Sample injection system and method with headspace sample injection and thermal desorption sample injection functions

Abstract

The invention discloses a sample introduction system and method with headspace sample introduction and thermal desorption sample introduction functions, and belongs to the technical field of sample introduction of analytic instruments.The system comprises a system composition module, a sample introduction module, a sample introduction module, a sample introduction module and a sample introduction module, comprising the following steps: releasing volatile components in a sample by heating through a thermal desorption function module, concentrating and enriching the volatile components through low-temperature adsorption concentration, and heating and desorbing the concentrated sample; the headspace sampling function module is used for releasing volatile components in a sample by heating the sample in a headspace bottle, pressurizing the headspace bottle to check whether a leakage condition exists or not, and quantitatively introducing the volatile components in the headspace bottle into an analytical instrument for analysis through pressure relief operation; the dynamic headspace concentration function module is used for performing concentration treatment on the sample gas after headspace sampling and performing heating desorption on the concentrated sample in combination with a thermal desorption function.

Description

Technical Field

[0001] The invention relates to the technical field of sample injection of analytical instruments, in particular to an injection system and method with headspace injection and thermal desorption injection functions. Background Art

[0002] Thermal desorption sampling technology and headspace sampling technology are both widely used sampling technologies at present, and are widely used in many fields such as life science, industry, agriculture, environmental protection, pharmaceuticals, tobacco, education, petrochemicals, toxicology, food, electronics, etc. The main equipment of thermal desorption sampling technology is thermal desorption instrument. Thermal desorption sampling technology is to place solid samples or adsorption tubes adsorbed with the analyte in a thermal desorption device, which is directly connected to the chromatograph. The carrier gas enters the chromatograph inlet through the thermal desorption device. When the thermal desorption device increases the temperature, the volatile components are released from the solid sample or adsorbent and enter the gas chromatography system with the carrier gas for analysis and determination. The main equipment of headspace sampling technology is headspace injector. The principle of headspace sampling technology is to place the sample to be tested (liquid or solid) in a closed container, and evaporate the volatile components from the sample by heating and raising the temperature to achieve gas-liquid equilibrium or gas-solid equilibrium, and then directly extract the top gas for chromatographic analysis, so as to determine the composition and content of the volatile components in the sample.

[0003] However, for thermal desorption injection technology, although it can effectively release volatile components from solid samples or adsorbents, when dealing with certain compounds with high boiling points or poor thermal stability, the high temperature may cause the compounds to decompose or denature, thus affecting the accuracy of the analysis. In addition, the adsorption tube in the thermal desorption device may also be contaminated or residual due to long-term use or processing of different samples, thereby affecting the accuracy of subsequent analysis. For headspace injection technology, although it avoids the contamination of the chromatographic column by non-volatile components in the sample, in some cases, such as when there is a large amount of interfering matrix in the sample or when it is impossible to prepare a calibration standard with the same matrix composition, the quantitative results may be affected. In addition, the traditional headspace injection process can usually only perform one extraction for each sample bottle, which limits the sensitivity and efficiency of the analysis to a certain extent; at the same time, the separation and enrichment effect of headspace injection technology on volatile components is also limited by factors such as the sealing of the sample bottle, heating temperature and time, and changes in these factors may affect the final analysis results. Summary of the invention

[0004] The object of the present invention is to provide a sampling system and method with head space sampling and thermal desorption sampling functions to solve the problems raised in the above background technology.

[0005] In order to solve the above technical problems, the present invention provides the following technical solutions: an injection system with head space injection and thermal desorption injection functions, the system comprising a system component module, a thermal desorption function module, a head space injection function module, and a dynamic head space concentration function module; The system component module is used to integrate various components of the system and realize different functions by controlling the connection status of each component; The thermal desorption function module is used to verify the sealing of the system and remove excess water vapor in the sample tube, and release the volatile components in the sample by heating, concentrate and enrich the volatile components by low-temperature adsorption concentration, and then remove the impurity gas remaining after concentration, and finally desorb the concentrated sample by heating; The headspace sampling function module is used to place the sample in a headspace bottle and release the volatile components in the sample by heating, and at the same time pressurize the headspace bottle to check whether there is leakage, and quantitatively introduce the volatile components in the headspace bottle into the analytical instrument for analysis through the pressure relief operation; The dynamic headspace concentration function module is used to concentrate the sample gas after headspace sampling and to perform temperature-raising desorption on the concentrated sample in combination with the thermal desorption function.

[0006] The system components include a six-way valve unit, a switch solenoid valve unit, a pressure sensor unit, a flow controller unit, a quantitative ring unit, a primary desorption unit, a secondary cold trap unit, a head space bottle, a head space injection needle, a damper, and a precision pressure regulating valve; The six-way valve unit includes four six-way valves, namely Va, Vb, Vc, and Vd. Each six-way valve includes six valves 1-6. In each six-way valve, when valve 6 is connected with valve 1, valve 2 is connected with valve 3, and valve 4 is connected with valve 5, it indicates that the six-way valve is in a closed state; when valve 1 is connected with valve 2, valve 3 is connected with valve 4, and valve 5 is connected with valve 6, it indicates that the six-way valve is in an open state. The switch solenoid valve unit includes 6 switch solenoid valves, namely, a thermal desorption carrier gas valve V1, a transfer carrier gas valve V2, a head space pressurization carrier gas valve V3, a thermal desorption dry blow carrier gas valve V4, a thermal desorption split and head space depressurization carrier gas valve V5, and a thermal desorption exhaust valve V6; The pressure sensor unit includes three pressure sensors, namely, a thermal desorption carrier gas leak detection pressure detector P1, a head space pressurization leak detection pressure detector P2, and a head space quantitative pressure detector P3; The flow control unit includes three flow controllers, namely flow controller 1, flow controller 2, and flow controller 3.

