A small-scale mass spectrometry analysis method and device for mixed gas

Abstract

The present invention relates to the technical field of environmental detection and medical diagnosis, and discloses a small-scale mass spectrometry analysis method and device for mixed gas. The present invention uses an ion source to ionize a reaction reagent into primary reaction ions, and uses a three-dimensional ion trap to obtain specific primary reaction ions therefrom, and introduces the mixed gas to be detected into the three-dimensional ion trap. The two react to generate secondary reaction ions, and the secondary reaction ions are driven to hit an ion detector to form a mass spectrum to detect the gas components of the mixed gas to be detected. The present invention has the advantages of low complexity and less required devices, and solves the problem in the prior art that the primary reaction ions generated by the ion source are disordered, which affects the secondary reaction ions generated by the subsequent reaction with the mixed gas to be detected, and is not conducive to the qualitative analysis of the mixed gas to be detected.

Description

Technical Field

[0001] The invention relates to the technical field of environmental detection and medical diagnosis, and in particular to a small-scale mass spectrometry analysis method and device for mixed gases. Background Art

[0002] Due to the advantages of mass spectrometry technology such as high specificity and high sensitivity, as well as the continuous development of miniaturized portable mass spectrometers, on-site online gas detection technology based on mass spectrometry platforms is gradually gaining favor and being widely used.

[0003] At present, the commonly used gas detection technologies based on mass spectrometry platforms include: gas chromatography-mass spectrometry technology, which can be used with different chromatographic columns according to different detection needs, and the powerful ionization ability of the EI ion source of 70eV can realize the detection of various organic and inorganic gases; soft ionization technology, which is a mild ionization technology developed to avoid the detection of fragment ion peaks produced by excessive energy of a single EI source without chromatographic separation, such as single photon ionization mass spectrometry, selected ion flow tube mass spectrometry, and proton transfer reaction mass spectrometry.

[0004] However, in gas chromatography-mass spectrometry technology, the chromatographic separation time is long, and different chromatographic columns are required for the separation of different gases. The system is highly complex and cannot meet the requirements for separation time during on-site detection. In addition, the primary ions generated by the existing gas analysis ion source through discharge are disordered, which affects the sample analysis results after subsequent secondary ionization and is not conducive to the qualitative analysis of the mixture. Summary of the invention

[0005] The purpose of the present invention is to provide a small-scale mass spectrometry analysis method and device for mixed gases, aiming to solve the problem in the prior art that the primary reaction ions generated by the ion source are disordered, which affects the secondary reaction ions generated by subsequent reactions with the mixed gas to be detected, and is not conducive to the qualitative analysis of the mixed gas to be detected.

[0006] In a first aspect, the present invention provides a small-scale mass spectrometry analysis method for a mixed gas, comprising:

[0007] Step S1: ionizing the reaction reagent to obtain primary reaction ions;

[0008] Step S2: screening the primary reaction ions to obtain specific primary reaction ions;

[0009] Step S3: guiding the mixed gas to be detected to react with the specific primary reaction ions to obtain secondary reaction ions;

[0010] Step S4: performing mass spectrometry analysis and detection on the secondary reaction ions.

[0011] In one embodiment, the step S1 comprises:

[0012] Step S11: introducing the reaction reagent into the ionization reaction chamber;

[0013] Step S12: starting the ion source disposed in the ionization reaction chamber to ionize the reaction reagent to obtain the primary reaction ions.

[0014] In one embodiment, the step S2 comprises:

[0015] Step S21: applying a high-voltage radio frequency signal of a specific frequency to the annular electrode of the three-dimensional ion trap, applying a DC voltage of less than 10V to the first end cap electrode, and applying a DC voltage of more than 30V to the second end cap electrode, so as to introduce the primary reaction ions into the three-dimensional ion trap; wherein the first end cap electrode and the second end cap electrode are respectively arranged at two ends of the annular electrode, the first end cap electrode and the second end cap electrode are both provided with openings, and the first end cap electrode is arranged toward the ionization reaction chamber, and the voltage amplitude of the high-voltage radio frequency signal is greater than 100V, and the frequency is greater than 500KHZ;

[0016] Step S22: increasing the DC voltage of the first end cap electrode to be the same as that of the second end cap electrode, so as to trap the primary reaction ions;

[0017] Step S23: applying a low-voltage auxiliary AC signal having the same movement frequency as the ions selected to be removed from the primary reaction ions between the first end cap electrode and the second end cap electrode to achieve screening and enrichment of the specific primary reaction ions; wherein the voltage amplitude of the low-voltage auxiliary AC signal is less than 10V.

[0018] In one embodiment, step S3 comprises:

[0019] Step S31: introducing the mixed gas to be detected into the three-dimensional ion trap;

[0020] Step S32: the mixed gas to be detected reacts with the specific primary reaction ions to generate secondary reaction ions.

[0021] In one embodiment, the S4 includes:

[0022] Step S41: applying a low-voltage auxiliary AC signal having the same movement frequency as the specific primary reaction ions between the first end cap electrode and the second end cap electrode, so that the specific primary reaction ions remaining after the reaction escape from the three-dimensional ion trap;

[0023] Step S42: Scan the amplitude of the high-voltage radio frequency signal applied to the annular electrode to allow the secondary reaction ions to be ejected from the three-dimensional ion trap in order from low to high according to the mass-to-charge ratio and hit the ion detector to form a mass spectrum to detect the secondary reaction ions.

