Ultraviolet optical microcavity structure for ionizing organic matter

Abstract

The invention discloses an ultraviolet optical microcavity structure for ionizing organic matters, comprising: an ionization chamber, the front end and the rear end of which are respectively provided with an inlet I and an outlet I; the ion trap mass analyzer is arranged in the ionization chamber, and the front end of the ion trap mass analyzer is provided with an inlet II and an outlet II; the ultraviolet reflecting film layers, the inner wall of the ionization chamber and the ion trap mass analyzer are plated with the ultraviolet reflecting film layers respectively, and the ultraviolet reflecting film layers form light pools in the ionization chamber and the ion trap mass analyzer respectively and are used for trapping ultraviolet light; the ultraviolet lamp is arranged outside the ionization chamber and corresponds to the inlet I, and the ultraviolet lamp is used for emitting ultraviolet rays into the ionization chamber and / or the ion trap mass analyzer. The ionization efficiency is greatly improved, the timeliness and reliability of detection are improved, and more powerful technical support is provided for the fields of environment monitoring, industrial production safety and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of photoionization, and particularly to an ultraviolet optical microcavity structure for ionizing organic substances. Background Art

[0002] Ultraviolet photoionization technology (UV Photoionization) is a technology based on irradiating sample molecules with ultraviolet light to ionize them, and is widely used in fields such as mass spectrometry and photoionization detectors (PID). Its basic principle is to use the photons of ultraviolet light to act on the sample molecules, causing the photoelectric effect to generate ions, and then analyzing the sample components by detecting the ion signals.

[0003] Currently, the typical structure of ultraviolet photoionization technology includes the following parts: Ultraviolet light source: Usually, an ultraviolet lamp (such as a krypton lamp) is used to generate vacuum ultraviolet light with a specific wavelength for ionizing organic substances. The wavelength is usually in the range of 10nm - 300nm. The single-photon energy commonly used for ionizing organic substances is 10.6eV, corresponding to a wavelength of 117nm.

[0004] Ionization chamber: In the ionization chamber, sample molecules are ionized under the action of ultraviolet light. The ionization chamber is made of conductive metal, and a specific electric field can be applied. On a PID sensor, it can be used to collect the ions generated by ionization and transmit them to the detector; in a mass spectrometer, an ion trap mass analyzer can be added in the ionization chamber to form a pile-up of ions to be measured while ionizing, or it can also be an independent ionization chamber.

[0005] The traditional ionization chamber structure is usually made of metal materials (such as stainless steel), and the inner surface is not specially treated. The ultraviolet light directly irradiates the sample molecules, and the unused photons are annihilated on the metal surface, resulting in a low photon utilization rate. The structure of the ion trap or independent ionization chamber in a mass spectrometer is simple, and the reflection and reuse of ultraviolet light are not considered. After the ultraviolet light directly irradiates the sample molecules in the ionization chamber, most of the photons are not absorbed and are lost, resulting in a low ionization efficiency. Due to the low photon utilization rate, the number of ions generated by ionization is small, resulting in insufficient detection sensitivity.

[0006] Based on the above technical problems, the present invention provides an ultraviolet optical microcavity structure for ionizing organic substances. Summary of the Invention

[0007] The purpose of the present invention is to provide an ultraviolet optical microcavity structure for ionizing organic substances to solve the problems existing in the prior art.

[0008] To achieve the above purpose, the present invention provides the following solution: The present invention provides an ultraviolet optical microcavity structure for ionizing organic substances, including:

[0009] An ionization chamber, with an inlet Ⅰ and an outlet Ⅰ respectively opened at the front end and the rear end of the ionization chamber;

[0010] An ion trap mass analyzer, the ion trap mass analyzer is arranged in the ionization chamber, an inlet II and an outlet II are respectively arranged at the front end of the ion trap mass analyzer, the inlet I is correspondingly arranged with the inlet II, and the outlet I is correspondingly arranged with the outlet II;

[0011] An ultraviolet reflective film layer, the inner wall of the ionization chamber and the ion trap mass analyzer are respectively coated with the ultraviolet reflective film layer, and the ultraviolet reflective film layer forms an optical cell in the ionization chamber and the ion trap mass analyzer respectively for trapping ultraviolet light;

[0012] An ultraviolet lamp, the ultraviolet lamp is arranged outside the ionization chamber and is correspondingly arranged with the inlet I, and the ultraviolet lamp is used for emitting ultraviolet light into the ionization chamber and / or the ion trap mass analyzer.

