A high-field asymmetric waveform ion mobility spectrometer and its use method

Abstract

The present invention discloses a high-field asymmetric waveform ion mobility spectrometer and a method for using the same. The high-field asymmetric waveform ion mobility spectrometer includes a compensation voltage plate, a separation voltage plate, a curtain voltage plate, and a gas channel for introducing gas. The separation voltage plate is located inside the compensation voltage plate, and a racetrack-shaped gap area is formed between the two. The racetrack-shaped gap area is formed by four gaps connected in sequence. The four gaps are sequentially referred to as a first gap, a second gap, a third gap, and a 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 on the left and right. The second gap and the fourth gap are both rectangular parallelepiped structure gaps, and the two are symmetrically arranged on the up-down direction. The gas channel is connected to the first gap, and the third gap is connected to the outside. The advantage is that the analyzer has both high sensitivity and high resolution.

Description

Technical Field

[0001] The present invention relates to a high-field asymmetric waveform ion mobility spectrometer technology, and in particular to a high-field asymmetric waveform ion mobility spectrometer and a method for using the same. Background Art

[0002] In vivo, the properties, functions, and activities of biomolecules are closely related to their three-dimensional structures. Biomolecules with different structures can play vastly different roles within the body. Therefore, the precise separation and resolution of biomolecular isomers is crucial for life science research. To this end, researchers have developed a variety of molecular structure separation and resolution techniques. Among these, high-field asymmetric waveform ion mobility spectrometry (HFAS) has experienced rapid development and widespread use in recent years due to its high sensitivity to molecular structural differences.

[0003] Based on their structural differences, existing high-field asymmetric waveform ion mobility spectrometers can be primarily categorized as cylindrical or flat. The cylindrical type primarily consists of two coaxial cylindrical electrodes of different diameters. Applying a separation voltage of a specific polarity to the two coaxial cylindrical electrodes creates a non-uniform, high-voltage, asymmetric electric field that focuses on specific ions, while dispersing other ions. In the cylindrical type, the type of ions focused or dispersed changes with the polarity of the high-voltage asymmetric electric field. After entering the cylindrical type, these focused ions can all pass through the analyzer, resulting in extremely high sensitivity. However, due to the focusing effect, the cylindrical type produces extremely wide peak widths when separating ions of different structures, with peaks easily overlapping, resulting in insufficient resolution. The flat-plate high-field asymmetric waveform ion mobility spectrometer is mainly composed 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-plate high-field asymmetric waveform ion mobility spectrometer are narrower and the resolution is much higher than that of the cylindrical high-field asymmetric waveform ion mobility spectrometer. However, due to the lack of focusing force to counteract Coulomb repulsion and thermal diffusion during the separation process, ions initially positioned close to the two planar electrodes of the flat-plate high-field asymmetric waveform ion mobility spectrometer 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 spectrometer. Summary of the Invention

[0004] One of the technical problems to be solved by the present invention is to provide a high-field asymmetric waveform ion mobility spectrometer with both high sensitivity and high resolution.

[0005] The technical solution adopted by the present invention to solve one of the above technical problems is: a high-field asymmetric waveform ion mobility spectrometer, including a compensation voltage plate for connecting to a scanning voltage, a separation voltage plate for connecting to a separation voltage, a curtain voltage plate for connecting to a curtain voltage and a gas channel for introducing a gas, wherein the separation voltage plate is located on the inner side of the compensation voltage plate, and a racetrack-shaped gap area is formed between the two. The racetrack-shaped gap area is formed by four gaps connected in sequence, and the four gaps are sequentially referred to as a first gap, a second gap, a third gap and a fourth gap, wherein the first gap and the third gap are both semicircular gaps with a semicircular cross-section along the up and down direction, and the two are symmetrically arranged on the left and right. The second gap and the fourth gap are both rectangular 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, and there is a potential difference between the curtain voltage plate and the compensation voltage plate, which is called the second A DC electric field is provided. The separation voltage plate generates a high-voltage asymmetric electric field, and the compensation voltage plate generates a DC electric field that changes as the scanning voltage to which it is connected changes. The DC electric 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 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 DC field act together on the gas-phase ions at the first gap to focus the gas-phase ions to the first gap along its semicircular cross-section. The gas at the second gap and the fourth gap pushes the focused gas-phase ions to the second gap and the fourth gap, and the high-voltage asymmetric electric field causes the gas-phase ions at the second gap and the fourth gap to shift in the up and down directions. The third DC electric field compensates for the shift of the gas-phase ions corresponding to the scanning voltage, and pulls the shifted gas-phase ions back to the middle area between the second gap and the fourth gap in the up and down directions. 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 together on the gas-phase ions at the third gap, causing the gas-phase ions to escape after being focused.