[0024] In a second aspect, the present invention provides a small-sized mass spectrometer for mixed gas, comprising:

[0025] A primary reaction assembly, a secondary reaction assembly, and an ion detector;

[0026] The primary reaction component comprises the ionization reaction chamber, an ion source and a reaction reagent introduction pipeline, wherein the ionization reaction chamber is provided with a chamber opening on one end facing the secondary reaction component, the ion source and the reaction reagent introduction pipeline are provided on the ionization reaction chamber, the reaction reagent introduction pipeline is used to introduce the reaction reagent into the ionization reaction chamber, and the ion source is used to ionize the reaction reagent in the ionization reaction chamber to generate primary reaction ions;

[0027] The secondary reaction component includes a three-dimensional ion trap and a mixed gas introduction pipeline to be detected, wherein the mixed gas introduction pipeline to be detected is arranged on the three-dimensional ion trap, the three-dimensional ion trap is used to absorb the primary reaction ions from the ionization reaction chamber, and exclude the unselected ions in the primary reaction ions to obtain specific primary reaction ions, and the mixed gas introduction pipeline is used to introduce the mixed gas to be detected into the three-dimensional ion trap to react with the specific primary reaction ions to generate secondary reaction ions;

[0028] The ion detector is arranged at the rear end of the three-dimensional ion trap, and is used to receive the secondary reaction ions and generate a mass spectrum to detect the secondary reaction ions.

[0029] In one embodiment, the three-dimensional ion trap includes a ring electrode, a first end cap electrode and a second end cap electrode;

[0030] The outer surface of the annular electrode is cylindrical, and the axial cross-section of the inner surface is any one of a rectangular and a hyperbolic shape. The side wall of the annular electrode is provided with a hole, and the hole is used to connect with the introduction pipe of the mixed gas to be detected, and the diameter of the hole is less than 1CM;

[0031] The first end cap electrode and the second end cap electrode are circular sheets, the thickness of the circular sheets is less than 0.5CM, and the center positions of the first end cap electrode and the second end cap electrode are provided with circular openings, the diameter of the openings is less than 1CM;

[0032] The first end cap electrode and the second end cap electrode are respectively arranged on both sides of the annular electrode to form a cavity with two openings, wherein the first end cap electrode is arranged toward the ionization reaction chamber, and the second end cap electrode is arranged toward the ion detector.

[0033] In one embodiment, the material of the annular electrode, the first end cap electrode and the second end cap electrode is any one of stainless steel, a conductive material with a gold plated surface, a conductive material with a silver plated surface and a conductive material with a platinum group metal plated surface. In one embodiment, the three-dimensional ion trap is connected to a voltage application signal system;

[0034] The voltage application signal system includes a high-frequency signal generator, a first DC voltage source, a second DC voltage source, and a low-frequency signal generator;

[0035] The high-frequency signal generator is connected to the annular electrode and is used to apply the high-voltage radio frequency signal to the annular electrode;

[0036] The first DC voltage source is connected to the first end cap electrode and is used to apply a DC voltage to the first end cap electrode;

[0037] The second DC voltage source is connected to the second end cap electrode and is used to apply a DC voltage to the second end cap electrode;

[0038] The low-frequency signal generator is connected to the first end cap electrode and the second end cap electrode, and is used to apply the low-voltage auxiliary AC signal to the first end cap electrode and the second end cap electrode. The frequency of the low-voltage auxiliary AC signal is different in different steps, and the highest frequency does not exceed half of the frequency of the high-voltage RF signal.

[0039] In one embodiment, the ion source is any one of an electron bombardment ion source and a plasma discharge ion source.

[0040] Compared with the prior art, an ion source is used to ionize a reaction reagent into primary reaction ions, and a three-dimensional ion trap is used to obtain specific primary reaction ions therefrom, and the mixed gas to be detected is introduced into the three-dimensional ion trap, and the two react to generate secondary reaction ions, and then the selected primary reaction ions are excluded. Only secondary reaction ions brought by the mixed gas exist in the ion trap, and the secondary reaction ions are driven to hit the ion detector to form a mass spectrum to detect the gas composition of the mixed gas to be detected. The present invention has the advantages of low complexity and less required equipment, and solves the problem in the prior art that the primary reaction ions generated by the ion source are disordered, which affects the secondary reaction ions generated by the subsequent reaction with the mixed gas to be detected, and is not conducive to the qualitative analysis of the mixed gas to be detected. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 It is a schematic diagram of the steps of a small-scale mass spectrometry analysis method for mixed gases provided by an embodiment of the present invention;

[0042] Figure 2 Schematic diagram of step S1 of a small-scale mass spectrometry analysis method for mixed gases provided in an embodiment of the present invention;

[0043] Figure 3 Schematic diagram of step S2 of a small-scale mass spectrometry analysis method for mixed gases provided in an embodiment of the present invention;

[0044] Figure 4 This is a schematic diagram of step S3 of a small-scale mass spectrometry analysis method for mixed gases provided in an embodiment of the present invention;

[0045] Figure 5 Schematic diagram of step S4 of a small-scale mass spectrometry analysis method for mixed gases provided in an embodiment of the present invention;

[0046] Figure 6 It is a structural schematic diagram of a small-scale mass spectrometry analysis device for mixed gases provided in an embodiment of the present invention;

[0047] Figure 7 It is a structural schematic diagram of a voltage signal application system of a small-scale mass spectrometer for mixed gases provided in an embodiment of the present invention;

[0048] Figure 8 It is a schematic axial cross-sectional view of two annular electrodes of a small-scale mass spectrometer for mixed gases provided in an embodiment of the present invention.

