Ultraviolet photoionization source and ultraviolet photoionization method

Abstract

The present invention discloses an ultraviolet photoionization source and an ultraviolet photoionization method. The ultraviolet photoionization source comprises an ultraviolet lamp, a first ionization chamber and a second ionization chamber. The first ionization chamber is provided with a light hole for receiving the output light of the ultraviolet lamp and a reverse purge gas inlet and a purge gas outlet. The second ionization chamber is connected to the first ionization chamber. A first electric field for introducing initial ions into the second ionization chamber is provided in the first ionization chamber. The initial ions produce a collision reaction with sample molecules in the second ionization chamber to ionize the sample molecules. In the embodiment of the present invention, a purge gas is introduced to remove neutral gases such as ozone generated by direct irradiation of the ultraviolet lamp, and a reverse purge gas flow is used to bring auxiliary reagents into the first ionization chamber to assist ionization. This is convenient for controlling the concentration and type of the auxiliary reagents, and at the same time, the auxiliary reagents are separated from the sample molecules to avoid ionization complication. The degree of contamination of the ultraviolet lamp can be reduced to a certain extent, the service life of the ultraviolet lamp can be extended, and the working stability of the ionization source can be improved.

Description

Technical Field

[0001] The invention relates to the technical field of ultraviolet photoionization, and in particular to an ultraviolet photoionization source and an ultraviolet photoionization method. Background Art

[0002] Vacuum ultraviolet light refers to deep ultraviolet light with a wavelength less than 200nm. It can cause single-photon ionization of compound molecules whose ionization energy is lower than its photon energy, producing a large number of molecular ions and almost no fragment ions. The ionization methods currently used in ultraviolet photoionization sources are direct ionization or auxiliary reagent ionization. The problem with direct ionization is that ultraviolet light irradiating the air will produce neutral gases such as ozone, which will affect the subsequent sample ionization. The commonly used method for auxiliary reagent ionization is to mix the auxiliary reagent with the sample and inject it together. This injection method will make the ionization process complicated and is not conducive to sample detection. Summary of the invention

[0003] In view of this, the embodiments of the present invention provide an ultraviolet photoionization source and an ultraviolet photoionization method to solve the technical problem of the complicated ionization process of the existing ultraviolet photoionization source.

[0004] The technical solution proposed by the present invention is as follows:

[0005] A first aspect of an embodiment of the present invention provides an ultraviolet photoionization source, comprising: an ultraviolet lamp, a first ionization chamber and a second ionization chamber; the first ionization chamber is provided with a light hole for receiving the output light of the ultraviolet lamp, the first ionization chamber is provided with a purge gas inlet and a purge gas outlet, the purge gas comprises a reverse purge gas flow and an auxiliary reagent, the auxiliary reagent is ionized to generate initial ions under the irradiation of the output light of the ultraviolet lamp, the ultraviolet lamp irradiates the reverse purge gas flow to generate neutral gas, the purge gas leads the neutral gas from the first ionization chamber to the outside through the purge gas outlet; the second ionization chamber is connected to the first ionization chamber, the first ionization chamber is provided with a first electric field for introducing the initial ions into the second ionization chamber, the initial ions produce a collision reaction with sample molecules in the second ionization chamber, the sample molecules are ionized through charge transfer, and sample ions are generated.

[0006] Optionally, a second electric field is provided in the second ionization chamber for driving the sample ions to move in a direction away from the first ionization chamber.

[0007] Optionally, the ultraviolet photoionization source further includes: a first electrode, a second electrode and a third electrode; the area between the first electrode and the second electrode constitutes the first ionization chamber, the area between the second electrode and the third electrode constitutes the second ionization chamber, a first electric field is generated between the first electrode and the second electrode, and a second electric field is generated between the second electrode and the third electrode.

[0008] Optionally, the light through hole is arranged on the first electrode; the second electrode is provided with an ion through hole, and the second ionization chamber and the first ionization chamber are connected through the ion through hole.

[0009] Optionally, a sample carrier gas inlet and a sample carrier gas outlet are respectively provided at the front end and the end of the second ionization chamber, and the sample carrier gas carrying the sample molecules enters the second ionization chamber from the sample carrier gas inlet, and the sample carrier gas flows out from the sample carrier gas outlet.

[0010] Optionally, the length of the first ionization chamber is 5 mm-30 mm, and the length of the second ionization chamber is 10 mm-50 mm.