[0007] The quantitative ring unit is connected to valve 1 and valve 4 of the six-way valve Va, valve 6 of the six-way valve Va is connected to the carrier gas path of the gas chromatograph GC, valve 3 of the six-way valve Va is connected to the head space quantitative pressure detector P3 and the thermal desorption shunt and head space pressure relief carrier gas valve V5, and the other end of the thermal desorption shunt and head space pressure relief carrier gas valve V5 is connected to the flow controller 2; The secondary cold trap unit is connected to valve 6 and valve 3 of the six-way valve Vb, valve 4 of the six-way valve Vb is connected to the carrier gas path of the gas chromatograph GC, and both ends of the thermal desorption exhaust valve V6 are respectively connected to valve 2 of the six-way valve Vb and flow controller 3; The first-stage desorption unit is connected to valve 6 and valve 3 of the six-way valve Vc, the two ends of the thermal desorption dry-purge carrier gas valve V4 are respectively connected to valve 2 and flow controller 1 of the six-way valve Vc, the two ends of the thermal desorption carrier gas leak detection pressure detector P1 are respectively connected to valve 1 of the six-way valve Vc and the thermal desorption carrier gas valve V1, the other end of the thermal desorption carrier gas valve V1 is connected to a precision pressure regulating valve, and the other end of the precision pressure regulating valve is used to receive the carrier gas; The head space bottle is connected to the valve 6 of the six-way valve Vd, the valve 1 of the six-way valve Vd is connected to the head space pressurization leak detection pressure detector P2 and the head space pressurization carrier gas valve V3, the other end of the head space pressurization carrier gas valve V3 is connected to the damper, and the other end of the damper is used to receive the carrier gas; the two ends of the transfer carrier gas valve V2 are respectively connected to the valve 4 of the six-way valve Vd and the precision pressure regulating valve; The valve 3 of the six-way valve Va is connected to the valve 1 of the six-way valve Vb, the valve 5 of the six-way valve Va is connected to the valve 5 of the six-way valve Vb, the valve 2 of the six-way valve Va is connected to the valve 5 of the six-way valve Vc, and the valve 4 of the six-way valve Vc is connected to the valve 5 of the six-way valve Vd.

[0008] In the above technical solution, by integrating the various components of the system, modularization and integration of functions are achieved, the overall performance and flexibility of the system are improved, and by controlling the conversion of different functional modules of each component, functional diversification is achieved to meet different analysis needs.

[0009] The primary desorption unit is used to release the volatile components in the sample by heating; the secondary cold trap unit concentrates the substance by adsorption of the filler at low temperature and desorbs the sample by instant heating after the concentration is completed; The thermal desorption functional module includes a primary leak detection and dry blowing unit, a primary desorption and diversion unit, a secondary dry blowing unit, and a secondary desorption unit; The first-level leak detection and dry-blowing unit connects the sample tube to the first-level desorption unit connected to the six-way valve Vc and opens the thermal desorption carrier gas valve V1, and the first-level desorption unit is inflated with carrier gas, and the inflating time is set. After the inflating is completed, the thermal desorption carrier gas valve V1 is closed, and then the thermal desorption carrier gas leak detection pressure detector P1 is used to perform pressure holding leak detection; after the leak detection passes, the thermal desorption carrier gas valve V1 and the thermal desorption dry-blowing carrier gas valve V4 are opened, and the excess water vapor in the sample tube is blown out of the system with dry carrier gas and the dry-blowing time is set. The carrier gas leaves the pipeline through the flow controller 1. After the dry-blowing time is reached, the thermal desorption carrier gas valve V1 and the thermal desorption dry-blowing carrier gas valve V4 are closed to complete the sealing verification of the system and remove the excess water vapor in the sample tube; The first-level desorption and shunt unit opens the six-way valve Vc, the transfer carrier gas valve V2, and the thermal desorption exhaust valve V6 after the first-level leak detection and dry blowing unit. The carrier gas brings the sample volatilized by heating in the sample tube into the second-level cold trap unit through the first-level desorption unit for low-temperature adsorption concentration and leaves the system from the flow controller 3; if the shunt function is to be added, the thermal desorption shunt and the head space pressure relief carrier gas valve V5 are opened simultaneously, and the shunt flow rate in the desorption stage is controlled by the flow controller 2. When the first-level desorption and shunt unit reaches the set time, the six-way valve Vc, the thermal desorption shunt and the head space pressure relief carrier gas valve V5 are closed to complete the low-temperature adsorption concentration process of the volatile components of the sample; The secondary dry blowing unit performs dry blowing on the secondary cold trap unit to remove the residual impurity gas after low-temperature adsorption concentration, opens the transfer carrier gas valve V2 and the thermal desorption exhaust valve V6 to allow the carrier gas to enter the system, pass through the secondary cold trap unit and be discharged from the system from the flow controller 3. After the secondary dry blowing time reaches the set time, the transfer carrier gas valve V2 and the thermal desorption exhaust valve V6 are closed to complete the removal process of the residual impurity gas after concentration; The secondary desorption unit opens the six-way valve Vb to allow the carrier gas of the gas chromatograph GC to enter the system, and then desorbs the adsorbed substance by instantaneously and rapidly heating the secondary cold trap unit, and brings it into the gas chromatograph GC for analysis with the carrier gas. After the secondary desorption unit reaches the set time, the six-way valve Vb is closed to complete the heating and desorption process of the sample in the secondary cold trap unit.

[0010] In the above technical solution, the volatile components in the sample are released by heating, which improves the sensitivity of the analysis. The volatile components are effectively enriched by low-temperature adsorption concentration, which further improves the accuracy of the analysis. The temperature desorption ensures that the sample can smoothly enter the gas chromatograph GC for analysis.

[0011] The quantitative ring unit is used to receive and store quantitative headspace samples; the headspace bottle is used to contain the sample to be analyzed and release the volatile components in the sample by heating for subsequent headspace sampling function; The head space sampling function module includes a pressurized leak detection unit, a pressure relief quantitative unit and a sampling unit; the pressurized leak detection unit places the head space bottle in a constant temperature furnace, performs constant temperature heating to release the volatile components in the sample and sets a heating time. After the heating time is reached, the head space sampling needle is inserted into the head space bottle, the head space pressurized carrier gas valve V3 is opened, and the carrier gas enters the head space bottle to pressurize the bottle. The pressurized pressure is detected by the head space pressurized leak detection pressure detector P2. When the pressurized pressure reaches the set value, the head space pressurized carrier gas valve V3 is closed, and the head space pressurized leak detection pressure detector P2 is used to perform real-time pressure holding detection on the system pressure in the bottle. When the cavity formed by the head space bottle and the head space sampling needle is leak-proof, the inspection of whether the head space bottle has leakage is completed and the pressure relief quantitative unit is entered; The pressure relief quantitative unit opens the six-way valve Va and the six-way valve Vd, opens the thermal desorption shunt and the head space pressure relief carrier gas valve V5, and the high-pressure gas in the head space bottle passes through the quantitative ring unit along the carrier gas path, and is discharged from the system from the flow controller 2. The pressure in the quantitative process is controlled by the head space quantitative pressure detector P3. When the pressure is released to the set value, the six-way valve Vd, the thermal desorption shunt and the head space pressure relief carrier gas valve V5 are closed to complete the quantitative filling process of the head space sample in the quantitative ring unit; After the pressure relief quantitative unit is completed, the sample injection unit closes the six-way valve Va, and the carrier gas brings the sample in the quantitative loop into the gas chromatograph GC for analysis.

