A method for controlling pulsed drift gas to improve the peak height of ion mobility spectra

Abstract

This invention provides a method for controlling pulsed drift gas to improve the peak height of ion mobility spectra, comprising the following steps: drift gas is introduced into the ion mobility tube from a Faraday disk, blown through the migration region and ion gate, and discharged from the outlet before the lamp ionization source in the reaction region; carrier gas is introduced into the ion mobility tube from the side of the ion gate near the reaction region, blown through the reaction region, and discharged from the outlet before the lamp ionization source in the reaction region; within a certain time interval, the drift gas flow rate is rapidly switched between high and low flow rates to generate pulsed drift gas; the sample to be tested is connected in series in the carrier gas path, and the sample to be tested is carried into the ion mobility tube by the carrier gas for ionization and detection, thereby improving the ion peak height. This invention improves the peak height of ion mobility spectra by rapidly controlling the pulsed drift gas change, i.e., rapidly switching the drift gas between two flow rates.

Description

Technical Field

[0001] This invention relates to the field of ion mobility spectroscopy, and more particularly to a method for controlling pulsed drift gas to increase the peak height of ion mobility spectra. Background Technology

[0002] Ion mobility spectrometry (IMS) is a technique that analyzes chemical substances by ionizing gaseous molecules using an ionization source and analyzing the differences in migration velocities of different gaseous ions in the same electric field. It is widely used in the rapid screening and detection of explosives, drugs, and toxic agents at the scene.

[0003] In ion mobility spectrometry (IMP), drift gas is a crucial analytical condition, ensuring the normal operation of the IMP spectrometer, signal stability, and detection effectiveness. Through its interaction with product ions, the drift gas helps to effectively distinguish different substances and removes neutral impurity molecules, ensuring the cleanliness of the migration zone. In an IMP spectrometer, product ions formed after sample ionization drift towards the signal receiving Faraday disk under the influence of an electric field. The presence of drift gas can collide with these ions, thus affecting their migration path and speed. Different substances generate product ions with different migration rates under the same electric field. Therefore, by measuring the time required for ions to traverse the drift zone, the ion migration rate can be calculated, and the detected substance can be identified accordingly. The drift gas flow rate and stability directly affect the ion migration time within the drift tube. Different drift gas flow rates and their fluctuations will lead to variations in ion migration time, thereby affecting the accuracy of the analytical results.

[0004] Among existing ion mobility spectrometry (IMS) techniques, Li Haiyang et al. invented an IMS pulse-purge negative pressure thermal desorption sampler and injection method (patent number 202111535952.X), which combines pulse-purge, negative pressure, and thermal desorption techniques for detecting solid, liquid, and gaseous samples. The sample undergoes a phase transition under negative pressure, and the gaseous sample molecules are carried into the ion mobility spectrometer by the carrier gas during pulse-purge for ionization and detection. The invention's pulse purge inlet is connected to the purge gas, which, in conjunction with the rotary sample feeding mechanism, converts the liquid or solid sample to be tested into a gaseous sample. The pulse purge frequency is set to 50 Hz, and the pulse width is 10 ms. The negative pressure extraction port is connected to the ion mobility spectrometer for negative pressure extraction and sample feeding. The pressure in the thermal desorption chamber is 70 kPa, and the carrier gas flow rate is 400 mL / min. Under the conditions of a carrier gas switch pulse frequency of 50 Hz and a pulse width of 10 ms, the pressure in the thermal desorption chamber is 70 kPa. The stability of the pressure indicates the stability of the carrier gas flow rate, therefore the carrier gas flow rate is fixed.

[0005] Wang Xin et al. invented a control gas path for an ion mobility spectrometry analyzer (patent number 201911136713.X). Using ion mobility spectrometry as the basic detection technology, the flow rates and directions of the carrier gas and drift gas are alternately changed in three ways during sample introduction, standby, and system cleaning. The final stable flow rates and control methods of the carrier and drift gas reduce system contamination and facilitate accurate and highly sensitive quantification of target samples. This invention changes the flow direction of the carrier and drift gas, and through stable flow rates, meets the operational requirements of the carrier and drift gas during sample introduction, standby, and system cleaning, without involving periodic switching of the drift and carrier gas flow rates.

