Mass spectrum ion source device based on soft ionization technology

Abstract

The invention relates to a mass spectrum ion source device based on a soft ionization technology, which comprises an ultraviolet lamp, a first electrode, a second electrode, a third electrode, a first lens, a second lens, a third lens, a deflection electrode and a fixed seat fixedly connected with the third electrode which are connected in sequence, and the ion output side of the deflection electrode is provided with a plate body or a cover body. And slits are formed in the plate body and the cover body. The resolution and the sensitivity of the mass spectrum ion source are improved, the detection line is mainly improved, the sensitivity is improved from the original 1 ppm detection line to 10 ppb detection line, the effect is remarkable, and the mass spectrum ion source has very important application value.

Description

Technical Field

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

[0002] The ion source is a key component of a mass spectrometer. Its main function is to convert sample molecules into ions. In mass spectrometry analysis, only by converting the sample into ions can the mass and relative abundance of the ions be determined by electric fields, magnetic fields, etc., so as to achieve qualitative and quantitative analysis of the sample. Therefore, without a suitable ion source to ionize the sample, the mass spectrometer cannot perform its analytical function.

[0003] Different types of ion sources work on different principles, but they are all based on the process of making sample molecules gain or lose electrons to form ions. The core feature of soft ionization technology is that it only provides the target molecule with energy slightly higher than its ionization energy, so that it undergoes mild ionization, introduces almost no internal energy, does not damage the molecular skeleton, thus preserving the molecular integrity to the maximum extent, producing almost no fragment ions, making it easy to obtain molecular ion peaks, and enabling rapid and accurate qualitative and quantitative analysis.

[0004] Currently, the development needs of mass spectrometry ion sources include: with the increasing demand for on-site detection, the development of miniaturized and portable mass spectrometry ion sources has become a trend. For example, some small ion sources based on micro-nano fabrication technology are small in size and low in power consumption, and can be integrated into portable mass spectrometers for rapid on-site detection, such as environmental emergency monitoring and on-site food safety screening; improving ionization efficiency and sensitivity: improving the design and working principle of ion sources to enhance ionization efficiency and sensitivity is of great significance for both scientific research and practical applications. Currently, there is relatively little research on high-sensitivity mass spectrometry ion source devices based on soft ionization technology. Summary of the Invention

[0005] The purpose of this invention is to provide a mass spectrometry ion source device based on soft ionization technology in order to solve the above-mentioned problems.

[0006] The present invention achieves the above objectives through the following technical solutions: A mass spectrometry ion source device based on soft ionization technology includes an ultraviolet lamp, a first electrode, a second electrode, a third electrode, a first lens, a second lens, a third lens, and a deflection electrode connected in sequence, a fixed base fixedly connected to the third electrode, and a plate or cover provided on the ion output side of the deflection electrode, with slits provided on both the plate and the cover.

[0007] It should be noted that this application uses ultraviolet photons with specific energies (such as 10.6 eV), which are just higher than the ionization energy of molecules. The energy is precise, there is no excess energy that would cause fragmentation, and no extra fragments are generated, which can better facilitate qualitative analysis.

[0008] As a further optimization of the present invention, when the ion output side of the deflection electrode is provided with a plate, a shielding electrode one and a shielding electrode two are provided between the deflection electrode and the slit, and a differential hole is provided on the third electrode, wherein the ion output end of the differential hole is designed in a conical shape.

[0009] As a further optimization of the present invention, when the ion output side of the deflection electrode is provided, a differential hole is provided on the third electrode. The ion input end and the ion output end of the differential hole are both designed in a conical shape, and the two conical openings are designed in a contracted shape.

[0010] As a further optimization of the present invention, the maximum diameter of the conical opening at the ion input end of the differential aperture is smaller than the maximum diameter of the conical opening at the ion output end, and the diameter of the straight section of the differential aperture is 0.5-1mm.