[0012] In the above technical solution, the pressurized leak detection unit ensures the sealing of the system and prevents analysis errors caused by sample leakage. The pressure relief quantitative unit realizes the precise quantification of volatile components and improves the accuracy of the analysis.

[0013] The dynamic headspace concentration functional module includes a multiple headspace concentration unit and a large-volume headspace concentration unit; The multiple headspace concentration unit first operates the pressurization leak detection unit, and then operates the pressure relief quantitative unit. After the quantitative ring unit is quantitatively completed, the transfer carrier gas valve V2 and the thermal desorption exhaust valve V6 are opened, and the carrier gas brings the sample with good headspace quantification into the secondary cold trap unit through the quantitative ring unit for concentration and enrichment and sets the time. After the set time is reached, the transfer carrier gas valve V2 and the thermal desorption exhaust valve V6 are closed to complete the transfer and concentration of the sample in the first quantitative ring unit, and then the above operation is repeated until the set number of cycles is reached, the concentration treatment of the sample after the headspace injection is completed, and the operation of the secondary desorption unit of the thermal desorption module is performed to heat and desorb the concentrated sample; The large-volume headspace concentration unit first performs the operation of the pressurized leak-picking unit, and after the operation is completed, the six-way valve Vd and the thermal desorption exhaust valve V6 are opened, and the high-pressure sample in the headspace bottle enters the secondary cold trap unit for concentration and enrichment, and the carrier gas is discharged from the system through the flow controller 3. The pressure inside the system is detected by the headspace quantitative pressure detector P3. When the internal pressure of the system reaches the set value, the thermal desorption exhaust valve V6 and the six-way valve Vd are closed to complete the concentration process of the sample after the headspace injection, and the operation of the secondary desorption unit of the thermal desorption module is performed to heat and desorb the concentrated sample; In the above technical scheme, the multiple headspace concentration unit realizes efficient enrichment of volatile components through cyclic operation, thereby improving the sensitivity of analysis; the large-volume headspace concentration unit can process large-volume samples, broadening the application scope of the system; and by combining the thermal desorption function, the temperature-raising desorption of the concentrated samples is realized, which is convenient for subsequent analysis.

[0014] A sampling method with headspace sampling and thermal desorption sampling functions, the method comprising the following steps: Step S100: preparing various components required for the method, connecting the various components and realizing different functions by controlling the connection states between the components, namely, thermal desorption function, headspace sampling function and dynamic headspace concentration function; Step S200: Implementing the thermal desorption function to verify the sealing of the system and remove excess water vapor in the sample tube, releasing the volatile components in the sample by heating and concentrating the volatile components by low-temperature adsorption concentration, removing the impurity gas remaining after concentration and performing temperature-raising desorption on the concentrated sample; Step S300: realizing the headspace sampling function, placing the sample in the headspace bottle and releasing the volatile components in the sample by heating, and at the same time pressurizing the headspace bottle to check whether there is leakage, and quantitatively introducing the volatile components in the headspace bottle into the analytical instrument for analysis by the pressure relief operation; Step S400: realizing the dynamic headspace concentration function, concentrating the sample gas after headspace injection and performing temperature-raising desorption on the concentrated sample in combination with the thermal desorption function.

[0015] The step S200 includes the following steps: step S201 performs a primary desorption and dry blowing operation; step S202 performs a primary desorption and flow splitting operation; step S203 performs a secondary dry blowing operation; step S204 performs a secondary desorption operation; The step S300 includes the following steps: step S301 performs a pressurized leak detection operation; step S302 performs a pressure relief quantitative operation; step S303 performs a sample injection operation; The step S400 includes the following steps: step S401 performs multiple headspace concentration operations; step S402 performs large-volume headspace concentration operations.

[0016] Compared with the prior art, the beneficial effects achieved by the present invention are: The present invention can realize the multi-position headspace sampling function and the multi-position secondary thermal desorption function. At the same time, the headspace function can be combined with the thermal desorption secondary concentration function to realize the dynamic concentration function of the headspace, and perfectly realize the application function of "1+1>2". The mode of combining headspace with thermal desorption in the present invention also enriches the function of headspace sample pretreatment, which can realize multiple headspace concentration functions and the pretreatment function of large-volume headspace concentration, greatly improving the sensitivity of low-concentration headspace sample detection; The present invention not only simplifies the experimental process but also greatly improves the analysis efficiency by integrating the head space sampling and thermal desorption sampling functions. Traditional analysis methods often require multiple devices to perform head space sampling and thermal desorption sampling respectively. The present invention cleverly combines these two functions together through modular design, making the operation simpler and also saving experimental space and time costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings: Figure 1 It is a system module diagram of an injection system with headspace injection and thermal desorption injection functions; Figure 2 It is a system composition module diagram of an injection system with headspace injection and thermal desorption injection functions; Figure 3 It is a first-level leak detection and dry blowing flow chart of an injection system with headspace injection and thermal desorption injection functions; Figure 4 It is a first-stage desorption and splitting flow chart of an injection system with headspace injection and thermal desorption injection functions; Figure 5 It is a two-stage dry-purge flow chart of an injection system with headspace injection and thermal desorption injection functions; Figure 6 It is a two-stage desorption flow chart of an injection system with headspace injection and thermal desorption injection functions; Figure 7 It is a flow chart of pressurized leak detection for an injection system with headspace injection and thermal desorption injection functions; Figure 8 It is a decompression quantitative flow chart of an injection system with headspace injection and thermal desorption injection functions; Fig. 9It is a headspace injection flow chart of an injection system with headspace injection and thermal desorption injection functions; Fig.10 It is a multiple headspace concentration flow chart of an injection system with headspace injection and thermal desorption injection functions; Fig.11 A flow chart of large volume headspace concentration for an injection system with headspace and thermal desorption injection capabilities. DETAILED DESCRIPTION

[0018] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0019] See also Figure 1-Figure 11 , the present invention provides a technical solution: a sampling system with head space sampling and thermal desorption sampling functions, the system includes a system component module, a thermal desorption function module, a head space sampling function module, and a dynamic head space concentration function module; The system component module is used to integrate various components of the system and realize different functions by controlling the connection status of each component; The thermal desorption function module is used to verify the sealing of the system and remove excess water vapor in the sample tube, and release the volatile components in the sample by heating, concentrate and enrich the volatile components by low-temperature adsorption concentration, and then remove the impurity gas remaining after concentration, and finally desorb the concentrated sample by heating; The headspace sampling function module is used to place the sample in a headspace bottle and release the volatile components in the sample by heating, and at the same time pressurize the headspace bottle to check whether there is leakage, and quantitatively introduce the volatile components in the headspace bottle into the analytical instrument for analysis through the pressure relief operation; The dynamic headspace concentration function module is used to concentrate the sample gas after headspace sampling and to perform temperature-raising desorption on the concentrated sample in combination with the thermal desorption function.

