High-field asymmetric waveform ion mobility spectrometry analyzer

Abstract

The utility model discloses a high-field asymmetric waveform ion mobility spectrometry analyzer, which comprises a compensation voltage polar plate, a separation voltage polar plate, a curtain voltage polar plate and a gas channel for introducing gas, and is characterized in that the separation voltage polar plate is positioned on the inner side of the compensation voltage polar plate; a runway-shaped gap area is formed between the first gap and the second gap, the runway-shaped gap area is formed by sequentially communicating four gaps, the four gaps are sequentially named as a first gap, a second gap, a third gap and a fourth gap, and the first gap and the third gap are semi-circular-ring-shaped gaps with semi-circular-ring-shaped sections in the vertical direction and are arranged in a bilateral symmetry mode; the second gap and the fourth gap are cuboid structure gaps and are symmetrically arranged up and down, the gas channel is communicated with the first gap, and the third gap is communicated with the outside; the utility model has the advantages of high sensitivity and high resolution.

Description

Technical Field

[0001] The utility model relates to the technology of high-field asymmetric waveform ion mobility spectrometry analyzers, and in particular to a high-field asymmetric waveform ion mobility spectrometry analyzer. Background Art

[0002] In living organisms, the properties, functions, and activities of biomolecules are closely related to their three-dimensional structures. Biomolecules with different structures may play completely different roles in living organisms. Therefore, accurately separating and analyzing the isomers of biomolecules is crucial for life science research. To this end, researchers have invented a variety of molecular structure separation and analysis techniques. Among these techniques, high-field asymmetric waveform ion mobility spectrometry technology has developed rapidly and been widely used in recent years due to its high sensitivity to molecular structure differences.

[0003] According to structural differences, existing high-field asymmetric waveform ion mobility spectrometry analyzers can be mainly divided into cylindrical and flat types. Among them, a cylindrical high-field asymmetric waveform ion mobility spectrometry analyzer mainly consists of two coaxial cylindrical electrodes with different diameters. By applying a separation voltage of a specific polarity to the two coaxial cylindrical electrodes of the cylindrical high-field asymmetric waveform ion mobility spectrometry analyzer, a non-uniform high-voltage asymmetric electric field that focuses on specific types of ions can be formed, while other types of ions will diverge. In a cylindrical high-field asymmetric waveform ion mobility spectrometry analyzer, the types of focused or divergent ions will change with the change of the polarity of the high-voltage asymmetric electric field. For the focused ions, after entering the cylindrical high-field asymmetric waveform ion mobility spectrometry analyzer, all such ions can pass through the cylindrical high-field asymmetric waveform ion mobility spectrometry analyzer, so it has extremely high sensitivity. However, also due to the focusing effect, when the cylindrical high-field asymmetric waveform ion mobility spectrometry analyzer separates ions with different structures, the peak width is extremely wide, and it is very easy for different peaks to overlap, so the resolution is insufficient. A flat high-field asymmetric waveform ion mobility spectrometry analyzer mainly consists of two parallel planar electrodes. When a separation voltage of a specific polarity is applied to the two planar electrodes, a uniform high-voltage asymmetric electric field can be established, avoiding the focusing effect. Therefore, the spectral peaks obtained by the flat high-field asymmetric waveform ion mobility spectrometry analyzer are narrower, and the resolution is much higher than that of the cylindrical high-field asymmetric waveform ion mobility spectrometry analyzer. However, due to the lack of focusing force to counteract the Coulomb repulsion and thermal diffusion during the separation process, ions initially close to the two planar electrodes of the flat high-field asymmetric waveform ion mobility spectrometry analyzer are very likely to collide with the two planar electrodes and be lost, making its sensitivity much lower than that of the cylindrical high-field asymmetric waveform ion mobility spectrometry analyzer. Summary of the Utility Model

[0004] The technical problem to be solved by the utility model is to provide a high-field asymmetric waveform ion mobility spectrometry analyzer with both high sensitivity and high resolution.

[0005] The technical solution adopted by the present utility model to solve the above technical problems is as follows: A high-field asymmetric waveform ion mobility spectrometry analyzer includes a compensation voltage plate for accessing a scanning voltage, a separation voltage plate for accessing a separation voltage, a curtain voltage plate for accessing a curtain voltage, and a gas channel for introducing gas. The separation voltage plate is located inside the compensation voltage plate, and a racetrack-shaped gap region is formed between the two. The racetrack-shaped gap region is formed by four gaps connected in sequence. The four gaps are sequentially referred to as the first gap, the second gap, the third gap, and the fourth gap. The first gap and the third gap are both semi-circular ring-shaped gaps with a semi-circular ring cross-section in the up-down direction, and they are symmetrically arranged left and right. The second gap and the fourth gap are both rectangular structure gaps, and they are symmetrically arranged up and down. The gas channel is connected to the first gap, and the third gap communicates with the outside. When the curtain voltage plate accesses the curtain voltage, the separation voltage plate accesses the separation voltage, the compensation voltage plate accesses the scanning voltage, and the gas channel introduces gas, when the electrospray ionization source is working, there is a potential difference between the curtain voltage plate and the electrospray ionization source, which will generate a DC electric field, and this DC electric field is called the first DC electric field. There is a potential difference between the curtain voltage plate and the compensation voltage plate, which will generate a DC electric field, and this DC electric field is called the second DC electric field. The separation voltage plate will generate a high-voltage asymmetric electric field, and the compensation voltage plate will generate a DC electric field that changes with the scanning voltage it accesses, and this DC electric field is called the third DC electric field. When the electrospray ionization source generates a charged droplet spray, after the charged droplet spray is dried by the gas, gas-phase ions are formed. The gas-phase ions move to the gas channel under the action of the first DC electric field. At this time, the second DC electric field and the gas act on the gas-phase ions together, pushing the gas-phase ions into the first gap. The high-voltage asymmetric electric field and the third DC electric field act on the gas-phase ions at the first gap together, focusing the gas-phase ions to the middle region in the radial direction of the semi-circular ring cross-section of the first gap, and then the gas at the first gap pushes the focused gas-phase ions to the second gap and the fourth gap. The high-voltage asymmetric electric field causes the gas-phase ions at the second gap and the fourth gap to deflect in the up-down direction, and the third DC electric field compensates for the deflection of the gas-phase ions corresponding to the scanning voltage, pulling the deflected gas-phase ions back to the middle region in the up-down direction of the second gap and the fourth gap. The gas at the second gap and the fourth gap pushes the compensated gas-phase ions to the third gap. The high-voltage asymmetric electric field and the third DC electric field act on the gas-phase ions at the third gap together, causing the gas-phase ions to be focused and then escape.

