A method for controlling pulsed carrier gas to improve ion mobility peak height

Abstract

This invention provides a method for controlling a pulsed carrier gas to improve the peak height of an ion mobility spectrum, comprising the following steps: a 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; a 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 carrier gas flow rate is rapidly switched between high and low flow rates to generate a pulsed carrier gas; the sample to be tested is connected in series in the carrier gas path, and the sample is carried by the carrier gas into the ion mobility tube for ionization and detection, thereby improving the ion peak height. This invention improves the peak height of the ion mobility spectrum by rapidly controlling the pulsed carrier gas change, i.e., rapidly switching the carrier 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 a pulsed carrier gas to increase the peak height of an ion mobility spectrum. 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), the carrier gas is a crucial analytical condition, ensuring the normal operation, signal stability, and detection performance of the IMP. The carrier gas is responsible for safely and efficiently transporting the sample to the reaction zone, ensuring a smooth detection process. Samples typically exist in the form of vapor or particles, which need to be carried into the reaction zone by the carrier gas to be ionized and form molecular ions. The carrier gas not only needs to effectively transport the sample but also avoid introducing impurities that may interfere with detection. Since the carrier gas participates in both sample transport and ion generation, different carrier gas flow rates typically lead to variations in sample carrying capacity and transport efficiency, thus affecting the quantity, efficiency, and types of ions generated. Therefore, IMP uses high-quality flow controllers to precisely regulate the carrier gas flow rate, ensuring its stability during analysis.

[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 high constant carrier gas flow rate results in a large dilution factor, and the lower the concentration of the gas mixture in the sample, the lower the ion peak height. Conversely, a low constant carrier gas flow rate results in a small dilution factor, and the higher the concentration of the gas mixture in the sample, the higher the ion peak height.

[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 increasing IMS peak heights by controlling a pulsed carrier gas. The invention primarily achieves this effect by controlling the pulsed carrier gas.

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

[0011] A method for controlling a pulsed carrier gas to improve the peak height of an ion mobility spectrum, characterized by comprising 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 carrier gas flow rate is controlled to switch rapidly between high and low flow rates to generate pulsed carrier 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 carrier gas enters radially along the reaction zone of the ion migration tube. When the carrier gas rapidly switches between high and low flow rates, the pulsed carrier gas alters the radial motion behavior of the sample molecules in the reaction zone, causing repeated fluctuations in the distance and time of movement of the sample molecules within the reaction zone. This increases the probability and number of sample molecules being ionized into sample ions, and increases the conversion rate of repeated collisions between sample molecules and ions, thereby improving the signal intensity / peak height of the sample ions.

[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 of controlling the pulsed carrier 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 carrier gas is 0.5 L / min, and the low flow rate of the carrier gas is 0.05 L / min.

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

[0023] Furthermore, when the carrier gas velocity 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.

[0024] Furthermore, when the carrier gas velocity 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.

[0025] Compared with the prior art, the present invention has the following advantages:

[0026] In common ion mobility spectrometry (IMS) 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 carrier gas changes, i.e., rapidly switching the carrier gas between two flow rates.

[0027] The carrier gas enters radially along the reaction zone of the ion migration tube. Sample molecules are ionized in the reaction zone to generate ions. When the carrier gas flows through the sample at a constant high flow rate, the sample concentration is low, the number of ions obtained from ionization is small, and the ion signal is low. When the carrier gas flows through the sample at a constant low flow rate, the sample concentration is high, the number of ions obtained from ionization is large, and the ion signal is high.

[0028] This invention controls the pulsed carrier gas, i.e., the carrier gas rapidly switches between two flow rates, high and low, which alters the radial motion behavior of sample molecules in the reaction zone. This causes repeated fluctuations in the distance and time of sample molecules within the reaction zone, increasing the probability and number of sample molecules being ionized into sample ions. It also increases the conversion rate of sample molecules and ions through repeated collisions and transformation into different ions, resulting in improved signal intensity / peak height of various ions. Attached Figure Description

[0029] 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.

[0030] Figure 1 This is a flowchart of the method of the present invention.

[0031] Figure 2 This is a peak height tracking diagram for improving the peak height of ion mobility spectra by controlling pulsed carrier gas according to the present invention.