[0013] According to the ultraviolet optical microcavity structure for ionizing organic substances provided by the present invention, the thickness of the ultraviolet reflective film layer is not less than 10 nm.

[0014] According to the ultraviolet optical microcavity structure for ionizing organic substances provided by the present invention, the surface roughness of the ultraviolet reflective film layer is not less than 200 nm.

[0015] According to the ultraviolet optical microcavity structure for ionizing organic substances provided by the present invention, the material of the ultraviolet reflective film layer includes but is not limited to one or more of Pt, pure Al, Al2O3, MgF2, Ag.

[0016] According to the ultraviolet optical microcavity structure for ionizing organic substances provided by the present invention, the ultraviolet reflective film layer is respectively coated on the inner wall of the ionization chamber and the inner wall of the ion trap mass analyzer through a coating device.

[0017] According to the ultraviolet optical microcavity structure for ionizing organic substances provided by the present invention, the ion trap mass analyzer includes a front end cap electrode, a rear end cap electrode and a ring electrode, the front end cap electrode and the rear end cap electrode are respectively arranged at the front and rear ends of the ring electrode, a hollow cavity is formed by enclosing between the front end cap electrode, the rear end cap electrode and the ring electrode, the inlet II is arranged on the front end cap electrode, and the outlet II is arranged on the rear end cap electrode; a jack is arranged on the ring electrode, a capillary is inserted into the jack, one end of the capillary passes through the ionization chamber, and the capillary is used for introducing gas.

[0018] According to the ultraviolet optical microcavity structure for ionizing organic substances provided by the present invention, an electron multiplier is arranged at the outlet II, and the electron multiplier is used for converting a weak ion signal into a detectable electrical signal.

[0019] According to the ultraviolet optical microcavity structure for ionizing organic substances provided by the present invention, the front end cover electrode, the rear end cover electrode and the ring electrode are respectively fixed by screws.

[0020] The present invention discloses the following technical effects:

[0021] By plating an ultraviolet mirror reflection film on the inner surface of the ionization chamber and the inner surface of the ion trap mass analyzer, the present invention enables ultraviolet photons to be reflected multiple times in the ionization chamber, thereby increasing the interaction opportunities with the molecules of the substance to be detected and improving the ionization efficiency.

[0022] For in-trap ionization in the ion trap, the reflection film is plated on the surface of the ion trap; for an independent ionization chamber, its metal surface is coated. This targeted coating strategy ensures that the role of the reflection film can be fully exerted in different detection environments, improving the ionization effect.

[0023] Compared with the traditional ultraviolet photoionization technology, the present invention greatly improves the ionization efficiency by increasing the number of interactions between photons and molecules, improves the timeliness and reliability of detection, and provides stronger technical support for fields such as environmental monitoring and industrial production safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0025] Figure 1 is a schematic structural diagram of the ultraviolet optical microcavity structure of the present invention;

[0026] Figure 2 is a schematic structural diagram of the ionization chamber of the present invention.

[0027] Among them, 1, ultraviolet ray reflection film layer; 2, capillary; 3, ultraviolet lamp; 4, rear end cover electrode; 5, front end cover electrode; 6, ring electrode; 7, electron multiplier; 8, ionization chamber. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0028] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0029] To make the above objects, features, and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0030] Referring to Figure 1-2 , the present invention provides an ultraviolet optical microcavity structure for ionizing organic matter, including:

[0031] An ionization chamber 8, with an inlet I and an outlet I respectively opened at the front end and the rear end of the ionization chamber 8;

[0032] An ion trap mass analyzer, which is arranged inside the ionization chamber 8. An inlet II and an outlet II are respectively arranged at the front end of the ion trap mass analyzer. The inlet I and the inlet II are correspondingly arranged, and the outlet I and the outlet II are correspondingly arranged;

[0033] An ultraviolet reflection film layer 1 is respectively plated on the inner wall of the ionization chamber 8 and the ion trap mass analyzer. The ultraviolet reflection film layer 1 forms an optical cell inside the ionization chamber 8 and the ion trap mass analyzer respectively for confining ultraviolet light;

[0034] An ultraviolet lamp 3 is arranged outside the ionization chamber 8 and is correspondingly arranged with the inlet I. The ultraviolet lamp 3 is used to emit ultraviolet light into the ionization chamber 8 and / or the ion trap mass analyzer.