[0006] The compensation voltage plate and the separation voltage plate are formed by opening a runway-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 runway-shaped cavity penetrates the first metal plate from front to back. The front and rear of the runway-shaped cavity are filled with fillers. The runway-shaped gap area is formed between the runway-shaped cavity and the fillers at its 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.

[0007] The curtain voltage plate includes a second metal plate and a third metal plate, the second metal plate 10 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-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 fitted 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 is in the same straight line as the center line of the second metal plate in the left-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, the first cylindrical hole and the second cylindrical hole are both coaxial with the third metal plate, and their diameters are smaller than the diameter 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 sequence, and escape through the first cylindrical hole.

[0008] The high-field asymmetric waveform ion mobility spectrometer further comprises a first shell and a second shell, wherein 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, and 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 surfaces 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 from left to right, the third metal plate is located in the gas channel, and the two are coaxial, the right end face of the third metal plate is located to the left 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 connecting 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 in the same plane as the upper end face of the first shell, the lower end face of the second shell is in the same plane as the lower end face of the first shell, the front end face of the second shell is in the same plane as the front end face of the first shell, the rear end face of the second shell is in the same plane as the rear end face of the first shell, the left end face of the second shell is fixed and in a fitted state with the right end face of the first shell, and the second shell has a rectangular parallelepiped cavity running through it from left to right. The length direction of the rectangular parallelepiped cavity 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 rectangular parallelepiped cavity and the gas The channels are butted together. The thickness and width of the rectangular cavity are both greater than the diameter of the gas channel. The first metal plate is positioned within the rectangular cavity, with its left end face flush with the left end face of the rectangular cavity. The first metal plate has a length equal to the length of the rectangular cavity, a width equal to the width of the rectangular cavity, and a thickness 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. 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 and fourth cylindrical holes 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.

[0009] A first protrusion protruding toward the rear side is provided 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 provided on the rear end surface of the rectangular cavity. The first protrusion and the second protrusion are symmetrical front to back and are facing 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 sealing the front-to-back direction of the runway-shaped cavity to form the runway-shaped gap area. In this structure, the first protrusion and the second protrusion can not only prevent the gas from carrying gas-phase ions out, but also ensure that the width of the racetrack-shaped gap area along the front-to-back direction remains consistent at any point, thereby avoiding the difference in width of the racetrack-shaped gap area along the front-to-back direction, which causes the offset distance of the gas-phase ions at the second gap and the fourth gap to change due to the high-voltage asymmetric electric field, making it impossible for the third DC electric field to 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 spectrometer of the present invention are: by arranging the separation voltage plate inside the compensation voltage plate, a racetrack-shaped gap area is formed between the two, and the racetrack-shaped gap area is formed by four gaps connected in sequence, and the four gaps are called the first gap, the second gap, the third gap and the fourth gap in sequence, the first gap and the third gap are both semi-circular gaps with a semi-circular cross-section along the up and down directions, and the two are symmetrically arranged on the left and right, the second gap and the fourth gap are both rectangular structure gaps, and the two are symmetrically arranged on the top and bottom, 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, When 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, which will generate a DC electric field, which is called the first DC electric field, and there is a potential difference between the curtain voltage plate and the compensation voltage plate, which will generate a DC electric field, which is called the second DC 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, which is called the third DC electric field. When the electrospray ion source produces a spray of charged droplets, the charged droplets will be generated. After the electro-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 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 DC 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 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 and down directions. The third DC electric field deflects the gas-phase ions corresponding to the scanning voltage. The shift is compensated and the offset gas-phase ions are pulled back to the middle area between the second gap and the fourth gap in 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 DC electric field act together on the gas-phase ions at the third gap, so that the gas-phase ions are focused to the middle area along the radial direction of their semicircular ring cross-section and then escape. The first gap and the third gap realize the focusing of the gas-phase ions and reduce the loss of the gas-phase ions. The second gap and the fourth gap are two parallel plane areas, which realize the high-resolution separation effect of the gas-phase ions. Therefore, the high-field asymmetric waveform ion mobility spectrometer of the present invention has both high sensitivity and high resolution.

[0012] The second technical problem to be solved by the present invention is to provide a method for using a high-field asymmetric waveform ion mobility spectrometer with both high sensitivity and high resolution.

