Mass spectrum ion source for ultra-high pressure sample introduction

Abstract

The utility model provides a mass spectrum ion source for ultrahigh air pressure sample introduction, which is suitable for ultrahigh air pressure (the air pressure is 100 MPa level) scenes, and comprises a conduction optical fiber, a laser, a capillary tube, an ionization chamber and an ion lens, a conduction optical fiber is arranged in the capillary tube, and a filling layer is arranged in an annular space between the conduction optical fiber and the inner wall of the capillary tube; the tube wall of the capillary tube is made of a high-pressure permeable material; one end of the capillary tube extends into the ionization chamber and is communicated with a sample inlet of the ionization chamber; a nano-silver coating layer is arranged at the end part of the conductive optical fiber at the end; positive high voltage is provided for the nano-silver coating layer by a positive high-voltage electrode; the laser is used for emitting laser to the conduction optical fiber, and the conduction optical fiber is used for guiding the laser to reach the nano-silver coating layer; a magnet for providing a magnetic field is arranged outside the ionization chamber; and an ion lens is arranged at a sample outlet of the ionization chamber.

Description

Technical Field

[0001] The utility model relates to a mass spectrometry ion source, in particular to a mass spectrometry ion source for sampling in an ultra-high pressure environment, belonging to the technical field of mass spectrometry. Background Art

[0002] Existing mass spectrometry technology is widely used for online measurement of gases in industrial pipelines. Mass spectrometry requires an ion source based on principles such as EI, CI, and PEI as its ionization method. The ion source also serves as the interface between the sample inlet and the high vacuum inside the mass spectrometer. Improper interface design can cause ion spectrum distortion or contamination at best, or even damage the vacuum or even destroy the instrument at worst. Gas pressures in industrial pipelines can reach MPa or even hundreds of MPa, making mass spectrometry measurement challenging.

[0003] The conventional method for mass spectrometry measurements on industrial pressure pipelines is pressure relief measurement, which involves releasing the ultra-high pressure to atmospheric pressure and then using an auxiliary high-vacuum pump to evacuate the pressure to a vacuum level below 0.1 Pa. This method loses in-situ information, reducing the reliability of the measurement results. Furthermore, it is bulky and power-intensive, hindering the miniaturization and integration of instrumentation.

[0004] In addition, most existing ion sources use a gas chamber plus filament structure, which has high requirements for environmental vacuum and small sample injection volume, and cannot be applied to ultra-high pressure (gas pressure of 100 MPa level) scenarios. Utility Model Content

[0005] In view of this, the utility model provides a mass spectrometry ion source for ultra-high pressure sampling, which is suitable for ultra-high pressure scenarios (pressure is at the level of hundreds of MPa). It can pass ultra-high pressure molecules into the ionization chamber through a capillary with a specially designed structure, generate charged ions in the ionization chamber, and provide a stable and high-intensity original signal for subsequent mass spectrometry detection, thereby improving the mass spectrometry detection limit and detection accuracy.

[0006] The technical solution of the utility model is: a mass spectrometry ion source for ultra-high pressure injection, comprising: a transmission optical fiber, a laser, a capillary, an ionization chamber and an ion lens;

[0007] A conducting optical fiber is provided inside the capillary tube, and a filling layer is provided in the annular space between the conducting optical fiber and the inner wall of the capillary tube; the tube wall of the capillary tube is made of a high-pressure permeable material;

[0008] One end of the capillary extends into the interior of the ionization chamber and is connected to the sample inlet of the ionization chamber; and a nano-silver coating is provided at the end of the conductive optical fiber at this end; the nano-silver coating is provided with a positive high voltage by the positive high-voltage electrode;

[0009] The laser is used to emit laser light to the transmission optical fiber, and the transmission optical fiber is used to guide the laser light to the nano silver coating;

[0010] A magnet for providing a magnetic field is arranged outside the ionization chamber; and an ion lens is arranged at the sample outlet of the ionization chamber.

[0011] As a preferred embodiment of the present invention, a fiber collimator is further included to adjust the light output angle of the laser.

[0012] As a preferred embodiment of the present invention, the outer wall of the conductive optical fiber has an optical fiber reflective coating.