[0035] The ultraviolet light emitted by the ultraviolet lamp 3 is reflected back into the ion trap, enabling the ultraviolet light to be reflected multiple times inside the ion trap, increasing the interaction opportunity between the ultraviolet light and the sample ions. This means that more sample ions can absorb the ultraviolet light energy, thereby improving the ionization efficiency, generating more ions for subsequent analysis, and helping to improve the detection sensitivity.

[0036] As a further optimized solution, the thickness of the ultraviolet reflection film layer 1 is not less than 10 nm.

[0037] Ultraviolet mirror films with different thicknesses will have different reflection effects on ultraviolet light of specific wavelengths. By changing the coating thickness, the film layer can achieve enhanced reflection, transmission, or absorption of ultraviolet light of specific wavelengths, thereby more precisely selecting and utilizing the required wavelength of ultraviolet light to meet the strict requirements of specific ion excitation, dissociation, etc. operations in the ion trap or ionization chamber 8 for the light wavelength.

[0038] As a further optimized solution, the surface roughness of the ultraviolet reflection film layer 1 is not less than 200 nm.

[0039] As a further optimized solution, the material of the ultraviolet reflection film layer 1 includes but is not limited to one or more of Pt, pure Al, Al2O3, MgF2, and Ag.

[0040] For different detection objects (such as detecting VOCs), specific coating materials are selected according to the photon energy.

[0041] For a further optimized solution, the ultraviolet reflection film layer 1 is respectively coated on the inner wall of the ionization chamber 8 and the inner wall of the ion trap mass analyzer through a coating device.

[0042] For a further optimized solution, the ion trap mass analyzer includes a front cover electrode 5, a rear cover electrode 4 and a ring electrode 6. The front cover electrode 5 and the rear cover electrode 4 are respectively arranged at the front and rear ends of the ring electrode 6. A hollow cavity is formed by surrounding between the front cover electrode 5, the rear cover electrode 4 and the ring electrode 6. An inlet II is opened on the front cover electrode 5, and an outlet II is opened on the rear cover electrode 4; a jack is opened on the ring electrode 6, and a capillary 2 is inserted into the jack. One end of the capillary 2 passes through the ionization chamber 8, and the capillary 2 is used for introducing gas.

[0043] The ultraviolet light emitted by the ultraviolet lamp 3 has relatively high energy. When the sample molecules absorb the energy of the ultraviolet photons, if their ionization energy is lower than the energy of the ultraviolet photons, the electrons in the molecules will obtain sufficient energy to escape from the molecules, causing the molecules or atoms to be ionized and generating ions.

[0044] For a further optimized solution, an electron multiplier 7 is arranged at the outlet II, and the electron multiplier 7 is used to convert weak ion signals into detectable electrical signals.

[0045] For a further optimized solution, the front cover electrode 5, the rear cover electrode 4 and the ring electrode 6 are respectively fixed by screws.

[0046] The end cover electrode and the ring electrode act together to form a specific electric field distribution in the ion trap, confining the ions in a specific spatial region inside the ion trap. The electric fields at the inlet and outlet cooperate with the electric field inside the ion trap, enabling the ions to move along a specific orbit in the trap and realizing the storage of ions.

[0047] Increasing the number of times of interaction between light and the sample: The light emitted by the vacuum ultraviolet lamp can be reflected back into the ionization chamber 8, causing the light to be reflected multiple times inside the ionization chamber 8. The ultraviolet mirror film can make the inner surface of the ion trap smoother and flatter, reducing the scattering of ultraviolet light in the ion trap, lowering the background light signal, improving the signal-to-noise ratio of ion detection, making the ion signal clearer, and being conducive to the precise detection and analysis of ions. Some ultraviolet mirror films may have special chemical properties and surface structures, which can prevent the adsorption of impurities on the inner surface of the ion trap, keep the inside of the ion trap clean, avoid the interference of impurities to ions, and improve the analysis performance and accuracy of the ion trap.