[0013] The technical solution adopted by the present invention to solve the second technical problem is: a method for using the high-field asymmetric waveform ion mobility spectrometer, comprising the following steps:

[0014] Step 1: Connecting the separation voltage plate to a high-field asymmetric voltage as a separation voltage, wherein the separation voltage plate generates a high-field asymmetric voltage using 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;

[0015] Step 2: Connecting the compensation voltage plate to a DC compensation voltage serving as a scanning voltage, wherein the DC compensation voltage is a scanning voltage that changes at a constant rate within a range of -200 V to +200 V, and a scanning frequency of 1 V / min. The compensation voltage plate generates a DC electric field that changes as the scanning voltage connected thereto changes, i.e., a third DC electric field.

[0016] Step 3: connecting the curtain voltage plate to a DC voltage serving as a curtain voltage, wherein the DC voltage is kept constant and set to a value between 500 V and 2500 V, preferably 1000 V;

[0017] Step 4: using an electrospray ion source to convert the sample to be tested into a charged droplet spray;

[0018] Step 5: Introducing gas into the gas channel through the two gas inlets on the first shell, where the gas may be nitrogen or a mixture of nitrogen and at least one of hydrogen, helium, and water vapor in any proportion; the total flow rate of the gas introduced is 0.5 L / min to 15 L / min, and the gas flow rate of each gas inlet is half of the total flow rate of the gas introduced into the gas channel;

[0019] Step 6: Based on the difference in cross-sectional area between the second cylindrical hole and the third cylindrical hole, 70% of the gas in the gas channel enters the first cylindrical hole through the second cylindrical hole, and 30% of the gas enters the first gap through the third cylindrical hole. The 70% of the gas entering the first cylindrical hole sprays and dries the charged droplets formed by the electrospray ion source to form gas-phase ions of the analysis sample. Under the action of a first DC electric field generated by the potential difference between the curtain voltage plate and the electrospray ion source, the gas-phase ions sequentially pass through the gas channel. At this time, a second DC electric field generated by the potential difference between the curtain voltage plate and the compensation voltage plate and 30% of the gas in the gas channel jointly act on the gas-phase ions, pushing the gas-phase ions through the third cylindrical hole and then into the first gap.

[0020] Step 7: The high-voltage asymmetric electric field and the third DC electric field act together on the gas-phase ions at the first gap, focusing the gas-phase ions to the middle region of the first gap along the radial direction of the semicircular cross-section of the first gap. Then, the gas entering the first gap pushes the focused gas-phase ions to the second gap and the fourth gap.

[0021] Step 8. Due to structural differences, gas-phase ions of analytes of different structures are deflected toward the separation voltage plate or the compensation voltage plate under the action of the high-voltage asymmetric electric field, and move in the deflected direction at different speeds, thereby achieving separation in the vertical direction, i.e., vertical distance. Simultaneously, 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 between the second gap and the fourth gap in the vertical direction. Gas-phase ions of a specific structure that can be maintained in the middle region between the second gap and the fourth gap in the vertical direction will be pushed by 30% of the gas entering the second gap and the fourth gap, moving from the second gap and the fourth gap toward the third gap. Gas-phase ions of other structures will collide with the separation voltage plate or the compensation voltage plate and be neutralized.

[0022] Step 9. When the gas-phase ions of a specific structure that can be maintained in the middle area between the second gap and the fourth gap in the vertical direction are pushed to enter the third gap, the high-voltage asymmetric electric field and the third DC electric field jointly act on the gas-phase ions at the third gap, so that the gas-phase ions are focused to the middle area of ​​the third gap along the radial direction of its semicircular ring cross-section, and then enter the fourth cylindrical hole under the push of 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 analyte ions of different structures can stably leave the high-field asymmetric waveform ion mobility spectrometer under the action of different scanning voltages and be detected, thereby obtaining the isomer ion distribution spectrum of the sample to be tested.

[0023] When the ion mass-to-charge ratio and signal intensity are detected, the detector is a mass spectrometer; when the ion current signal intensity is detected, the detector is an electrometer.

