Spatially distributed double ionization source device

Abstract

The invention relates to a mass spectrometry instrument, in particular to a double-ionization-source device distributed in space. Comprising a double-opening electrode, an ionization source I, an ionization source II, a vacuum cavity, a rectangular rod group and a cylindrical rod group, one end of the vacuum cavity is provided with the double-opening electrode, and the other end of the vacuum cavity is provided with an ion output port; the double-hole electrode is provided with two circular through holes, the ionization source I and the ionization source II are arranged at the outer side ends of the two circular through holes of the double-hole electrode respectively, and the rectangular rod set and the cylindrical rod set are sequentially arranged in the vacuum cavity at intervals in the ion conveying direction. Direct-current voltage is applied to the double-hole electrode, the rectangular electrode stem group and the cylindrical electrode stem group and is gradually reduced in sequence, and radio-frequency voltage is also applied to the rectangular electrode stem group and the cylindrical electrode stem group. Combination of multiple different ionization sources is achieved, so that samples can be ionized in different ionization modes, the qualitative ability is greatly enhanced, and the application range is effectively widened.

Description

Technical Field

[0001] The invention relates to a mass spectrometer, in particular to a dual ionization source device distributed in space. Background Art

[0002] In the field of complex environmental analysis, soft ionization source technology has become a highly respected analytical method due to its excellent high-molecular ion output efficiency and convenience of spectral analysis. Despite this, the current application scope of various soft ionization sources faces certain limitations. Specifically, the photoionization technology using commercial Kr lamps as light sources has significantly limited ionization efficiency when dealing with substances with low photoionization cross-sections or required ionization energies exceeding 10.6eV; while proton transfer ionization technology performs poorly for compounds with proton affinity lower than that of water molecules. More importantly, in the key analytical link of identifying isomers, soft ionization sources lack the ability to directly obtain structural information, and there is a potential risk of misjudgment. In comparison, although electron bombardment ionization technology has the ability to provide fragment ion information, when faced with complex environmental samples, the problems of increased complexity in spectrum analysis and decreased sensitivity have seriously restricted the application and promotion of this technology in a wider range of fields. Summary of the invention

[0003] In view of the above problems, the object of the present invention is to provide a dual ionization source device distributed in space to solve the problem that a single ionization source has insufficient information acquisition and a narrow application range.

[0004] In order to achieve the above object, the present invention adopts the following technical solutions:

[0005] The present invention provides a spatially distributed dual ionization source device, comprising a dual-aperture electrode, an ionization source I, an ionization source II, a vacuum chamber, a rectangular rod group and a cylindrical rod group, wherein one end of the vacuum chamber is provided with a dual-aperture electrode, and the other end is provided with an ion output port;

[0006] The double-opening electrode has two circular through holes, and the ionization source I and the ionization source II are respectively arranged at the outer ends of the two circular through holes of the double-opening electrode, and the rectangular rod group and the cylindrical rod group are sequentially arranged in the vacuum chamber at intervals along the ion transport direction;

[0007] A direct current voltage is applied to the double-opening electrode, the rectangular electrode rod group and the cylindrical electrode rod group in a decreasing order, and a radio frequency voltage is also applied to the rectangular electrode rod group and the cylindrical electrode rod group.

[0008] The double-opening electrode is a conical structure protruding outward, and the conical structure is coaxial with the ion output port;

[0009] The two circular through holes have a horizontal plane passing through the apex of the double-aperture electrode as a symmetry plane, and the central axes of the two circular through holes are located on the same plane as the apex of the double-aperture electrode and the axial center line of the ion output port.

[0010] The thickness of the double-opening electrode is 2-4 mm; the diameter of the circular through hole is 1-2 mm.

[0011] The ionization source I and the ionization source II are respectively located in the central axis direction of the two circular through holes of the double-opening electrode, and are connected to the outer surface of the double-opening electrode.

[0012] The rectangular rod group includes at least four rectangular electrode rods uniformly distributed along the circumferential direction and arranged parallel to the axis of the double-opening electrode, and the number of the rectangular electrode rods is an even number.

[0013] In the cross section of the rectangular rod group, the centers of the plurality of rectangular electrode rods are located on the same circumference A; the wide surface of each rectangular electrode rod is perpendicular to the line connecting the center of the circumference A and the center point of the rectangular electrode rod on the circumference A.

