CN111751479B

CN111751479B - Gaseous and granular semi-volatile organic compound on-line enrichment system and method and application

Info

Publication number: CN111751479B
Application number: CN202010692411.7A
Authority: CN
Inventors: 陈仕意; 朱媛; 曾立民
Original assignee: Peking University
Current assignee: Peking University
Priority date: 2020-07-17
Filing date: 2020-07-17
Publication date: 2024-06-25
Anticipated expiration: 2040-07-17
Also published as: CN111751479A

Abstract

The invention relates to an online enrichment system of gaseous and granular semi-volatile organic compounds, which comprises a gasification chamber, an electromagnetic three-way valve, a first two-position six-way valve, a granular trapping device, a primary trapping trap, a secondary focusing trap, a second two-position six-way valve, a first mass flow controller, a second mass flow controller, an air pump, a gas chromatograph mass spectrum detection system, an enrichment-thermal analysis device, an air supply and pressure control system, a sample injection pipe and a heat tracing system. The system has simple gas circuit, can perform on-line enrichment direct measurement on the gaseous and granular SVOCs, has the time resolution of 85min, can perform on-line trapping and measurement on the gaseous and granular semi-volatile organic matters, avoids errors of the traditional indirect measurement and calculation method, has higher time resolution, less energy consumption, compact structure, small device, simple operation and reliable result, and can realize on-line accurate measurement on the gaseous and granular semi-volatile organic matters.

Description

Gaseous and granular semi-volatile organic compound on-line enrichment system and method and application

Technical Field

The invention belongs to the technical field of environmental monitoring, and particularly relates to a gaseous and granular semi-volatile organic compound on-line enrichment system and method and application.

Background

In recent years, the problem of atmospheric environment is remarkable, wherein the pollution problem of aerosol and ozone is serious, and volatile organic matters and semi-volatile organic matters are important sources of secondary organic aerosol and important precursors for generating ozone. In addition to volatile organic compounds (Volatile Organic Compounds, VOCs), there are also more molecular weight, more complex molecular structures of Semi-volatile organic compounds (Semi-organic Compounds, SVOCs). The semi-volatile organic compounds are important environmental pollutants, particularly have great contribution to the generation of Secondary atmospheric organic aerosols (Secondary OrganicAerosol, SOA), and cause harm to human health while polluting the environment, so that the on-line monitoring of the atmospheric gaseous and granular semi-volatile organic compounds is the basis for quantitatively researching pollution characteristics of the generation, evolution, distribution, transmission and the like of the organic pollutants in the atmosphere, and has great significance for the generation mechanism and pollution distribution research of the Secondary atmospheric organic aerosols.

At present, after an active sampler (such as a sampling gun) or an adsorption medium (such as polyurethane foam PUF and quartz filter membrane) is generally adopted for sampling in China, SVOCs are extracted through technologies such as Soxhlet Extraction (SE), ultrasonic extraction (USE), accelerated Solvent Extraction (ASE), microwave-assisted extraction (MAE) and the like, and then a rotary evaporator and a concentrator are utilized for pre-concentration, and the SVOCs are sent to back-end detection equipment such as GC-MS, GC-FID and the like for analysis. The foreign mature method is the same as domestic method, and simultaneously, the method for collecting samples by developing adsorbents such as active carbon, molecular sieve and high molecular polymer, heating an adsorption tube by adopting a thermal analyzer after collecting, desorbing the adsorbed SVOCS from the tube, and sending the desorbed SVOCS into a back-end detection device such as GC-MS for analysis.