[0006] Chen Chuang et al. invented a photoionization ion migration tube (patent number 202210882322.8) with tunable reaction reagent ions. The ion migration tube contains a first ionization region, a second ionization region, and a third ionization region placed adjacent to each other from left to right. The first ionization region is for initial electron generation and ultraviolet light transmission path control; the second ionization region is for generating reaction reagent ions; and the third ionization region is for ionizing the sample to be tested. By rapidly switching the concentration of the dopant reagent in the first ionization region, different reaction reagent ions can be rapidly switched and generated with high purity in the second ionization region. Utilizing the difference in reaction selectivity between different reaction reagent ions, highly selective detection of the sample to be tested can be achieved. Alternatively, by utilizing the difference in product ions formed by different reaction reagent ions and the sample to be tested, more one-dimensional information can be provided for the qualitative and quantitative analysis of the sample to be tested. This invention enables rapid switching of the concentration of doped reagents in the first ionization region, allowing for rapid switching and high-purity generation of different reactive reagent ions in the second ionization region. The bleaching gas flow rate and the carrier gas flow rate are fixed, without altering the flow rates of either the bleaching gas or the carrier gas.

[0007] A higher drift gas velocity increases the migration time, which reduces the peak height of the gas ion to be measured; a lower drift gas velocity reduces the migration time, which increases the peak height of the gas ion to be measured.

[0008] The aforementioned common ion mobility spectrometry techniques produce relatively low ion intensities / peak heights, resulting in low sensitivity of the analytical methods. Therefore, new technologies are needed to increase ion peak heights and improve the sensitivity of the analytical methods. Summary of the Invention

[0009] To address the aforementioned technical problem of low peak heights in existing ion mobility spectrometry (IMS) techniques, this invention provides a method for controlling pulsed drift gas to increase peak heights in IMS. This invention primarily achieves the effect of increasing peak heights in IMS by controlling the pulsed drift gas.

[0010] The technical means employed in this invention are as follows:

[0011] A method for controlling pulsed drift gas to improve the peak height of ion mobility spectra includes the following steps:

[0012] The drift gas is fed into the ion migration tube from the Faraday disk. The drift gas is blown through the migration zone and the ion gate, and is discharged from the gas outlet in front of the lamp ionization source in the reaction zone.

[0013] The carrier gas is fed into the ion migration tube from the side of the ion gate near the reaction zone. The carrier gas is blown through the reaction zone and discharged from the outlet in front of the lamp ionization source in the reaction zone.

[0014] Within a certain time interval, the drift gas velocity is controlled to switch rapidly between high and low velocity to generate pulsed drift gas.

[0015] The sample to be tested is connected in series in the carrier gas path. The sample to be tested is carried by the carrier gas into the ion migration tube for ionization and detection.

[0016] The drift gas flows axially along the migration zone of the ion migration tube. When the drift gas rapidly switches between high and low flow rates, it alters the collision behavior between the sample ions and drift gas molecules in the migration zone. This causes the collisions between the sample ions and drift gas molecules in the migration zone to produce axially fluctuating collisions, which weakens the radial diffusion of the sample ions or causes radially diffused ions to return to the central axis, thereby increasing the ion signal intensity / peak height.

[0017] Furthermore, the sample to be tested is one of the following: a gas sample, a gas sample generated by heating a liquid sample, or a gas sample generated by heating a solid sample.

[0018] Furthermore, the method for controlling pulsed drift gas to improve the peak height of the ion migration spectrum is based on an ion migration tube, which includes a lamp ionization source, an ion gate, an electrode ring and an insulating ring, a Faraday disk, and a voltage divider plate.

[0019] The reaction zone is formed between the lamp ionization source, the electrode ring and the insulating ring, and the ion gate. A carrier gas port and a gas outlet are provided in the reaction zone.

[0020] The ion gate, electrode ring, insulating ring, and Faraday disk form a migration zone, and a drift gas port is provided on the side of the Faraday disk.

[0021] Furthermore, the high flow rate of the bleaching gas is 1 L / min, and the low flow rate of the bleaching gas is 0.3 L / min.

[0022] Furthermore, the specified time interval is between 1 and 20 seconds.

[0023] Furthermore, when the drifting flow rate rapidly switches between high and low flow rates, the response speed from low to high flow rate is between 0.6 and 1.1 seconds.