[0014] The cylindrical rod group comprises at least four cylindrical electrode rods uniformly distributed along the circumferential direction and arranged parallel to the axis of the double-opening electrode, and the number of the cylindrical electrode rods is an even number;

[0015] In the cross section of the cylindrical rod group, the centers of the plurality of cylindrical rod groups are located on the same circumference B, and the radius of the circumference B is smaller than the radius of the circumference A.

[0016] The dimensions of the rectangular electrode rods in the rectangular electrode rod group are consistent, with a length of 10-30 mm, a width of 5-15 mm, a thickness of 2-6 mm, and a radius of circle A of 10-20 mm;

[0017] The dimensions of the cylindrical electrode rods in the cylindrical electrode rod group are consistent, with a length of 60-120 mm, a radius of 4-8 mm, and a radius of circle B of 10-15 mm;

[0018] The electrodes in the double-opening electrode, the rectangular electrode rod group and the cylindrical electrode rod group are made of conductive metal or are plated with a conductive metal layer.

[0019] The DC voltages applied to the double-aperture electrode, the rectangular electrode rod group, and the cylindrical electrode rod group are sequentially reduced to form a DC gradient electric field, and the gradient voltage is 1-20 V / cm;

[0020] The RF peak-to-peak amplitudes applied to each two adjacent rectangular electrode rods in the rectangular electrode rod group are equal and opposite in phase; the RF peak-to-peak amplitudes applied to each two adjacent cylindrical electrode rods in the cylindrical electrode rod group are equal and opposite in phase; the applied RF frequency is 0.5-5MHz, and the RF peak-to-peak value is 10-500V.

[0021] The vacuum chamber is a horizontally placed rectangular cylindrical structure; a vacuum exhaust port is provided on the lower side wall of the vacuum chamber near the ion output port, and the exhaust port is externally connected to a vacuum pump for maintaining the vacuum in the vacuum chamber. The air pressure in the vacuum chamber is maintained between 0.1-2Pa.

[0022] The advantages and beneficial effects of the present invention are as follows: the present invention provides a spatially distributed dual ionization source device, which realizes efficient focusing transmission of a wide range of ions after the ionization source through the combination of short quadrupole rectangular rods and quadrupole cylindrical rods, thereby ensuring the sensitivity of the spatially distributed dual ionization source. In addition, the gas pressures between the two spatially distributed ionization sources are independent of each other, so a combination of multiple different ionization sources can be realized, so that samples can be ionized in different ionization modes, greatly enhancing the qualitative ability and effectively broadening the scope of application. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic structural diagram of a spatially distributed dual ionization source device of the present invention;

[0024] Figure 2 It is the transmission efficiency result of ions of m / z 100 after the ionization source in the SIMION simulation in the embodiment of the present invention.

[0025] In the figure: 1-double-opening electrode, 2-ionization source I, 3-ionization source II, 4-vacuum chamber, 5-rectangular rod group, 6-cylindrical rod group, 7-ion output port, 8-vacuum exhaust port. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0027] See also Figure 1As shown, the present invention provides a spatially distributed dual ionization source device, comprising a dual-aperture electrode 1, an ionization source I2, an ionization source II3, a vacuum chamber 4, a rectangular rod group 5 and a cylindrical rod group 6, wherein one end of the vacuum chamber 4 is provided with the dual-aperture electrode 1, and the other end is provided with an ion output port 7; the dual-aperture electrode 1 has two circular through holes, the ionization source I2 and the ionization source II3 are respectively arranged at the outer ends of the two circular through holes of the dual-aperture electrode 1, and the rectangular rod group 5 and the cylindrical rod group 6 are sequentially arranged in the vacuum chamber 4 along the ion transport direction; a DC voltage is applied to the dual-aperture electrode 1, the rectangular electrode rod group 5 and the cylindrical electrode rod group 6 and decreases in sequence, and a radio frequency voltage is also applied to the rectangular electrode rod group 5 and the cylindrical electrode rod group 6.

[0028] In the embodiment of the present invention, the vacuum chamber 4 is a horizontally placed rectangular cylindrical structure; a vacuum exhaust port 8 is provided on the lower side wall of the vacuum chamber 4 near the ion output port 7, and the exhaust port 8 is externally connected to a vacuum pump to maintain the vacuum in the vacuum chamber 4. The air pressure in the vacuum chamber 4 is maintained between 0.1-2Pa.