At present, no commercial instrument capable of directly measuring the gaseous and granular SVOCs on line at the same time is published in the literature and patent at home and abroad, and only the off-line on-line measuring technology of the granular SVOCs, such as TAG, exists. In recent years, a gaseous semi-volatile organic compound measurement technology has been developed, for example, a dual-channel SV-TAG is developed, the technology is that gaseous and granular semi-volatile organic compounds are all trapped through a metal filter membrane, the total semi-volatile organic compound content and the granular semi-volatile organic compound content are subjected to difference calculation to obtain the gaseous semi-volatile organic compound content, and the gaseous semi-volatile organic compound content obtained by a difference method has the problem of larger gas particle distribution error, so that data lacks scientificity.

The current SVOCs measurement technique has the following problems: the gaseous granular semi-volatile organic compound can not be directly measured, the offline sampling time is discontinuous, the collecting time is overlong, the direct analysis of the low SVOCs content in the sample can not meet the detection limit requirement of the detector, the recovery rate is low, the instrument volume is overlarge, and the like. Aiming at the problems, the invention provides a method and a device for on-line enrichment of gaseous and granular semi-volatile organic matters, which realize direct on-line measurement of atmospheric gaseous and granular semi-volatile organic matters.

By searching, no patent publication related to the present patent application has been found.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provide a gaseous and granular semi-volatile organic compound on-line enrichment system and method and application.

The invention solves the technical problems by adopting the following technical scheme:

the system comprises a gasification chamber, an electromagnetic three-way valve, a first two-position six-way valve, a particle state trapping device, a primary trapping well, a secondary focusing well, a second two-position six-way valve, a first mass flow controller, a second mass flow controller, a sampling pump, a gas chromatography mass spectrum detection system, an enrichment-thermal analysis device, a gas supply and pressure control system, a sample injection pipe and a heat tracing system, wherein the electromagnetic three-way valve comprises an inlet end A, an outlet end B and an outlet end C, the outlet end of the gas supply and pressure control system is connected with the inlet end A of the electromagnetic three-way valve, the gas supply pipe is connected with the inlet end of the particle state trapping device, the outlet end B of the electromagnetic three-way valve is also connected with the inlet end of the particle state trapping device, the outlet end of the particle state trapping device is connected with the first two-position six-way valve, the first two-position six-way valve is also connected with the outlet end C of the electromagnetic three-way valve, the primary trapping well and the second two-position six-way valve, and the primary trapping device is also connected with the focusing well;

the secondary focusing trap is also connected with a second two-position six-way valve, the outlet end of the second two-position six-way valve is connected with a second mass flow controller and a sampling pump in sequence, and the outlet end of the second two-position six-way valve is also connected with a gas chromatography mass spectrometry detection system;

The outlet end of the particle state trapping device is also connected with the inlet end of the first mass flow controller, and the outlet end of the first mass flow controller is connected with the inlet end of the second mass flow controller;

The gasification chamber and the sample injection pipe are detachably connected with the gas supply and pressure control system and the particle state trapping device through stainless steel passivation tee joints respectively;

The primary trapping well and the secondary focusing well are connected with an enrichment-thermal analysis device, and the enrichment-thermal analysis device can provide constant enrichment low temperature and constant desorption high temperature for the primary trapping well and the secondary focusing well;

The gas chromatography mass spectrometry detection device comprises a gas chromatography mass spectrometry detection system, a gas chromatography mass spectrometry detection system and a gas chromatography mass spectrometry detection system.

Moreover, the constant enrichment low temperature is constant 0 ℃ enrichment low temperature, and the constant desorption high temperature is constant 300 ℃ thermal desorption high temperature;

the heat trace system is capable of providing a constant temperature of 300 ℃;

Or the valve bodies of the first two-position six-way valve and the second two-position six-way valve are respectively provided with a heat tracing system, and the heat tracing systems can provide constant temperature of 300 ℃;

Or the inlet end A of the electromagnetic three-way valve is connected with the air supply and pressure control system through a stainless steel pipeline, the outlet end B of the electromagnetic three-way valve is connected with the particle state trapping device through a stainless steel pipeline, and the outlet end C of the electromagnetic three-way valve is connected with the first two-position six-way valve through a stainless steel pipeline.

