Chemical ionization source device based on thermal desorption

Abstract

The utility model provides a chemical ionization source device based on thermal desorption, and belongs to the technical field of mass spectrum devices. The device comprises a thermal desorption source, a three-axis moving platform, an analysis plate and an atmospheric pressure ion source, a through hole is formed in the three-axis moving platform, the analysis plate is placed above the three-axis moving platform, a plurality of analysis holes are formed in the analysis plate, at least one analysis hole is aligned to the through hole, a metal alloy supporting plate used for placing a sample is installed in the analysis hole, and the atmospheric pressure ion source is arranged on the metal alloy supporting plate. The thermal desorption source is arranged below the through hole and faces the metal alloy supporting plate, an input port of the atmospheric pressure ion source is provided with a transmission pipe used for inputting gas, the front end of the transmission pipe can be inserted into and cover the analysis hole, and the output end of the atmospheric pressure ion source is used for being connected with a mass spectrometer. The chemical ionization source device based on thermal desorption is simple to operate, can ionize a sample more efficiently, so that the plasma obtaining efficiency is improved, and the practicability is good.

Description

Technical Field

[0001] This invention belongs to the field of mass spectrometry device technology, specifically relating to a chemical ionization source device based on thermal desorption. Background Technology

[0002] Whether for developing new drugs to treat diseases such as cancer and obesity, analyzing drugs in blood, plasma, and urine, or detecting trace amounts of pesticides in environmental samples, the need to improve the efficiency and speed of sampling and analysis remains a crucial issue. Laser melt ionization (LME) technology can directly analyze and measure solid / liquid samples, offering advantages such as convenience and sensitivity, and is particularly suitable for surface elemental analysis and imaging. The principle of LME mass spectrometry is based on using a high-power laser to melt the plasma generated on a surface, obtaining chemical information by analyzing and detecting the mass-to-charge ratio of ions in the plasma.

[0003] However, with the increasing productivity and diversification of products in industries such as pharmaceuticals, environmental protection, and food processing, there is a growing need for more frequent and larger-volume analyses, placing higher demands on the efficiency of analytical equipment. However, commonly used analytical techniques, such as liquid chromatography and gas chromatography, have limitations that significantly hinder the achievement of these productivity goals. For example, sample preparation time, chromatographic system optimization time, the risk of cross-contamination and "sample residue" affecting the accuracy and repeatability of results, high maintenance costs, and long analysis times are all major limitations that users of conventional chromatographic techniques such as LC-MS and GC-MS inevitably encounter. Summary of the Invention

[0004] In view of the problems existing in the background technology, the purpose of this utility model is to provide a chemical ionization source device based on thermal desorption, which can eliminate the chromatographic separation step and greatly improve the ionization efficiency.

[0005] The objective of this utility model can be achieved through the following technical solution: A chemical ionization source device based on thermal desorption, characterized in that it includes a thermal desorption source, a triaxial moving platform, an analytical plate, and an atmospheric pressure ion source. The triaxial moving platform has a through hole, the analytical plate is placed above the triaxial moving platform, and the analytical plate has a plurality of analytical holes, at least one of which is aligned with the through hole. A metal alloy support plate for placing samples is installed in the analytical hole. The thermal desorption source is located below the through hole and facing the metal alloy support plate. The input port of the atmospheric pressure ion source is provided with a transmission tube for inputting gas. The front end of the transmission tube can be inserted into and cover the analytical hole. The output end of the atmospheric pressure ion source is used to connect to a mass spectrometer.

[0006] Preferably, the atmospheric pressure ion source includes an ionization chamber, the rear end of the transmission tube is inserted into the ionization chamber, and the ionization chamber is provided with an ionization device capable of ionizing the gas transported by the transmission tube.

[0007] Preferably, the ionization device is an APCI discharge needle, which is located at the rear end port of the transmission tube.

[0008] Preferably, the ionization device is a dielectric barrier discharge device, which is installed on the outer wall of the rear end of the transmission tube.

[0009] Preferably, the front end of the transmission tube includes an outer tube and an inner tube, the upper end of the outer tube is sealed to the outer wall of the inner tube, there is a downward-opening and annular gap between the outer tube and the inner tube, a carrier gas tube is inserted into the wall of the outer tube, and the carrier gas tube is connected to the gap.

[0010] Preferably, the inner tube protrudes downward relative to the outer tube.