[0011] Optionally, the ultraviolet photoionization source further includes a shell, the shell includes a lampshade and a fixed shell, the upper end of the fixed shell is connected to the lampshade, the ultraviolet lamp is arranged in the lampshade, and the first ionization chamber and the second ionization chamber are arranged in the fixed shell.

[0012] The second aspect of the embodiment of the present invention provides an ultraviolet photoionization method, which is applied to the ultraviolet photoionization source provided in the first aspect of the embodiment of the present invention and any one of the first aspects, including: using a reverse purge gas flow to deliver an auxiliary reagent from a purge gas inlet into a first ionization chamber; irradiating the auxiliary reagent with the output light of an ultraviolet lamp in the first ionization chamber for initial ionization to generate initial ions; using a purge gas to lead a neutral gas from the first ionization chamber to the outside through the purge gas outlet, the neutral gas is generated by irradiating the reverse purge gas flow by the ultraviolet lamp, and the purge gas includes a reverse purge gas flow and an auxiliary reagent; introducing the initial ions from the first ionization chamber to a second ionization chamber through a first electric field in the first ionization chamber; in the second ionization chamber, the collision reaction between the initial ions and sample molecules ionizes the sample molecules through charge transfer to generate sample ions.

[0013] Optionally, the ultraviolet photoionization method further includes: driving the sample ions to move in a direction away from the first ionization chamber by a second electric field in the second ionization chamber.

[0014] Optionally, the flow rate of the purge gas is 200 mL / min-800 mL / min

[0015] It can be seen from the above technical solutions that the embodiments of the present invention have the following advantages:

[0016] An ultraviolet photoionization source and an ultraviolet photoionization method are provided in an embodiment of the present invention. The ultraviolet photoionization source comprises: an ultraviolet lamp, a first ionization chamber and a second ionization chamber; the first ionization chamber is provided with a light hole for receiving the output light of the ultraviolet lamp, the first ionization chamber is provided with a purge gas inlet and a purge gas outlet, the purge gas comprises a reverse purge gas flow and an auxiliary reagent, the auxiliary reagent is ionized to generate initial ions under the irradiation of the output light of the ultraviolet lamp, the ultraviolet lamp irradiates the reverse purge gas flow to generate neutral gas, and the purge gas leads the neutral gas from the first ionization chamber to the outside through the purge gas outlet; the second ionization chamber is connected to the first ionization chamber, and a first electric field for introducing the initial ions into the second ionization chamber is provided in the first ionization chamber, the initial ions produce a collision reaction with sample molecules in the second ionization chamber, and the sample molecules are ionized through charge transfer to generate sample ions. In the embodiment of the present invention, the auxiliary reagent is brought into the first ionization chamber through the reverse purge gas flow for ionization to generate initial ions, which can not only separate the auxiliary reagent from the sample molecules to avoid ionization complexity, but also facilitate the control of the concentration and type of the auxiliary reagent. At the same time, after the initial ions are generated, they move to the second ionization chamber under the action of the first electric field, and the sample molecules do not need to be close to the ultraviolet lamp window, which can reduce the degree of contamination of the ultraviolet lamp to a certain extent, extend the service life of the ultraviolet lamp, and improve the working stability of the ionization source. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly express the technical solutions of the embodiments of the present invention, the drawings required for describing the embodiments are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0018] Figure 1 It is a structural schematic diagram of a sampling method of the ultraviolet photoionization source in an embodiment of the present invention;

[0019] Figure 2 Schematic diagram of another injection method of the ultraviolet photoionization source in an embodiment of the present invention;

[0020] Figure 3 FIG. 1 is a mechanical structure diagram of an ultraviolet photoionization source in an embodiment of the present invention;

[0021] Figure 4 is a cross-sectional view of an ultraviolet photoionization source in an embodiment of the present invention;

[0022] Figure 5 is a mechanical structure diagram of the first electrode in an embodiment of the present invention;

[0023] Figure 6 is a mechanical structure diagram of the second electrode in an embodiment of the present invention;

[0024] Figure 7 is a mechanical structure diagram of the third electrode in an embodiment of the present invention;

[0025] Figure 8 It is a mechanical structure diagram of the ultraviolet photoionization source connected to the sample injector in an embodiment of the present invention;