[0020] The system components include a six-way valve unit, a switch solenoid valve unit, a pressure sensor unit, a flow controller unit, a quantitative ring unit, a primary desorption unit, a secondary cold trap unit, a head space bottle, a head space injection needle, a damper, and a precision pressure regulating valve; The six-way valve unit includes four six-way valves, namely Va, Vb, Vc, and Vd. Each six-way valve includes six valves 1-6. In each six-way valve, when valve 6 is connected with valve 1, valve 2 is connected with valve 3, and valve 4 is connected with valve 5, it indicates that the six-way valve is in a closed state; when valve 1 is connected with valve 2, valve 3 is connected with valve 4, and valve 5 is connected with valve 6, it indicates that the six-way valve is in an open state. The switch solenoid valve unit includes 6 switch solenoid valves, namely, a thermal desorption carrier gas valve V1, a transfer carrier gas valve V2, a head space pressurization carrier gas valve V3, a thermal desorption dry blow carrier gas valve V4, a thermal desorption split and head space depressurization carrier gas valve V5, and a thermal desorption exhaust valve V6; The pressure sensor unit includes three pressure sensors, namely, a thermal desorption carrier gas leak detection pressure detector P1, a head space pressurization leak detection pressure detector P2, and a head space quantitative pressure detector P3; The flow control unit includes three flow controllers, namely flow controller 1, flow controller 2, and flow controller 3.

[0021] The quantitative ring unit is connected to valve 1 and valve 4 of the six-way valve Va, valve 6 of the six-way valve Va is connected to the carrier gas path of the gas chromatograph GC, valve 3 of the six-way valve Va is connected to the head space quantitative pressure detector P3 and the thermal desorption shunt and head space pressure relief carrier gas valve V5, and the other end of the thermal desorption shunt and head space pressure relief carrier gas valve V5 is connected to the flow controller 2; The secondary cold trap unit is connected to valve 6 and valve 3 of the six-way valve Vb, valve 4 of the six-way valve Vb is connected to the carrier gas path of the gas chromatograph GC, and both ends of the thermal desorption exhaust valve V6 are respectively connected to valve 2 of the six-way valve Vb and flow controller 3; The first-stage desorption unit is connected to valve 6 and valve 3 of the six-way valve Vc, the two ends of the thermal desorption dry-purge carrier gas valve V4 are respectively connected to valve 2 and flow controller 1 of the six-way valve Vc, the two ends of the thermal desorption carrier gas leak detection pressure detector P1 are respectively connected to valve 1 of the six-way valve Vc and the thermal desorption carrier gas valve V1, the other end of the thermal desorption carrier gas valve V1 is connected to a precision pressure regulating valve, and the other end of the precision pressure regulating valve is used to receive the carrier gas; The head space bottle is connected to the valve 6 of the six-way valve Vd, the valve 1 of the six-way valve Vd is connected to the head space pressurization leak detection pressure detector P2 and the head space pressurization carrier gas valve V3, the other end of the head space pressurization carrier gas valve V3 is connected to the damper, and the other end of the damper is used to receive the carrier gas; the two ends of the transfer carrier gas valve V2 are respectively connected to the valve 4 of the six-way valve Vd and the precision pressure regulating valve; The valve 3 of the six-way valve Va is connected to the valve 1 of the six-way valve Vb, the valve 5 of the six-way valve Va is connected to the valve 5 of the six-way valve Vb, the valve 2 of the six-way valve Va is connected to the valve 5 of the six-way valve Vc, and the valve 4 of the six-way valve Vc is connected to the valve 5 of the six-way valve Vd.

[0022] In the above technical solution, by integrating the various components of the system, modularization and integration of functions are achieved, the overall performance and flexibility of the system are improved, and by controlling the conversion of different functional modules of each component, functional diversification is achieved to meet different analysis needs.

[0023] The primary desorption unit is used to release the volatile components in the sample by heating; the secondary cold trap unit concentrates the substance by adsorption of the filler at low temperature and desorbs the sample by instant heating after the concentration is completed; The thermal desorption functional module includes a primary leak detection and dry blowing unit, a primary desorption and diversion unit, a secondary dry blowing unit, and a secondary desorption unit; The first-level leak detection and dry-blowing unit connects the sample tube to the first-level desorption unit connected to the six-way valve Vc and opens the thermal desorption carrier gas valve V1, and the first-level desorption unit is inflated with carrier gas, and the inflating time is set. After the inflating is completed, the thermal desorption carrier gas valve V1 is closed, and then the thermal desorption carrier gas leak detection pressure detector P1 is used to perform pressure holding leak detection; after the leak detection passes, the thermal desorption carrier gas valve V1 and the thermal desorption dry-blowing carrier gas valve V4 are opened, and the excess water vapor in the sample tube is blown out of the system with dry carrier gas and the dry-blowing time is set. The carrier gas leaves the pipeline through the flow controller 1. After the dry-blowing time is reached, the thermal desorption carrier gas valve V1 and the thermal desorption dry-blowing carrier gas valve V4 are closed to complete the sealing verification of the system and remove the excess water vapor in the sample tube; The first-level desorption and shunt unit opens the six-way valve Vc, the transfer carrier gas valve V2, and the thermal desorption exhaust valve V6 after the first-level leak detection and dry blowing unit. The carrier gas brings the sample volatilized by heating in the sample tube into the second-level cold trap unit through the first-level desorption unit for low-temperature adsorption concentration and leaves the system from the flow controller 3; if the shunt function is to be added, the thermal desorption shunt and the head space pressure relief carrier gas valve V5 are opened simultaneously, and the shunt flow rate in the desorption stage is controlled by the flow controller 2. When the first-level desorption and shunt unit reaches the set time, the six-way valve Vc, the thermal desorption shunt and the head space pressure relief carrier gas valve V5 are closed to complete the low-temperature adsorption concentration process of the volatile components of the sample; The secondary dry blowing unit performs dry blowing on the secondary cold trap unit to remove the residual impurity gas after low-temperature adsorption concentration, opens the transfer carrier gas valve V2 and the thermal desorption exhaust valve V6 to allow the carrier gas to enter the system, pass through the secondary cold trap unit and be discharged from the system from the flow controller 3. After the secondary dry blowing time reaches the set time, the transfer carrier gas valve V2 and the thermal desorption exhaust valve V6 are closed to complete the removal process of the residual impurity gas after concentration; The secondary desorption unit opens the six-way valve Vb to allow the carrier gas of the gas chromatograph GC to enter the system, and then desorbs the adsorbed substance by instantaneously and rapidly heating the secondary cold trap unit, and brings it into the gas chromatograph GC for analysis with the carrier gas. After the secondary desorption unit reaches the set time, the six-way valve Vb is closed to complete the heating and desorption process of the sample in the secondary cold trap unit.