[0006] The compensation voltage electrode plate and the separation voltage electrode plate are formed by opening a racetrack-shaped cavity in a rectangular parallelepiped metal plate, which is called the first metal plate. The first metal plate is divided into two independent parts. The part located on the outside is the compensation voltage electrode plate, and the part located on the inside is the separation voltage electrode plate. The length direction of the first metal plate is along the left-right direction, the width direction is along the front-back direction, and the thickness direction is along the up-down direction. The racetrack-shaped cavity runs through the first metal plate from front to back. The front and rear parts of the racetrack-shaped cavity are filled with fillers. A racetrack-shaped gap region is formed between the racetrack-shaped cavity and the fillers in its front and rear parts. The length directions of the second gap and the fourth gap are both along the left-right direction, the width directions are both along the front-back direction, and the thickness directions are both along the up-down direction. The width directions of the first gap and the third gap are both along the front-back direction, and the thickness directions are along the radial directions of their semi-circular cross-sections respectively.

[0007] The curtain voltage electrode plate includes a second metal plate and a third metal plate. The second metal plate 10 is of a rectangular parallelepiped structure, and the third metal plate is of a cylindrical structure. The length direction of the second metal plate is along the front-back direction, the width direction is along the up-down direction, and the thickness direction is along the left-right direction. The axial direction of the third metal plate is along the left-right direction. The third metal plate is located on the right side of the second metal plate. The left end face of the third metal plate is fixed and in contact with the right end face of the second metal plate. The diameter of the third metal plate is smaller than the smaller of the length and width of the second metal plate. The central axis of the third metal plate and the center line of the second metal plate along the left-right direction are on the same straight line. The first cylindrical hole is opened on the second metal plate and the third metal plate. The second cylindrical hole is opened on the third metal plate. The first cylindrical hole and the second cylindrical hole are both coaxial with the third metal plate and have diameters smaller than that of the third metal plate. The left end face of the first cylindrical hole is flush with the left end face of the second metal plate. The second cylindrical hole is located on the right side of the first cylindrical hole. The diameter of the second cylindrical hole is smaller than that of the first cylindrical hole. The left end face of the second cylindrical hole is connected and in contact with the right end face of the first cylindrical hole. The right end face of the second cylindrical hole is flush with the right end face of the third metal plate. The right end face of the second cylindrical hole communicates with the gas channel. The gas entering through the gas channel can sequentially enter the second cylindrical hole and the first cylindrical hole and escape through the first cylindrical hole.

[0008] The described high-field asymmetric waveform ion mobility spectrometry analyzer further includes a first housing and a second housing. The first housing is located on the right side of the second metal plate. The first housing has a cuboid structure, with its length direction along the front-back direction, width direction along the up-down direction, and thickness direction along the left-right direction. The upper end surface of the first housing and the upper end surface of the second metal plate are in the same plane. The lower end surface of the first housing and the lower end surface of the second metal plate are in the same plane. The front end surface of the first housing and the front end surface of the second metal plate are in the same plane. The rear end surface of the first housing and the rear end surface of the second metal plate are in the same plane. The left end surface of the first housing and the right end surface of the second metal plate are fixed and in a fitting state. The first housing is provided with the gas channel. The gas channel is a cylindrical hole that penetrates from left to right. The third metal plate is located inside the gas channel and they are coaxial. The right end surface of the third metal plate is located on the left side of the right end surface of the gas channel. An air inlet for communicating the gas channel with the outside is respectively opened at the upper and lower ends of the first housing. The diameter of the gas channel is larger than the diameter of the third metal plate and smaller than the smaller value of the length and width of the first housing;The second housing is located on the right side of the first housing. The second housing is in a cuboid structure, with its length direction along the left-right direction, width direction along the front-back direction, and thickness direction along the up-down direction. The upper end face of the second housing and the upper end face of the first housing are in the same plane. The lower end face of the second housing and the lower end face of the first housing are in the same plane. The front end face of the second housing and the front end face of the first housing are in the same plane. The rear end face of the second housing and the rear end face of the first housing are in the same plane. The left end face of the second housing is fixed and in a fitting state with the right end face of the first housing. The second housing has a cuboid cavity that penetrates from left to right, with its length direction along the left-right direction, width direction along the front-back direction, and thickness direction along the up-down direction. The cuboid cavity is docked with the gas passage. The thickness and width of the cuboid cavity are both greater than the diameter of the gas passage. The first metal plate is located within the cuboid cavity. The left end face of the first metal plate is flush with the left end face of the cuboid cavity. The length of the first metal plate is equal to the length of the cuboid cavity, the width is equal to the width of the cuboid cavity, and the thickness is equal to the thickness of the cuboid cavity. A third cylindrical hole is formed in the first metal plate, extending from its left end face to communicate with the first gap. A fourth cylindrical hole is formed in the first metal plate, extending from its right end face to communicate with the third gap. The third cylindrical hole, the fourth cylindrical hole, and the second cylindrical hole are coaxial, and the ratio of the circular cross-sectional area of the third cylindrical hole to the circular cross-sectional area of the second cylindrical hole is 3:7.;