[0011] Preferably, the metal alloy support plate has a downwardly concave spherical structure. This structural design allows analyte or sample droplets that crystallize during solvent evaporation to be concentrated in the central region.

[0012] Preferably, the metal alloy support plate is a stainless steel plate.

[0013] Preferably, the thermal desorption source is a laser diode that emits infrared laser light in the range of 760-1000 nm.

[0014] Compared with existing technologies, this invention has the following advantages: by combining laser diode thermal desorption with atmospheric pressure chemical ionization technology, the chromatographic separation step is eliminated, significantly shortening the analysis time to just a few seconds, and greatly improving ionization efficiency; the precise lifting and translation of the three-axis moving platform enables rapid insertion / separation between different analytical holes and the front end of the atmospheric pressure ion source transmission tube, thereby quickly changing the sample to be analyzed, making the operation simple, convenient, and highly efficient; the concave metal alloy tray structure allows the sample to be more concentrated, and the radiation effect of the thermal desorption source on the sample is better. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the chemical ionization source device based on thermal desorption of this invention in Embodiment 1.

[0016] Figure 2 for Figure 1 Enlarged view of point A in the middle.

[0017] Figure 3 This is a schematic diagram of the chemical ionization source device based on thermal desorption of this invention in Embodiment 2.

[0018] In the figure, 1. Thermal desorption source; 2. Triaxial moving platform; 2a. Through hole; 3. Analytical plate; 3a. Analytical hole; 3b. Metal alloy support plate; 4. Atmospheric pressure ion source; 4a. Ionization chamber; 5. Transfer tube; 5a. Outer tube; 5b. Inner tube; 5c. Gap; 5d. Carrier gas tube; 6. Mass spectrometer interface; 7. Ionization device; 8. Sample; 9. Carrier gas. Detailed Implementation

[0019] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this utility model, and should not be construed as limiting this utility model.

[0020] Example 1:

[0021] like Figure 1 As shown, this utility model provides a chemical ionization source device based on thermal desorption. The device includes a thermal desorption source 1, a triaxial moving platform 2, an analytical plate 3, and an atmospheric pressure ion source 4. The triaxial moving platform 2 has a through hole 2a. The analytical plate 3 is placed above the triaxial moving platform 2 and has several analytical holes 3a, such as a 96-hole analytical plate 3. In use, an analytical hole 3a is selected and aligned with the through hole 2a. A metal alloy support plate 3b for placing a sample 8 is installed inside the analytical hole 3a. The thermal desorption source 1 is positioned below the through hole 2a and facing the metal alloy support plate 3b. The input port of the atmospheric pressure ion source 4 has a transmission tube 5 for inputting gas. The front end of the transmission tube 5 can be inserted into and cover the analytical hole 3a. The output end of the atmospheric pressure ion source 4 is used to connect to a mass spectrometer and is equipped with a mass spectrometer interface 6.

[0022] Specifically, the three-axis moving platform 2 employs an X-axis translation mechanism, a Y-axis translation mechanism, and a lifting mechanism. Each mechanism is driven by a linear motor to move the slider. This structure is commonly used in three-axis moving systems and will not be elaborated upon further. Through three-axis movement, precise positioning can be achieved, facilitating the alignment of the analysis hole 3a and the through hole 2a, allowing the thermal desorption source 1 to accurately radiate to the bottom of the metal alloy support plate 3b. It also facilitates the insertion of the front end of the transmission pipe 5 into the analysis hole 3a, thereby sealing the analysis hole 3a.

[0023] The atmospheric pressure ion source 4 includes an ionization chamber 4a, with the rear end of the transmission tube 5 inserted into the ionization chamber 4a. The ionization chamber 4a contains an ionization device 7 capable of ionizing the gas transported by the transmission tube 5. The ionization device 7 is an APCI discharge needle, located at the rear end port of the transmission tube 5. Figure 2As shown, the front end of the transfer tube 5 includes an outer tube 5a and an inner tube 5b. The upper end of the outer tube 5a is sealed to the outer wall of the inner tube 5b, and the inner tube 5b protrudes downward relative to the outer tube 5a. There is a downward-opening, annular gap 5c between the outer tube 5a and the inner tube 5b. A carrier gas tube 5d is inserted into the wall of the outer tube 5a, and the carrier gas tube 5d is connected to the gap 5c. With this design, the carrier gas 9 input through the carrier gas tube 5d can flow downward along the annular gap 5c. Due to the obstruction at the lower end of the inner tube 5b, the carrier gas 9 can better impact the sample 8, thereby better delivering the sample 8 to the ionization region.

