Ion source device for component analysis of VOC mixture, ion trap mass spectrometer and use method

Abstract

The invention discloses an ion source device and an ion trap mass spectrometer for component analysis of a VOC (volatile organic compound) mixture. The ion source device comprises a control panel, a heating controller and a heating gasification device which are electrically connected in sequence, the heating gasification device comprises a cavity heating body, a sealing cover, a gas gathering hood, a gas outlet pipe and a heating vessel; an electric heating plate is arranged at the bottom of the cavity heating body; the heating vessel is used for containing a VOC mixture and is arranged on the electric heating plate; the sealing cover is detachably and hermetically connected with the upper end of the cavity heating body; the air outlet pipe hermetically penetrates through the sealing cover; the lower end of the gas gathering cover is opened and covers the heating vessel, and the area of the cross section of the gas gathering cover is gradually reduced from bottom to top; an air outlet communicated with the air outlet pipe is formed in the upper end; an electric heating tube is embedded in the electric heating disc, the electric heating tube is electrically connected with the heating controller, and the heating controller outputs corresponding voltage to the electric heating tube according to control parameters input by the control panel. The device is high in portability and easy to operate, and can be used for gas, liquid or liquid volatile sample analysis.

Description

Technical Field

[0001] The present invention relates to the technical field of mixture component analysis, and in particular to an ion source device, an ion trap mass spectrometer and a usage method for VOC mixture component analysis. Background Art

[0002] Volatile components refer to chemical substances that are easily converted from liquid or solid to gas at room temperature or slightly higher temperatures. They usually have the characteristics of low boiling point, small molecular weight and high vapor pressure. Such components are widely present in nature and industrial products, such as volatile oils of traditional Chinese medicine, volatile organic compounds (VOCs) in the air and aroma molecules in food. However, the existing volatile component analysis technology faces two major bottlenecks: first, traditional mass spectrometry relies on laboratory environment, the equipment is bulky, expensive, and has a long analysis cycle, which makes it difficult to meet the needs of on-site testing; second, for components such as volatile oils of traditional Chinese medicine, existing detection relies on complex processes such as supercritical CO2 extraction combined with gas chromatography-mass spectrometry, which has the risk of component loss and cannot be adapted to online monitoring scenarios.

[0003] The core principle of a small mass spectrometer is similar to that of a traditional large mass spectrometer, but it is smaller in size, lower in cost, and suitable for rapid on-site detection. Small mass spectrometers can be used in conjunction with electrospray ionization and atmospheric pressure chemical ionization plasma sources for real-time analysis. Compared with large mass spectrometers, the portability and rapid response of small mass spectrometers make them more advantageous in environmental monitoring, food safety, and clinical diagnosis. However, although electrospray ionization and atmospheric pressure chemical ionization sources can achieve ionization of some volatile components, their dynamic coverage of wide boiling range VOCs is insufficient, and they are not compatible with the in-situ analysis requirements of volatile substances on the surface of solid medicinal materials.

[0004] Currently, the detection of VOC components mainly collects VOCs in the gaseous state, and there is a lack of detection and analysis devices and analysis methods for VOC components in solid, liquid and their mixtures. Summary of the Invention

[0005] The present invention aims to solve the technical problems existing in the known technology and provides an ion source device, an ion trap mass spectrometer and a method of use for analyzing the components of a VOC mixture.

[0006] The technical solution adopted by the present invention to solve the technical problems existing in the known technology is:

[0007] An ion source device for analyzing the composition of a VOC mixture comprises a control panel, a heating controller, and a heating and vaporizing device electrically connected in sequence; the heating and vaporizing device is used to heat the VOC mixture and vaporize it; the heating controller is used to control the operation of the heating and vaporizing device; the control panel is used to start and stop the heating controller, input heating process parameters to the heating controller, and display the operating status of the heating and vaporizing device;