[0009] A first protrusion protruding toward the rear side is arranged on the front end surface of the rectangular cavity, and the first protrusion is runway-shaped. The shape and size of the first protrusion are the same as those of the runway-shaped cavity, except that the width in the front-to-back direction is less than 5% of the width of the runway-shaped cavity in the front-to-back direction. A second protrusion protruding toward the front side is arranged on the rear end surface of the rectangular cavity, and the first protrusion and the second protrusion are symmetrical front to back and face the runway-shaped cavity. The first protrusion is embedded in the runway-shaped cavity from front to back as a filler in the front part of the runway-shaped cavity, and the second protrusion is embedded in the runway-shaped cavity from back to front as a filler in the rear part of the runway-shaped cavity, thereby closing the front-to-back direction of the runway-shaped cavity and forming the runway-shaped gap area. In this structure, the first protrusion and the second protrusion can prevent the gas from carrying gas-phase ions and at the same time ensure that the width of the racetrack-shaped gap area in the front-to-back direction remains consistent at any point, thereby avoiding the difference in the width of the racetrack-shaped gap area in the front-to-back direction, which causes the gas-phase ions to change their offset distances at the second gap and the fourth gap due to the high-voltage asymmetric electric field, so that the third DC electric field cannot effectively compensate for the offset of the gas-phase ions corresponding to the scanning voltage, thereby affecting the sensitivity of the analyzer connected to the high-field asymmetric waveform ion mobility spectrometer.

[0010] The gas is either nitrogen or a mixed gas formed by mixing nitrogen with at least one of hydrogen, helium and water vapor in any proportion.

[0011] Compared with the prior art, the advantages of the high-field asymmetric waveform ion mobility spectrometry analyzer of the present utility model are as follows: By arranging the separation voltage electrode plate inside the compensation voltage electrode plate, a racetrack-shaped gap region is formed between the two. The racetrack-shaped gap region is formed by connecting four gaps in sequence. The four gaps are sequentially referred to as the first gap, the second gap, the third gap, and the fourth gap. Both the first gap and the third gap are semi-annular gaps with a semi-circular ring cross-section in the up-down direction, and they are symmetrically arranged left and right. Both the second gap and the fourth gap are rectangular parallelepiped structure gaps, and they are symmetrically arranged up and down. The gas channel is connected to the first gap, and the third gap communicates with the outside. When the curtain voltage electrode plate is connected to the curtain voltage, the separation voltage electrode plate is connected to the separation voltage, the compensation voltage electrode plate is connected to the scanning voltage, and the gas channel introduces gas, when the electrospray ion source is working, there is a potential difference between the curtain voltage electrode plate and the electrospray ion source, and a DC electric field will be generated. This DC electric field is called the first DC electric field. There is a potential difference between the curtain voltage electrode plate and the compensation voltage electrode plate, and a DC electric field will be generated. This DC electric field is called the second DC electric field. The separation voltage electrode plate will generate a high-voltage asymmetric electric field, and the compensation voltage electrode plate will generate a DC electric field that changes with the scanning voltage connected thereto. This DC electric field is called the third DC electric field. When the electrospray ion source generates a charged droplet spray, after the charged droplet spray is dried by the gas, gas-phase ions are formed. The gas-phase ions move to the gas channel under the action of the first DC electric field. At this time, the second DC electric field and the gas act on the gas-phase ions together, pushing the gas-phase ions into the first gap. The high-voltage asymmetric electric field and the third DC electric field act on the gas-phase ions at the first gap together, focusing the gas-phase ions to the middle region in the radial direction of the semi-circular ring cross-section of the first gap. Then, the gas at the first gap pushes the focused gas-phase ions to the second gap and the fourth gap. The high-voltage asymmetric electric field causes the gas-phase ions at the second gap and the fourth gap to deflect in the up-down direction. The third DC electric field compensates for the deflection of the gas-phase ions corresponding to the scanning voltage, pulling the deflected gas-phase ions back to the middle region in the up-down direction of the second gap and the fourth gap. The gas at the second gap and the fourth gap pushes the compensated gas-phase ions to the third gap. The high-voltage asymmetric electric field and the third DC electric field act on the gas-phase ions at the third gap together, causing the gas-phase ions to focus to the middle region in the radial direction of the semi-circular ring cross-section and then escape. The first gap and the third gap achieve the focusing of gas-phase ions, reducing the loss of gas-phase ions. The second gap and the fourth gap are two parallel plane regions, achieving a high-resolution separation effect of gas-phase ions. Thus, the high-field asymmetric waveform ion mobility spectrometry analyzer of the present utility model has both high sensitivity and high resolution. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 is a schematic structural diagram of the high-field asymmetric waveform ion mobility spectrometry analyzer of the present utility model;

[0013] Figure 2 This is the structural diagram of the compensation voltage electrode plate of the high-field asymmetric waveform ion mobility spectrometry analyzer of the present utility model;

[0014] Figure 3 This is the structural diagram of the separation voltage electrode plate of the high-field asymmetric waveform ion mobility spectrometry analyzer of the present utility model;

[0015] Figure 4 This is the schematic structural diagram of the first housing of the high-field asymmetric waveform ion mobility spectrometry analyzer of the present utility model;

[0016] Figure 5 This is the partial structural schematic diagram of the second housing of the high-field asymmetric waveform ion mobility spectrometry analyzer of the present utility model. Specific embodiments

[0017] The present utility model discloses a high-field asymmetric waveform ion mobility spectrometry analyzer. The following further describes in detail a high-field asymmetric waveform ion mobility spectrometry analyzer of the present utility model in conjunction with the accompanying drawings and embodiments.

