of the discharge capillary 420 can be 1.3mm, 1.4mm, 1.5mm, 1.6mm, or 1.7mm, and the outer diameter can be 1.8mm, 1.9mm, 2mm, 2.1mm, or 2.2mm. Of course, the inner diameter of the discharge capillary 420 can also be other values ​​within the range of 1.3mm-1.7mm, and is not limited to the examples mentioned above. Similarly, the outer diameter of the discharge capillary 420 can also be other values ​​within the range of 1.8mm-2.2mm, and is not limited to the examples mentioned above. Understandably, if the inner and outer diameters of the discharge capillary 420 are too small, it will be detrimental to the secondary ionization of the sample to be analyzed. If the inner and outer diameters of the discharge capillary 420 are too large, it will be inconvenient to seal the connection with the inner electrode 410, and gaps may easily appear. In this embodiment, the inner diameter of the discharge capillary 420 is set to 1.3mm-1.7mm, and the outer diameter of the inner electrode 410 is set to 1.8mm-2.2mm. This is beneficial for the secondary ionization of the sample to be analyzed and also facilitates the sealing connection with the inner electrode 410, avoiding gaps.

[0037] Optionally, the length of the discharge capillary 420 is 1cm-2cm. Specifically, the length of the discharge capillary 420 can be 1cm, 1.1cm, 1.2cm, 1.3cm, 1.4cm, 1.5cm, 1.6cm, 1.7cm, 1.8cm, 1.9cm, or 2cm. Of course, other values ​​within the range of 1cm-2cm are also possible. If the length of the discharge capillary 420 is too long, it occupies too much space; if the length of the discharge capillary 420 is too short, the volume of the discharge chamber 401 is too small, which is not conducive to the secondary ionization of the sample to be analyzed. In this embodiment, the length of the discharge capillary 420 is set to 1cm-2cm, which can control the size of the discharge capillary 420 and is also conducive to the secondary ionization of the sample to be analyzed.

[0038] Optionally, the external electrode 430 is a conductive foil wrapped around the outer wall of the discharge capillary 420. It is understood that the external electrode 430 is formed by tightly winding a conductive foil around the outside of the discharge capillary 420, which simplifies the structure of the external electrode 430 and facilitates the assembly of the dielectric barrier discharge module 400. Further optionally, the conductive foil is a copper foil.

[0039] Optional, see reference Figure 1 As shown, the sample stage 100 includes a base 110 and a stage 120. The base 110 has a receiving groove, and the stage 120 is installed within the receiving groove. Understandably, during the experiment, the position of the stage 120 relative to the base 110 can be adjusted to ensure that the stage 120 is directly below the laser emitter 200, facilitating laser ablation. To ensure the stability of the connection between the stage 120 and the base 110, expansion blocks or set screws can be used to fix the stage 120.

[0040] Example 2: refer to Figure 2 As shown, the mass spectrometry imaging device in this embodiment is largely the same as that in Embodiment 1. The difference is that the electrospray module 300 of the mass spectrometry imaging device in this embodiment includes an electrospray capillary 310, an encapsulation structure 340, a DC high-voltage power supply 330, and an infusion pump 350. One end of the electrospray capillary 310 has an outlet 301, and the other end is open. At least a portion of the encapsulation structure 340 is made of conductive material. The DC high-voltage power supply 330 is connected to the encapsulation structure 340. The infusion pump 350 passes through the encapsulation structure 340 and is used to input liquid into the electrospray capillary 310. It can be understood that in actual operation, the encapsulation structure 340 can be a pipe connector, connected to the DC high-voltage power supply 330 through an electrode clamp. During the experiment, the output flow rate of the infusion pump 350 can be adjusted to control the flow rate of the liquid entering the electrospray capillary 310, thereby achieving more precise flow control of the charged solution.

[0041] Optionally, the output flow rate of the infusion pump 350 can be adjusted in the range of 0.1 μL / min to 1000 μL / min.