[0026] Fig. 9 is a flow chart of the ultraviolet photoionization method in an embodiment of the present invention;

[0027] Description of reference numerals:

[0028] 1-ultraviolet lamp; 2-first electrode; 3-second electrode; 4-third electrode; 5-lamp cover; 6-fixed housing; 7-injector; 201-light hole; 301-ion hole. DETAILED DESCRIPTION

[0029] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] The present invention provides an ultraviolet photoionization source. Figure 1 , Figure 2 , Figure 3 and Figure 4 , including: an ultraviolet lamp 1, a first ionization chamber and a second ionization chamber. The ultraviolet lamp 1 includes but is not limited to a krypton lamp, a mercury lamp, a xenon lamp, etc. The ultraviolet lamp 1, the first ionization chamber and the second ionization chamber are adjacent to each other in sequence, and the second electrode divides the ionization chamber into a first ionization chamber and a second ionization chamber. In the first ionization chamber, the auxiliary reagent is initially ionized under ultraviolet light irradiation, and in the second ionization chamber, the sample molecules and the initial ions generated by the initial ionization produce a collision reaction to ionize the sample molecules.

[0031] The first ionization chamber is provided with a light hole 201 for receiving the output light of the ultraviolet lamp 1. The first ionization chamber is provided with a purge gas inlet and a purge gas outlet. The purge gas includes a reverse purge gas flow and an auxiliary reagent. The auxiliary reagent is ionized to produce initial ions under the irradiation of the output light of the ultraviolet lamp 1. The ultraviolet lamp irradiates the reverse purge gas flow to produce neutral gas. The purge gas leads the neutral gas from the first ionization chamber to the outside through the purge gas outlet. The first ionization chamber is adjacent to the ultraviolet lamp 1. The output light of the ultraviolet lamp 1 enters the first ionization chamber through the light hole 201. The purge gas carries the auxiliary reagent and enters the first ionization chamber through the purge gas inlet. When the ultraviolet light irradiates the auxiliary reagent, the auxiliary reagent will be ionized to produce initial ions. The auxiliary reagent includes but is not limited to acetone and toluene. The neutral gas includes neutral active oxygen atoms and ozone. The purge gas in the first ionization chamber flows out from the purge gas outlet, and at the same time, the neutral active oxygen atoms and ozone are purged, so that the active oxygen atoms and ozone flow out of the first ionization chamber, thereby preventing the presence of neutral active oxygen atoms and ozone from affecting the subsequent ionization process of the sample molecules, making the ion products of the sample molecules complicated and the ionization efficiency reduced. The embodiment of the present invention can remove neutral active oxygen atoms and ozone by introducing a purge gas into the first ionization chamber, thereby improving the ionization efficiency. The purge gas inlet and the purge gas outlet of the purge gas are both arranged in the first ionization chamber, and the purge gas will not affect the sample. In addition, in the embodiment of the present invention, the second ionization chamber close to the ultraviolet lamp 1 from the purge gas inlet is independent of the sample molecule ionization. The use of a reverse purge gas flow to bring in auxiliary reagents from the purge gas inlet can avoid the mixing of auxiliary reagents with the sample gas, thereby causing problems such as a cluttered detection spectrum and a complicated ionization process. At the same time, in the embodiment of the present invention, the concentration and type of the auxiliary reagent can be clarified through experiments and the sample molecules are kept away from the window of the ultraviolet lamp 1, which can reduce the degree of damage to the window of the ultraviolet lamp 1 to a certain extent, thereby extending the service life of the ultraviolet lamp 1 and improving the working stability of the ionization source.

[0032] The second ionization chamber is connected to the first ionization chamber, and a first electric field E1 is provided in the first ionization chamber to introduce initial ions into the second ionization chamber. The initial ions produce collision reactions with sample molecules in the second ionization chamber to ionize the sample molecules through charge transfer. Specifically, the electric field strength of the first electric field E1 is preferably 10Vmm-100V / mm. The first electric field E1 is generated by arranging electrodes in the first ionization chamber, and the first electric field E1 is used to move the charged initial ions from the first ionization chamber into the second ionization chamber, and the direction of the first electric field E1 is parallel to the direction of the entrance of the second ionization chamber and the first ionization chamber.