[0024] In the above technical solution, the volatile components in the sample are released by heating, which improves the sensitivity of the analysis. The volatile components are effectively enriched by low-temperature adsorption concentration, which further improves the accuracy of the analysis. The temperature desorption ensures that the sample can smoothly enter the gas chromatograph GC for analysis.

[0025] The quantitative ring unit is used to receive and store quantitative headspace samples; the headspace bottle is used to contain the sample to be analyzed and release the volatile components in the sample by heating for subsequent headspace sampling function; The head space sampling function module includes a pressurized leak detection unit, a pressure relief quantitative unit and a sampling unit; the pressurized leak detection unit places the head space bottle in a constant temperature furnace, performs constant temperature heating to release the volatile components in the sample and sets a heating time. After the heating time is reached, the head space sampling needle is inserted into the head space bottle, the head space pressurized carrier gas valve V3 is opened, and the carrier gas enters the head space bottle to pressurize the bottle. The pressurized pressure is detected by the head space pressurized leak detection pressure detector P2. When the pressurized pressure reaches the set value, the head space pressurized carrier gas valve V3 is closed, and the head space pressurized leak detection pressure detector P2 is used to perform real-time pressure holding detection on the system pressure in the bottle. When the cavity formed by the head space bottle and the head space sampling needle is leak-proof, the inspection of whether the head space bottle has leakage is completed and the pressure relief quantitative unit is entered; The pressure relief quantitative unit opens the six-way valve Va and the six-way valve Vd, opens the thermal desorption shunt and the head space pressure relief carrier gas valve V5, and the high-pressure gas in the head space bottle passes through the quantitative ring unit along the carrier gas path, and is discharged from the system from the flow controller 2. The pressure in the quantitative process is controlled by the head space quantitative pressure detector P3. When the pressure is released to the set value, the six-way valve Vd, the thermal desorption shunt and the head space pressure relief carrier gas valve V5 are closed to complete the quantitative filling process of the head space sample in the quantitative ring unit; After the pressure relief quantitative unit is completed, the sample injection unit closes the six-way valve Va, and the carrier gas brings the sample in the quantitative loop into the gas chromatograph GC for analysis.

[0026] In the above technical solution, the pressurized leak detection unit ensures the sealing of the system and prevents analysis errors caused by sample leakage. The pressure relief quantitative unit realizes the precise quantification of volatile components and improves the accuracy of the analysis.

[0027] The dynamic headspace concentration functional module includes a multiple headspace concentration unit and a large-volume headspace concentration unit; The multiple headspace concentration unit first performs the operation of the pressurization leak detection unit and then the pressure relief quantitative unit. After the quantitative ring unit is quantitatively completed, the transfer carrier gas valve V2 and the thermal desorption exhaust valve V6 are opened, and the carrier gas brings the sample with good headspace quantification into the secondary cold trap unit through the quantitative ring unit for concentration and enrichment and sets the time. After the set time is reached, the transfer carrier gas valve V2 and the thermal desorption exhaust valve V6 are closed to complete the transfer and concentration of the sample in the first quantitative ring unit, and then the above operation is repeated until the set number of cycles is reached, the concentration treatment of the sample after the headspace injection is completed, and the operation of the secondary desorption unit of the thermal desorption module is performed to heat and desorb the concentrated sample; The large-volume headspace concentration unit first performs the operation of the pressurized leak-picking unit, and after the operation is completed, the six-way valve Vd and the thermal desorption exhaust valve V6 are opened, and the high-pressure sample in the headspace bottle enters the secondary cold trap unit for concentration and enrichment, and the carrier gas is discharged from the system through the flow controller 3. The pressure inside the system is detected by the headspace quantitative pressure detector P3. When the internal pressure of the system reaches the set value, the thermal desorption exhaust valve V6 and the six-way valve Vd are closed to complete the concentration process of the sample after the headspace injection, and the operation of the secondary desorption unit of the thermal desorption module is performed to heat and desorb the concentrated sample; In the above technical scheme, the multiple headspace concentration unit realizes efficient enrichment of volatile components through cyclic operation, thereby improving the sensitivity of analysis; the large-volume headspace concentration unit can process large-volume samples, broadening the application scope of the system; and by combining the thermal desorption function, the temperature-raising desorption of the concentrated samples is realized, which is convenient for subsequent analysis.

[0028] A sampling method with headspace sampling and thermal desorption sampling functions, the method comprising the following steps: Step S100: preparing various components required for the method, connecting the various components and realizing different functions by controlling the connection states between the components, namely, thermal desorption function, headspace sampling function and dynamic headspace concentration function; Step S200: Implementing the thermal desorption function to verify the sealing of the system and remove excess water vapor in the sample tube, releasing the volatile components in the sample by heating and concentrating the volatile components by low-temperature adsorption concentration, removing the impurity gas remaining after concentration and performing temperature-raising desorption on the concentrated sample; Step S300: realizing the headspace sampling function, placing the sample in the headspace bottle and releasing the volatile components in the sample by heating, and at the same time pressurizing the headspace bottle to check whether there is leakage, and quantitatively introducing the volatile components in the headspace bottle into the analytical instrument for analysis by the pressure relief operation; Step S400: realizing the dynamic headspace concentration function, concentrating the sample gas after headspace injection and performing temperature-raising desorption on the concentrated sample in combination with the thermal desorption function.