[0049] Figure numerals: 1-primary reaction component, 2-secondary reaction component, 11-ionization reaction chamber, 12-ion source, 13-reaction reagent introduction pipe, 110-chamber opening, 21-three-dimensional ion trap, 22-mixed gas introduction pipe to be detected, 211-annular electrode, 212-first end cover electrode, 213-second end cover electrode, 214-opening, 215-hole, 3-voltage signal application system, 31-high frequency signal generator, 32-first DC voltage source, 33-second DC voltage source, 34-low frequency signal generator, 4-ion detector. DETAILED DESCRIPTION

[0050] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0051] The same or similar numbers in the drawings of this embodiment correspond to the same or similar parts; in the description of the present invention, it should be understood that if the terms "upper", "lower", "left", "right" and the like indicate directions or positional relationships based on the directions or positional relationships shown in the drawings, it is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, the terms describing the positional relationship in the drawings are only used for illustrative purposes and cannot be understood as limitations on this patent. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0052] The implementation of the present invention is described in detail below in conjunction with specific embodiments.

[0053] Reference Figure 1 , Figure 6 As shown, a preferred embodiment of the present invention is provided. In a first aspect, the present invention provides a small-scale mass spectrometry analysis method for a mixed gas, comprising:

[0054] Step S1: Ionize the reaction reagent to obtain primary reaction ions.

[0055] Specifically, when the reaction reagent receives ionization, primary reaction ions can be generated. The primary reaction ions include multiple types of reaction ions. Each type of reaction ion can react with a gas to produce a secondary reaction ion. Therefore, the gas component that reacts with the primary reaction ion can be determined by detecting the secondary reaction ions.

[0056] Step S2: Screening the primary reaction ions to obtain specific primary reaction ions.

[0057] Specifically, after the reaction reagent receives ionization, primary reaction ions will be generated. Some of the primary reaction ions are selected as specific primary reaction ions for reacting with the mixed gas to be detected, and some will have a negative impact on the reaction of the former. If these unselected primary reaction ions are retained, it will affect the subsequent specific primary reaction ions and the secondary reaction ions generated by the reaction of the mixed gas to be detected, which is not conducive to the qualitative analysis of the mixed gas to be detected. Therefore, these unselected primary reaction ions need to be excluded, and then specific primary reaction ions can be obtained.

[0058] Step S3: guiding the mixed gas to be detected to react with specific primary reaction ions to obtain secondary reaction ions.

[0059] Specifically, the mixed gas to be detected includes several gas components. When each gas component reacts with a specific primary reaction ion, a different secondary reaction ion will be generated. Therefore, the gas component of the mixed gas to be detected that reacts with the specific primary reaction ion can be determined by detecting the secondary reaction ions.

[0060] Step S4: performing mass spectrometry analysis and detection on the secondary reaction ions.

[0061] Specifically, after the specific primary reaction ions react with the mixed gas to be detected, secondary reaction ions will be generated. At this time, the specific primary reaction ions still have some unreacted reserves. In order to ensure the accuracy of the detection, the specific primary reaction ions need to be excluded first, and then the secondary reaction ions need to be detected.

[0062] More specifically, the secondary reaction ions are detected by applying a gradually increasing radio frequency voltage to the secondary reaction ions, and ions of different mass numbers are ejected under different radio frequency voltages and hit the ion detector 4, forming a mass spectrum for detecting ions.

[0063] In the small-scale mass spectrometry analysis method for a mixed gas provided above, an ion source 12 is used to ionize a reaction reagent into primary reaction ions, and a three-dimensional ion trap 21 is used to obtain specific primary reaction ions therefrom, and the mixed gas to be detected is introduced into the three-dimensional ion trap 21, the two react to generate secondary reaction ions, and the secondary reaction ions are driven to hit the ion detector 4 to form a mass spectrum to detect the gas composition of the mixed gas to be detected. The present invention has the advantages of low complexity and less required equipment, and solves the problem in the prior art that the primary reaction ions generated by the ion source are disordered, which affects the secondary reaction ions generated by the subsequent reaction with the mixed gas to be detected, and is not conducive to the qualitative analysis of the mixed gas to be detected.

[0064] Reference Figure 2 As shown, step S1 includes:

[0065] Step S11 : introducing reaction reagents into the ionization reaction chamber 11 .

[0066] Specifically, ionization refers to the process in which uncharged particles are transformed into charged particles under the action of high-voltage arcs or high-energy rays. The ionization reaction chamber 11 has the function of accommodating reaction reagents, and the reaction reagents undergo ionization reaction in the ionization reaction chamber 11 to generate primary reaction ions.

[0067] More specifically, the ionization reaction chamber 11 has a reaction reagent introduction pipe 13 for the reaction reagent to enter, and the reaction reagent can be introduced into the ionization reaction chamber 11 through the reaction reagent introduction pipe 13 .

[0068] More specifically, when the ionization reaction reagent generates primary reaction ions, a containing cavity is required to prevent the primary reaction ions from escaping and causing harm. Therefore, a reaction reagent introduction pipe 13 is provided on the ionization reaction chamber 11 to introduce the reaction reagent into the ionization reaction chamber 11.