[0033] An ultraviolet photoionization source and an ultraviolet photoionization method according to an embodiment of the present invention are provided with an ultraviolet lamp 1, a first ionization chamber and a second ionization chamber, wherein the first ionization chamber is provided with a light hole 201 for receiving the output light of the ultraviolet lamp 1, the first ionization chamber is provided with a purge gas inlet and a purge gas outlet, the purge gas includes a reverse purge gas flow and an auxiliary reagent, the auxiliary reagent is ionized to generate initial ions under the irradiation of the output light of the ultraviolet lamp 1, the purge gas leads the neutral gas from the first ionization chamber to the outside through the purge gas outlet, the second ionization chamber is connected to the first ionization chamber, a first electric field E1 for introducing the initial ions into the second ionization chamber is provided in the first ionization chamber, the initial ions produce a collision reaction with the sample molecules in the second ionization chamber, and the sample molecules are ionized through charge transfer to generate sample ions. In the embodiment of the present invention, the auxiliary reagent is brought into the first ionization chamber through the purge gas for ionization to generate initial ions, which can separate the auxiliary reagent from the sample molecules to avoid the complication of ionization, and can also conveniently control the concentration and type of the auxiliary reagent. At the same time, after the initial ions are generated, they move to the second ionization chamber under the action of the first electric field E1. The sample molecules do not need to be close to the window of the ultraviolet lamp 1, which can reduce the degree of contamination of the ultraviolet lamp 1 to a certain extent, extend the service life of the ultraviolet lamp 1, and improve the working stability of the ionization source.

[0034] In one embodiment, a second electric field E2 is provided in the second ionization chamber for driving the sample ions to move in a direction away from the first ionization chamber. The intensity of the first electric field E1 is preferably 10V / mm-100V / mm. The second electric field E2 is generated by providing electrodes in the second ionization chamber, and the second electric field E2 is used to drive the sample ions to move in a direction away from the first ionization chamber, thereby avoiding the accumulation of sample ions and facilitating subsequent detection.

[0035] In one embodiment, the ultraviolet photoionization source further includes: a first electrode 2, a second electrode 3 and a third electrode 4; the area between the first electrode 2 and the second electrode 3 constitutes a first ionization chamber, the area between the second electrode 3 and the third electrode 4 constitutes a second ionization chamber, a first electric field E1 is generated between the first electrode 2 and the second electrode 3, and a second electric field E2 is generated between the second electrode 3 and the third electrode 4. Specifically, the first electrode 2, the second electrode 3 and the third electrode 4 are respectively a window electrode, a counter electrode and a reaction zone electrode, and the second electrode 3 divides the ionization chamber in the ultraviolet photoionization source into a first ionization chamber and a second ionization chamber. Figure 5 , Figure 6 and Figure 7 As shown, the first electrode 2, the second electrode 3 and the third electrode 4 are all in the shape of a disk and have a circular hole in the middle. The circular hole in the middle of the first electrode 2 and the second electrode 3 has a smaller diameter, and the circular hole in the middle of the third electrode 4 has a larger diameter. The first electrode 2, the second electrode 3 and the third electrode 4 are used to form the first ionization chamber and the second ionization chamber, and are also used to generate the first electric field E1 and the second electric field E2, thereby simplifying the structure of the ultraviolet photoionization source.

[0036] In one embodiment, the light through hole 201 is arranged on the first electrode 2, and the ion through hole 301 is arranged on the second electrode 3, and the second ionization chamber and the first ionization chamber are connected through the ion through hole 301. The light through hole 201 is a circular hole arranged in the middle of the first electrode 2, and ultraviolet light enters the first ionization chamber through the light through hole 201. The ion through hole 301 is a channel for the initial ions to enter the second ionization chamber. The diameters of the light through hole 201 and the ion through hole 301 can be set according to the situation. The diameter of the first electrode 2 is close to the size of the light exit window of the ultraviolet lamp 1, and the thickness is preferably 0.1mm-3mm. The first ionization chamber is enclosed by the first electrode 2, the second electrode 3 and the shell, and the second ionization chamber is enclosed by the second electrode 3, the third electrode 4 and the shell. A reverse purge channel is left between the first electrode 2 and the lamp exit window of the ultraviolet lamp 1, and the spacing of the reverse purge channel is preferably 0.1mm-1mm. The purge gas outlet is located at the end of the reverse purge channel, that is, the reverse purge gas flow carries the auxiliary reagent into the first ionization chamber from the purge gas inlet, and then passes through the light hole 201 and the reverse purge channel and flows out from the purge gas outlet carrying the active oxygen atoms and ozone.