[0024] Compared with the prior art, the advantages of the method for using the high-field asymmetric waveform ion mobility spectrometer of the present invention are as follows: a first protrusion protruding toward the rear side is provided on the front end face of the rectangular parallelepiped cavity, the first protrusion is racetrack-shaped, and the shape and size of the first protrusion are the same as those of the racetrack-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 racetrack-shaped cavity. A second protrusion protruding toward the front side is provided on the rear end face of the rectangular parallelepiped cavity, the first protrusion and the second protrusion are symmetrical front to back and face the racetrack-shaped cavity. The first protrusion is embedded in the racetrack-shaped cavity from front to back as a filler at the front of the racetrack-shaped cavity, and the second protrusion is embedded in the racetrack-shaped cavity from back to front as a filler at the rear of the racetrack-shaped cavity. Embedded forward in the racetrack-shaped cavity, the front-to-back directions of the racetrack-shaped cavity are sealed to form a racetrack-shaped gap area. The first protrusion and the second protrusion can prevent the gas from carrying gas-phase ions from overflowing, while ensuring that the width of the racetrack-shaped gap area along the front-to-back direction remains consistent at any point, thereby avoiding the difference in width of the racetrack-shaped gap area along the front-to-back direction, which causes the gas-phase ions to change in the offset distance generated by the high-voltage asymmetric electric field at the second gap and the fourth gap, making it impossible for the third DC electric field to 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. When the electrospray ion source generates charged droplets During spraying, 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 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 DC 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 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 and down directions. The third DC electric field acts on the gas-phase ions corresponding to the scanning voltage. The offset is compensated, and the offset gas-phase ions are pulled back to the middle area between the second gap and the fourth gap in the up and down directions. 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 together on the gas-phase ions at the third gap, so that the gas-phase ions are focused to the middle area along the radial direction of their semicircular ring cross-section and then escape. The first gap and the third gap realize the focusing of the gas-phase ions and reduce the loss of gas-phase ions. The second gap and the fourth gap are two parallel plane areas, which realize the high-resolution separation effect of the gas-phase ions. Therefore, the use method of the high-field asymmetric waveform ion mobility spectrometer of the present invention has both high sensitivity and high resolution. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 Schematic diagram of the structure of the high-field asymmetric waveform ion mobility spectrometer of the present invention;

[0026] Figure 2 A structural diagram of a compensation voltage electrode plate of a high-field asymmetric waveform ion mobility spectrometer according to the present invention;

[0027] Figure 3 A structural diagram of a separation voltage plate of a high-field asymmetric waveform ion mobility spectrometer according to the present invention;

[0028] Figure 4 This is a schematic structural diagram of the first housing of the high-field asymmetric waveform ion mobility spectrometer of the present invention;

[0029] Figure 5 It is a schematic diagram of the partial structure of the second shell of the high-field asymmetric waveform ion mobility spectrometer of the present invention. DETAILED DESCRIPTION

[0030] The present invention discloses a high-field asymmetric waveform ion mobility spectrometer. The high-field asymmetric waveform ion mobility spectrometer of the present invention is further described in detail below with reference to the accompanying drawings and embodiments.

[0031] Example 1: Figure 1As shown, a high-field asymmetric waveform ion mobility spectrometer includes a compensation voltage plate 1 for connecting to a scanning voltage, a separation voltage plate 2 for connecting to a separation voltage, a curtain voltage plate 3 for connecting to a curtain voltage, and a gas channel 4 for introducing a 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 four gaps connected in sequence. 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. The first gap 5 and the third gap 7 are both semicircular gaps with a semicircular cross-section along the vertical direction, and the two are symmetrically arranged. The second gap 6 and the fourth gap 8 are both rectangular structure gaps, and the two are symmetrically arranged up and down, the gas channel 4 is connected to the first gap 5, and the third gap 7 is connected to the outside; when the curtain voltage plate 3 is connected to the curtain voltage, the separation voltage plate 2 is connected to the separation voltage, the compensation voltage plate 1 is connected to the scanning voltage, and the gas channel 4 introduces gas, when the electrospray ion source 9 is working, there is a potential difference between the curtain voltage plate 3 and the electrospray ion source 9, and a DC electric field is generated, which is called the first DC electric field, and there is a potential difference between the curtain voltage plate 3 and the compensation voltage plate 1, which is called the second DC field, and the separation voltage plate 3 is connected to the compensation voltage plate 1. The 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 as the scanning voltage it is connected to changes. This DC electric field is called the third DC electric field. When the electrospray ion source 9 generates a charged droplet spray, the charged droplet spray is blown dry 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 together on the gas-phase ions, pushing the gas-phase ions into the first gap 5. The high-voltage asymmetric electric field and the third DC field act together on the gas-phase ions in the first gap 5, focusing the gas-phase ions to the first gap 5 along its semicircular ring. The gas at the second gap 6 and the fourth gap 8 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 shift in the up and down directions. The third DC electric field compensates for the shift of the gas-phase ions corresponding to the scanning voltage, and pulls the shifted gas-phase ions back to the middle area between the second gap 6 and the fourth gap 8 in the up and down directions. 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 together on the gas-phase ions at the third gap 7, causing the gas-phase ions to escape after being focused.