[0069] Step S12: starting the ion source 12 disposed in the ionization reaction chamber 11 to ionize the reaction reagent to obtain primary reaction ions.

[0070] Specifically, the ion source 12 is a device that ionizes neutral atoms or molecules and draws out an ion beam therefrom; the ion source 12 is disposed in the ionization reaction chamber 11 and is used to ionize the reaction reagents to obtain primary reaction ions, which will be ejected in a specified direction under the action of the ion source 12, and a three-dimensional ion trap 21 is disposed in the specified direction for subsequent reactions.

[0071] More specifically, the ion source 12 is disposed on the ionization reaction chamber 11 . When the reaction reagent enters the ionization reaction chamber 11 , the ion source 12 is started to ionize the reaction reagent.

[0072] Reference Figure 3 As shown, step S2 includes:

[0073] Step S21: A high-voltage radio frequency signal of a specific frequency is applied to the annular electrode 211 of the three-dimensional ion trap 21, a DC voltage of less than 10V is applied to the first end cap electrode 212, and a DC voltage of more than 30V is applied to the second end cap electrode 213 to introduce primary reaction ions into the three-dimensional ion trap 21.

[0074] Specifically, the three-dimensional ion trap 21 is composed of a pair of annular electrodes 211, a first end cap electrode 212 and a second end cap electrode 213. It is a device that uses an electric field or a magnetic field to capture and confine ions (i.e., charged atoms or molecules) within a certain range, wherein the first end cap electrode 212 and the second end cap electrode 213 are respectively arranged at the two ends of the annular electrode 211, and openings 214 are arranged on the first end cap electrode 212 and the second end cap electrode 213, and ions can enter and exit the three-dimensional ion trap 21 through the openings 214.

[0075] More specifically, the three-dimensional ion trap 21 is arranged on the outside of the ionization reaction chamber 11, and the two are on the same reference line. A chamber opening 110 is arranged on one end of the ionization reaction chamber 11 facing the three-dimensional ion trap 21, and the first port electrode 211 is arranged toward the ionization reaction chamber 11. The primary reaction ions can be transferred from the ionization reaction chamber 11 to the three-dimensional ion trap 21 through the chamber opening 110 and the opening 214.

[0076] More specifically, the end cap electrode 212 is divided into two states: when the first end cap electrode 212 and the second end cap electrode 213 maintain a DC voltage of more than 30V, the first end cap electrode 212 and the second end cap electrode 213 are in a closed state, and ions cannot enter or leave the three-dimensional ion trap 21; when the DC voltage of either the first end cap electrode 212 or the second end cap electrode 213 is below 10V, the first end cap electrode 212 and the second end cap electrode 213 are in an open state, and ions can enter or leave the three-dimensional ion trap 21 through the opening 214 of the end cap electrode with a DC voltage below 10V.

[0077] It is understandable that when the ion source 12 ionizes the reaction reagent, the DC voltage of the first end cap electrode 212 is reduced to make it enter the open state, and the primary reaction ions in the ionization reaction chamber 11 are sucked into the three-dimensional ion trap 21 through the chamber opening 110 and the opening 214.

[0078] More specifically, a high-voltage radio frequency signal of a specific frequency is applied to the annular electrode 211 to trap specific primary reaction ions in the three-dimensional ion trap 21 so that they exist stably in the three-dimensional ion trap 21 .

[0079] More specifically, the voltage of the high-voltage radio frequency signal is greater than 100V, and the frequency is greater than 500KHZ.

[0080] Step S22: increasing the DC voltage of the first end cap electrode 212 to be the same as that of the second end cap electrode 213 to trap the primary reaction ions.

[0081] Specifically, the first end cap electrode 212 of the three-dimensional ion trap 21 is used to introduce ions into the three-dimensional ion trap 21 through a lower direct current and to prevent ions from entering or leaving through a higher direct current, while the annular electrode 211 is used to bind and relax ions in the three-dimensional ion trap 21; more specifically, among the primary reaction ions entering the three-dimensional ion trap 21, a part is used to react with the mixed gas to be detected to generate specific primary reaction ions for generating secondary reaction ions, and the other part needs to be discharged to avoid interfering with the secondary reaction ions.

[0082] More specifically, after the primary reaction ions enter the three-dimensional ion trap 21 , the DC voltage of the first end cap electrode 212 is increased to make the first end cap electrode 212 enter a closed state, at which time the primary reaction ions will be trapped in the three-dimensional ion trap 21 and cannot leave.

[0083] Step S23: applying a low-voltage auxiliary AC signal having the same movement frequency as the primary reaction ions selected for removal between the first end cap electrode 212 and the second end cap electrode 213 to achieve screening and enrichment of specific primary reaction ions.

[0084] S23: A low-voltage auxiliary AC signal having the same movement frequency as the ions selected to be removed from the primary reaction ions is applied between the first end cap electrode 212 and the second end cap electrode 213 to achieve screening and enrichment of specific primary reaction ions.

[0085] Specifically, all primary reaction ions are trapped in the three-dimensional ion trap 21, and all primary reaction ions are divided into specific reaction ions and unselected primary reaction ions. A low-voltage auxiliary AC signal of the movement frequency of the primary reaction ions selected for removal is applied to the first end cap electrode 212 and the second end cap electrode 213, so that the primary reaction ions selected for removal can leave the three-dimensional ion trap 21 through the opening 214 of the first end cap electrode 212 and the second end cap electrode 213, so as to achieve the screening and enrichment of specific primary reaction ions.