[0008] The heating and vaporization device includes: a cavity heating body, a sealing cover, a gas collecting cover, an exhaust pipe, and a heating dish; the cavity heating body is open at the top and has an electric heating plate at the bottom; the heating dish is used to hold the VOC mixture and is placed on the electric heating plate; the sealing cover is detachably and hermetically connected to the upper end of the cavity heating body; the exhaust pipe is sealed and passes through the sealing cover; the gas collecting cover is located within the cavity heating body, has an open lower end and covers the heating dish, and its cross-sectional area gradually decreases from bottom to top; and has an exhaust hole at its upper end connected to the exhaust pipe;

[0009] The heating controller outputs the corresponding voltage to the electric heating plate according to the heating process parameters input from the control panel.

[0010] Furthermore, the heating and gasification device also includes a feed pipe sealed through a sealing cover, the outlet end of the feed pipe passes through a gas collecting hood and is located above the heating dish; both the outlet end of the gas outlet pipe and the inlet end of the feed pipe are provided with an opening and closing device to open and close the pipeline; the VOC mixture is input into the heating dish through the feed pipe.

[0011] Furthermore, the opening and closing device is an openable and closable cover, a manual stop valve or an electric stop valve; when the opening and closing device is an electric stop valve, the heating controller outputs an electrical signal to the electric stop valve to control the opening and closing of the electric stop valve; the openable and closable cover is a snap-on flip cover or a screw-on cover, and the screw-on cover is threadedly sealed with the outlet end of the air outlet pipe and the inlet end of the feed pipe; the snap-on flip cover is sealed and snap-connected with the outlet end of the air outlet pipe and the inlet end of the feed pipe.

[0012] Furthermore, the heating controller includes a microprocessor and a power pulse width modulator. The microprocessor inputs heating process parameters from the control panel and outputs a control signal to the power pulse width modulator, so that the power pulse width modulator changes the output voltage by adjusting the pulse width.

[0013] Furthermore, the heating controller is provided with a plurality of heating working modes, and the control panel is provided with a numeric keyboard and / or a multi-speed switch for selecting the heating working mode, and each speed of the multi-speed switch corresponds to a heating working mode; the multi-speed switch is a knob multi-speed switch or a binary dial combination multi-speed switch; the binary dial combination multi-speed switch includes a plurality of dial switches; each dial switch is independently set to an on or off state; when the dial switch is set to the on state, its binary code is 1; when the dial switch is set to the off state, its binary code is 0; different heating working modes are represented by combinations of dial switches in different positions.

[0014] Furthermore, a temperature sensor is provided inside the electric heating plate and / or on the surface of the electric heating plate; the temperature sensor is electrically connected to the heating controller, and the detection signal of the temperature sensor is input to the heating controller as a temperature feedback signal, and the heating controller adjusts the input voltage or input current of the electric heating plate according to the temperature feedback signal.

[0015] Furthermore, the control panel is provided with a working status indicator light and a liquid crystal display; the heating controller outputs a temperature digital signal to the liquid crystal display, and the liquid crystal display displays the internal or surface temperature of the electric heating plate; the control panel is a handheld operation panel, and wireless communication is carried out between the control panel and the heating controller.

[0016] The present invention also provides an ion trap mass spectrometer for analyzing the components of VOC mixtures. The ion trap mass spectrometer includes a gas mass spectrometer and the above-mentioned ion source device for analyzing the components of VOC mixtures; the gas mass spectrometer is used to analyze the components of gaseous substances.

[0017] The present invention also provides a method for using the above-mentioned ion trap mass spectrometer for analyzing the components of a VOC mixture, comprising the following steps:

[0018] Place the heating dish on the electric heating plate and seal the sealing cover to the upper end of the cavity heating body;

[0019] Connect the gas mass spectrometer inlet pipe to the gas outlet pipe of the heating gasification device;

[0020] Operate the control panel to set the heating process parameters according to the boiling point differences of the VOC mixture components and send a heating start signal;

[0021] The heating controller outputs the corresponding voltage to the electric heating plate according to the heating process parameters and heating start signal input from the control panel. The electric heating plate starts working, heating the VOC mixture in the heating dish and gradually vaporizing it.