[0029] The step S200 includes the following steps: step S201 performs a primary desorption and dry blowing operation; step S202 performs a primary desorption and flow splitting operation; step S203 performs a secondary dry blowing operation; step S204 performs a secondary desorption operation; The step S300 includes the following steps: step S301 performs a pressurized leak detection operation; step S302 performs a pressure relief quantitative operation; step S303 performs a sample injection operation; The step S400 includes the following steps: step S401 performs multiple headspace concentration operations; step S402 performs large-volume headspace concentration operations.

[0030] In an embodiment of the present invention, the thermal desorption functional module includes a primary leak detection and dry blowing unit, a primary desorption and diversion unit, a secondary dry blowing unit, and a secondary desorption unit; like Figure 3 As shown in the first-level leak detection and dry-blow flow chart, the sample tube is connected to the first-level desorption unit by manual or mechanical movement and the thermal desorption carrier gas valve V1 is opened. The first-level desorption unit is flushed with carrier gas. After 5 seconds, the thermal desorption carrier gas valve V1 is closed, and then the thermal desorption carrier gas leak detection pressure detector P1 is used to hold the pressure for leak detection; after the leak detection is passed, the thermal desorption carrier gas valve V1 and the thermal desorption dry-blow carrier gas valve V4 are opened, and the carrier gas leaves the pipeline through the flow controller 1, and the dry-blow time is set. After the dry-blow time is reached, the thermal desorption carrier gas valve V1 and the thermal desorption dry-blow carrier gas valve V4 are closed; like Figure 4 As shown in the first-stage desorption and diversion flow chart, open the six-way valve Vc, transfer carrier gas valve V2, and thermal desorption exhaust valve V6, and the carrier gas will bring the sample volatilized by heating in the sample tube into the second-stage cold trap unit through the first-stage desorption unit for low-temperature adsorption concentration and leave the system from the flow controller 3; if the diversion function is to be added, open the thermal desorption diversion and headspace pressure relief carrier gas valve V5 simultaneously, and control the diversion flow rate in the desorption stage through the flow controller 2. When the first-stage desorption and diversion unit reaches the set time, close the six-way valve Vc, thermal desorption diversion and headspace pressure relief carrier gas valve V5; like Figure 5 Secondary dry blowing flow chart, open the transfer carrier gas valve V2 and the thermal desorption exhaust valve V6 to allow the carrier gas to enter the system, pass through the secondary cold trap unit and be discharged from the system from the flow controller 3. After the secondary dry blowing time reaches the set time, close the transfer carrier gas valve V2 and the thermal desorption exhaust valve V6; like Figure 6Secondary desorption flow chart: open the six-way valve Vb to allow the carrier gas of the gas chromatograph GC to enter the system, and then desorb the adsorbed substance by instantaneously and rapidly heating the secondary cold trap unit, and bring it into the gas chromatograph GC with the carrier gas for analysis. After the secondary desorption time reaches the set time, close the six-way valve Vb.

[0031] The headspace sampling function module includes a pressurized leak detection unit, a pressure relief quantitative unit and a sampling unit; like Figure 7 As shown in the flow chart of pressurized leak detection, the headspace bottle is placed in a constant temperature furnace by manual or mechanical movement, a constant temperature heating process is carried out and a heating time is set. After the heating time is reached, the headspace injection needle is inserted into the headspace bottle, the headspace pressurized carrier gas valve V3 is opened, and the carrier gas enters the headspace bottle to pressurize the bottle. The pressurized pressure is detected by the headspace pressurized leak detection pressure detector P2. When the pressurized pressure reaches the set value, the headspace pressurized carrier gas valve V3 is closed, and the headspace pressurized leak detection pressure detector P2 is used to perform real-time pressure holding detection on the system pressure in the bottle. When the cavity formed by the headspace bottle and the headspace injection needle is leak-proof, it enters the pressure relief quantitative unit. like Figure 8 As shown in the pressure relief quantitative flow chart, open the six-way valve Va and the six-way valve Vd, open the thermal desorption shunt and the headspace pressure relief carrier gas valve V5, the high-pressure gas in the headspace bottle passes through the quantitative ring unit along the carrier gas path, and is discharged from the system from the flow controller 2. The pressure in the quantitative process is controlled by the headspace quantitative pressure detector P3. When the pressure is released to the set value, close the six-way valve Vd, the thermal desorption shunt and the headspace pressure relief carrier gas valve V5; like Fig. 9 As shown in the injection flow chart, after the pressure relief quantitative process is completed, the six-way valve Va is closed, and the carrier gas brings the sample in the quantitative loop into the gas chromatograph GC for analysis.

[0032] The dynamic headspace concentration function module includes a multiple headspace concentration unit and a multiple headspace concentration unit; like Fig.10 As shown in the multiple headspace concentration flow chart, the pressurization leak detection unit and the pressure relief quantitative unit are operated first. After the quantitative ring unit is quantitatively completed, the transfer carrier gas valve V2 and the thermal desorption exhaust valve V6 are opened, and the carrier gas brings the sample with good headspace quantification into the secondary cold trap unit through the quantitative ring unit for concentration and enrichment, and the time is set. After the set time is reached, the transfer carrier gas valve V2 and the thermal desorption exhaust valve V6 are closed to complete the transfer and concentration of the sample in the first quantitative ring unit. Then the above operation is repeated until the set number of cycles is reached, and the operation of the secondary desorption unit of the thermal desorption module is performed; like Fig.11As shown in the large-volume headspace concentration flow chart, the advanced pressurization leak detection unit is operated. After completion, the six-way valve Vd and the thermal desorption exhaust valve V6 are opened, and the high-pressure sample in the headspace bottle enters the secondary cold trap unit for concentration and enrichment. The carrier gas is discharged from the system through the flow controller 3, and the pressure inside the system is detected by the headspace quantitative pressure detector P3. When the internal pressure of the system reaches the set value, the thermal desorption exhaust valve V6 and the six-way valve Vd are closed to perform the operation of the secondary desorption unit of the thermal desorption module.