[0037] In one embodiment, a sample carrier gas inlet and a sample carrier gas outlet are respectively provided at the front end and the end of the second ionization chamber, and the sample carrier gas carries sample molecules into the second ionization chamber from the sample inlet, and the sample carrier gas flows out from the sample carrier gas outlet. Specifically, the gas flow direction of the sample carrier gas can be freely set, for example, it can flow from the left side of the second ionization chamber to the right side, or from the right side to the left side. The positions of the sample carrier gas inlet and the sample carrier gas outlet can also be adjusted according to the situation, for example, they can be set above or below the second ionization chamber. The sample carrier gas inlet and the sample carrier gas outlet are used for the intake and exhaust of the sample carrier gas. The sample carrier gas carries sample molecules into the second ionization chamber and the initial ion collision ionization. At the same time, the sample carrier gas inlet and the sample carrier gas outlet are connected to the second ionization chamber without passing through the first ionization chamber, so as to ensure that the sample carrier gas and the purge gas flow independently of each other without interference.

[0038] like Figure 8 As shown, the sample carrier gas inlet is connected to the outlet of the injector 7, and the injector 7 is used for the injection of the sample carrier gas and the sample molecules; in the embodiment of the present invention, the flow rate of the purge gas is preferably 200mL / min-800mL / min, and the flow rate of the injection carrier gas is preferably 30mL / min-200mL / min. At this gas flow rate, the gas is fully ionized and relatively stable.

[0039] In one embodiment, the length of the first ionization chamber is 5 mm-30 mm, and the length of the second ionization chamber is 10 mm-50 mm. For example, within these two lengths, the length of the first ionization chamber is 10 mm, and the length of the second ionization chamber is 30 mm, which is sufficient for auxiliary reagent ionization and sample molecule ionization.

[0040] In one embodiment, the ultraviolet photoionization source further includes a housing, the housing includes a lampshade 5 and a fixed housing 6, the upper end of the fixed housing 6 is connected to the lampshade 5, the ultraviolet lamp 1 is arranged in the lampshade 5, and the first ionization chamber and the second ionization chamber are arranged in the fixed housing 6. The lampshade 5 is mainly used to protect the ultraviolet lamp 1, the fixed housing 6 is mainly used to fix the lampshade 5 and the first electrode 2, the second electrode 3 and the third electrode 4, and a connecting assembly is also arranged on the fixed housing 6 to connect with the injector 7. The connecting assembly includes but is not limited to a bolt assembly, a connecting pipe, etc.

[0041] The embodiment of the present invention further provides an ultraviolet photoionization method, which is applied to the ultraviolet photoionization source as described above in the embodiment of the present invention. The ultraviolet photoionization method comprises:

[0042] Step S1: using a reverse purge gas flow to deliver the auxiliary reagent from the purge gas inlet into the first ionization chamber.

[0043] Step S2: In the first ionization chamber, the output light of the ultraviolet lamp is irradiated on the auxiliary reagent for initial ionization to generate initial ions.

[0044] Step S3: using a purge gas to lead the neutral gas from the first ionization chamber to the outside through a purge gas outlet, the neutral gas is generated by irradiating the reverse purge gas flow by the ultraviolet lamp, and the purge gas includes a reverse purge gas flow and an auxiliary reagent.

[0045] Step S4: introducing the initial ions from the first ionization chamber into the second ionization chamber through the first electric field in the first ionization chamber.

[0046] Step S5: In the second ionization chamber, the collision reaction between the initial ions and the sample molecules ionizes the sample molecules through charge transfer to generate sample ions. The ultraviolet photoionization method of the embodiment of the present invention brings the auxiliary reagent into the first ionization chamber through the reverse purge gas flow for ionization to generate initial ions, which can separate the auxiliary reagent from the sample molecules to avoid ionization complexity, and can also conveniently control the concentration and type of the auxiliary reagent. At the same time, after the initial ions are generated, they move to the second ionization chamber under the action of the first electric field E1, and the sample molecules do not need to be close to the ultraviolet lamp 1 and its output light, which can reduce the degree of contamination of the ultraviolet lamp 1 to a certain extent, extend the service life of the ultraviolet lamp 1, and improve the working stability of the ionization source.