[0022] The gaseous VOC mixture enters the gas mass spectrometer, which performs component analysis. The temporal separation of the VOC mixture is achieved by the difference in boiling points of the components.

[0023] After the gas mass spectrometer analysis is completed, open the sealing cover and replace or clean the heating dish.

[0024] Furthermore, the heating process parameters include heating curve parameters, and the heating curve parameters include heating rate and heating time, holding time, cooling rate and cooling time.

[0025] The advantages and positive effects of the present invention are:

[0026] The present invention provides an ion source device for analyzing the composition of a VOC mixture. The device can heat a liquid or solid VOC mixture to convert it into a gaseous state. By connecting the ion source device to a gas mass spectrometer in the prior art, the gas after the VOC mixture is vaporized is input into the gas mass spectrometer, and the gas mass spectrometer performs component analysis.

[0027] The ion trap mass spectrometer of the present invention is used for analyzing the components of VOC mixtures. It is equipped with an ion source device, is highly portable, easy to operate, has a fast analysis speed and is inexpensive. It can be used for analyzing volatile samples in gas, liquid or liquid state. By operating the control panel, heating working parameters are set according to the boiling point differences of the components of the VOC mixture, and the temporal separation of the VOC mixture is achieved by the boiling point differences of the components. The ion trap mass spectrometer can analyze the volatile components in traditional Chinese medicine and further be used for dynamic detection of hydrolysis changes of the effective substances in traditional Chinese medicine. It shows broad application prospects in environmental monitoring, air quality assessment, traditional Chinese medicine quality control and medical diagnosis. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a partial cross-sectional view of a heating and gasification device in an ion source device for analyzing VOC mixture components according to the present invention.

[0029] Figure 2 The present invention is a control principle block diagram of an ion source device for analyzing VOC mixture components.

[0030] Figure 3 It is a schematic diagram of the heating curve of a VOC mixture.

[0031] Figure 4 This is the primary mass spectrum of a toluene standard.

[0032] Figure 5 This is the primary mass spectrum of a naphthalene standard.

[0033] Figure 6 This is a primary mass spectrum of a DEET standard.

[0034] Figure 7 This is the MS / MS spectrum of a toluene standard.

[0035] Figure 8 This is the MS / MS spectrum of a naphthalene standard.

[0036] Figure 9 This is the MS / MS spectrum of a DEET standard.

[0037] Figure 10 This is the MS / MS spectrum of a menthol standard.

[0038] Figure 11 This is the MS / MS spectrum of a cinnamaldehyde standard.

[0039] Figure 12 This is a secondary mass spectrum of pulegone.

[0040] Figure 13 This is the MS / MS spectrum of a eucalyptol standard.

[0041] In the figure: 1. air outlet pipe; 2. electric stop valve; 3. sealing cover; 4. gas collecting hood; 5. heating dish; 6. cavity heating body; 7. electric heating plate.

[0042] M in the figure + 、[M+H] + represents the molecular ion or quasi-molecular ion of the corresponding compound, m / z represents the mass-to-charge ratio, and CID represents collision-induced dissociation. DETAILED DESCRIPTION

[0043] The present invention will be described in detail below with reference to the accompanying drawings and in combination with embodiments. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention and are not used to limit the present invention.

[0044] The Chinese meanings of the following English words, phrases and abbreviations in this application are as follows:

[0045] Relative Intensity: Relative intensity.

[0046] VOC: Volatile organic compounds.

[0047] PWM: Pulse Width Modulation.

[0048] MCH: Metal ceramic heating element.

[0049] In the description of the present invention, the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and do not require that the present invention must be constructed and operated in a specific direction. Therefore, they should not be understood as limitations on the present invention. The terms "connected" and "connection" used in the present invention should be understood in a broad sense. For example, it can be a fixed connection or a detachable connection; it can be a direct connection or an indirect connection through an intermediate component; it can also be an electrical connection or signal transmission. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to the specific circumstances.