[0024] Furthermore, when the drifting flow rate rapidly switches between high and low flow rates, the response speed from high to low flow rate is between 0.6 and 1.1 seconds.

[0025] Furthermore, the sample to be tested is acetone. The acetone liquid is placed in a reagent bottle with a vent hole on the cap, through which volatile acetone gas is released. At a constant temperature, the amount of acetone volatilized is constant.

[0026] Compared with the prior art, the present invention has the following advantages:

[0027] In common ion mobility spectrometry (IMP) techniques, the carrier gas flow rate and drift gas flow rate are constant, resulting in relatively low ion intensity / peak height values, leading to low sensitivity of the analytical method. Therefore, new technologies are needed to increase ion peak height and improve the sensitivity of the analytical method. This invention improves ion mobility spectrometry peak height by rapidly controlling pulsed drift gas changes, i.e., rapidly switching the drift gas between two flow rates.

[0028] The drift gas flows axially along the migration zone of the ion migration tube. Under normal circumstances, when the drift gas flow rate is constant at a high flow rate, the number of axial collisions between sample ions and drift gas molecules in the migration zone increases, and the radial diffusion of ions is greater. As a result, the migration time of ions increases, and the ion signal intensity / peak height decreases accordingly. Conversely, when the drift gas flow rate is constant at a low flow rate, the number of axial collisions between sample ions and drift gas molecules in the migration zone decreases, and the radial diffusion of ions decreases. As a result, the migration time of ions decreases, and the ion signal intensity / peak height increases accordingly.

[0029] This invention controls the pulsed drift gas, i.e., the drift gas rapidly switches between two flow rates, high and low, which changes the collision behavior between sample ions and drift gas molecules in the migration region. This makes the collision between sample ions and drift gas molecules in the migration region an axially fluctuating collision, which weakens the radial diffusion of ions or causes radially diffused ions to return to the central axis. As a result, the ion signal intensity / peak height is improved. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0031] Figure 1 This is a flowchart of the method of the present invention.

[0032] Figure 2 This is a peak height tracking diagram for improving the peak height of ion mobility spectra by controlling pulsed drift gas according to the present invention.

[0033] Figure 3 The drift gas flow rate diagram is for the purpose of controlling pulsed drift gas to improve the peak height of ion migration spectrum according to the present invention. Detailed Implementation

[0034] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0035] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0036] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0037] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of the invention. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following figures denote similar items; therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0038] The sample to be tested is one of the following: a gas sample, a gas sample generated by heating a liquid sample, or a gas sample generated by heating a solid sample.

[0039] The method of the present invention is based on an ion migration tube, which includes a lamp ionization source, an ion gate, an electrode ring and an insulating ring, a Faraday disk, and a pressure dividing plate; the lamp ionization source, the electrode ring and the insulating ring, and the ion gate form a reaction zone, and a carrier gas port and a gas outlet are provided in the reaction zone; the ion gate, the electrode ring and the insulating ring, and the Faraday disk form a migration zone, and a drift gas port is provided on the side of the Faraday disk.

[0040] like Figure 1 As shown, the present invention provides a method for controlling pulsed gas drift to improve the peak height of ion mobility spectra, comprising the following steps:

[0041] The drift gas is fed into the ion migration tube from the Faraday disk. The drift gas is blown through the migration zone and the ion gate, and is discharged from the gas outlet in front of the lamp ionization source in the reaction zone.

[0042] The carrier gas is fed into the ion migration tube from the side of the ion gate near the reaction zone. The carrier gas is blown through the reaction zone and discharged from the outlet in front of the lamp ionization source in the reaction zone.

[0043] Preferably, the sample to be tested is acetone. The acetone liquid is placed in a reagent bottle with a vent hole on the cap, through which the volatile acetone gas sample is released. At a constant temperature, the amount of acetone volatilization is constant.

[0044] The sample to be tested is connected in series in the carrier gas path. The sample to be tested is carried by the carrier gas into the ion migration tube for ionization and detection.

[0045] Within a certain time interval, the drift gas velocity is rapidly switched between high and low velocity to generate pulsed drift gas; the high velocity of the drift gas is 1 L / min, and the low velocity of the drift gas is 0.3 L / min. The certain time interval is between 1 and 20 seconds.