[0032] In this embodiment, the first gap 5 and the third gap 7 realize the focusing of gas-phase ions and reduce the loss of gas-phase ions. The second gap 6 and the fourth gap 8 are two parallel plane areas, which realize the high-resolution separation effect of gas-phase ions. Therefore, the high-field asymmetric waveform ion mobility spectrometer of the present invention has both high sensitivity and high resolution.

[0033] Example 2: This example is basically the same as Example 1, except that: in this example, Figure 2 and Figure 3 As shown, the compensation voltage plate 1 and the separation voltage plate 2 are formed by opening a runway-shaped cavity on a metal plate with a rectangular structure. The metal plate is called the first metal plate, and the first metal plate is divided into two independent parts, wherein the part located on the outside is the compensation voltage plate 1, and the part located on the inside is the separation voltage plate 2. 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 runway-shaped cavity passes through the first metal plate from front to back. The front and rear of the runway-shaped cavity are filled with fillers, and a runway-shaped gap area is formed between the runway-shaped cavity and the fillers at its front and rear. 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-to-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-to-back direction, and the thickness directions are respectively along the radial direction of their semicircular ring cross-sections.

[0034] Embodiment 3: This embodiment is basically the same as Embodiment 2, except that: in this embodiment, the curtain voltage plate 3 includes a second metal plate 10 and a third metal plate 11, the second metal plate 10 is a rectangular parallelepiped structure, the third metal plate 11 is a cylindrical structure, the length direction of the second metal plate 10 is along the front-to-back direction, the width direction is along the up-down direction, 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 to and in contact with the right end face of the second metal plate 10, the diameter of the third metal plate 11 is smaller than the smaller of the length and width of the second metal plate 10, the central axis of the third metal plate 11 is in the same straight line as the center line of the second metal plate 10 in the left-right direction, and the second metal plate 10 and the third metal plate 11 are provided with a first cylindrical shaped hole 12, a second cylindrical hole 13 is provided on the third metal plate 11, the first cylindrical hole 12 and the second cylindrical hole 13 are coaxial with the third metal plate 11, and the diameter is smaller than the diameter 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 the diameter of the first cylindrical hole 12, the left end face of the second cylindrical hole 13 is connected with the right end face of the first cylindrical hole 12, and are in a fitted state, the right end face of the second cylindrical hole 13 is flush with the right end face of the third metal plate 11, and the right end face of the second cylindrical hole 13 is connected with the gas channel 4, and the gas entering through the gas channel 4 can enter the second cylindrical hole 13 and the first cylindrical hole 12 in sequence, and escape through the first cylindrical hole 12.

[0035] In this embodiment, Figure 4 and Figure 5As shown, a high-field asymmetric waveform ion mobility spectrometer further includes a first shell 14 and a second shell 15. The first shell 14 is located on the right side of the second metal plate 10. The first shell 14 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 14 and the upper end face of the second metal plate 10 are located in the same plane, the lower end face of the first shell 14 and the lower end face of the second metal plate 10 are located in the same plane, the front end face of the first shell 14 and the front end face of the second metal plate 10 are located in the same plane, the rear end face of the first shell 14 and the rear end face of the second metal plate 10 are located in the same plane, and the left end face of the first shell 14 and the second metal plate 10 are located in the same plane. The right end face is fixed and in a fitted state. A gas channel 4 is provided on the first shell 14. The gas channel 4 is a cylindrical hole that passes through from left to right. The third metal plate 11 is located in the gas channel 4, and the two are coaxial. The right end face of the third metal plate 11 is located on the left side of the right end face of the gas channel 4. An air inlet 16 is respectively provided at the upper and lower ends of the first shell 14 to connect the gas channel 4 with the outside. The diameter of the gas channel 4 is larger than the diameter of the third metal plate 11 and smaller than the smaller of the length and width of the first shell 14. The second shell 15 is located on the right side of the first shell 14. The second shell 15 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 surface of the shell 15 is located in the same plane as the upper end surface of the first shell 14, the lower end surface of the second shell 15 is located in the same plane as the lower end surface of the first shell 14, the front end surface of the second shell 15 is located in the same plane as the front end surface of the first shell 14, the rear end surface of the second shell 15 is located in the same plane as the rear end surface of the first shell 14, the left end surface of the second shell 15 is fixed to the right end surface of the first shell 14 and is in a fitted state, the second shell 15 has a rectangular cavity 17 that runs through the left and right sides, the length direction of the rectangular cavity 17 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 17 is docked with the gas channel 4, and the thickness and width of the rectangular cavity 17 are both greater than the gas channel 4 The diameter of the first metal plate is , The left end face of the first metal plate is flush with the left end face 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, The thickness is equal to the thickness of the cuboid cavity 17, A third cylindrical hole 18 is provided on the first metal plate, Extending from its left end face to communicate with the first gap 5, The first metal plate is provided with a fourth cylindrical hole 19, Extending from its right end face to communicate with the third gap 7, The third cylindrical hole 18 and the fourth cylindrical hole 19 are coaxial with the second cylindrical hole 13, 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.