[0086] More specifically, the voltage amplitude of the low voltage auxiliary AC signal is less than 10V.

[0087] Reference Figure 4 As shown, step S3 includes:

[0088] Step S31 : introducing the mixed gas to be detected into the three-dimensional ion trap 21 .

[0089] Specifically, a mixed gas introduction pipe 22 to be detected is provided on the three-dimensional ion trap 21, which is used to introduce the mixed gas to be detected into the three-dimensional ion trap 21. It can be understood that the specific primary reaction ions are bound in the three-dimensional ion trap 21 by the annular electrode 211, so the specific primary reaction ions will not leave the three-dimensional ion trap 21 through the gas introduction pipe.

[0090] More specifically, specific primary reaction ions can react with the mixed gas to be detected, and the two react to generate secondary reaction ions.

[0091] Step S32: the mixed gas to be detected reacts with specific primary reaction ions to generate secondary reaction ions.

[0092] Specifically, the mixed gas to be detected and the specific primary reaction ions will react in the three-dimensional ion trap 21 to generate secondary reaction ions. The reaction between the mixed gas to be detected and the specific primary reaction ions takes some time. After the mixed gas to be detected is introduced, it is necessary to wait for a period of time to allow the mixed gas to be detected and the specific primary reaction ions to fully react. It can be understood that when the mixed gas to be detected completes the reaction to generate secondary reaction ions, some specific primary reaction ions will still remain.

[0093] Reference Figure 5 As shown, step S4 includes:

[0094] Step S41 : applying a low-voltage auxiliary AC signal having the same movement frequency as the specific primary reaction ion between the first end cap electrode 212 and the second end cap electrode 213 to allow the specific primary reaction ion to escape from the three-dimensional ion trap 21 .

[0095] Specifically, in order to ensure that the mixed gas to be detected can react completely, it is necessary to set an excess of specific primary reaction ions in the three-dimensional ion trap 21. Therefore, after the mixed gas to be detected reacts with the specific primary reaction ions, some specific primary reaction ions will remain in the three-dimensional ion trap 21. In order to avoid interfering with the detection of secondary reaction ions, it is necessary to exclude these retained specific primary reaction ions.

[0096] More specifically, the first end cap electrode 212 and the second end cap electrode 213 apply a low-voltage auxiliary AC signal of the movement frequency of specific primary reaction ions. The specific primary reaction ions in the three-dimensional ion trap 21 will move under the action of the low-voltage auxiliary AC signal, thereby escaping from the three-dimensional ion trap 21. At this time, only secondary reaction ions are left in the three-dimensional ion trap 21.

[0097] Step S42: Scan the amplitude of the high-voltage radio frequency signal applied to the annular electrode 211, so that the secondary reaction ions are ejected from the three-dimensional ion trap 21 in order from low to high according to the mass-to-charge ratio, and hit the ion detector 4 to form a mass spectrum to realize the detection of the secondary reaction ions.

[0098] Specifically, the secondary reaction ions are amplitude scanned using RF voltage. Driven by the RF voltage, the secondary reaction ions are ejected from the three-dimensional ion trap 21 and hit the ion detector 4 to complete the detection. The type of the secondary reaction ions can be determined, and the gas composition of the mixed gas to be detected can be determined in turn.

[0099] More specifically, a high-frequency and high-voltage radio frequency signal is applied to the secondary reaction ions by the annular electrode 211. Driven by the radio frequency signal of the scanning amplitude, the secondary reaction ions are ejected from the three-dimensional ion trap 21 through the opening 214 on the second port electrode. Different secondary reaction ions have different masses, so the secondary reaction ions will be ejected from the three-dimensional ion trap 21 when driven by different radio frequency voltages. As the radio frequency voltage increases, ions of different mass numbers are ejected in turn and hit the ion detector 4 to form a mass spectrum. One secondary reaction ion corresponds to one component of the mixed gas to be detected. Therefore, the component analysis of the mixed gas to be detected can be performed through the mass spectrum.

[0100] More specifically, while scanning the amplitude of the high-frequency and high-voltage RF signal, the first end cap electrode 212 and the second end cap electrode 213 can also directly apply a fixed-frequency low-voltage auxiliary AC signal to enhance the ion emission effect and obtain a better mass spectrometry signal.

[0101] See also Figure 6 As shown, in a second aspect, the present invention provides a small-sized mass spectrometry analysis device for mixed gas, comprising:

[0102] A primary reaction component 1, a secondary reaction component 2 and an ion detector 4.

[0103] Specifically, the primary reaction component 1 includes an ionization reaction chamber 11 , an ion source 12 , and a reaction reagent introduction pipeline 13 , and the secondary reaction component 2 includes a three-dimensional ion trap 21 and a mixed gas introduction pipeline 22 to be detected.

[0104] More specifically, the primary reaction component 1 and the secondary reaction component 2 are arranged on the same baseline. More specifically, the ion source 12 and the reaction reagent introduction pipe 13 are arranged on the ionization reaction chamber 11. A chamber opening 110 is arranged on one end of the ionization reaction chamber 11 facing the secondary reaction component 2. The mixed gas to be detected is arranged on the three-dimensional ion trap 21. It can be understood that the ionization reaction chamber 11 and the three-dimensional ion trap 21 are arranged on the same baseline.

[0105] More specifically, the primary reaction assembly 1 is used to generate primary reaction ions: the reaction reagent enters the ionization reaction chamber 11 through the reaction reagent introduction pipe 13 and is ionized by the ion source 12 to generate primary reaction ions.