The first two-position six-way valve comprises an interface A, an interface B, an interface C, an interface D, an interface E and an interface F, the second two-position six-way valve comprises an interface A, an interface B, an interface C, an interface D, an interface E and an interface F, the interface A of the first two-position six-way valve is connected with the outlet end C of the electromagnetic three-way valve through a passivated stainless steel pipeline, and the interface B of the first two-position six-way valve is connected with the interface A of the second two-position six-way valve through a passivated stainless steel pipeline; the C interface of the first two-position six-way valve is connected with the outlet end of the primary trap through a passivated stainless steel pipeline; the D interface of the first two-position six-way valve is connected with the E interface of the second two-position six-way valve through a passivated stainless steel pipeline; the E interface of the first two-position six-way valve is connected with one end of a quartz adapter through a passivated stainless steel pipeline, the other end of the quartz adapter is connected with the inlet end of the particle state collecting pipe, and the F interface of the first two-position six-way valve is connected with the inlet of the primary collecting trap through the passivated stainless steel pipeline;

The interface B of the second two-position six-way valve is connected with the gas chromatography mass spectrometry detection system through a passivated stainless steel pipeline, the interface C of the second two-position six-way valve is connected with the outlet end of the secondary focusing trap through the passivated stainless steel pipeline, the interface F of the second two-position six-way valve is connected with the inlet end of the secondary focusing trap through the passivated stainless steel pipeline, and the interface D of the second two-position six-way valve is connected with the inlet end of the second mass flow controller through the passivated stainless steel pipeline;

or the air supply and pressure control system can provide helium, hydrogen and compressed air with purity not lower than 99.999 percent and can control the air path pressure of the helium, the hydrogen and the compressed air;

or the heat tracing system is an electric heating wire heat tracing system, and the heat tracing temperature of the system is constant at 300 ℃;

Or the enrichment thermal desorption system can provide a constant low temperature of 0 ℃ and a constant high temperature of 300 ℃.

The primary trap comprises a primary trap inner column, a primary trap stainless steel outer sleeve, an adsorbent, a stainless steel reducing tee joint and passivated quartz cotton, wherein the primary trap inner column is arranged in the horizontal direction, the horizontal two ends of the primary trap inner column are detachably arranged with the stainless steel reducing tee joint, the stainless steel reducing tee joint is penetrated out of the horizontal two ends of the primary trap inner column, the primary trap stainless steel outer sleeve is closely sleeved on the outer surface of the primary trap inner column at coaxial intervals, the horizontal two ends of the primary trap stainless steel outer sleeve are detachably connected with the stainless steel reducing tee joint, the adsorbent is arranged in the middle of the primary trap inner column, the passivated quartz cotton is arranged on the two sides of the adsorbent in a connecting mode, and the passivated quartz cotton is also arranged in the primary trap inner column;

The secondary focusing trap comprises a secondary focusing trap inner column, a secondary focusing trap stainless steel outer sleeve, an adsorbent, a stainless steel reducing tee joint and passivated quartz cotton, wherein the secondary focusing trap inner column is arranged along the horizontal direction, the horizontal two ends of the secondary focusing trap inner column are detachably arranged with the stainless steel reducing tee joint, the horizontal two ends of the secondary focusing trap inner column penetrate through the stainless steel reducing tee joint, the outer surface of the secondary focusing trap inner column is coaxially and closely sleeved with the secondary focusing trap stainless steel outer sleeve at intervals, the horizontal two ends of the secondary focusing trap stainless steel outer sleeve are detachably connected with the stainless steel reducing tee joint, the adsorbent is arranged in the middle of the secondary focusing trap inner column, the passivated quartz cotton is connected and arranged on the two sides of the adsorbent, and the passivated quartz cotton is also arranged in the secondary focusing trap inner column;

The stainless steel reducing tee joint is provided with a heat tracing system which can provide a constant temperature of 300 ℃.