[0011] As a further optimization of the present invention, the diameter depth of the cone at the ion input end of the differential aperture is smaller than the diameter depth of the cone at the ion output end.

[0012] As a further optimization of the present invention, a capillary inlet for inputting samples is provided on the cavity between the first electrode and the second electrode.

[0013] The beneficial effects of this invention are as follows: The resolution and sensitivity of the mass spectrometry ion source of this invention are improved, mainly by improving the detection line. The sensitivity is increased from the original 1ppm detection line to 10ppb detection line, which is a significant improvement and has great application value. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the overall structure of Embodiment 1 of the present invention.

[0015] Figure 2 This is the invention Figure 1 A sectional view of the overall structure.

[0016] Figure 3 This is a schematic diagram of the overall structure of Embodiment 2 of the present invention.

[0017] Figure 4 This is the invention Figure 3 A sectional view of the overall structure.

[0018] Figure 5 This is a sensitivity test diagram of the instrument in Embodiment 1 of the present invention.

[0019] Figure 6 This is a sensitivity test diagram of the instrument in Embodiment 2 of the present invention.

[0020] In the diagram: 1. Ultraviolet lamp; 2. First electrode; 3. Second electrode; 4. Third electrode; 5. Mount; 61. Plate; 62. Cover; 7. First lens; 8. Second lens; 9. Third lens; 10. Deflection electrode; 11. Shielding electrode one; 12. Shielding electrode two; 13. Slit. Detailed Implementation

[0021] The present application will now be described in further detail with reference to the accompanying drawings. It should be noted that the following specific embodiments are only used to further illustrate the present application and should not be construed as limiting the scope of protection of the present application. Those skilled in the art can make some non-essential improvements and adjustments to the present application based on the above application content.

[0022] Example 1

[0023] like Figure 1-2 as well as Figure 5 As shown, a mass spectrometry ion source device based on soft ionization technology includes an ultraviolet lamp 1, a first electrode 2, a second electrode, a third electrode 4, a first lens 7, a second lens 8, a third lens 9, a deflection electrode 10, and a fixed base 5 fixedly connected to the third electrode 4. The ion output side of the deflection electrode 10 is provided with a plate 61, and a slit 13 is provided on the plate 61.

[0024] Preferably, when the ion output side of the deflection electrode 10 is provided with a plate 61, a shielding electrode 11 and a shielding electrode 2 12 are provided between the deflection electrode 10 and the slit 13, and a differential hole is provided on the third electrode 4, the ion output end of which is designed in a conical shape.

[0025] Preferably, the cavity between the first electrode 2 and the second electrode is provided with a capillary inlet for sample input. The capillary delivers the sample into the ionization region. The sample is ionized by ultraviolet light irradiation. The ionized ions enter through the differential aperture, are captured and initially focused by the first lens 7, further compressed by the second lens 8, and finally collimated and energy matched by the third lens 9. The three lenses are connected in series, enabling ions to enter the high-vacuum mass analyzer from the atmospheric pressure ionization region efficiently and with low loss. This ensures that the ion beam has good spatial collimation and energy consistency, thereby improving the sensitivity and resolution of the mass spectrometer.

[0026] Example 2

[0027] like Figure 3-4 as well as Figure 6As shown, a mass spectrometry ion source device based on soft ionization technology includes an ultraviolet lamp 1, a first electrode 2, a second electrode, a third electrode 4, a first lens 7, a second lens 8, a third lens 9, a deflection electrode 10, and a fixed base 5 fixedly connected to the third electrode 4. The ion output side of the deflection electrode 10 is provided with a cover 62, and a slit 13 is provided on the cover 62.

[0028] Preferably, when the ion output side of the deflection electrode 10 is provided with 6, a differential hole is provided on the third electrode 4. The ion input end and the ion output end of the differential hole are both designed in a conical shape, and the two conical openings are designed in a contracted shape.

[0029] Preferably, the cavity between the first electrode 2 and the second electrode is provided with a capillary inlet for inputting samples.