[0032] Figure 3 The image shows the carrier gas flow rate for controlling pulsed carrier gas to improve the peak height of ion migration spectrum according to the present invention.

[0033] Figure 4 This is the ion migration spectrum of the acetone-butanone mixture when the carrier gas flow rate is fixed at 0.05 L / min according to the present invention.

[0034] Figure 5 This is the ion migration spectrum of the acetone-butanone mixture when the carrier gas flow rate is fixed at 0.5 L / min according to the present invention. Detailed Implementation

[0035] 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.

[0036] 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.

[0037] 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.

[0038] 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.

[0039] 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.

[0040] 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.

[0041] like Figure 1 As shown, the present invention provides a method for controlling a pulsed carrier gas to improve the peak height of an ion migration spectrum, comprising the following steps:

[0042] 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.

[0043] 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.

[0044] Preferably, the sample to be tested is acetone-butanone. The acetone-butanone mixture is placed in a reagent bottle with a small hole in the cap to release the volatile acetone-butanone mixture gas sample. At a constant temperature, the amount of acetone-butanone mixture volatilization is constant.

[0045] Within a certain time interval, the carrier gas flow rate is rapidly switched between high and low flow rates to generate pulsed carrier gas; the high flow rate of the carrier gas is 0.5 L / min, and the low flow rate of the carrier gas is 0.05 L / min. The certain time interval is between 1 and 20 seconds.

[0046] When the carrier gas velocity 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] The sample to be tested is connected in series in the carrier gas path. The sample is carried by the carrier gas into the ion migration tube for ionization and detection, thereby increasing the ion peak height.

[0048] Figure 2This is a peak height tracking diagram for improving ion mobility spectrum peak height by controlling pulsed carrier gas according to the present invention. From left to right, during the tracking time of 0-50 seconds, the carrier gas flow rate is constant at a low flow rate of 0.05 L / min; during the tracking time of 50-100 seconds, the carrier gas flow rate is constant at a high flow rate of 0.5 L / min; after the tracking time of 100 seconds, the carrier gas flow rate is pulsedly controlled between the high flow rate of 0.5 L / min and the low flow rate of 0.05 L / min, only changing the pulse interval time. The pulse interval times from left to right are 20 seconds (tracking time 100-200 seconds), 10 seconds (tracking time 200-300 seconds), 5 seconds (tracking time 300-400 seconds), 3 seconds (tracking time 400-500 seconds), and 1 second (tracking time 500-700 seconds).

[0049] Figure 3 This is a carrier gas flow rate diagram for controlling pulsed carrier gas to improve the peak height of ion mobility spectra according to the present invention. The high carrier gas flow rate is 0.5 L / min, and the low flow rate is 0.05 L / min. The pulse intervals for switching between high and low flow rates, from left to right, are 20, 10, 5, 3, and 1 second, respectively.

[0050] Figure 4 This is the ion migration spectrum of the acetone-butanone mixture when the carrier gas flow rate is fixed at 0.05 L / min. The acetone-butanone composite peak has a migration time of 3.64 ms and a peak height of 3.0 V.

[0051] Figure 5 This is the ion migration spectrum of the acetone-butanone mixture when the carrier gas flow rate is fixed at 0.5 L / min. The acetone-butanone composite peak has a migration time of 3.67 ms and a peak height of 1.9 V.

[0052] Example 1

[0053] A method for controlling the pulsed carrier gas to improve the peak height of ion mobility spectra, wherein the analytical conditions for ion mobility spectra are as follows:

[0054] 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 drift gas was 0.5L / min, the drift gas and the carrier gas flowed in the same direction, and the outlet was at the end of the reaction zone. A mixture of acetone and methyl ethyl ketone volatile gases at 33℃ was used as a dopant for analysis. There were three peaks in the analysis spectrum, of which the middle peak was the acetone-methyl ethyl ketone composite peak.

[0055] When the carrier gas flow rate is fixed at 0.05-0.5 L / min, the migration time of the acetone-butanone composite peak is 3.64 ms, and the peak height is 3.2-1.9 V.