[0047] In one embodiment, the ultraviolet photoionization method further includes: driving the sample ions to move in a direction away from the first ionization chamber by a second electric field E2 in the second ionization chamber. The intensity of the second electric field E2 is preferably 10V / mm-100V / mm. The second electric field E2 is generated by arranging electrodes in the second ionization chamber, and the second electric field E2 is used to drive the sample ions to move in a direction away from the first ionization chamber to avoid sample ion accumulation and facilitate subsequent detection.

[0048] In one embodiment, the flow rate of the purge gas is 200 mL / min-800 mL / min, and the flow rate of the injection carrier gas is preferably 30 mL / min-200 mL / min. At this gas flow rate, the gas is fully ionized and the reaction is stable.

[0049] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features thereof may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An ultraviolet photoionization source, characterized in that: include: An ultraviolet lamp, a first ionization chamber, and a second ionization chamber; The first ionization chamber is provided with a light hole for receiving the output light of the ultraviolet lamp, and the first ionization chamber is provided with a purge gas inlet and a purge gas outlet, the purge gas includes a reverse purge gas flow and an auxiliary reagent, the auxiliary reagent is ionized to generate initial ions under the irradiation of the output light of the ultraviolet lamp, the ultraviolet lamp irradiates the reverse purge gas flow to generate neutral gas, and the purge gas leads the neutral gas from the first ionization chamber to the outside through the purge gas outlet; The second ionization chamber is connected to the first ionization chamber, and a first electric field is provided in the first ionization chamber to introduce the initial ions into the second ionization chamber. The initial ions produce collision reactions with sample molecules in the second ionization chamber to ionize the sample molecules through charge transfer to generate sample ions; and a second electric field is provided in the second ionization chamber to drive the sample ions to move in a direction away from the first ionization chamber; The front end and the end of the second ionization chamber are respectively provided with a sample carrier gas inlet and a sample carrier gas outlet. The sample carrier gas carries the sample molecules into the second ionization chamber from the sample carrier gas inlet, and the sample carrier gas flows from the sample carrier gas outlet.

2. The ultraviolet photoionization source according to claim 1, characterized in that Also includes: A first electrode, a second electrode and a third electrode; the area between the first electrode and the second electrode constitutes the first ionization chamber, the area between the second electrode and the third electrode constitutes the second ionization chamber, a first electric field is generated between the first electrode and the second electrode, and a second electric field is generated between the second electrode and the third electrode.

3. The ultraviolet photoionization source according to claim 2, characterized in that The light-through hole is arranged on the first electrode; The second electrode is provided with an ion through hole, and the second ionization chamber and the first ionization chamber are communicated with each other through the ion through hole.

4. The ultraviolet photoionization source according to claim 1, characterized in that The length of the first ionization chamber is 5 mm-30 mm, and the length of the second ionization chamber is 10 mm-50 mm.

5. The ultraviolet photoionization source according to claim 1, characterized in that It also includes a shell, which includes a lampshade and a fixed shell. The upper end of the fixed shell is connected to the lampshade, the ultraviolet lamp is arranged in the lampshade, and the first ionization chamber and the second ionization chamber are arranged in the fixed shell.

6. An ultraviolet photoionization method, characterized in that: The ultraviolet photoionization source as claimed in any one of claims 1 to 5, comprising: Using a reverse purge gas flow to deliver the auxiliary reagent from the purge gas inlet into the first ionization chamber; The auxiliary reagent is irradiated with the output light of the ultraviolet lamp in the first ionization chamber to perform initial ionization and generate initial ions; Using purge gas to lead neutral gas from the first ionization chamber to the outside through a purge gas outlet, the neutral gas is generated by irradiating the reverse purge gas flow by the ultraviolet lamp, and the purge gas includes a reverse purge gas flow and an auxiliary reagent; introducing the initial ions from the first ionization chamber into the second ionization chamber through a first electric field in the first ionization chamber; In the second ionization chamber, the collision reaction between the initial ions and the sample molecules ionizes the sample molecules through charge transfer to generate sample ions.

7. The ultraviolet photoionization method according to claim 6, characterized in that: Also includes: The sample ions are driven to move in a direction away from the first ionization chamber by a second electric field in the second ionization chamber.

8. The ultraviolet photoionization method according to claim 6, characterized in that: The flow rate of the purge gas is 200 mL / min-800 mL / min.

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