[0029] join Figure 1 As shown, in the embodiment of the present invention, the double-aperture electrode 1 is a conical structure protruding outward, and the conical structure is coaxial with the ion output port 7; the apex of the cone of the double-aperture electrode 1 faces left, the central axis of the two circular through holes is perpendicular to the outer wall of the double-aperture electrode 1, the two circular through holes use the horizontal plane passing through the apex of the double-aperture electrode 1 as the symmetry plane, and the central axis of the two circular through holes and the apex of the double-aperture electrode 1 and the axial center line of the ion output port 7 are located on the same plane.

[0030] Preferably, the thickness of the double-opening electrode 1 is 2-4 mm; and the diameter of the circular through hole is 1-2 mm.

[0031] In the embodiment of the present invention, the ionization source I2 and the ionization source II3 are respectively located in the central axis direction of the two circular through holes of the double-aperture electrode 1, and are connected to the outer surface of the double-aperture electrode 1. Specifically, the gas pressures of the ionization source I2 and the ionization source II3 are independent of each other, and can be a photoionization source, a proton transfer ionization source, an electron bombardment ionization source, etc.

[0032] join Figure 1 As shown, in the embodiment of the present invention, the rectangular rod group 5 includes at least four rectangular electrode rods uniformly distributed along the circumferential direction and arranged parallel to the axis of the double-opening electrode 1, and the number of the rectangular electrode rods is an even number. One end surface of each rectangular electrode rod is respectively located close to the double-opening electrode 1 and has a gap with the double-opening electrode 1, and the other end surface of each rectangular electrode rod is respectively located away from the double-opening electrode 1.

[0033] Specifically, in the cross section of the rectangular rod group 5 , the centers of the multiple rectangular electrode rods are located on the same circumference A; the wide surface of each rectangular electrode rod is perpendicular to the center of the circumference A and the line connecting the center point of the rectangular electrode rod on the circumference A.

[0034] join Figure 1 As shown, in the embodiment of the present invention, the cylindrical rod group 6 includes at least four cylindrical electrode rods uniformly distributed along the circumferential direction and arranged parallel to the axis of the double-aperture electrode 1, and the number of cylindrical electrode rods is an even number; in the cross section of the cylindrical rod group 6, the centers of the plurality of cylindrical rod groups 6 are located on the same circumference B, and the radius of the circumference B is smaller than the radius of the circumference A. One end face of each cylindrical electrode rod is respectively opposite to the other end face of a corresponding rectangular electrode rod and has a gap, and the other end face of each cylindrical electrode rod is located on a side close to the ion output port 7 and has a gap with the ion output port 7. Specifically, the plane where the circumference A is located and the plane where the circumference B is located are parallel to each other, and the apex of the double-aperture electrode 1, the center of the circumference A, the center of the circumference B and the axial center line of the ion output port 7 are all collinear.

[0035] Preferably, the dimensions of the rectangular electrode rods in the rectangular electrode rod group 5 are consistent, with a length of 10-30 mm, a width of 5-15 mm, a thickness of 2-6 mm, and a radius of circle A of 10-20 mm; the dimensions of the cylindrical electrode rods in the cylindrical electrode rod group 6 are consistent, with a length of 60-120 mm, a radius of 4-8 mm, and a radius of circle B of 10-15 mm; the electrodes in the double-opening electrode 1, the rectangular electrode rod group 5 and the cylindrical electrode rod group 6 are made of conductive metal or have a conductive metal layer plated on the surface.

[0036] In this embodiment, the DC voltages applied to the double-aperture electrode 1, the rectangular electrode rod group 5 and the cylindrical electrode rod group 6 are successively reduced to form a DC gradient electric field, and the gradient voltage is 1-20V / cm; the peak-to-peak amplitudes of the radio frequency applied to each two adjacent rectangular electrode rods in the rectangular electrode rod group 5 are equal and the phases are opposite; the peak-to-peak amplitudes of the radio frequency applied to each two adjacent cylindrical electrode rods in the cylindrical electrode rod group 6 are equal and the phases are opposite; the applied radio frequency frequency is 0.5-5MHz, and the radio frequency peak-to-peak value is 10-500V.