[0024] The thermal desorption source 1 is a laser diode that emits infrared laser light in the 760-1000nm range. The infrared laser light irradiates the bottom of the metal alloy support plate 3b, which rapidly absorbs the heat energy and transfers it to the sample 8, thus achieving thermal desorption. To enable the laser diode to better irradiate the sample 8, the metal alloy support plate 3b is designed with a downwardly concave spherical structure and is made of stainless steel. This ensures that the analyte crystals or sample 8 droplets formed during solvent evaporation are concentrated in the central region.

[0025] In practical use, this utility model allows operators to adjust the desorption temperature by controlling the power of the laser diode according to the type of sample 8, thereby improving its practicality and applicability.

[0026] Example 2:

[0027] like Figure 3 As shown, the structure and principle of this embodiment are basically the same as those of Embodiment 1. The difference is that the ionization device 7 adopts a dielectric barrier discharge device, which is installed on the outer wall of the rear end of the transmission tube 5. This structure enables faster and more uniform ionization to obtain plasma.

[0028] The specific embodiments described herein are merely illustrative examples illustrating the spirit of this utility model. Those skilled in the art to which this utility model pertains may make various modifications or additions to the described specific embodiments or use similar methods to substitute them, without departing from the spirit of this utility model or exceeding the scope defined by the appended claims.

Claims

1. A chemical ionization source device based on thermal desorption, characterized in that, The system includes a thermal desorption source (1), a triaxial moving platform (2), an analytical plate (3), and an atmospheric pressure ion source (4). The triaxial moving platform (2) has a through hole (2a). The analytical plate (3) is placed above the triaxial moving platform (2). The analytical plate (3) has several analytical holes (3a). One of the analytical holes (3a) is aligned with the through hole (2a). A metal alloy support plate (3b) for placing a sample (8) is installed in the analytical hole (3a). The thermal desorption source (1) is located below the through hole (2a) and faces the metal alloy support plate (3b). The input port of the atmospheric pressure ion source (4) is provided with a transmission tube (5) for inputting gas. The front end of the transmission tube (5) can be inserted into and cover the analytical hole (3a). The output end of the atmospheric pressure ion source (4) is used to connect to a mass spectrometer.

2. The chemical ionization source device based on thermal desorption according to claim 1, characterized in that, The atmospheric pressure ion source (4) includes an ionization chamber (4a), the rear end of the transmission tube (5) is inserted into the ionization chamber (4a), and the ionization chamber (4a) is provided with an ionization device (7) capable of ionizing the gas transported by the transmission tube (5).

3. The chemical ionization source device based on thermal desorption according to claim 2, characterized in that, The ionization device (7) is an APCI discharge needle, which is located at the rear end port of the transmission tube (5).

4. The chemical ionization source device based on thermal desorption according to claim 2, characterized in that, The ionization device (7) is a dielectric barrier discharge device, which is installed on the outer wall of the rear end of the transmission tube (5).

5. A chemical ionization source device based on thermal desorption according to any one of claims 1-4, characterized in that, The front end of the transmission tube (5) includes an outer tube (5a) and an inner tube (5b). The upper end of the outer tube (5a) is sealed to the outer wall of the inner tube (5b). There is a downward-opening and annular gap (5c) between the outer tube (5a) and the inner tube (5b). A carrier gas tube (5d) is inserted into the wall of the outer tube (5a). The carrier gas tube (5d) and the gap (5c) are connected.

6. The chemical ionization source device based on thermal desorption according to claim 5, characterized in that, The inner tube (5b) protrudes downward relative to the outer tube (5a).

7. A chemical ionization source device based on thermal desorption according to any one of claims 1-4, characterized in that, The metal alloy support plate (3b) has a downwardly concave spherical structure.

8. The chemical ionization source device based on thermal desorption according to claim 7, characterized in that, The metal alloy support plate (3b) is made of stainless steel.

9. A chemical ionization source device based on thermal desorption according to any one of claims 1-4, characterized in that, The thermal desorption source (1) is a laser diode that emits infrared laser light at a wavelength of 760-1000nm.

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