[0048] The present invention solves the problems of low ionization efficiency, insufficient sensitivity, poor photon utilization rate, etc. in the existing ultraviolet photoionization technology through the reflection microcavity ionization technology, and at the same time optimizes the material selection and application range, providing a highly sensitive and efficient detection means for fields such as mass spectrometry and PID sensors.

[0049] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the present invention.

[0050] The above-described embodiments are only descriptions of the preferred embodiments of the present invention and do not limit the scope of the present invention. Without departing from the design spirit of the present invention, various deformations and improvements made by those of ordinary skill in the art to the technical solutions of the present invention shall fall within the protection scope determined by the claims of the present invention.

Claims

1. An ultraviolet optical microcavity structure for ionizing organic substances, characterized in that, Comprising: An ionization chamber (8), with an inlet Ⅰ and an outlet Ⅰ respectively opened at the front end and the rear end of the ionization chamber (8); An ion trap mass analyzer, which is arranged inside the ionization chamber (8). The front end of the ion trap mass analyzer is respectively provided with an inlet Ⅱ and an outlet Ⅱ. The inlet Ⅰ and the inlet Ⅱ are correspondingly arranged, and the outlet Ⅰ and the outlet Ⅱ are correspondingly arranged; An ultraviolet reflection film layer (1), which is respectively plated on the inner wall of the ionization chamber (8) and the ion trap mass analyzer. The ultraviolet reflection film layer (1) forms an optical cell inside the ionization chamber (8) and the ion trap mass analyzer respectively, for confining ultraviolet light; An ultraviolet lamp (3), which is arranged outside the ionization chamber (8) and is correspondingly arranged with the inlet Ⅰ. The ultraviolet lamp (3) is used for emitting ultraviolet rays into the ionization chamber (8) and / or the ion trap mass analyzer.

2. The ultraviolet optical microcavity structure for ionizing organic substances according to claim 1, characterized in that: The thickness of the ultraviolet reflection film layer (1) is not less than 10 nm.

3. The ultraviolet optical microcavity structure for ionizing organic substances according to claim 1, wherein: The surface roughness of the ultraviolet reflection film layer (1) is not less than 200 nm.

4. The ultraviolet optical microcavity structure for ionizing organic substances according to claim 1, characterized in that: The material of the ultraviolet reflection film layer (1) includes but is not limited to one or several of Pt, pure Al, Al2O3, MgF2, Ag.

5. The ultraviolet optical microcavity structure for ionizing organic substances according to claim 1, characterized in that: The ultraviolet reflection film layer (1) is respectively plated on the inner wall of the ionization chamber (8) and the inner wall of the ion trap mass analyzer through a coating device.

6. The ultraviolet optical microcavity structure for ionizing organic substances according to claim 1, characterized in that: The ion trap mass analyzer includes a front end cap electrode (5), a rear end cap electrode (4) and a ring electrode (6). The front end cap electrode (5) and the rear end cap electrode (4) are respectively arranged at the front and rear ends of the ring electrode (6). A hollow cavity is formed by enclosing between the front end cap electrode (5), the rear end cap electrode (4) and the ring electrode (6). The inlet Ⅱ is opened on the front end cap electrode (5), and the outlet Ⅱ is opened on the rear end cap electrode (4); A jack is opened on the ring electrode (6), and a capillary (2) is inserted into the jack. One end of the capillary (2) passes through the ionization chamber (8), and the capillary (2) is used for introducing gas.

7. An ultraviolet optical microcavity structure for ionizing organic substances according to claim 6, characterized in that: An electron multiplier (7) is arranged at the outlet Ⅱ, and the electron multiplier (7) is used for converting a weak ion signal into a detectable electrical signal.

8. An ultraviolet optical microcavity structure for ionizing organic substances according to claim 6, characterized in that: The front end cap electrode (5), the rear end cap electrode (4) and the ring electrode (6) are respectively fixed by screws.

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