[0036] In this embodiment, a first protrusion 20 protruding toward the rear side is provided on the front end surface of the rectangular cavity 17. The first protrusion 20 is runway-shaped. 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-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 provided on the rear end surface of the rectangular cavity 17. The first protrusion 20 and the second protrusion are symmetrical front to back and face the runway-shaped cavity. The first protrusion 20 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 sealing the front-to-back direction of the runway-shaped cavity and forming a runway-shaped gap area.

[0037] In this embodiment, the first protrusion 20 and the second protrusion can not only prevent the gas from carrying gas-phase ions out, but also ensure that the width of the racetrack-shaped gap area along the front-to-back direction remains consistent at any point, thereby avoiding the difference in width of the racetrack-shaped gap area along the front-to-back direction, which causes the offset distance of the gas-phase ions at the second gap 6 and the fourth gap 8 due to the high-voltage asymmetric electric field to change, making it impossible for the third DC electric field to 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.

[0038] Example 4: This example is basically the same as Example 1, except that: in this example, 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.

[0039] In this embodiment, for analyte ions of a specific structure whose position can be maintained in the middle area of ​​the racetrack-type gap area, they have specific motion trajectory characteristics in the racetrack-type high-field asymmetric waveform ion mobility spectrometer. For analyte ions of a specific structure whose position can be maintained in the middle area of ​​the racetrack-type gap area, such ions will first be focused in the middle area of ​​the first gap 5 by the focusing effect of the cylindrical high-field asymmetric waveform ion mobility spectrometer, but there are multiple analyte ions of specific structures in the first gap 5 that are focused; the analyte ions of specific structure focused in the middle area of ​​the first gap 5 will be pushed by 30% of the gas entering the first gap 5, and will enter the two parallel plane areas of the second gap 6 and the fourth gap 8 from the middle area of ​​the first gap 5. In these two parallel plane areas, analyte ions of different structures will be efficiently separated; under the action of a specific scanning voltage, only analyte ions of a single specific structure can not deviate toward the separation voltage plate 2 or the compensation voltage plate 1; for analyte ions of a single specific structure that will not deviate toward the separation voltage plate 2 or the compensation voltage plate 1, The fixed structure analyte ions will continue to move to the right side within the two parallel plane areas under the push of the 30% gas entering the two parallel plane areas; in this process, the volume of the ion clusters formed by all single specific structure analyte ions that will not deviate toward the separation voltage plate 2 or the compensation voltage plate 1 will continue to expand under the action of Coulomb repulsion and thermal diffusion, causing some single specific structure analyte ions to collide with the separation voltage plate or the compensation voltage plate and be neutralized; for the specific structure analyte ions that can pass through the two parallel plane areas, they will be refocused in the middle area at the third gap 7, and finally pass through the fourth cylindrical hole 19 under the push of the 30% gas entering the third gap 7, and enter the detector in the form of a dense ion cluster to be detected, ensuring the high ion transmission efficiency between the racetrack-type high-field asymmetric waveform ion mobility spectrometer and the detector.

[0040] The present invention also discloses a method for using the high-field asymmetric waveform ion mobility spectrometer. The method for using the high-field asymmetric waveform ion mobility spectrometer of the present invention is further described in detail below with reference to the accompanying drawings and embodiments.

[0041] Example 1: A method for using a high-field asymmetric waveform ion mobility spectrometer, comprising the following steps:

[0042] Step 1: Connect the separation voltage plate 2 to a high-field asymmetric voltage as a 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.

[0043] 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 changes at a constant rate within a range of -200 V to +200 V, with a scanning frequency of 1 V / min. The compensation voltage plate 1 generates a DC electric field that changes as the scanning voltage connected thereto changes, i.e., a third DC electric field.