[0018] Embodiment 1: As Figure 1As shown in the figure, a high-field asymmetric waveform ion mobility spectrometry analyzer includes a compensation voltage plate 1 for accessing a scanning voltage, a separation voltage plate 2 for accessing a separation voltage, a curtain voltage plate 3 for accessing a curtain voltage, and a gas channel 4 for introducing gas. The separation voltage plate 2 is located inside the compensation voltage plate 1, and a racetrack-shaped gap region is formed between the two. The racetrack-shaped gap region is formed by sequentially connecting four gaps, and the four gaps are sequentially referred to as a first gap 5, a second gap 6, a third gap 7, and a fourth gap 8. Both the first gap 5 and the third gap 7 are semi-circular ring-shaped gaps with a semi-circular ring cross-section in the up-down direction, and they are symmetrically arranged left and right. Both the second gap 6 and the fourth gap 8 are rectangular structure gaps, and they are symmetrically arranged up and down. The gas channel 4 is connected to the first gap 5, and the third gap 7 communicates with the outside. When the curtain voltage plate 3 accesses the curtain voltage, the separation voltage plate 2 accesses the separation voltage, the compensation voltage plate 1 accesses the scanning voltage, and the gas channel 4 introduces gas, when the electrospray ionization source 9 is working, there is a potential difference between the curtain voltage plate 3 and the electrospray ionization source 9, and a DC electric field will be generated. This DC electric field is called the first DC electric field. There is a potential difference between the curtain voltage plate 3 and the compensation voltage plate 1, and a DC electric field will be generated. This DC electric field is called the second DC electric field. The separation voltage plate 2 will generate a high-voltage asymmetric electric field, and the compensation voltage plate 1 will generate a DC electric field that changes with the scanning voltage it accesses. This DC electric field is called the third DC electric field. When the electrospray ionization source 9 generates a charged droplet spray, the charged droplet spray is dried by the gas to form gas-phase ions. The gas-phase ions move to the gas channel 4 under the action of the first DC electric field. At this time, the second DC electric field and the gas act on the gas-phase ions together, pushing the gas-phase ions into the first gap 5. The high-voltage asymmetric electric field and the third DC electric field act on the gas-phase ions at the first gap 5 together, focusing the gas-phase ions to the middle region in the radial direction of the semi-circular ring cross-section of the first gap 5, and then the gas at the first gap 5 pushes the focused gas-phase ions to the second gap 6 and the fourth gap 8. The high-voltage asymmetric electric field causes the gas-phase ions at the second gap 6 and the fourth gap 8 to deflect in the up-down direction. The third DC electric field compensates for the deflection of the gas-phase ions corresponding to the scanning voltage, pulling the deflected gas-phase ions back to the middle region in the up-down direction of the second gap 6 and the fourth gap 8. The gas at the second gap 6 and the fourth gap 8 pushes the compensated gas-phase ions to the third gap 7. The high-voltage asymmetric electric field and the third DC electric field act on the gas-phase ions at the third gap 7 together, causing the gas-phase ions to be focused and then escape.

[0019] In this embodiment, the first gap 5 and the third gap 7 achieve the focusing of gas-phase ions, reducing the loss of gas-phase ions. The second gap 6 and the fourth gap 8 are two parallel planar regions, achieving a high-resolution separation effect of gas-phase ions. Thus, the high-field asymmetric waveform ion mobility spectrometry analyzer of the present utility model has both high sensitivity and high resolution.

[0020] Embodiment 2: This embodiment is basically the same as Embodiment 1, except that: in this embodiment, as Figure 2 and Figure 3 shown, the compensation voltage electrode plate 1 and the separation voltage electrode plate 2 are formed by opening a racetrack-shaped cavity in a rectangular parallelepiped metal plate. This metal plate is referred to as the first metal plate. The first metal plate is divided into two independent parts. The part located on the outside is the compensation voltage electrode plate 1, and the part located on the inside is the separation voltage electrode plate 2. The length direction of the first metal plate is along the left-right direction, the width direction is along the front-back direction, and the thickness direction is along the up-down direction. The racetrack-shaped cavity penetrates the first metal plate from front to back. Both the front part and the rear part of the racetrack-shaped cavity are filled with fillers. A racetrack-shaped gap region is formed between the racetrack-shaped cavity and the fillers in its front part and rear part. The length directions of the second gap 6 and the fourth gap 8 are both along the left-right direction, the width directions are both along the front-back direction, and the thickness directions are both along the up-down direction. The width directions of the first gap 5 and the third gap 7 are both along the front-back direction, and the thickness directions are respectively along the radial directions of their semi-circular cross-sections.