[0050] See Figures 1 to 13 An ion source device for analyzing the components of a VOC mixture includes a control panel, a heating controller, and a heating and vaporization device electrically connected in sequence; the heating and vaporization device is used to heat the VOC mixture and vaporize it; the heating controller is used to control the operation of the heating and vaporization device; the control panel is used to start and stop the heating controller, input heating process parameters to the heating controller, and display the working status of the heating and vaporization device.

[0051] The heating and vaporization device includes: a cavity heating body 6, a sealing cover 3, a gas gathering hood 4, an outlet pipe 1 and a heating dish 5; the cavity heating body 6 has an open top and an electric heating plate 7 at its bottom; the heating dish 5 is used to hold the VOC mixture and is placed on the electric heating plate 7; the sealing cover 3 is detachably and sealedly connected to the upper end of the cavity heating body 6; the outlet pipe 1 passes through the sealing cover 3 in a sealed manner; the gas gathering hood 4 is located in the cavity heating body 6, has an open lower end and covers the heating dish 5, and its cross-sectional profile area gradually decreases from bottom to top; and an outlet hole connected to the outlet pipe 1 is opened at its upper end.

[0052] The heating controller outputs the corresponding voltage to the electric heating plate 7 according to the heating process parameters input from the control panel.

[0053] The electric heating plate 7 may be embedded with an electric heating tube, which is electrically connected to a heating controller. The heating controller outputs a corresponding voltage to the electric heating tube according to the heating process parameters inputted from the control panel.

[0054] The electric heating plate 7 can be embedded with an MCH ceramic heating element. The core principle of the MCH ceramic heating element is to embed the metal resistance heating layer into the ceramic matrix through high-temperature co-fired multi-layer ceramic substrate technology, and use the Joule effect generated by the current passing through the resistance material to achieve efficient electric heat conversion.

[0055] A detachable sealed connection structure is adopted between the sealing cover 3 and the upper end of the cavity heating body 6, and a heating dish 5 is used to hold the VOC mixture; it is convenient to clean the residue of the VOC mixture and replace the VOC mixture; it is also convenient to remove the residual gas of the vaporized VOC mixture, which is convenient for the composition analysis of the next VOC mixture.

[0056] Preferably, the heating and gasification device may further include a feed pipe sealed through the sealing cover 3, with the outlet end of the feed pipe passing through the gas collecting hood 4 and located above the heating dish 5. Both the outlet end of the gas outlet pipe 1 and the inlet end of the feed pipe are equipped with an opening and closing device to open and close the pipes. The VOC mixture is fed into the heating dish 5 through the feed pipe. The feed end of the feed pipe may be flared, allowing a dropper to be used to draw in the liquid VOC mixture and release the liquid VOC mixture at the flared end.

[0057] Preferably, the opening and closing device can be an openable and closable cover, a manual stop valve or an electric stop valve 2; when the opening and closing device is an electric stop valve 2, the heating controller outputs an electrical signal to the electric stop valve 2 to control the opening and closing of the electric stop valve 2; the openable and closable cover is a snap-on flip cover or a screw-on cover, and the screw-on cover is threadedly sealed with the outlet end of the air outlet pipe 1 and the inlet end of the feed pipe; the snap-on flip cover is sealed and snap-fitted with the outlet end of the air outlet pipe 1 and the inlet end of the feed pipe.

[0058] The snap-on flip cover can adopt the snap-on bottle cap structure in the prior art. The screw-on cap can adopt the screw-on bottle cap structure in the prior art.

[0059] The electric shut-off valve 2 can utilize the German Memetis normally closed microvalve. With a width of only 5 mm, the Memetis normally closed microvalve allows for the integration of multiple valves within a small installation space, thus creating a powerful fluid system. The current-regulating valve offers silent switching, proportional control, and media separation. Its operating principle is as follows: When the current is applied, the actuator acts on a spring element, releasing a ball from the valve opening, thus opening the pipeline. When the current is turned off, the spring element pushes the ball back onto the valve opening, closing the pipeline.