[0056] The carrier gas low flow rate was set to 0.05 L / min and the carrier gas high flow rate to 0.5 L / min. The carrier gas was controlled to switch rapidly between the low and high flow rates. The pulse interval for switching was changed from 20 to 1 second. The minimum peak height, maximum peak height, peak height difference, and ratio of the average peak height in pulse mode to the peak height without pulse mode were obtained and are shown in the table below.

[0057] Switching the pulsed carrier gas rate between 0.05 L / min and 0.5 L / min resulted in an increase in the signal strength of the ion mobility spectrum peak by 1.4 to 2.1 times.

[0058] When the carrier gas velocity is rapidly switched between high and low flow rates, the response time from low flow rate to high flow rate is 0.6 seconds; the response time from high flow rate to low flow rate is 0.6 seconds.

[0059]

[0060]

[0061] Example 2

[0062] A method for controlling the pulsed carrier gas to improve the peak height of ion mobility spectra, wherein the analytical conditions for ion mobility spectra are as follows:

[0063] 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 drift gas was 0.5L / min, the drift gas and the carrier gas flowed in the same direction, and the outlet was at the end of the reaction zone. A mixture of acetone and methyl ethyl ketone volatile gases at 33℃ was used as a dopant for analysis. There were three peaks in the analysis spectrum, of which the middle peak was the acetone-methyl ethyl ketone composite peak.

[0064] When the carrier gas flow rate is fixed at 0.05-0.3 L / min, the migration time of the acetone-butanone composite peak is 3.64 ms, and the peak height is 3.2-2.4 V.

[0065] The carrier gas low flow rate was set to 0.05 L / min and the carrier gas high flow rate to 0.3 L / min. The carrier gas was controlled to switch rapidly between the low and high flow rates. The pulse interval for switching was changed from 20 to 1 second. The minimum peak height, maximum peak height, peak height difference, and ratio of the average peak height in pulse mode to the peak height without pulse mode are shown in the table below.

[0066] Switching the pulsed carrier gas rate between 0.05 L / min and 0.3 L / min resulted in an increase in the signal strength of the ion mobility spectrum peak by 1.4 to 2.2 times.

[0067] When the carrier gas velocity is rapidly switched between high and low flow rates, the response time from low flow rate to high flow rate is 1.1 seconds; the response time from high flow rate to low flow rate is 1.1 seconds.

[0068]

[0069]

[0070] Example 3

[0071] A method for controlling the pulsed carrier gas to improve the peak height of ion mobility spectra, wherein the analytical conditions for ion mobility spectra are as follows:

[0072] 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 drift gas was 0.5L / min, the drift gas and the carrier gas flowed in the same direction, and the outlet was at the end of the reaction zone. A mixture of acetone and methyl ethyl ketone volatile gases at 33℃ was used as a dopant for analysis. There were three peaks in the analysis spectrum, of which the middle peak was the acetone-methyl ethyl ketone composite peak.

[0073] When the carrier gas flow rate is fixed at 0.1-0.4 L / min, the migration time of the acetone-butanone composite peak is 3.64 ms and the peak height is 2.5-2.3 V.

[0074] The carrier gas low flow rate was set to 0.1 L / min and the carrier gas high flow rate to 0.4 L / min. The carrier gas was controlled to switch rapidly between the low and high flow rates. The pulse interval for switching was changed from 20 to 1 second. The minimum peak height, maximum peak height, peak height difference, and ratio of the average peak height in pulse mode to the peak height in no pulse mode are shown in the table below.

[0075] Switching the pulsed carrier gas rate between 0.1 L / min and 0.4 L / min resulted in an increase in the signal intensity of the ion mobility spectrum peak by 2.6 to 5.2 times.

[0076] When the carrier gas velocity is rapidly switched between high and low flow rates, the response time from low flow rate to high flow rate is 0.9 seconds; the response time from high flow rate to low flow rate is 0.9 seconds.

[0077]

[0078] Example 4

[0079] A method for controlling the pulsed carrier gas to improve the peak height of ion mobility spectra, wherein the analytical conditions for ion mobility spectra are as follows:

[0080] 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 drift gas was 0.5L / min, the drift gas and the carrier gas flowed in the same direction, and the outlet was at the end of the reaction zone. A mixture of acetone and methyl ethyl ketone volatile gases at 33℃ was used as a dopant for analysis. There were three peaks in the analysis spectrum, of which the middle peak was the acetone-methyl ethyl ketone composite peak.