[0021] Embodiment 3: This embodiment is basically the same as Embodiment 2, except that: in this embodiment, the curtain voltage electrode plate 3 includes a second metal plate 10 and a third metal plate 11. The second metal plate 10 is of a cuboid structure, and the third metal plate 11 is of a cylindrical structure. The length direction of the second metal plate 10 is along the front-back direction, the width direction is along the up-down direction, and the thickness direction is along the left-right direction. The axial direction of the third metal plate 11 is along the left-right direction. The third metal plate 11 is located on the right side of the second metal plate 10. The left end face of the third metal plate 11 is fixed and in a fitting state with the right end face of the second metal plate 10. The diameter of the third metal plate 11 is smaller than the smaller value of the length and width of the second metal plate 10. The central axis of the third metal plate 11 and the center line of the second metal plate 10 along the left-right direction are on the same straight line. The second metal plate 10 and the third metal plate 11 are provided with a first cylindrical hole 12, and the third metal plate 11 is provided with a second cylindrical hole 13. The first cylindrical hole 12 and the second cylindrical hole 13 are both coaxial with the third metal plate 11 and have a diameter smaller than that of the third metal plate 11. The left end face of the first cylindrical hole 12 is flush with the left end face of the second metal plate 10. The second cylindrical hole 13 is located on the right side of the first cylindrical hole 12. The diameter of the second cylindrical hole 13 is smaller than that of the first cylindrical hole 12. The left end face of the second cylindrical hole 13 is communicated with the right end face of the first cylindrical hole 12 and is in a fitting state. The right end face of the second cylindrical hole 13 is flush with the right end face of the third metal plate 11. The right end face of the second cylindrical hole 13 is communicated with the gas channel 4. The gas entering through the gas channel 4 can sequentially enter the second cylindrical hole 13 and the first cylindrical hole 12 and escape through the first cylindrical hole 12.

[0022] In this embodiment, as Figure 4 and Figure 5As shown in the figure, a high-field asymmetric waveform ion mobility spectrometry analyzer further includes a first housing 14 and a second housing 15. The first housing 14 is located on the right side of the second metal plate 10. The first housing 14 is in a cuboid structure, and its length direction is along the front-back direction, the width direction is along the up-down direction, and the thickness direction is along the left-right direction. The upper end surface of the first housing 14 and the upper end surface of the second metal plate 10 are in the same plane. The lower end surface of the first housing 14 and the lower end surface of the second metal plate 10 are in the same plane. The front end surface of the first housing 14 and the front end surface of the second metal plate 10 are in the same plane. The rear end surface of the first housing 14 and the rear end surface of the second metal plate 10 are in the same plane. The left end surface of the first housing 14 and the right end surface of the second metal plate 10 are fixed and in a fitting state. A gas channel 4 is provided on the first housing 14. The gas channel 4 is a cylindrical hole penetrating from left to right. The third metal plate 11 is located in the gas channel 4 and the two are coaxial. The right end surface of the third metal plate 11 is located on the left side of the right end surface of the gas channel 4. An air inlet 16 that communicates the gas channel 4 with the outside is respectively provided at the upper and lower ends of the first housing 14. The diameter of the gas channel 4 is larger than the diameter of the third metal plate 11 and smaller than the smaller value of the length and width of the first housing 14. The second housing 15 is located on the right side of the first housing 14. The second housing 15 is in a cuboid structure, and its length direction is along the left-right direction, the width direction is along the front-back direction, and the thickness direction is along the up-down direction. The upper end surface of the second housing 15 and the upper end surface of the first housing 14 are in the same plane. The lower end surface of the second housing 15 and the lower end surface of the first housing 14 are in the same plane. The front end surface of the second housing 15 and the front end surface of the first housing 14 are in the same plane. The rear end surface of the second housing 15 and the rear end surface of the first housing 14 are in the same plane. The left end surface of the second housing 15 and the right end surface of the first housing 14 are fixed and in a fitting state. The second housing 15 has a cuboid cavity 17 penetrating from left to right. The length direction of the cuboid cavity 17 is along the left-right direction, the width direction is along the front-back direction, and the thickness direction is along the up-down direction. The cuboid cavity 17 is docked with the gas channel 4. The thickness and width of the cuboid cavity 17 are both larger than the diameter of the gas channel 4. The first metal plate is located in the cuboid cavity 17. The left end surface of the first metal plate is flush with the left end surface of the cuboid cavity 17. The length of the first metal plate is equal to the length of the cuboid cavity 17, the width is equal to the width of the cuboid cavity 17, and the thickness is equal to the thickness of the cuboid cavity 17. A third cylindrical hole 18 extending from its left end surface to communicate with the first gap 5 is provided on the first metal plate. A fourth cylindrical hole 19 extending from its right end surface to communicate with the third gap 7 is provided on the first metal plate. The third cylindrical hole 18, the fourth cylindrical hole 19 and the second cylindrical hole 13 are coaxial, and the ratio of the circular cross-sectional area of the third cylindrical hole 18 to the circular cross-sectional area of the second cylindrical hole 13 is 3:7.

[0023] In this embodiment, a first protrusion 20 protruding backward is provided on the front end face of the cuboid cavity 17. The first protrusion 20 is in a runway shape. The shape and size of the first protrusion 20 are the same as those of the runway-shaped cavity, except that the width in the front-back direction is less than 5% of the width of the runway-shaped cavity in the front-back direction. A second protrusion protruding forward is provided on the rear end face of the cuboid cavity 17. The first protrusion 20 and the second protrusion are symmetric in the front-back direction and are opposite to the runway-shaped cavity. The first protrusion 20 is embedded into the runway-shaped cavity from front to back as a filler for the front part of the runway-shaped cavity, and the second protrusion is embedded into the runway-shaped cavity from back to front as a filler for the rear part of the runway-shaped cavity to seal the front-back direction of the runway-shaped cavity, forming a runway-shaped gap region.