[0046] When the drifting current speed rapidly switches between high and low flow rates, the response time from low to high flow rate is between 0.6 and 1.1 seconds.

[0047] Figure 2This is a peak height tracking diagram for improving ion mobility spectrum peak height by controlling pulsed drift gas according to the present invention. The drift gas flow rates are: low flow rate 0.3 L / min (tracking time 0-50 s), high flow rate 0.5 L / min (tracking time 50-100 s), and high flow rate 1.0 L / min (tracking time 100-200 s). After 200 s, the drift gas flow rate switches between high and low flow rates. The pulse intervals from left to right are: 20 seconds (tracking time 200-340 s), 10 seconds (tracking time 340-400 s), 5 seconds (tracking time 400-450 s), 3 seconds (tracking time 450-500 s), and 1 second (tracking time 500-650 s).

[0048] Figure 3 This is a flow rate diagram for controlling pulsed drift gas to improve the peak height of ion mobility spectra according to the present invention. The drift gas flow rates are: low flow rate 0.3 L / min (tracking time 0-50 s), high flow rate 0.5 L / min (tracking time 50-100 s), and high flow rate 1.0 L / min (tracking time 100-200 s). After 200 s, the drift gas flow rate switches between high and low flow rates. The pulse intervals from left to right are: 20 s (tracking time 200-340 s), 10 s (tracking time 340-400 s), 5 s (tracking time 400-450 s), 3 s (tracking time 450-500 s), and 1 s (tracking time 500-650 s).

[0049] Example 1

[0050] A method for controlling pulsed drift gas to improve the peak height of ion mobility spectra, wherein the analytical conditions for ion mobility spectra are as follows:

[0051] The migration tube temperature was 110℃, the migration zone inner diameter was 16mm and the length was 7cm, the high voltage was 9.9kv, the opening time was 50us, the carrier gas was 0.1L / min, the drift gas and the carrier gas flowed in the same direction, the outlet was at the end of the reaction zone, and acetone volatile gas at 33℃ was used as a dopant for analysis.

[0052] When the bleaching gas flow rate is fixed at 0.3 L / min, the migration time of acetone is 3.42 ms and the peak height is 1.8 V; when the bleaching gas flow rate is fixed at 1.0 L / min, the migration time of acetone is 3.5 ms and the peak height is 0.8 V. The difference between the migration times of 3.42 ms and 3.5 ms is taken as 1, respectively. By normalizing the peak migration times of substances under various conditions, qualitative and quantitative comparisons and analyses can be achieved.

[0053] The low flow rate of the bleaching gas was set to 0.3 L / min and the high flow rate was set to 1.0 L / min. The bleaching gas was controlled to switch rapidly between the low and high flow rates. The pulse interval between the switching was changed from 5 to 1 second. The minimum peak height, maximum peak height, peak height difference, and the ratio of the average peak height in pulse mode to the peak height in no pulse mode are shown in the table below.

[0054] Switching the pulsed drift gas flow rate between 0.3 L / min and 1.0 L / min resulted in an enhancement factor of 4.4 to 5.3 times for the peak signal of the ion migration spectrum.

[0055] When the drifting flow rate rapidly switches between high and low flow rates, the response time from low to high flow rate is 0.6 seconds; the response time from high to low flow rate is 0.6 seconds.

[0056]

[0057] Example 2

[0058] A method for controlling pulsed drift gas to improve the peak height of ion mobility spectra, wherein the analytical conditions for ion mobility spectra are as follows:

[0059] The migration tube temperature was 110℃, the migration zone inner diameter was 16mm and the length was 7cm, the high voltage was 9.9kv, the opening time was 50us, the carrier gas was 0.1L / min, the drift gas and the carrier gas flowed in the same direction, the outlet was at the end of the reaction zone, and acetone volatile gas at 33℃ was used as a dopant for analysis.

[0060] When the bleaching gas flow rate is fixed at 0.3 L / min, the migration time of acetone is 3.42 ms and the peak height is 1.8 V; when the bleaching gas flow rate is fixed at 0.5 L / min, the migration time of acetone is 3.46 ms and the peak height is 1.2 V. The difference between the migration times of 3.42 ms and 3.46 ms is taken as 1, respectively. By normalizing the peak migration times of substances under various conditions, qualitative and quantitative comparisons and analyses can be achieved.