[0106] More specifically, the secondary reaction component 2 is used to generate and detect secondary reaction ions: the three-dimensional ion trap 21 first obtains primary reaction ions from the ionization reaction chamber 11, and excludes ions other than specific primary reaction ions therefrom, so that only specific primary reaction ions are retained in the three-dimensional ion trap 21. At this time, the mixed gas to be detected is introduced into the three-dimensional ion trap 21 through the mixed gas introduction pipe 22 to allow the two to react to generate secondary reaction ions. The three-dimensional ion trap 21 controls the secondary reaction ions to be ejected from the three-dimensional ion trap 21. The ejected secondary reaction ions are received by the ion detector 4 to form a mass spectrum. Since different ions will be ejected from the three-dimensional ion trap 21 under different RF voltage drives, the type of secondary reaction ions can be determined, thereby realizing the detection of the mixed gas to be detected.

[0107] More specifically, both ends of the three-dimensional ion trap 21 are provided with openings 214 for ions to enter and exit, and the side of the ionization reaction chamber 11 facing the three-dimensional ion trap 21 also has a chamber opening 110 for primary reaction ions to be transferred into the three-dimensional ion trap 21 .

[0108] More specifically, when the primary reaction ions are in the ionization reaction chamber 11 , the end cap electrode 212 of the three-dimensional ion trap 21 is activated to transfer the primary reaction ions in the ionization reaction chamber 11 to the three-dimensional ion trap 21 .

[0109] More specifically, when the primary reaction ions are in the three-dimensional ion trap 21, the annular electrode 211 of the three-dimensional ion trap 21 is started to trap the primary reaction ions in the three-dimensional ion trap 21, and a low-voltage auxiliary AC signal of the frequency of the primary reaction ions to be removed is applied between the first end cover electrode 212 and the second end cover electrode 213 to remove these ions. At this time, only specific primary reaction ions are retained in the three-dimensional ion trap 21.

[0110] More specifically, after the mixed gas to be detected reacts with specific primary reaction ions to generate secondary reaction ions, the first end cap electrode 212 and the second end cap electrode 213 are used to remove the remaining specific primary reaction ions. At this time, only secondary reaction ions are left in the three-dimensional ion trap 21. At this time, the secondary reaction ions are amplitude scanned using an RF voltage, and the secondary reaction ions are ejected from the opening 214 of the second end cap electrode 213 driven by the RF voltage. Different secondary reaction ions have different masses, so the secondary reaction ions are ejected from the three-dimensional ion trap 21 driven by different RF voltages. It can be understood that as the RF voltage gradually increases, different secondary reaction ions are ejected in turn and hit the ion detector 4 to form a mass spectrometer. Because one secondary reaction ion corresponds to one component of the mixed gas to be detected, the component analysis of the mixed gas to be detected can be performed through the mass spectrometer.

[0111] In the miniaturized mass spectrometry analysis device for a mixed gas provided above, an ion source 12 and a reaction reagent introduction pipe 13 are arranged on an ionization reaction chamber 11 to form a primary reaction component 1, and a mixed gas introduction pipe 22 to be detected is arranged on a three-dimensional ion trap 21 to form a secondary reaction component 2. The primary reaction component 1 is used to generate primary reaction ions, and the secondary reaction component 2 is used to obtain primary reaction ions and react them with the mixed gas to be detected to generate secondary reaction ions, and the mixed gas to be detected is analyzed by detecting the secondary reaction ions. The present invention has the advantages of low complexity and less required equipment, and solves the problem in the prior art that the use of gas chromatography technology leads to high system complexity and cannot meet the requirements of separation time during on-site detection.

[0112] In some embodiments, the three-dimensional ion trap 21 includes a ring electrode 211 , a first end cap electrode 212 , and a second end cap electrode 213 .

[0113] Specifically, see Figure 8As shown, the outer surface of the annular electrode 211 is cylindrical, and the axial cross-section of the inner surface is any one of a rectangular and a hyperbolic shape, that is, the annular electrode 211 can be a cylindrical barrel, or a barrel with a hyperbolic electrode inner surface, and a hole 215 is arranged on the side wall of the annular electrode 211, and the hole 215 is used to be connected to the introduction pipe 13 of the mixed gas to be detected, so that the mixed gas to be detected will enter the three-dimensional ion trap 21. More specifically, the diameter of the hole 215 is less than 1CM.

[0114] More specifically, the first end cap electrode 212 and the second end cap electrode 213 are both circular thin sheets with a thickness of less than 0.5CM. A circular opening 214 is provided at the center of the first end cap electrode 212 and the second end cap electrode 213. The opening is used for ions to enter and exit the three-dimensional ion trap 21. More specifically, the diameter of the opening 214 is limited to 1CM.

[0115] More specifically, the first end cap electrode 212 and the second end cap electrode 213 are both arranged on both sides of the annular electrode 211 to form a cavity with two openings 214, wherein the first end cap electrode 212 is arranged toward the ionization reaction chamber 11 to receive the primary reaction ions generated in the ionization reaction chamber 11, and the second end cap electrode 213 is arranged toward the ion detector 4 to emit secondary reaction ions onto the ion detector 4 to form a mass spectrometer.

[0116] In some embodiments, the material of the annular electrode 211 , the first end cap electrode 212 and the second end cap electrode 213 includes any one of stainless steel, a conductive material with a gold-plated surface, a conductive material with a silver-plated surface and a conductive material with a platinum group metal-plated surface.