[0024] In this embodiment, the first protrusion 20 and the second protrusion can not only prevent the gas from carrying the gas-phase ions from overflowing, but also ensure that the width of the runway-shaped gap region in the front-back direction remains consistent at any position, avoiding the change in the offset distance of the gas-phase ions generated by the high-voltage asymmetric electric field at the second gap 6 and the fourth gap 8 due to the different widths of the runway-shaped gap region in the front-back direction, so that the third DC electric field cannot effectively compensate for the offset of the gas-phase ions corresponding to the scanning voltage, thus affecting the sensitivity of the analyzer connected to the high-field asymmetric waveform ion mobility spectrometer.

[0025] In this embodiment, the gas is either nitrogen or a mixed gas formed by mixing nitrogen with at least one of hydrogen, helium, and water vapor in any proportion.

[0026] In this embodiment, for the analyte ions with a specific structure whose positions can be maintained in the middle region of the racetrack-shaped gap region, there are specific trajectory characteristics in the racetrack-shaped high-field asymmetric waveform ion mobility spectrometry analyzer. For the analyte ions with a specific structure whose positions can be maintained in the middle region of the racetrack-shaped gap region, such ions will first be focused in the middle region of the first gap 5 by the focusing effect of the cylindrical high-field asymmetric waveform ion mobility spectrometry analyzer in the first gap 5. However, there are various analyte ions with specific structures focused in the first gap 5; the analyte ions with a specific structure focused in the middle region of the first gap 5 will enter the two parallel plane regions of the second gap 6 and the fourth gap 8 under the push of 30% of the gas entering the first gap 5. In these two parallel plane regions, the analyte ions with different structures will be efficiently separated; under the action of a specific scanning voltage, only the analyte ions with a single specific structure can avoid shifting towards the separation voltage plate 2 or the compensation voltage plate 1; for the single specific structure analyte ions that do not shift towards the separation voltage plate 2 or the compensation voltage plate 1, they will continue to move to the right in these two parallel plane regions under the push of 30% of the gas entering these two parallel plane regions; during this process, the volume of the ion cluster formed by all the single specific structure analyte ions that do not shift towards the separation voltage plate 2 or the compensation voltage plate 1 will continuously expand under the action of Coulomb repulsion and thermal diffusion, resulting in some single specific structure analyte ions hitting the separation voltage plate or the compensation voltage plate and being neutralized; for the analyte ions with a specific structure that can pass through these two parallel plane regions, they will be refocused in the middle region at the third gap 7 and finally pass through the fourth cylindrical hole 19 under the push of 30% of the gas entering the third gap 7, and enter the detector in the form of a dense ion cluster for detection, ensuring high ion transmission efficiency between the racetrack-shaped high-field asymmetric waveform ion mobility spectrometry analyzer and the detector.

[0027] A high-field asymmetric waveform ion mobility spectrometry analyzer according to this embodiment can be used by the following method. The specific process is as follows:

[0028] Step 1: Connect the separation voltage plate 2 to the high-field asymmetric voltage serving as the separation voltage. The separation voltage plate 2 generates a high-voltage asymmetric electric field. The high-field asymmetric voltage adopts a square wave or a double sine wave, with an output amplitude in the range of -1.0 kV to -5.0 kV or +1.0 kV to +5.0 kV, and a frequency of 1 kHz to 100 MHz;

[0029] Step 2: Connect the compensation voltage plate 1 to a DC compensation voltage serving as a scanning voltage. The DC compensation voltage is a scanning voltage that varies at a constant speed within the range of -200V to +200V. Preferably, the scanning frequency is 1V / min. The compensation voltage plate 1 generates a DC electric field that changes with the applied scanning voltage, i.e., the third DC electric field;

[0030] Step 3: Connect the curtain voltage plate 3 to a DC voltage serving as the curtain voltage. The voltage value of the DC voltage remains constant and is set between 500V and 2500V, preferably 1000V;

[0031] Step 4: Use the electrospray ion source 9 to convert the sample to be measured into charged liquid droplet spray;

[0032] Step 5: Pass gas into the gas channel 4 through two gas inlets 16 on the first housing 14. The gas passed in is either nitrogen or a mixed gas composed of nitrogen and at least one of hydrogen, helium, and water vapor in any proportion. The total flow rate of the gas passed in is 0.5L / min to 15L / min, and the gas flow rate of each gas inlet is half of the total flow rate of the gas passed into the gas channel 4;

[0033] Step 6: According to the cross-sectional area difference between the second cylindrical hole 13 and the third cylindrical hole 18, 70% of the gas in the gas channel 4 enters the first cylindrical hole 12 through the second cylindrical hole 13, and 30% of the gas enters the first gap 5 through the third cylindrical hole 18. 70% of the gas entering the first cylindrical hole 12 dries the charged liquid droplet spray formed by the electrospray ion source 9 to form gaseous ions of the analysis sample. Under the action of the first DC electric field generated by the potential difference between the curtain voltage plate 3 and the electrospray ion source 9, the gaseous ions sequentially pass through the gas channel 4. At this time, the second DC electric field generated by the potential difference between the curtain voltage plate 3 and the compensation voltage plate 1 and 30% of the gas in the gas channel 4 jointly act on the gaseous ions, pushing the gaseous ions through the third cylindrical hole 18 and then into the first gap 5;