[0061] The low flow rate of the bleaching gas was set to 0.3 L / min and the high flow rate was set to 0.5 L / min. The bleaching gas was controlled to switch rapidly between the low and high flow rates. The pulse interval between the switching was changed from 20 to 1 second. The minimum peak height, maximum peak height, peak height difference, and the ratio of the average peak height in pulse mode to the peak height in no pulse mode are shown in the table below.

[0062] By controlling the pulsed drift gas flow rate to switch between 0.3 L / min and 0.5 L / min, the signal enhancement factor of the ion migration spectrum peak was 1.9 to 2.5 times.

[0063] When the drifting flow rate rapidly switches between high and low flow rates, the response time from low to high flow rate is 1.1 seconds; the response time from high to low flow rate is 1.1 seconds.

[0064]

[0065]

[0066] Example 3

[0067] A method for controlling pulsed drift gas to improve the peak height of ion mobility spectra, wherein the analytical conditions for ion mobility spectra are as follows:

[0068] The migration tube temperature was 110℃, the migration zone inner diameter was 16mm and the length was 7cm, the high voltage was 9.9kv, the opening time was 50us, the carrier gas was 0.1L / min, the drift gas and the carrier gas flowed in the same direction, the outlet was at the end of the reaction zone, and acetone volatile gas at 33℃ was used as a dopant for analysis.

[0069] When the bleaching gas flow rate is fixed at 0.3 L / min, the migration time of acetone is 3.42 ms and the peak height is 1.8 V; when the bleaching gas flow rate is fixed at 0.7 L / min, the migration time of acetone is 3.49 ms and the peak height is 0.9 V. The difference between the migration times of 3.42 ms and 3.49 ms is taken as 1, respectively. By normalizing the peak migration times of substances under various conditions, qualitative and quantitative comparisons and analyses can be achieved.

[0070] The low flow rate of the drift gas was set to 0.3 L / min and the high flow rate was set to 0.7 L / min. The drift gas was controlled to switch rapidly between the low and high flow rates. The pulse interval between the switching was changed from 20 to 1 second. The minimum peak height, maximum peak height, peak height difference, and the ratio of the average peak height in pulse mode to the peak height in no pulse mode are shown in the table below.

[0071] By controlling the pulsed drift gas flow rate to switch between 0.3 L / min and 0.7 L / min, the signal enhancement factor of the ion migration spectrum peak was 3.0 to 3.9 times.

[0072] When the drifting flow rate rapidly switches between high and low flow rates, the response time from low to high flow rate is 0.9 seconds; the response time from high to low flow rate is 0.9 seconds.

[0073]

[0074]

[0075] Example 4

[0076] A method for controlling pulsed drift gas to improve the peak height of ion mobility spectra, wherein the analytical conditions for ion mobility spectra are as follows:

[0077] The migration tube temperature was 110℃, the migration zone inner diameter was 16mm and the length was 7cm, the high voltage was 9.9kv, the opening time was 50us, the carrier gas was 0.1L / min, the drift gas and the carrier gas flowed in the same direction, the outlet was at the end of the reaction zone, and acetone volatile gas at 33℃ was used as a dopant for analysis.

[0078] The low flow rate of the drift gas was set to 0.3 L / min, and the high flow rate of the drift gas was set to 0.5 to 1.0 L / min. The drift gas was controlled to switch rapidly between the low flow rate and the high flow rate. The pulse interval between the switching was fixed at 3 seconds. The minimum peak height, maximum peak height, peak height difference, and the ratio of the average peak height in pulse mode to the peak height in no pulse mode are shown in the table below.

[0079] By controlling the pulsed drift gas flow rate to switch between 0.3 L / min and 0.5-1.0 L / min, the signal enhancement factor of the ion migration spectrum peak was 1.8 to 4.7 times.

[0080] When the drifting flow rate rapidly switches between high and low flow rates, the response time from low to high flow rate is 1.0 second; the response time from high to low flow rate is 1.0 second.

[0081]

[0082]

[0083] Example 5

[0084] A method for controlling pulsed drift gas to improve the peak height of ion mobility spectra, wherein the analytical conditions for ion mobility spectra are as follows:

[0085] The migration tube temperature was 110℃, the migration zone inner diameter was 16mm and the length was 7cm, the high voltage was 9.9kv, the opening time was 50us, the carrier gas was 0.1L / min, the drift gas and the carrier gas flowed in the same direction, the outlet was at the end of the reaction zone, and acetone volatile gas at 33℃ was used as a dopant for analysis.