[0042] In the description of this specification, references to terms such as "some embodiments," "other embodiments," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0043] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art will be able to make various obvious changes, readjustments, and substitutions without departing from the scope of protection of the present invention. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A mass spectrometry imaging device for a laser ablation electrospray-dielectric barrier discharge composite ionization source, characterized in that, include: A sample stage (100) is used to hold the sample to be analyzed; A laser emitter (200) is located above the sample stage (100) and is used to emit a laser beam toward the sample to be analyzed. An electrospray module (300) is located on one side of the sample stage (100) and is used to spray charged droplets toward the sample to be analyzed. A dielectric barrier discharge module (400) is located on the other side of the sample stage (100). The dielectric barrier discharge module (400) has a discharge cavity (401). The discharge inlet (402) of the discharge cavity (401) is correspondingly set to the outlet (301) of the electrospray module (300). The discharge outlet (403) of the discharge cavity (401) is connected to the ion transmission tube (510) of the mass spectrometer (500).

2. The laser ablation electrospray-dielectric barrier discharge composite ionization source mass spectrometry imaging device according to claim 1, characterized in that, The electrospray module (300) includes: An electrospray capillary (310) has an outlet (301) at one end and is open at the other end. An electrospray electrode (320) is provided, which is inserted into the electrospray capillary (310) from the open end of the electrospray capillary (310); A DC high-voltage power supply (330) is connected to the electrospray electrode (320).

3. The laser ablation electrospray-dielectric barrier discharge composite ionization source mass spectrometry imaging device according to claim 1, characterized in that, The electrospray module (300) includes: An electrospray capillary (310) has an outlet (301) at one end and is open at the other end. The encapsulation structure (340) is at least partly a conductive material portion; A DC high voltage power supply (330) is connected to the package structure (340); An infusion pump (350) is disposed within the encapsulation structure (340) and is used to input liquid into the electrospray capillary (310).

4. The laser ablation electrospray-dielectric barrier discharge composite ionization source mass spectrometry imaging device according to claim 2 or 3, characterized in that, The electrospray capillary (310) has a tapered portion (311) with a gradually decreasing diameter at one end forming the nozzle (301), and the small end of the tapered portion (311) forms the nozzle (301).

5. The laser ablation electrospray-dielectric barrier discharge composite ionization source mass spectrometry imaging device according to claim 1, characterized in that, The dielectric barrier discharge module (400) includes: An inner electrode (410) is a tubular structure, and one end of the inner electrode (410) forms the discharge inlet (402); A discharge capillary (420) is provided, one end of which is sleeved on the end of the inner electrode (410) away from the discharge inlet (402) and is sealed to the inner electrode (410). The other end of the discharge capillary (420) forms the discharge outlet (403). An external electrode (430) is sleeved on the discharge capillary (420); An AC high-voltage power supply (440) is electrically connected to the inner electrode (410) and the outer electrode (430).

6. The laser ablation electrospray-dielectric barrier discharge composite ionization source mass spectrometry imaging device according to claim 5, characterized in that, The discharge capillary (420) and the inner electrode (410) are sealed together by sealant.

7. The laser ablation electrospray-dielectric barrier discharge composite ionization source mass spectrometry imaging device according to claim 5, characterized in that, The dielectric barrier discharge module (400) also includes: A connecting conduit (450) is provided with both ends open, and one end is connected to the end of the discharge capillary (420) that forms the discharge outlet (403); A sealing cap (460) is connected to one end of the connecting conduit (450) away from the discharge outlet (403), and the sealing cap (460) has a sealing communication port connected to the ion transport tube (510).

8. The laser ablation electrospray-dielectric barrier discharge composite ionization source mass spectrometry imaging device according to claim 5, characterized in that, The inner diameter of the inner electrode (410) is 0.6mm-1mm, the outer diameter of the inner electrode (410) is 0.8mm-1.2mm, and the length of the inner electrode (410) is 2cm-4cm; and / or: The discharge capillary (420) has an inner diameter of 1.3mm-1.7mm, an outer diameter of 1.8mm-2.2mm, and a length of 1cm-2cm.

9. The laser ablation electrospray-dielectric barrier discharge composite ionization source mass spectrometry imaging device according to claim 5, characterized in that, The external electrode (430) is a conductive foil wrapped around the outer wall of the discharge capillary (420).

10. The laser ablation electrospray-dielectric barrier discharge composite ionization source mass spectrometry imaging device according to claim 1, characterized in that, The sample stage (100) includes: A base (110) having a receiving groove provided thereon; A stage (120) is installed in the receiving slot.

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