[0117] Specifically, the annular electrode 211, the first end cap electrode 212 and the second end cap electrode 213 have the function of being applied with current and radio frequency signals, that is, the annular electrode 211, the first end cap electrode 212 and the second end cap electrode 213 need to have good electrical conductivity. Therefore, the material of the annular electrode 211, the first end cap electrode 212 and the second end cap electrode 213 can be stainless steel, or gold, silver or platinum group metal plating on the conductive material.

[0118] See also Figure 7 As shown, in some embodiments, the three-dimensional ion trap 21 is connected to the voltage application signal system 3 .

[0119] Specifically, the three-dimensional ion trap 21 includes an annular electrode 211 , a first end cap electrode 212 and a second end cap electrode 213 , and the voltage application signal system 3 includes a high-frequency signal generator 31 , a first DC voltage source 32 , a second DC voltage source 33 and a low-frequency signal generator 34 .

[0120] More specifically, the high-frequency signal generator 31 is connected to the annular electrode 211 and is used to apply a high-voltage radio frequency signal to the annular electrode 211 .

[0121] More specifically, the first DC voltage source 32 is connected to the first end cap electrode 212 and is used to apply a DC voltage to the first end cap electrode 212 .

[0122] More specifically, the second DC voltage source 33 is connected to the second end cap electrode 213 and is used to apply a DC voltage to the second end cap electrode 213 .

[0123] More specifically, the low-frequency signal generator 34 is connected to the first end cap electrode 212 and the second end cap electrode 213, and is used to apply a low-voltage auxiliary AC signal to the first end cap electrode 212 and the second end cap electrode 213. The frequency of this low-voltage auxiliary AC signal is adjusted and set as needed according to different steps, and its maximum frequency is less than half of the frequency of the high-voltage RF signal. For example, when the frequency of the high-voltage RF signal is 1MHZ, the frequency of the low-voltage auxiliary AC signal is less than 500KHZ.

[0124] In some embodiments, the ion source 12 is any one of an electron bombardment ion source and a plasma discharge ion source.

[0125] Specifically, the electron bombardment ion source uses a high-speed (high-energy) electron beam to impact the sample, thereby generating electrons and molecular ions M+. M+ continues to be bombarded by electrons, causing chemical bond breakage or molecular rearrangement, and instantly generating multiple ions; the plasma discharge ion source is an ion source in which the cathode thermally emits electrons to maintain gas discharge. More specifically, its anode can be made into a cylindrical shape, and a uniform magnetic field parallel to the axis can be selectively added. The magnetic field can well constrain the electron flow emitted by the cathode, ionize the atoms (or molecules) of the gas in the anode cavity, and form an arc column with a high plasma density. The ion beam can be drawn out laterally perpendicular to the axis direction, or along the axis direction.

[0126] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A small-scale mass spectrometry method for mixed gas, characterized in that: include: Step S1: ionizing the reaction reagent to obtain primary reaction ions; Step S2: screening the primary reaction ions to obtain specific primary reaction ions; Step S3: guiding the mixed gas to be detected to react with the specific primary reaction ions to obtain secondary reaction ions; Step S4: performing mass spectrometry analysis and detection on the secondary reaction ions; The step S2 comprises: Step S21: applying a high-voltage radio frequency signal of a specific frequency to the annular electrode of the three-dimensional ion trap, applying a DC voltage of less than 10V to the first end cap electrode, and applying a DC voltage of more than 30V to the second end cap electrode, so as to introduce the primary reaction ions into the three-dimensional ion trap; wherein the first end cap electrode and the second end cap electrode are respectively arranged at two ends of the annular electrode, the first end cap electrode and the second end cap electrode are both provided with openings, and the first end cap electrode is arranged toward the ionization reaction chamber, and the voltage amplitude of the high-voltage radio frequency signal is greater than 100V, and the frequency is greater than 500KHZ; Step S22: increasing the DC voltage of the first end cap electrode to be the same as that of the second end cap electrode, so as to trap the primary reaction ions; Step S23: applying a low-voltage auxiliary AC signal having the same movement frequency as the ions selected to be removed from the primary reaction ions between the first end cap electrode and the second end cap electrode to achieve screening and enrichment of the specific primary reaction ions; wherein the voltage amplitude of the low-voltage auxiliary AC signal is less than 10V, and the maximum frequency does not exceed half of the frequency of the high-voltage RF signal.

2. A small-scale mass spectrometry analysis method for mixed gases as claimed in claim 1, characterized in that: The step S1 comprises: Step S11: introducing the reaction reagent into the ionization reaction chamber; Step S12: starting the ion source disposed in the ionization reaction chamber to ionize the reaction reagent to obtain the primary reaction ions.

3. A small-scale mass spectrometry analysis method for mixed gases as claimed in claim 1, characterized in that: The step S3 comprises: Step S31: introducing the mixed gas to be detected into the three-dimensional ion trap; Step S32: the mixed gas to be detected reacts with the specific primary reaction ions to generate secondary reaction ions.