[0044] Step 3: Connect the curtain voltage plate 3 to a DC voltage serving as the curtain voltage, wherein the DC voltage is kept constant and set to a value between 500 V and 2500 V, preferably 1000 V;

[0045] Step 4: using the electrospray ion source 9 to convert the sample to be tested into a charged droplet spray;

[0046] Step 5: Introduce gas into the gas channel 4 through the two gas inlets 16 on the first housing 14. The gas introduced may be nitrogen or a mixture of nitrogen and at least one of hydrogen, helium, and water vapor in any proportion. The total flow rate of the introduced gas is 0.5 L / min to 15 L / min, and the gas flow rate of each gas inlet is half of the total flow rate of the gas introduced into the gas channel 4.

[0047] Step 6: Based on the difference in cross-sectional area 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. The 70% of the gas entering the first cylindrical hole 12 dries the charged droplet spray formed by the electrospray ion source 9 to form gas-phase 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 gas-phase ions pass through the gas channel 4 in sequence. 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 act together on the gas-phase ions, pushing the gas-phase ions through the third cylindrical hole 18 and then into the first gap 5.

[0048] Step 7: The high-voltage asymmetric electric field and the third DC electric field act together on the gas-phase ions at the first gap 5, focusing the gas-phase ions to the middle region of the first gap 5 along the radial direction of the semicircular cross-section. Then, the gas entering the first gap 5 pushes the focused gas-phase ions to the second gap 6 and the fourth gap 8.

[0049] Step 8. Due to structural differences, gas-phase ions of analytes of different structures are deflected toward the separation voltage plate 2 or the compensation voltage plate 1 under the action of the high-voltage asymmetric electric field, and move in the deflected direction at different speeds, thereby achieving separation in the vertical direction, that is, the vertical distance. At the same time, 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 between the second gap 6 and the fourth gap 8 in the vertical direction. Gas-phase ions of a specific structure that can maintain their position in the middle region between the second gap 6 and the fourth gap 8 in the vertical direction will be pushed by 30% of the gas entering the second gap 6 and the fourth gap 8 and move from the second gap 6 and the fourth gap 8 toward the third gap 7. Gas-phase ions of other structures will collide with the separation voltage plate 2 or the compensation voltage plate 1 and be neutralized.

[0050] Step 9. When the gas-phase ions of a specific structure that can be maintained in the middle area between the second gap 6 and the fourth gap 8 in the vertical direction are pushed to enter the third gap 7, the high-voltage asymmetric electric field and the third DC electric field jointly act on the gas-phase ions at the third gap 7, so that the gas-phase ions are focused to the middle area of ​​the third gap 7 along the radial direction of its semicircular ring cross-section, 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 of different structures can stably leave the high-field asymmetric waveform ion mobility spectrometer under different scanning voltages and be detected, thereby obtaining the isomer ion distribution spectrum of the sample to be tested.

[0051] Example 2: This example is basically the same as Example 1, except that in this example, when detecting the ion mass-to-charge ratio and signal intensity, the detector is a mass spectrometer, and 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 receiving a scanning voltage, a separation voltage plate for receiving a separation voltage, a curtain voltage plate for receiving 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 vertical direction, and the two are symmetrically arranged. The second gap and the fourth gap are both rectangular parallelepiped structure gaps, and the two are symmetrically arranged in the vertical direction. 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, and a DC electric field is generated, 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, which 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 field The field and the gas act together on the gas-phase ions, pushing the gas-phase ions into the first gap. The high-voltage asymmetric electric field and the third DC electric field act together on the gas-phase ions at the first gap, focusing 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 and down directions. The third DC electric field compensates for the offset 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 and down directions. 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 field act together on the gas-phase ions at the third gap, causing 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 runway-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 runway-shaped cavity penetrates the first metal plate from front to back. The front and rear of the runway-shaped cavity are filled with fillers. The runway-shaped gap area is formed between the runway-shaped cavity and the fillers at its 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-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 a fitted state 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 is in the same straight line with the center line of the second metal plate in the left-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 the diameter 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 sequence, 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. And 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, and the upper end and lower end of the first shell are respectively provided with an air inlet that connects the gas channel with the outside, and the diameter of the gas channel is greater than the diameter of the third metal plate and is 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, and 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 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 face of the second shell is located in the same plane, the front end face of the second shell is located in the same plane as the front end face of the first shell, the rear end face of the second shell is located in the same plane as the rear end face of the first shell, the left end face of the second shell is fixed and fitted with the right end face of the first shell, the second shell has a rectangular cavity running through it from left to 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 docked with the gas channel, the thickness and width of the rectangular cavity are both greater than the diameter of the gas channel, the first metal plate is located in the rectangular cavity, and the second 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. The high-field asymmetric waveform ion mobility spectrometer according to claim 4, characterized in that A first protrusion protruding toward the rear side is provided 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 provided on the rear end surface of the rectangular cavity. The first protrusion and the second protrusion are symmetrical front to back and are facing 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 sealing 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 either nitrogen or a mixed gas formed by mixing nitrogen with at least one of hydrogen, helium and water vapor in any proportion.