[0033] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A sampling system with headspace sampling and thermal desorption sampling functions, characterized in that: The system comprises a system composition module, a thermal desorption function module, a headspace injection function module, and a dynamic headspace concentration function module; The system component module is used to integrate various components of the system and realize different functions by controlling the connection status of each component; The thermal desorption function module is used to verify the sealing of the system and remove excess water vapor in the sample tube, and release the volatile components in the sample by heating, concentrate and enrich the volatile components by low-temperature adsorption concentration, and then remove the impurity gas remaining after concentration, and finally desorb the concentrated sample by heating; The headspace sampling function module is used to place the sample in a headspace bottle and release the volatile components in the sample by heating, and at the same time pressurize the headspace bottle to check whether there is leakage, and quantitatively introduce the volatile components in the headspace bottle into the analytical instrument for analysis through the pressure relief operation; The dynamic headspace concentration function module is used to concentrate the sample gas after headspace sampling and to perform temperature-raising desorption on the concentrated sample in combination with the thermal desorption function.

2. The sampling system with head space sampling and thermal desorption sampling functions according to claim 1, characterized in that: The system components include a six-way valve unit, a switch solenoid valve unit, a pressure sensor unit, a flow controller unit, a quantitative ring unit, a primary desorption unit, a secondary cold trap unit, a headspace bottle, a headspace injection needle, a damper, a precision pressure regulating valve, and a gas chromatograph GC; The six-way valve unit includes four six-way valves, namely Va, Vb, Vc, and Vd. Each six-way valve includes six valves 1-6. In each six-way valve, when valve 6 is connected with valve 1, valve 2 is connected with valve 3, and valve 4 is connected with valve 5, it indicates that the six-way valve is in a closed state; when valve 1 is connected with valve 2, valve 3 is connected with valve 4, and valve 5 is connected with valve 6, it indicates that the six-way valve is in an open state. The switch solenoid valve unit includes 6 switch solenoid valves, namely, a thermal desorption carrier gas valve V1, a transfer carrier gas valve V2, a head space pressurization carrier gas valve V3, a thermal desorption dry blow carrier gas valve V4, a thermal desorption split and head space depressurization carrier gas valve V5, and a thermal desorption exhaust valve V6; The pressure sensor unit includes three pressure sensors, namely, a thermal desorption carrier gas leak detection pressure detector P1, a head space pressurization leak detection pressure detector P2, and a head space quantitative pressure detector P3; The flow control unit includes three flow controllers, namely flow controller 1, flow controller 2, and flow controller 3.

3. The sampling system with head space sampling and thermal desorption sampling functions according to claim 2, characterized in that: The quantitative ring unit is connected to valve 1 and valve 4 of the six-way valve Va, valve 6 of the six-way valve Va is connected to the carrier gas path of the gas chromatograph GC, valve 3 of the six-way valve Va is connected to the head space quantitative pressure detector P3 and the thermal desorption shunt and head space pressure relief carrier gas valve V5, and the other end of the thermal desorption shunt and head space pressure relief carrier gas valve V5 is connected to the flow controller 2; The secondary cold trap unit is connected to valve 6 and valve 3 of the six-way valve Vb, valve 4 of the six-way valve Vb is connected to the carrier gas path of the gas chromatograph GC, and both ends of the thermal desorption exhaust valve V6 are respectively connected to valve 2 of the six-way valve Vb and flow controller 3; The first-stage desorption unit is connected to valve 6 and valve 3 of the six-way valve Vc, the two ends of the thermal desorption dry-purge carrier gas valve V4 are respectively connected to valve 2 and flow controller 1 of the six-way valve Vc, the two ends of the thermal desorption carrier gas leak detection pressure detector P1 are respectively connected to valve 1 of the six-way valve Vc and the thermal desorption carrier gas valve V1, the other end of the thermal desorption carrier gas valve V1 is connected to a precision pressure regulating valve, and the other end of the precision pressure regulating valve is used to receive the carrier gas; The head space bottle is connected to the valve 6 of the six-way valve Vd, the valve 1 of the six-way valve Vd is connected to the head space pressurization leak detection pressure detector P2 and the head space pressurization carrier gas valve V3, the other end of the head space pressurization carrier gas valve V3 is connected to the damper, and the other end of the damper is used to receive the carrier gas; the two ends of the transfer carrier gas valve V2 are respectively connected to the valve 4 of the six-way valve Vd and the precision pressure regulating valve; The valve 3 of the six-way valve Va is connected to the valve 1 of the six-way valve Vb, the valve 5 of the six-way valve Va is connected to the valve 5 of the six-way valve Vb, the valve 2 of the six-way valve Va is connected to the valve 5 of the six-way valve Vc, and the valve 4 of the six-way valve Vc is connected to the valve 5 of the six-way valve Vd.

4. The sampling system with head space sampling and thermal desorption sampling functions according to claim 2, characterized in that: The primary desorption unit is used to release the volatile components in the sample by heating; the secondary cold trap unit concentrates the substance by adsorption of the filler at low temperature and desorbs the sample by instant heating after the concentration is completed; The thermal desorption functional module includes a primary leak detection and dry blowing unit, a primary desorption and diversion unit, a secondary dry blowing unit, and a secondary desorption unit; The first-level leak detection and dry-blowing unit connects the sample tube to the first-level desorption unit connected to the six-way valve Vc and opens the thermal desorption carrier gas valve V1, and the first-level desorption unit is inflated with carrier gas, and the inflating time is set. After the inflating is completed, the thermal desorption carrier gas valve V1 is closed, and then the thermal desorption carrier gas leak detection pressure detector P1 is used to perform pressure holding leak detection; after the leak detection passes, the thermal desorption carrier gas valve V1 and the thermal desorption dry-blowing carrier gas valve V4 are opened, and the excess water vapor in the sample tube is blown out of the system with dry carrier gas and the dry-blowing time is set. The carrier gas leaves the pipeline through the flow controller 1. After the dry-blowing time is reached, the thermal desorption carrier gas valve V1 and the thermal desorption dry-blowing carrier gas valve V4 are closed to complete the sealing verification of the system and remove the excess water vapor in the sample tube; The first-level desorption and diversion unit is behind the first-level leak detection and dry blowing unit, and opens the six-way valve Vc, the carrier gas transfer valve V2, and the thermal desorption exhaust valve V6. The carrier gas passes through the first-level desorption unit to bring the sample volatilized by heating in the sample tube into the second-level cold trap unit for low-temperature adsorption concentration and leaves the system from the flow controller 3; If the diversion function is to be added, the thermal desorption diversion and the headspace pressure relief carrier gas valve V5 are opened simultaneously, and the diversion flow rate in the desorption stage is controlled by the flow controller 2. When the first-stage desorption and diversion unit reaches the set time, the six-way valve Vc, the thermal desorption diversion and the headspace pressure relief carrier gas valve V5 are closed to complete the low-temperature adsorption concentration process of the volatile components of the sample; The secondary dry blowing unit performs dry blowing on the secondary cold trap unit to remove the residual impurity gas after low-temperature adsorption concentration, opens the transfer carrier gas valve V2 and the thermal desorption exhaust valve V6 to allow the carrier gas to enter the system, pass through the secondary cold trap unit and be discharged from the system from the flow controller 3. After the secondary dry blowing time reaches the set time, the transfer carrier gas valve V2 and the thermal desorption exhaust valve V6 are closed to complete the removal process of the residual impurity gas after concentration; The secondary desorption unit opens the six-way valve Vb to allow the carrier gas of the gas chromatograph GC to enter the system, and then desorbs the adsorbed substance by instantaneously and rapidly heating the secondary cold trap unit, and brings it into the gas chromatograph GC for analysis with the carrier gas. After the secondary desorption unit reaches the set time, the six-way valve Vb is closed to complete the heating and desorption process of the sample in the secondary cold trap unit.