[0030] Furthermore, the maximum diameter of the ion input cone of the differential aperture is smaller than the maximum diameter of the ion output cone, and the diameter of the straight section of the differential aperture is 0.5-1mm, preferably 0.6mm.

[0031] Furthermore, the diameter and depth of the ion input cone of the differential aperture are smaller than the diameter and depth of the ion output cone, and the overall depth of the differential aperture is 1 mm.

[0032] Experimental test: (1) COMSOL simulation experiment The COMSOL simulation software was used to verify the total sample density and total incident molecular weight through the differential pore under the same vacuum conditions, with only the differential pore structure being changed. The COMSOL simulation data of the mass spectrometry ion source in Example 1 are shown in Table 1: Table 1. COMSOL simulation data of the mass spectrometry ion source in Example 1 ; Note: Aperture refers to the diameter of the straight section of the differential aperture on the third electrode 4; Ion chamber pressure refers to the pressure of the vacuum chamber of the ion source.

[0033] The data from the COMSOL simulation experiment of the mass spectrometry ion source in Example 2 are shown in Table 2: Table 2. COMSOL simulation data of the mass spectrometry ion source in Example 2 ; Note: Aperture refers to the diameter of the straight section of the differential aperture on the third electrode 4; Ion chamber pressure refers to the pressure of the vacuum chamber of the ion source.

[0034] Experimental conclusions: Data analysis in Table 1-2 shows that, under the same experimental conditions, the total density of the sample and the total incident molecular weight through the differential aperture in Example 2 are significantly higher than those in Example 1.

[0035] (2) Instrument sensitivity test experiment By collecting the signal intensities of toluene and benzene at different concentrations, the following results were obtained: Figure 5-6 The experimental results shown indicate that, compared to Example 1, the resolution and sensitivity of the mass spectrometry ion source in Example 2, which was optimized, were improved, mainly by increasing the detection line, with the sensitivity increasing from the original 1 ppm detection line to the 10 ppb detection line.

[0036] The embodiments described above are merely examples of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention.

Claims

1. A mass spectrometry ion source device based on soft ionization technology, characterized in that: The device includes an ultraviolet lamp (1), a first electrode (2), a second electrode, a third electrode (4), a first lens (7), a second lens (8), a third lens (9), a deflection electrode (10), and a fixing seat (5) fixedly connected to the third electrode (4). The ion output side of the deflection electrode (10) is provided with a plate (61) or a cover (62). Both the plate (61) and the cover (62) are provided with slits (13).

2. The mass spectrometry ion source device based on soft ionization technology according to claim 1, characterized in that: When the plate (61) is provided on the ion output side of the deflection electrode (10), a shielding electrode one (11) and a shielding electrode two (12) are provided between the deflection electrode (10) and the slit (13), and a differential hole is provided on the third electrode (4), the ion output end of the differential hole is designed in a conical shape.

3. The mass spectrometry ion source device based on soft ionization technology according to claim 1, characterized in that: When the ion output side of the deflection electrode (10) is provided with (6), a differential hole is provided on the third electrode (4). The ion input end and ion output end of the differential hole are both designed in a conical shape, and the two conical holes are designed in a contracted shape.

4. The mass spectrometry ion source device based on soft ionization technology according to claim 3, characterized in that: The maximum diameter of the conical opening at the ion input end of the differential aperture is smaller than the maximum diameter of the conical opening at the ion output end, and the diameter of the straight section of the differential aperture is 0.5-1mm.

5. A mass spectrometry ion source device based on soft ionization technology according to claim 4, characterized in that: The diameter and depth of the conical opening at the ion input end of the differential aperture are smaller than the diameter and depth of the conical opening at the ion output end.

6. The mass spectrometry ion source device based on soft ionization technology according to claim 1, characterized in that: The cavity between the first electrode (2) and the second electrode is provided with a capillary inlet for inputting samples.

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