7. A method for using the high-field asymmetric waveform ion mobility spectrometer according to claim 4, characterized in that The following steps are involved: Step 1: Connecting the separation voltage plate to a high-field asymmetric voltage as a separation voltage, wherein the separation voltage plate generates a high-voltage asymmetric electric field, wherein the high-field asymmetric voltage adopts a square wave or a double sine wave, has 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 in the range of 1 kHz to 100 MHz; Step 2: Connecting the compensation voltage plate to a DC compensation voltage serving as a scanning voltage, wherein the DC compensation voltage is a scanning voltage that changes at a constant rate within a range of -200 V to +200 V, and a scanning frequency of 1 V / min. The compensation voltage plate generates a DC electric field that changes as the scanning voltage connected thereto changes, i.e., a third DC electric field. Step 3: Connecting the curtain voltage plate to a DC voltage serving as a curtain voltage, wherein the DC voltage is kept constant and set to a value between 500 V and 2500 V; Step 4: using an electrospray ion source to convert the sample to be tested into a charged droplet spray; Step 5: Introducing gas into the gas channel through the two gas inlets on the first shell, where the gas may be nitrogen or a mixture of nitrogen and at least one of hydrogen, helium, and water vapor in any proportion; the total flow rate of the gas introduced is 0.5 L / min to 15 L / min, and the gas flow rate of each gas inlet is half of the total flow rate of the gas introduced into the gas channel; Step 6: Based on the difference in cross-sectional area between the second cylindrical hole and the third cylindrical hole, 70% of the gas in the gas channel enters the first cylindrical hole through the second cylindrical hole, and 30% of the gas enters the first gap through the third cylindrical hole. The 70% of the gas entering the first cylindrical hole dries the charged droplets formed by the electrospray ion source to form gas-phase ions of the analysis sample. Under the action of a first DC electric field generated by the potential difference between the curtain voltage plate and the electrospray ion source, the gas-phase ions sequentially pass through the gas channel. At this time, a second DC electric field generated by the potential difference between the curtain voltage plate and the compensation voltage plate and 30% of the gas in the gas channel act together on the gas-phase ions, pushing the gas-phase ions through the third cylindrical hole and then into the first gap. Step 7: The high-voltage asymmetric electric field and the third DC electric field act together on the gas-phase ions at the first gap, focusing the gas-phase ions to the middle region of the first gap along the radial direction of the semicircular cross-section of the first gap. Then, the gas entering the first gap pushes the focused gas-phase ions to the second gap and the fourth gap. Step 8. Due to structural differences, gas-phase ions of analytes of different structures are deflected toward the separation voltage plate or the compensation voltage plate under the action of the high-voltage asymmetric electric field, and move in the deflected direction at different speeds, thereby achieving separation in the vertical direction, i.e., vertical distance. Simultaneously, 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 between the second gap and the fourth gap in the vertical direction. Gas-phase ions of a specific structure that can be maintained in the middle region between the second gap and the fourth gap in the vertical direction will be pushed by 30% of the gas entering the second gap and the fourth gap, moving from the second gap and the fourth gap toward the third gap. Gas-phase ions of other structures will collide with the separation voltage plate or the compensation voltage plate and be neutralized. Step 9. When the gas-phase ions of a specific structure that can be maintained in the middle area between the second gap and the fourth gap in the vertical direction are pushed to enter the third gap, the high-voltage asymmetric electric field and the third DC electric field jointly act on the gas-phase ions at the third gap, so that the gas-phase ions are focused to the middle area of ​​the third gap along the radial direction of its semicircular ring cross-section, and then enter the fourth cylindrical hole under the push of 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 analyte ions of different structures can stably leave the high-field asymmetric waveform ion mobility spectrometer under the action of different scanning voltages and be detected, thereby obtaining the isomer ion distribution spectrum of the sample to be tested.

8. The method for using a high-field asymmetric waveform ion mobility spectrometer according to claim 7, characterized in that When the ion mass-to-charge ratio and signal intensity are detected, the detector is a mass spectrometer; when the ion current signal intensity is detected, the detector is an electrometer.

Images