[0037] In this embodiment, the thickness of the double-aperture electrode 1 is 2mm; the diameter of the through hole is 1mm; the size of each rectangular electrode rod in the rectangular electrode rod group 5 is consistent, with a length of 20mm, a width of 10mm, a thickness of 4mm, and a radius of circumference A of 20mm; the size of each cylindrical electrode rod in the cylindrical electrode rod group 6 is consistent, with a length of 110mm, a radius of 6mm, and a radius of circumference B of 11mm; the electrodes in the double-aperture electrode 1, the rectangular electrode rod group 5, and the cylindrical electrode rod group 6 are stainless steel electrodes. The DC voltages applied to the double-aperture electrode 1, the rectangular electrode rod group 5, and the cylindrical electrode rod group 6 are 11V, 8V, and 3V, respectively; the peak-to-peak amplitudes of the radio frequency applied to each adjacent two rectangular electrode rods in the rectangular electrode rod group 5 are equal and opposite in phase; the peak-to-peak amplitudes of the radio frequency applied to each adjacent two cylindrical electrode rods in the cylindrical electrode rod group 6 are equal and opposite in phase; the applied radio frequency frequency is 1.0MHz, and the peak-to-peak value of the radio frequency is 200V. One end surface of each rectangular electrode rod is located in the same plane, and one end surface of each cylindrical electrode rod is located in the same plane.

[0038] Furthermore, a mass analyzer is provided outside the vacuum chamber 4, and the sample input end of the mass analyzer is connected to the ion output port 7. The mass analyzer is a time-of-flight mass analyzer, a quadrupole mass analyzer, an ion trap mass analyzer, a sector magnetic field mass analyzer or an ion cyclotron resonance mass analyzer. The gas pressures of the ionization source I2 and the ionization source II3 are independent of each other, and they are a photoionization source and a proton transfer ionization source.

[0039] The axial center lines of the two circular through holes on the double-aperture electrode 1 and the axial center line of the ion output port are located on the same plane; the plane where the circle A is located and the plane where the circle B is located are parallel to each other, and the vertex of the double-aperture electrode 1, the center of the circle A, the center of the circle B and the axial center line of the ion output port are all collinear; the air pressure in the vacuum chamber 4 is maintained at 1Pa.

[0040] Example

[0041] like Figure 1 As shown, the present invention provides a spatially distributed dual ionization source device. When working, the DC voltages applied to the double-aperture electrode 1, the rectangular electrode rod group 5 and the cylindrical electrode rod group 6 are 11V, 8V, and 3V respectively; the radio frequency applied to the rectangular electrode rod group 5 and the cylindrical electrode rod group 6 is 1.0MHz, the radio frequency peak-to-peak value is 200V, and the vacuum in the vacuum chamber 4 is maintained at 1Pa.

[0042] The transmission efficiency of the dual-source structure was simulated using SIMION software under the above conditions, such as Figure 2The mass-to-charge ratio of the ions used was 100, the number was 200, the ion incident angle was 45°, and the final transmission efficiency was 93%, indicating that the combination of short quadrupole rectangular rods and quadrupole cylindrical rods can achieve efficient focusing transmission of a wide range of ions after the ionization source, thereby ensuring the sensitivity of the spatially distributed dual ionization source.

[0043] In the present invention, the combination of short quadrupole rectangular rods and quadrupole cylindrical rods realizes efficient focusing transmission of wide range ions behind the ionization source, thereby ensuring the sensitivity of the spatially distributed dual ionization source. In addition, the gas pressures between the two spatially distributed ionization sources are independent of each other, so a combination of multiple different ionization sources can be realized, so that samples can be ionized in different ionization modes, greatly enhancing the qualitative ability and effectively broadening the scope of application.

[0044] The above description is only an embodiment of the present invention and is not intended to limit the protection scope of the present invention. Any modification, equivalent replacement, improvement, expansion, etc. made within the spirit and principle of the present invention are included in the protection scope of the present invention.

Claims

1. A spatially distributed dual ionization source device, characterized in that: It comprises a double-opening electrode (1), an ionization source I (2), an ionization source II (3), a vacuum chamber (4), a rectangular rod group (5) and a cylindrical rod group (6), wherein one end of the vacuum chamber (4) is provided with the double-opening electrode (1), and the other end is provided with an ion output port (7); The double-opening electrode (1) has two circular through holes, the ionization source I (2) and the ionization source II (3) are respectively arranged at the outer ends of the two circular through holes of the double-opening electrode (1), and the rectangular rod group (5) and the cylindrical rod group (6) are sequentially arranged at intervals in the vacuum chamber (4) along the ion transport direction; A direct current voltage is applied to the double-opening electrode (1), the rectangular electrode rod group (5) and the cylindrical electrode rod group (6) in a decreasing order, and a radio frequency voltage is also applied to the rectangular electrode rod group (5) and the cylindrical electrode rod group (6).