[0034] Step 7: The high-voltage asymmetric electric field and the third DC electric field jointly act on the gaseous ions at the first gap 5, focusing the gaseous ions to the middle region along the radial direction of the semi-circular cross-section of the first gap 5, and then the gas entering the first gap 5 pushes the focused gaseous ions to the second gap 6 and the fourth gap 8;

[0035] Step 8: Due to the structural differences, the gas-phase ions of analytes with different structures are deflected towards the separation voltage plate 2 or the compensation voltage plate 1 under the action of the high-voltage asymmetric electric field and move towards the deflection direction at different speeds. Thus, separation is achieved in the up-down direction, i.e., the vertical distance. Meanwhile, the third DC electric field compensates for the deflection of the gas-phase ions corresponding to the scanning voltage, pulling the deflected gas-phase ions back to the middle region in the up-down direction of the second gap 6 and the fourth gap 8. For the gas-phase ions with a specific structure whose positions can be maintained in the middle region in the up-down direction of the second gap 6 and the fourth gap 8, they will move from the second gap 6 and the fourth gap 8 towards the third gap 7 under the push of 30% of the gas entering the second gap 6 and the fourth gap 8, while the gas-phase ions with other structures will collide with the separation voltage plate 2 or the compensation voltage plate 1 and be neutralized;

[0036] Step 9: When the gas-phase ions with a specific structure whose positions can be maintained in the middle region in the up-down direction of the second gap 6 and the fourth gap 8 are pushed into the third gap 7, the high-voltage asymmetric electric field and the third DC electric field act together on the gas-phase ions at the third gap 7, causing the gas-phase ions to be focused to the middle region in the radial direction of the semi-circular cross-section of the third gap 7 and then enter the fourth cylindrical hole 19 under the push of the gas and escape into the detector for detection. Repeat steps 4 to 9 and continuously change the voltage value of the scanning voltage, so that the analyte ions with different structures can stably leave the high-field asymmetric waveform ion mobility spectrometer under the action of different scanning voltages and be detected, obtaining the isomer ion distribution spectrum of the sample to be tested.

[0037] When detecting the ion mass-to-charge ratio and signal intensity, the detector is a mass spectrometer; when detecting the ion current signal intensity, the detector is an electrometer.

Claims

1. A high-field asymmetric waveform ion mobility spectrometer, comprising a compensation voltage plate for connecting a scanning voltage, a separation voltage plate for connecting a separation voltage, a curtain voltage plate for connecting a curtain voltage, and a gas channel for introducing a gas, characterized in that The separation voltage plate is located inside the compensation voltage plate, and a racetrack-shaped gap region is formed between the two. The racetrack-shaped gap region is formed by four gaps connected in sequence. The four gaps are sequentially referred to as the first gap, the second gap, the third gap and the fourth gap. The first gap and the third gap are both semicircular gaps with a semicircular cross-section along the up-down direction, and the two are symmetrically arranged left and right. The second gap and the fourth gap are both cuboid structure gaps, and the two are symmetrically arranged up and down. The gas channel is connected to the first gap, and the third gap is connected to the outside. When the curtain voltage plate is connected to the curtain voltage, the separation voltage plate is connected to the separation voltage, the compensation voltage plate is connected to the scanning voltage, and the gas is introduced into the gas channel, when the electrospray ion source is working, there is a potential difference between the curtain voltage plate and the electrospray ion source, and a DC electric field is generated, which is called the first DC electric field. There is a potential difference between the curtain voltage plate and the compensation voltage plate, which is called the second DC electric field. The separation voltage plate will generate a high-voltage asymmetric electric field, and the compensation voltage plate will generate a DC electric field that changes as the scanning voltage it is connected to changes. This DC field is called the third DC electric field. When the electrospray ion source generates a charged droplet spray, the charged droplet spray is dried by the gas to form gas-phase ions. The gas-phase ions move to the gas channel under the action of the first DC electric field. At this time, the second DC electric field The field and the gas act together on the gas-phase ions to push the gas-phase ions into the first gap. The high-voltage asymmetric electric field and the third direct current electric field act together on the gas-phase ions at the first gap to focus the gas-phase ions to the middle area of ​​the first gap along the radial direction of its semicircular ring cross-section. Then the gas entering the first gap pushes the focused gas-phase ions to the second gap and the fourth gap. The high-voltage asymmetric electric field causes the gas-phase ions at the second gap and the fourth gap to deviate in the up-down direction. The third direct current electric field compensates for the deviation of the gas-phase ions corresponding to the scanning voltage and pulls the deviated gas-phase ions back to the middle area of ​​the second gap and the fourth gap along the up-down direction. The gas at the second gap and the fourth gap pushes the compensated gas-phase ions to the third gap. The high-voltage asymmetric electric field and the third direct current electric field act together on the gas-phase ions at the third gap to cause the gas-phase ions to escape after being focused.

2. A high-field asymmetric waveform ion mobility spectrometer according to claim 1, characterized in that The compensation voltage plate and the separation voltage plate are formed by opening a racetrack-shaped cavity on a metal plate with a rectangular structure. The metal plate is called the first metal plate. The first metal plate is divided into two independent parts, wherein the part located on the outside is the compensation voltage plate, and the part located on the inside is the separation voltage plate. The length direction of the first metal plate is along the left-right direction, the width direction is along the front-to-back direction, and the thickness direction is along the up-down direction. The racetrack-shaped cavity penetrates the first metal plate from front to back. The front and rear of the racetrack-shaped cavity are filled with fillers. The racetrack-shaped gap area is formed between the racetrack-shaped cavity and the fillers at the front and rear. The length directions of the second gap and the fourth gap are both along the left-right direction, the width directions are both along the front-to-back direction, and the thickness directions are both along the up-down direction. The width directions of the first gap and the third gap are both along the front-to-back direction, and the thickness directions are respectively along the radial direction of their semicircular ring cross-sections.