[0060] Manual stop valves can use spring-loaded button stop valves. Pressing the spring releases a ball from the valve opening, opening the pipeline. Pressing the button again resets the spring, pushing the ball back to the valve opening, closing the pipeline.

[0061] Preferably, the heating controller may include a microprocessor and a power pulse width modulator. The microprocessor inputs heating process parameters from a control panel and outputs control signals to the power pulse width modulator, causing the power pulse width modulator to change the output voltage by adjusting the pulse width. The microprocessor may be a single-chip microcomputer. The power pulse width modulator may include a PWM step-by-step generator and a PWM driver.

[0062] The heating controller can also use a PLC controller and a power pulse width modulator. The PLC controller inputs the heating process parameters from the control panel and outputs a control signal to the power pulse width modulator, which changes the output voltage by adjusting the pulse width.

[0063] Preferably, the heating controller can be set to multiple heating working modes, and the control panel can be provided with a numeric keyboard and / or a multi-speed switch for selecting the heating working mode, and each speed of the multi-speed switch corresponds to a heating working mode; the multi-speed switch can be a knob multi-speed switch or a binary dial combination multi-speed switch; the binary dial combination multi-speed switch can include multiple dial switches; each dial switch is independently set to the on or off state; when the dial switch is set to the on state, its binary code is 1; when the dial switch is set to the off state, its binary code is 0; different heating working modes are represented by the combination of dial switches in different positions.

[0064] Preferably, a temperature sensor may be provided inside the electric heating plate 7 and / or on the surface of the electric heating plate 7; the temperature sensor is electrically connected to the heating controller, and the detection signal of the temperature sensor is input to the heating controller as a temperature feedback signal, and the heating controller adjusts the input voltage or input current of the electric heating plate 7 according to the temperature feedback signal.

[0065] Preferably, the control panel is provided with a working status indicator light and a liquid crystal display; the heating controller outputs a temperature digital signal to the liquid crystal display, and the liquid crystal display displays the internal or surface temperature of the electric heating plate 7. The liquid crystal display can also display the heating time and the heating curve.

[0066] The control panel may adopt a text display with a numeric keyboard, a touch screen or the like.

[0067] Preferably, the control panel is a handheld operation panel, and wireless communication is carried out between the control panel and the heating controller. The control panel can be a mobile phone, tablet or other device, and the heating process parameters can be input to the heating controller through a built-in application.

[0068] Preferably, the device may further include a housing, on which the heating controller and the heating and vaporizing device are mounted, forming an integrated portable structure, with an insulation layer provided between the heating controller and the heating and vaporizing device. The housing may be provided with an insulation jacket made of an insulating material, with the cavity heating body 6 located within the insulation jacket.

[0069] The thermal insulation layer can be made of materials such as rock wool, glass wool, expanded perlite, etc. These materials not only have good thermal insulation effects, but also have good fire resistance and chemical stability.

[0070] Insulation materials can be glass wool, rock wool and aluminum silicate fiber. These materials have good high temperature resistance, chemical stability and fire retardant properties.

[0071] The present invention also provides an ion trap mass spectrometer for analyzing the components of a VOC mixture. The ion trap mass spectrometer comprises a gas mass spectrometer and the above-mentioned VOC mixture component analysis ion source device; the gas mass spectrometer is used to analyze the components of gaseous substances.

[0072] The gas mass spectrometer may be a gas mass spectrometer used in the prior art for analyzing the composition of gaseous substances, and may be a portable gas mass spectrometer or a fixed gas mass spectrometer.

[0073] The present invention also provides a method for using the above-mentioned ion trap mass spectrometer for analyzing the components of a VOC mixture, the method comprising the following steps:

[0074] The heating dish 5 is placed on the electric heating plate 7 , and the sealing cover 3 is sealed and connected to the upper end of the cavity heating body 6 .