2. The spatially distributed dual ionization source device according to claim 1, characterized in that: The double-opening electrode (1) is a conical structure protruding outward, and the conical structure is coaxial with the ion output port (7); The two circular through holes have a horizontal plane passing through the apex of the double-aperture electrode (1) as a symmetry plane, and the central axes of the two circular through holes are located on the same plane as the apex of the double-aperture electrode (1) and the axial center line of the ion output port (7).

3. The spatially distributed dual ionization source device according to claim 2, characterized in that: The thickness of the double-opening electrode (1) is 2-4 mm; the diameter of the circular through hole is 1-2 mm.

4. The spatially distributed dual ionization source device according to claim 2, characterized in that: The ionization source I (2) and the ionization source II (3) are respectively located in the central axis direction of the two circular through holes of the double-opening electrode (1), and are connected to the outer surface of the double-opening electrode (1).

5. The spatially distributed dual ionization source device according to claim 2, characterized in that: The rectangular rod group (5) comprises at least four rectangular electrode rods which are evenly distributed along the circumferential direction and arranged parallel to the axis of the double-opening electrode (1), and the number of the rectangular electrode rods is an even number.

6. The spatially distributed dual ionization source device according to claim 5, characterized in that: In the cross section of the rectangular rod group (5), the centers of the plurality of rectangular electrode rods are located on the same circumference A; the wide surface of each rectangular electrode rod is perpendicular to the line connecting the center of the circumference A and the center point of the rectangular electrode rod on the circumference A.

7. The spatially distributed dual ionization source device according to claim 6, characterized in that: The cylindrical rod group (6) comprises at least four cylindrical electrode rods uniformly distributed along the circumferential direction and arranged parallel to the axis of the double-opening electrode (1), and the number of the cylindrical electrode rods is an even number; In the cross section of the cylindrical rod group (6), the centers of the plurality of cylindrical rod groups (6) are located on the same circumference B, and the radius of the circumference B is smaller than the radius of the circumference A.

8. The spatially distributed dual ionization source device according to claim 7, characterized in that: The dimensions of the rectangular electrode rods in the rectangular electrode rod group (5) are consistent, with a length of 10-30 mm, a width of 5-15 mm, a thickness of 2-6 mm, and a radius of the circle A of 10-20 mm; The dimensions of the cylindrical electrode rods in the cylindrical electrode rod group (6) are consistent, with a length of 60-120 mm, a radius of 4-8 mm, and a radius of circle B of 10-15 mm; The electrodes in the double-opening electrode (1), the rectangular electrode rod group (5) and the cylindrical electrode rod group (6) are made of conductive metal or have a conductive metal layer plated on their surfaces.

9. The spatially distributed dual ionization source device according to claim 7, characterized in that: The DC voltages applied to the double-aperture electrode (1), the rectangular electrode rod group (5) and the cylindrical electrode rod group (6) are sequentially reduced to form a DC gradient electric field, and the gradient voltage is 1-20 V / cm; The radio frequency peak-to-peak amplitudes applied to each two adjacent rectangular electrode rods in the rectangular electrode rod group (5) are equal and the phases are opposite; the radio frequency peak-to-peak amplitudes applied to each two adjacent cylindrical electrode rods in the cylindrical electrode rod group (6) are equal and the phases are opposite; the applied radio frequency frequency is 0.5-5MHz, and the radio frequency peak-to-peak value is 10-500V.

10. The spatially distributed dual ionization source device according to claim 1, characterized in that: The vacuum chamber (4) is a horizontally placed rectangular cylindrical structure; a vacuum exhaust port (8) is provided on the lower side wall of the vacuum chamber (4) close to the ion output port (7); the exhaust port (8) is externally connected to a vacuum pump for maintaining the vacuum in the vacuum chamber (4); and the air pressure in the vacuum chamber (4) is maintained between 0.1 and 2 Pa.

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