[0013] As a preferred embodiment of the present invention, the filling layer is silicon dioxide.

[0014] As a preferred embodiment of the present invention, the conductive optical fiber, the nano-silver coating and the ion focusing hole of the ion lens are coaxial.

[0015] Beneficial effects:

[0016] (1) The ion source of the utility model adopts the method of penetrating material + laser irradiation + high voltage discharge to allow ultra-high pressure molecules to enter the ionization chamber through a capillary with a specially designed structure, and generate charged ions in the ionization chamber, providing a stable and high-intensity original signal for subsequent mass spectrometry detection, thereby improving the mass spectrometry detection limit and detection accuracy; the ion source can work stably under an ultra-high pressure of 100MPa.

[0017] (2) In the present invention, the optical fiber collimator is used to change the laser light angle and thus the optical path, thereby reducing the number of laser reflections in the transmission optical fiber.

[0018] (3) In the present invention, the outer wall of the conducting optical fiber has an optical fiber reflective coating, which can prevent the laser from scattering out of the optical fiber and preserve the energy of the laser as much as possible.

[0019] (4) In the present invention, the laser, the nano silver coating with positive high voltage and the ion focusing hole of the ion lens are in the same straight line, which can effectively accelerate the ions and guide the ion flow into the ultra-high vacuum environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a schematic diagram of the use of the mass spectrometry ion source of the present invention;

[0021] Figure 2 A cross-sectional view of the ion source of the present invention;

[0022] Figure 3 It is a cross-sectional view of the capillary tube of the present invention.

[0023] Among them: 1-fiber collimator, 2-conduction fiber, 3-fiber reflective coating, 4-filling layer, 5-nanosilver coating, 6-capillary, 7-positive high-voltage electrode, 8-magnet, 9-ion lens, 10-ionization chamber. DETAILED DESCRIPTION

[0024] The present invention will be described in further detail below with reference to the accompanying drawings and embodiments.

[0025] This embodiment provides a mass spectrometry ion source for ultra-high pressure injection, which adopts the method of permeable material + laser irradiation + high-voltage discharge to allow ultra-high pressure molecules to enter the ionization chamber through a specially designed capillary, generate charged ions in the ionization chamber, and provide a stable and high-intensity original signal for subsequent mass spectrometry detection, thereby improving the mass spectrometry detection limit and detection accuracy.

[0026] like Figure 1-Figure 3 As shown, the mass spectrometry ion source includes: a fiber collimator 1, a transmission fiber 2, a laser, a capillary 6, an ionization chamber 10 and an ion lens 9; wherein one end of the capillary 6 extends into the interior of the ionization chamber 10 and is connected to the sample inlet of the ionization chamber 10.

[0027] The capillary tube 6 is made of a high-pressure permeable material, i.e., the wall of the capillary tube 6 is made of a high-pressure permeable material, such as Teflon. A conductive optical fiber 2 is coaxially arranged inside the capillary tube 6 (the conductive optical fiber 2 is the same length as the capillary tube 6). A filling layer 4 is provided in the annular space between the conductive optical fiber 2 and the inner wall of the capillary tube 6. The capillary tube 6 of this structural form can block the air pressure inside and outside the capillary tube 6 through the high-pressure permeable material (i.e., the high-pressure permeable material blocks the pressure difference between the inside and outside of the capillary tube 6, ensuring that the ion source has a lower air pressure in the ionization chamber 10 when the ion source is operating; due to the ultra-high air pressure outside, only a portion of the gas can penetrate into the capillary tube 6, and the air pressure inside and outside the capillary tube 6 is different). The external high-pressure gas penetrates the permeable material to reach the interior of the capillary tube 6 and passes through the filling layer 4 between the inner wall of the capillary tube 6 and the conductive optical fiber 2 to reach the ionization chamber 10.

[0028] The filling layer 4 is used to support the conducting optical fiber 2 inside the capillary tube 6 and increase the air resistance inside the tube. As an example, the filling layer 4 is made of high-purity silica.