3. A high-field asymmetric waveform ion mobility spectrometer according to claim 2, characterized in that The curtain voltage plate includes a second metal plate and a third metal plate, the second metal plate is a rectangular parallelepiped structure, the third metal plate is a cylindrical structure, the length direction of the second metal plate is along the front-to-back direction, the width direction is along the up-down direction, the thickness direction is along the left-to-right direction, the axial direction of the third metal plate is along the left-to-right direction, the third metal plate is located on the right side of the second metal plate, the left end face of the third metal plate is fixed and fitted to the right end face of the second metal plate, the diameter of the third metal plate is smaller than the smaller of the length and width of the second metal plate, the central axis of the third metal plate is in the same straight line as the center line of the second metal plate in the left-to-right direction, the second metal plate and the third metal plate are provided with a first cylindrical hole, and the third metal plate is provided with a second cylindrical hole. Cylindrical hole, the first cylindrical hole and the second cylindrical hole are both coaxial with the third metal plate, and their diameters are smaller than that of the third metal plate, the left end face of the first cylindrical hole is flush with the left end face of the second metal plate, the second cylindrical hole is located on the right side of the first cylindrical hole, the diameter of the second cylindrical hole is smaller than the diameter of the first cylindrical hole, the left end face of the second cylindrical hole is connected with the right end face of the first cylindrical hole, and are in a fitted state, the right end face of the second cylindrical hole is flush with the right end face of the third metal plate, the right end face of the second cylindrical hole is connected with the gas channel, and the gas entering through the gas channel can enter the second cylindrical hole and the first cylindrical hole in turn, and escape through the first cylindrical hole.

4. A high-field asymmetric waveform ion mobility spectrometer according to claim 3, characterized in that It also includes a first shell and a second shell, the first shell is located on the right side of the second metal plate, the first shell is a rectangular parallelepiped structure, and its length direction is along the front-to-back direction, the width direction is along the up-down direction, and the thickness direction is along the left-right direction. The upper end face of the first shell and the upper end face of the second metal plate are located in the same plane, the lower end face of the first shell and the lower end face of the second metal plate are located in the same plane, the front end face of the first shell and the front end face of the second metal plate are located in the same plane, the rear end face of the first shell and the rear end face of the second metal plate are located in the same plane, the left end face of the first shell and the right end face of the second metal plate are fixed and in a fitted state, the first shell is provided with the gas channel, the gas channel is a cylindrical hole running through the left and right sides, and the third metal plate is located in the gas channel. The two are coaxial, the right end face of the third metal plate is located on the left side of the right end face of the gas channel, the upper end and the lower end of the first shell are respectively provided with an air inlet that connects the gas channel with the outside, the diameter of the gas channel is larger than the diameter of the third metal plate, and smaller than the smaller of the length and width of the first shell; the second shell is located on the right side of the first shell, the second shell is a rectangular parallelepiped structure, and its length direction is along the left-right direction, the width direction is along the front-back direction, and the thickness direction is along the up-down direction, the upper end face of the second shell is located in the same plane as the upper end face of the first shell, and the lower end face of the second shell is in the same plane as the first shell The lower end surface of the second shell is located in the same plane, the front end surface of the second shell is located in the same plane as the front end surface of the first shell, the rear end surface of the second shell is located in the same plane as the rear end surface of the first shell, the left end surface of the second shell is fixed and fitted with the right end surface of the first shell, the second shell has a rectangular cavity running through the left and right, the length direction of the rectangular cavity is along the left and right direction, the width direction is along the front and back direction, and the thickness direction is along the up and down direction, the rectangular cavity is connected to the gas channel, the thickness and width of the rectangular cavity are greater than the diameter of the gas channel, the first metal plate is located in the rectangular cavity, and the first The left end face of a metal plate is flush with the left end face of the rectangular cavity, the length of the first metal plate is equal to the length of the rectangular cavity, the width is equal to the width of the rectangular cavity, and the thickness is equal to the thickness of the rectangular cavity. The first metal plate is provided with a third cylindrical hole extending from its left end face to communicate with the first gap, and the first metal plate is provided with a fourth cylindrical hole extending from its right end face to communicate with the third gap. The third cylindrical hole and the fourth cylindrical hole are coaxial with the second cylindrical hole, and the ratio of the circular cross-sectional area of ​​the third cylindrical hole to the circular cross-sectional area of ​​the second cylindrical hole is 3:

7.

5. A high-field asymmetric waveform ion mobility spectrometer according to claim 4, characterized in that A first protrusion protruding toward the rear side is arranged on the front end surface of the rectangular cavity, and the first protrusion is runway-shaped. The shape and size of the first protrusion are the same as those of the runway-shaped cavity, except that the width in the front-to-back direction is less than 5% of the width in the front-to-back direction of the runway-shaped cavity. A second protrusion protruding toward the front side is arranged on the rear end surface of the rectangular cavity, and the first protrusion and the second protrusion are symmetrical front to back and face the runway-shaped cavity. The first protrusion is embedded in the runway-shaped cavity from front to back as a filler in the front part of the runway-shaped cavity, and the second protrusion is embedded in the runway-shaped cavity from back to front as a filler in the rear part of the runway-shaped cavity, thereby closing the front-to-back direction of the runway-shaped cavity to form the runway-shaped gap area.

6. The high-field asymmetric waveform ion mobility spectrometer according to claim 1, characterized in that The gas is nitrogen.

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