[0086] The low flow rate of the drift gas was set to 0.3 L / min, and the high flow rate of the drift gas was set to 0.5 to 1.0 L / min. The drift gas was controlled to switch rapidly between the low flow rate and the high flow rate. The pulse interval between the switching was fixed at 1 second. The minimum peak height, maximum peak height, peak height difference, and the ratio of the average peak height in pulse mode to the peak height in no pulse mode are shown in the table below.

[0087] Switching the pulsed drift gas flow rate between 0.3 L / min and 0.5-1.0 L / min resulted in an enhancement factor of 2.1 to 4.8 times for the peak signal of the ion migration spectrum.

[0088] When the drifting flow rate rapidly switches between high and low flow rates, the response time from low to high flow rate is 1.0 second; the response time from high to low flow rate is 1.0 second.

[0089]

[0090]

[0091] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for controlling pulsed drift gas to improve the peak height of ion mobility spectra, characterized in that, Includes the following steps: The drift gas is fed into the ion migration tube from the Faraday disk. The drift gas is blown through the migration zone and the ion gate, and is discharged from the gas outlet in front of the lamp ionization source in the reaction zone. The carrier gas is fed into the ion migration tube from the side of the ion gate near the reaction zone. The carrier gas is blown through the reaction zone and discharged from the outlet in front of the lamp ionization source in the reaction zone. Within a certain time interval, the drift gas velocity is controlled to switch rapidly between high and low velocity to generate pulsed drift gas. The sample to be tested is connected in series in the carrier gas path. The sample to be tested is carried by the carrier gas into the ion migration tube for ionization and detection. The drift gas flows axially along the migration zone of the ion migration tube. When the drift gas rapidly switches between high and low flow rates, it alters the collision behavior between the sample ions and drift gas molecules in the migration zone. This causes the sample ions and drift gas molecules to collide in the migration zone with axial undulating collisions, which weakens the radial diffusion of the sample ions or causes radially diffused ions to return to the central axis, thereby increasing the ion signal intensity / peak height.

2. The method for controlling pulsed gas drift to improve ion mobility peak height according to claim 1, characterized in that, The sample to be tested is one of the following: a gas sample, a gas sample generated by heating a liquid sample, or a gas sample generated by heating a solid sample.

3. The method for controlling pulsed gas drift to improve ion mobility peak height according to claim 1, characterized in that, The method for controlling pulsed drift gas to improve the peak height of ion mobility spectrum is based on an ion migration tube, which includes a lamp ionization source, an ion gate, an electrode ring and an insulating ring, a Faraday disk, and a voltage divider plate. The reaction zone is formed between the lamp ionization source, the electrode ring and the insulating ring, and the ion gate. A carrier gas port and a gas outlet are provided in the reaction zone. The ion gate, electrode ring, insulating ring, and Faraday disk form a migration zone, and a drift gas port is provided on the side of the Faraday disk.

4. The method for controlling pulsed gas drift to improve ion mobility peak height according to claim 1, characterized in that, The high flow rate of the bleaching gas is 1 L / min, and the low flow rate of the bleaching gas is 0.3 L / min.

5. The method for controlling pulsed gas drift to improve ion mobility peak height according to claim 1, characterized in that, The specified time interval is between 1 and 20 seconds.

6. The method for controlling pulsed gas drift to improve ion mobility peak height according to claim 1, characterized in that, When the drifting flow rate rapidly switches between high and low flow rates, the response time from low to high flow rate is between 0.6 and 1.1 seconds.

7. The method for controlling pulsed drift gas to improve ion mobility spectrum peak height according to claim 1, characterized in that, When the drifting flow rate rapidly switches between high and low flow rates, the response time from high to low flow rate is between 0.6 and 1.1 seconds.

8. The method for controlling pulsed drift gas to improve ion mobility spectrum peak height according to claim 1, characterized in that, The sample to be tested is acetone. The acetone liquid is placed in a reagent bottle with a vent hole on the cap, through which volatile acetone gas is released. At a constant temperature, the amount of acetone volatilized is constant.

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