4. A small-scale mass spectrometry analysis method for mixed gases as claimed in claim 1, characterized in that: The S4 includes: Step S41: applying a low-voltage auxiliary AC signal having the same movement frequency as the specific primary reaction ions between the first end cap electrode and the second end cap electrode, so that the specific primary reaction ions remaining after the reaction escape from the three-dimensional ion trap; Step S42: Scan the amplitude of the high-voltage radio frequency signal applied to the annular electrode to allow the secondary reaction ions to be ejected from the three-dimensional ion trap in order from low to high according to the mass-to-charge ratio and hit the ion detector to form a mass spectrum to detect the secondary reaction ions.

5. A small mass spectrometer for mixed gases, characterized in that: include: A primary reaction assembly, a secondary reaction assembly, and an ion detector; The primary reaction component comprises an ionization reaction chamber, an ion source and a reaction reagent introduction pipeline, wherein a chamber opening is arranged on one end of the ionization reaction chamber facing the secondary reaction component, the ion source and the reaction reagent introduction pipeline are arranged on the ionization reaction chamber, the reaction reagent introduction pipeline is used to introduce the reaction reagent into the ionization reaction chamber, and the ion source is used to ionize the reaction reagent in the ionization reaction chamber to generate primary reaction ions; The secondary reaction component includes a three-dimensional ion trap and a mixed gas introduction pipeline to be detected. The ionization reaction chamber and the three-dimensional ion trap are arranged on the same baseline. The mixed gas introduction pipeline to be detected is arranged on the three-dimensional ion trap. The three-dimensional ion trap is used to absorb the primary reaction ions from the ionization reaction chamber and exclude the unselected ions in the primary reaction ions to obtain specific primary reaction ions. The mixed gas introduction pipeline is used to introduce the mixed gas to be detected into the three-dimensional ion trap to react with the specific primary reaction ions to generate secondary reaction ions, and the three-dimensional ion trap is used to apply different radio frequency voltages to different secondary reaction ions, so that different secondary reaction ions are ejected from the three-dimensional ion trap under the drive of different radio frequency voltages, thereby judging the type of secondary reaction ions and realizing the detection of the mixed gas to be detected; The ion detector is arranged at the rear end of the three-dimensional ion trap, and is used to receive the secondary reaction ions and generate a mass spectrum to detect the secondary reaction ions; The three-dimensional ion trap comprises a ring electrode, a first end cap electrode and a second end cap electrode; The outer surface of the annular electrode is cylindrical, and the axial cross-section of the inner surface is any one of a rectangular and a hyperbolic shape. The side wall of the annular electrode is provided with a hole, and the hole is used to connect with the introduction pipe of the mixed gas to be detected, and the diameter of the hole is less than 1CM; The first end cap electrode and the second end cap electrode are circular sheets, the thickness of the circular sheets is less than 0.5CM, and the center positions of the first end cap electrode and the second end cap electrode are provided with circular openings, the diameter of the openings is less than 1CM; The first end cap electrode and the second end cap electrode are respectively arranged on both sides of the annular electrode to form a cavity having two openings, wherein the first end cap electrode is arranged toward the ionization reaction chamber, and the second end cap electrode is arranged toward the ion detector; The first end cap electrode and the second end cap electrode are used to remove residual specific primary reaction ions. At this time, only secondary reaction ions are left in the three-dimensional ion trap. At this time, the secondary reaction ions are amplitude scanned using radio frequency voltage. The secondary reaction ions will be ejected from the opening of the second end cap electrode driven by the radio frequency voltage. Different secondary reaction ions have different masses, so the secondary reaction ions will be ejected from the three-dimensional ion trap driven by different radio frequency voltages. The radio frequency voltage gradually increases, and different secondary reaction ions are ejected in turn and hit the ion detector to form a mass spectrum. One secondary reaction ion corresponds to a component of the mixed gas to be detected, so the component analysis of the mixed gas to be detected can be performed through the mass spectrum.

6. A small-sized mixed gas mass spectrometer as claimed in claim 5, characterized in that: The material of the annular electrode, the first end cap electrode and the second end cap electrode is any one of stainless steel, a conductive material with a gold-plated surface, a conductive material with a silver-plated surface and a conductive material with a platinum group metal-plated surface.

7. A small-sized mixed gas mass spectrometer as claimed in claim 5, characterized in that: The three-dimensional ion trap is connected to a voltage application signal system; The voltage application signal system includes a high-frequency signal generator, a first DC voltage source, a second DC voltage source, and a low-frequency signal generator; The high-frequency signal generator is connected to the annular electrode and is used to apply a high-voltage radio frequency signal to the annular electrode; The first DC voltage source is connected to the first end cap electrode and is used to apply a DC voltage to the first end cap electrode; The second DC voltage source is connected to the second end cap electrode and is used to apply a DC voltage to the second end cap electrode; The low-frequency signal generator is connected to the first end cap electrode and the second end cap electrode, and is used to apply a low-voltage auxiliary AC signal to the first end cap electrode and the second end cap electrode. The frequency of the low-voltage auxiliary AC signal is different in different steps, and the highest frequency does not exceed half of the frequency of the high-voltage RF signal.

8. A small-sized mixed gas mass spectrometer as claimed in claim 5, characterized in that: The ion source is any one of an electron bombardment ion source and a plasma discharge ion source. The ion source is an ion source in which gas discharge is maintained by cathode thermal emission of electrons in a uniform magnetic field. The anode of the ion source is cylindrical in shape. The cylindrical anode of the ion source is in a uniform magnetic field parallel to the cathode axis to constrain the electron flow emitted by the cathode, thereby generating a high plasma density arc column in the anode cavity and leading it out in a side direction perpendicular to the axis direction or along the axis direction.

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