[0075] If a solid or liquid-solid VOC mixture is to be heated, the VOC mixture can be placed directly in the heating vessel 5 . If a liquid VOC mixture is to be heated, the mixture can be fed into the heating vessel 5 through a feeding tube.

[0076] Connect the gas inlet pipe of the gas mass spectrometer to the gas outlet pipe 1 of the heating gasification device; if an opening and closing device is provided at the outlet end of the gas outlet pipe 1 of the heating gasification device, open the opening and closing device to connect the gas outlet pipe 1 of the heating gasification device to the gas inlet pipe of the gas mass spectrometer.

[0077] Operate the control panel to set the heating parameters according to the boiling point differences of the VOC mixture components and send a heating start signal.

[0078] The heating controller outputs a corresponding voltage to the electric heating tube according to the heating process parameters and the heating start signal input from the control panel. The electric heating tube starts working to heat the VOC mixture in the heating dish 5 and gradually vaporize it.

[0079] The gaseous VOC mixture enters the gas mass spectrometer and is analyzed by the ion trap mass spectrometer; the VOC mixture is separated in time by the difference in boiling points of the components;

[0080] After the ion trap mass spectrometer analysis is completed, the sealing cover 3 is opened and the heating dish 5 is replaced or cleaned.

[0081] Preferably, the heating operating parameters may include heating curve parameters, including heating rate and heating time, holding time, cooling rate and cooling time. When the heating time of the heating curve parameters expires, the ion trap mass spectrometer analysis may be terminated.

[0082] The purpose of setting the heating curve parameters is to control the temperature rise rate, so that the VOC mixture is gradually vaporized according to the boiling point difference of the components, and the VOC mixture is separated in a time-sequential manner from low to high boiling points.

[0083] The above-mentioned gas mass spectrometer, cavity heating body 6, sealing cover 3, gas collection cover 4, gas outlet pipe, feed pipe, heating dish 5, opening and closing device, openable and closable sealing cover, manual stop valve, electric stop valve 2, microprocessor, power pulse width modulator, knob multi-speed switch, binary dial combination multi-speed switch, temperature sensor, PLC controller, control panel, indicator light, liquid crystal display, shell, text display, touch screen, thermal insulation layer, thermal insulation cover, mobile phone, tablet computer, etc. can adopt applicable devices and structures in the existing technology, or adopt applicable devices and structures in the existing technology and construct with conventional technical means.

[0084] The embodiments described above are only used to illustrate the technical ideas and features of the present invention. Their purpose is to enable those skilled in the art to understand the contents of the present invention and implement them accordingly. The scope of the patent of the present invention cannot be limited by these embodiments alone. That is, any equivalent changes or modifications made to the spirit disclosed by the present invention still fall within the scope of the patent of the present invention.

Claims

1. An ion source device for VOC mixture component analysis, characterized in that: It includes a control panel, a heating controller and a heating and gasification device which are electrically connected in sequence; the heating and gasification device is used to heat the VOC mixture and gasify it; the heating controller is used to control the operation of the heating and gasification device; the control panel is used to start and stop the heating controller, input heating process parameters to the heating controller and display the working status of the heating and gasification device; The heating and vaporization device includes: a cavity heating body, a sealing cover, a gas collecting cover, an exhaust pipe, and a heating dish; the cavity heating body is open at the top and has an electric heating plate at the bottom; the heating dish is used to hold the VOC mixture and is placed on the electric heating plate; the sealing cover is detachably and hermetically connected to the upper end of the cavity heating body; the exhaust pipe is sealed and passes through the sealing cover; the gas collecting cover is located within the cavity heating body, has an open lower end and covers the heating dish, and its cross-sectional area gradually decreases from bottom to top; and has an exhaust hole at its upper end connected to the exhaust pipe; The heating controller outputs the corresponding voltage to the electric heating plate according to the heating process parameters input from the control panel.