[0029] Opposite to the other open end of the capillary 6, a fiber collimator 1 and a laser are provided. The fiber collimator 1 is used to adjust the light output angle of the laser so that the laser light emitted by the laser enters the transmission fiber 2 inside the capillary 6. By changing the laser light input angle through the fiber collimator 1, the light path is changed, and the number of laser reflections in the transmission fiber 2 is reduced. Figure 1 As shown, the laser light emitted by the laser is reflected by the fiber collimator 1 and horizontally enters the transmission fiber 2 inside the capillary 6. The outer wall of the transmission fiber 2 has a fiber reflection coating 3 to prevent the laser light from scattering out of the fiber and to preserve the laser energy as much as possible.

[0030] The end of the transmission fiber 2 located within the ionization chamber 10 is coated with a nanosilver coating 5. This serves to guide the laser light to the nanosilver coating 5. The nanosilver coating 5 exhibits both excellent light transmittance, ensuring that the laser energy reaches the ionization chamber 10 intact, and excellent electrical conductivity, ensuring high-voltage discharge and ion-guiding properties. During operation, a positive high-voltage electrode 7 supplies the nanosilver coating 5 with a positive voltage.

[0031] A magnet 8 for providing a magnetic field is provided outside the ionization chamber 10. Under the action of the magnetic field, the ion beam inside the ionization chamber 10 performs a spiral motion in the ionization region, increasing the probability of collision with neutral gas molecules, thereby ensuring ionization efficiency.

[0032] The sample outlet of the ionization chamber 10 is provided with an ion lens 9, which is used to focus ions, form an ion flow, exclude neutral particles, and reduce background noise.

[0033] Preferably, the conducting optical fiber 2, the nanosilver coating 5 and the ion focusing hole of the ion lens 9 are coaxial, and the laser, the nanosilver coating 5 with positive high voltage and the ion focusing hole of the ion lens 9 are in the same straight line, which can effectively accelerate the ions and guide the ion flow into the ultra-high vacuum environment.

[0034] The ion source can operate stably under an ultra-high gas pressure of 100 MPa. At the same time, the structure can effectively improve the ionization efficiency, thereby providing a higher original signal and improving the detection limit and detection accuracy of the mass spectrometer.

[0035] Although the present invention has been described in detail above using general descriptions and specific embodiments, it will be apparent to those skilled in the art that modifications or improvements may be made to the present invention. Therefore, such modifications or improvements, without departing from the spirit of the present invention, are within the scope of protection claimed herein.

Claims

1. A mass spectrometry ion source for ultra-high pressure injection, characterized in that: include: Transmission fiber (2), laser, capillary (6), ionization chamber (10) and ion lens (9); A conducting optical fiber (2) is provided inside the capillary tube (6), and a filling layer (4) is provided in the annular space between the conducting optical fiber (2) and the inner wall of the capillary tube (6); the tube wall of the capillary tube (6) is made of a high-pressure permeable material; One end of the capillary tube (6) extends into the interior of the ionization chamber (10) and is connected to the sample inlet of the ionization chamber (10); and a nano-silver coating (5) is provided at the end of the conductive optical fiber (2) at this end; the nano-silver coating (5) is provided with a positive high voltage by the positive high voltage electrode (7); The laser is used to emit laser light to the transmission optical fiber (2), and the transmission optical fiber (2) is used to guide the laser light to reach the nano silver coating (5); A magnet (8) for providing a magnetic field is provided outside the ionization chamber (10); and an ion lens (9) is provided at the sample outlet of the ionization chamber (10).

2. The mass spectrometry ion source for ultra-high pressure injection according to claim 1, wherein: It also includes a fiber collimator (1) for adjusting the light output angle of the laser.

3. The ultra-high pressure injection mass spectrometry ion source according to claim 1, wherein: The outer wall of the conducting optical fiber (2) is provided with an optical fiber reflection coating (3).

4. The ultra-high pressure injection mass spectrometry ion source according to any one of claims 1 to 3, characterized in that: The filling layer (4) is silicon dioxide.

5. The ultra-high pressure injection mass spectrometry ion source according to any one of claims 1 to 3, characterized in that: The conducting optical fiber (2), the nanosilver coating (5), and the ion focusing hole of the ion lens (9) are coaxial.

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