[0081] The carrier gas low flow rate was set to 0.05 L / min, and the carrier gas high flow rate was set to 0.1 to 0.5 L / min. The carrier gas was controlled to switch rapidly between the low and high flow rates, and the pulse interval between the switching was fixed at 3 seconds. The minimum peak height, maximum peak height, peak height difference, and ratio of the average peak height in pulse mode to the peak height in no pulse mode are shown in the table below.

[0082] Switching the pulsed carrier gas rate between 0.05 L / min and 0.1-0.5 L / min resulted in an increase in the signal strength of the ion mobility spectrum peak by 0.8 to 1.9 times.

[0083] When the carrier gas velocity is rapidly switched between high and low flow rates, the response time from low flow rate to high flow rate is 1.0 second; the response time from high flow rate to low flow rate is 1.0 second.

[0084]

[0085] Example 5

[0086] A method for controlling the pulsed carrier gas to improve the peak height of ion mobility spectra, wherein the analytical conditions for ion mobility spectra are as follows:

[0087] 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 drift gas was 0.5L / min, the drift gas and the carrier gas flowed in the same direction, and the outlet was at the end of the reaction zone. A mixture of acetone and methyl ethyl ketone volatile gases at 33℃ was used as a dopant for analysis. There were three peaks in the analysis spectrum, of which the middle peak was the acetone-methyl ethyl ketone composite peak.

[0088] The carrier gas low flow rate was set to 0.05 L / min, and the carrier gas high flow rate was set to 0.1 to 0.5 L / min. The carrier gas was controlled to switch rapidly between the low and high flow rates, and the pulse interval between the switching was fixed at 1 second. The minimum peak height, maximum peak height, peak height difference, and ratio of the average peak height in pulse mode to the peak height in no pulse mode are shown in the table below.

[0089] Switching the pulsed carrier gas rate between 0.05 L / min and 0.1-0.5 L / min resulted in an increase in the signal strength of the ion mobility spectrum peak by 0.8 to 2.8 times.

[0090] When the carrier gas velocity is rapidly switched between high and low flow rates, the response time from low flow rate to high flow rate is 1.0 second; the response time from high flow rate to low flow rate is 1.0 second.

[0091]

[0092] 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 a pulsed carrier gas to improve the peak height of an ion migration spectrum, 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 carrier gas flow rate is controlled to switch rapidly between high and low flow rates to generate pulsed carrier 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 carrier gas enters radially along the reaction zone of the ion migration tube. When the carrier gas rapidly switches between high and low flow rates, the pulsed carrier gas alters the radial motion behavior of the sample molecules in the reaction zone, causing repeated fluctuations in the distance and time of movement of the sample molecules within the reaction zone. This increases the probability and number of sample molecules being ionized into sample ions, and increases the conversion rate of repeated collisions between sample molecules and ions, thereby improving the signal intensity / peak height of the sample ions.

2. The method for controlling pulsed carrier gas to improve ion mobility spectrum 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 carrier gas to improve ion mobility peak height according to claim 1, characterized in that, The method of controlling the pulsed carrier gas to improve the peak height of the 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 carrier gas to improve ion mobility peak height according to claim 1, characterized in that, The high flow rate of the carrier gas is 0.5 L / min, and the low flow rate of the carrier gas is 0.05 L / min.

5. The method for controlling pulsed carrier gas 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 carrier gas to improve ion mobility peak height according to claim 1, characterized in that, When the carrier gas velocity is rapidly switched 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 carrier gas to improve ion mobility peak height according to claim 1, characterized in that, When the carrier gas velocity is rapidly switched 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 carrier gas to improve ion mobility peak height according to claim 1, characterized in that, The sample to be tested is acetone-butanone. The acetone-butanone mixture is placed in a reagent bottle with a vent on the cap, through which the volatile acetone-butanone mixture gas sample is released. At a constant temperature, the evaporation rate of the acetone-butanone mixture is constant.

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