2. The ion source device for VOC mixture component analysis according to claim 1, characterized in that: The heating and gasification device also includes a feed pipe sealed through a sealing cover, the outlet end of the feed pipe passes through a gas collecting hood and is located above the heating dish; both the outlet end of the gas outlet pipe and the inlet end of the feed pipe are provided with an opening and closing device to open and close the pipeline; the VOC mixture is input into the heating dish through the feed pipe.

3. The ion source device for VOC mixture component analysis according to claim 2, characterized in that: The opening and closing device is an openable and closable cover, a manual stop valve or an electric stop valve; when the opening and closing device is an electric stop valve, the heating controller outputs an electrical signal to the electric stop valve to control the opening and closing of the electric stop valve; the openable and closable cover is a snap-on flip cover or a screw-on cover, the screw-on cover is threadedly sealed with the outlet end of the air outlet pipe and the inlet end of the feed pipe; the snap-on flip cover is sealed and snap-fitted with the outlet end of the air outlet pipe and the inlet end of the feed pipe.

4. The ion source device for VOC mixture component analysis according to claim 1, characterized in that: The heating controller includes a microprocessor and a power pulse width modulator. The microprocessor inputs the heating process parameters from the control panel and outputs a control signal to the power pulse width modulator, so that the power pulse width modulator changes the output voltage by adjusting the pulse width.

5. The ion source device for VOC mixture component analysis according to claim 1, characterized in that: The heating controller is provided with a plurality of heating working modes, and the control panel is provided with a numeric keyboard and / or a multi-position switch for selecting the heating working mode. Each position of the multi-position switch corresponds to a heating working mode. The multi-position switch is a knob multi-position switch or a binary dial combination multi-position switch. The binary dial combination multi-position switch includes a plurality of dial switches. Each dial switch is independently set to an on or off state. When the dial switch is set to the on state, its binary code is 1; when the dial switch is set to the off state, its binary code is 0. Different heating working modes are represented by combinations of dial switches in different positions.

6. The ion source device for VOC mixture component analysis according to claim 1, characterized in that: A temperature sensor is provided inside the electric heating plate and / or on the surface of the electric heating plate; the temperature sensor is electrically connected to the heating controller, and the detection signal of the temperature sensor is input to the heating controller as a temperature feedback signal. The heating controller adjusts the input voltage or input current of the electric heating plate according to the temperature feedback signal.

7. The ion source device for VOC mixture component analysis according to claim 6, characterized in that: The control panel is equipped with a working status indicator light and a liquid crystal display; the heating controller outputs a temperature digital signal to the liquid crystal display, and the liquid crystal display displays the internal or surface temperature of the electric heating plate; the control panel is a handheld operation panel, and wireless communication is carried out between the control panel and the heating controller.

8. An ion trap mass spectrometer for analyzing the composition of VOC mixtures, characterized in that: The ion trap mass spectrometer comprises a gas mass spectrometer and an ion source device for VOC mixture component analysis according to any one of claims 1 to 7; the gas mass spectrometer is used for component analysis of gaseous substances.

9. A method for using the ion trap mass spectrometer for analyzing VOC mixture components according to claim 8, characterized in that: The method comprises the following steps: Place the heating dish on the electric heating plate and seal the sealing cover to the upper end of the cavity heating body; Connect the gas mass spectrometer inlet pipe to the gas outlet pipe of the heating gasification device; Operate the control panel to set the heating process parameters according to the boiling point differences of the VOC mixture components and send a heating start signal; The heating controller outputs the corresponding voltage to the electric heating plate according to the heating process parameters and heating start signal input from the control panel. The electric heating plate starts working, heating the VOC mixture in the heating dish and gradually vaporizing it. The gaseous VOC mixture enters the gas mass spectrometer, which performs component analysis. The temporal separation of the VOC mixture is achieved by the difference in boiling points of the components. After the gas mass spectrometer analysis is completed, open the sealing cover and replace or clean the heating dish.

10. The method for using the ion trap mass spectrometer for analyzing VOC mixture components according to claim 9, characterized in that: The heating process parameters include heating curve parameters, which include heating rate and heating time, holding time, cooling rate and cooling time.

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