5. The sampling system with head space sampling and thermal desorption sampling functions according to claim 2, characterized in that: The quantitative ring unit is used to receive and store quantitative headspace samples; the headspace bottle is used to contain the sample to be analyzed and release the volatile components in the sample by heating for subsequent headspace sampling function; The head space sampling function module includes a pressurized leak detection unit, a pressure relief quantitative unit and a sampling unit; the pressurized leak detection unit places the head space bottle in a constant temperature furnace, performs constant temperature heating to release the volatile components in the sample and sets a heating time. After the heating time is reached, the head space sampling needle is inserted into the head space bottle, the head space pressurized carrier gas valve V3 is opened, and the carrier gas enters the head space bottle to pressurize the bottle. The pressurized pressure is detected by the head space pressurized leak detection pressure detector P2. When the pressurized pressure reaches the set value, the head space pressurized carrier gas valve V3 is closed, and the head space pressurized leak detection pressure detector P2 is used to perform real-time pressure holding detection on the system pressure in the bottle. When the cavity formed by the head space bottle and the head space sampling needle is leak-proof, the inspection of whether the head space bottle has leakage is completed and the pressure relief quantitative unit is entered; The pressure relief quantitative unit opens the six-way valve Va and the six-way valve Vd, opens the thermal desorption shunt and the head space pressure relief carrier gas valve V5, and the high-pressure gas in the head space bottle passes through the quantitative ring unit along the carrier gas path, and is discharged from the system from the flow controller 2. The pressure in the quantitative process is controlled by the head space quantitative pressure detector P3. When the pressure is released to the set value, the six-way valve Vd, the thermal desorption shunt and the head space pressure relief carrier gas valve V5 are closed to complete the quantitative filling process of the head space sample in the quantitative ring unit; After the pressure relief quantitative unit is completed, the sample injection unit closes the six-way valve Va, and the carrier gas brings the sample in the quantitative loop into the gas chromatograph GC for analysis.

6. The sampling system with head space sampling and thermal desorption sampling functions according to claim 2, characterized in that: The dynamic headspace concentration functional module includes a multiple headspace concentration unit and a large-volume headspace concentration unit; The multiple headspace concentration unit first operates the pressurization leak detection unit, and then operates the pressure relief quantitative unit. After the quantitative ring unit is quantitatively completed, the transfer carrier gas valve V2 and the thermal desorption exhaust valve V6 are opened, and the carrier gas brings the sample with good headspace quantification into the secondary cold trap unit through the quantitative ring unit for concentration and enrichment and sets the time. After the set time is reached, the transfer carrier gas valve V2 and the thermal desorption exhaust valve V6 are closed to complete the transfer and concentration of the sample in the first quantitative ring unit, and then the above operation is repeated until the set number of cycles is reached, the concentration treatment of the sample after the headspace injection is completed, and the operation of the secondary desorption unit of the thermal desorption module is performed to heat and desorb the concentrated sample; The large-volume headspace concentration unit first performs the operation of the pressurized leak detection unit. After the operation is completed, the six-way valve Vd and the thermal desorption exhaust valve V6 are opened, and the high-pressure sample in the headspace bottle enters the secondary cold trap unit for concentration and enrichment. The carrier gas is discharged from the system through the flow controller 3, and the pressure inside the system is detected by the headspace quantitative pressure detector P3. When the internal pressure of the system reaches the set value, the thermal desorption exhaust valve V6 and the six-way valve Vd are closed to complete the concentration process of the sample after the headspace injection, and the operation of the secondary desorption unit of the thermal desorption module is performed to heat and desorb the concentrated sample.

7. A sampling method with head space sampling and thermal desorption sampling functions, applied to a sampling system with head space sampling and thermal desorption sampling functions as claimed in any one of claims 1 to 6, characterized in that: The method comprises the following steps: Step S100: preparing various components required for the method, connecting the various components and realizing different functions by controlling the connection states between the components, namely, thermal desorption function, headspace injection function and dynamic headspace concentration function; Step S200: Implementing the thermal desorption function to verify the sealing of the system and remove excess water vapor in the sample tube, releasing the volatile components in the sample by heating and concentrating the volatile components by low-temperature adsorption concentration, removing the impurity gas remaining after concentration and performing temperature-raising desorption on the concentrated sample; Step S300: realizing the headspace sampling function, placing the sample in the headspace bottle and releasing the volatile components in the sample by heating, and at the same time pressurizing the headspace bottle to check whether there is leakage, and quantitatively introducing the volatile components in the headspace bottle into the analytical instrument for analysis by the pressure relief operation; Step S400: realizing the dynamic headspace concentration function, concentrating the sample gas after headspace sampling and performing temperature-raising desorption on the concentrated sample in combination with the thermal desorption function.

8. The sampling method with head space sampling and thermal desorption sampling functions according to claim 7, characterized in that: The step S200 includes the following steps: step S201 performs a primary desorption and dry blowing operation; step S202 performs a primary desorption and flow splitting operation; step S203 performs a secondary dry blowing operation; step S204 performs a secondary desorption operation; The step S300 includes the following steps: step S301 performs a pressurized leak detection operation; step S302 performs a pressure relief quantitative operation; step S303 performs a sample injection operation; The step S400 includes the following steps: step S401 performs multiple headspace concentration operations; Step S402 performs a large volume headspace concentration operation.

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