The enrichment-thermal analysis device comprises heating and refrigerating equipment and an enrichment-thermal analysis cavity, wherein the heating and refrigerating equipment comprises an optical radiation heating rod, a temperature sensor, a temperature transmitter, an air compressor, a vortex tube, a proportional valve and a ceramic clamping seat, the optical radiation heating rod is arranged in the horizontal direction, and the two horizontal ends of the optical radiation heating rod are detachably connected with each other to form the ceramic clamping seat;

The temperature sensor is arranged on the outer surface of the middle part of the primary trap inner column between the primary trap inner column and the primary trap stainless steel outer sleeve, or the temperature sensor is arranged on the outer surface of the middle part of the secondary focus inner column between the secondary focus inner column and the secondary focus inner sleeve; the temperature sensor is connected with the temperature transmitter and can receive and transmit the temperature detected by the temperature sensor; the temperature sensor is used for detecting the temperature of the sample in the primary trap inner column or the secondary focusing trap inner column and transmitting the temperature to the temperature transmitter;

The enrichment-thermal analysis cavity comprises an aluminum box, screws, an aluminum box cover plate and a three-way heat tracing heating block, wherein the aluminum box is arranged along the horizontal direction, the middle parts of the two horizontal ends of the aluminum box are symmetrically arranged in an inward concave manner, U-shaped grooves are formed in the side walls of the inward concave aluminum box, the shape of the U-shaped grooves is matched with the shape of a stainless steel reducing three-way joint, the stainless steel reducing three-way joint can be detachably and tightly arranged on the U-shaped grooves, and the two U-shaped grooves are symmetrically arranged along the horizontal direction; clamping seat mounting holes are symmetrically formed in the horizontal side walls of the aluminum box on the two longitudinal sides of the U-shaped groove along the longitudinal direction, and ceramic clamping seats can be mounted on the clamping seat mounting holes;

the aluminum box cover plate is detachably arranged on the upper surface of the aluminum box through screws;

The tee joint heat tracing heating block is arranged in a shape matched with the stainless steel reducing tee joint, the stainless steel reducing tee joint is connected with the tee joint heat tracing heating block, and the tee joint heat tracing heating block can heat and preserve heat for the stainless steel reducing tee joint.

And the particle state trapping device comprises a particle state trapping pipe, wherein the particle state trapping pipe comprises an upper trapping pipe component, a lower trapping pipe component, a hollow quartz cylinder, a tetrafluoro O-shaped ring, a stainless steel passivation spring, a quartz filter membrane and a spherical interface clamp, wherein the tetrafluoro O-shaped ring is tightly arranged between the upper trapping pipe component and the lower trapping pipe component, the upper trapping pipe component and the lower trapping pipe component are tightly connected and detachably arranged together through the spherical interface clamp, the hollow quartz cylinder is arranged in the upper trapping pipe component, the stainless steel passivation spring is connected between the hollow quartz cylinder and the lower trapping pipe component, and the quartz filter membrane is arranged in the upper trapping pipe component above the hollow quartz cylinder.

The upper collecting pipe component comprises a hollow quartz cylinder A, a hollow quartz pipe B, a quartz wafer I, a hollow quartz cylinder C and a hemispherical quartz ball bowl D which are coaxially and tightly connected in sequence from top to bottom, wherein the hollow quartz cylinder A and the hollow quartz cylinder C are hollow cylinders with openings at the top and the bottom, the hollow quartz pipe B is in a hollow cone shape with openings at the top and the bottom, the diameter of the hollow quartz cylinder A is equal to the diameter of the top of the hollow quartz pipe B, the diameter of the bottom of the hollow quartz pipe B is equal to the diameter of the hollow quartz cylinder C, and the diameter of the hollow quartz cylinder C is larger than the diameter of the hollow quartz cylinder A;

the quartz wafer I is arranged between the hollow quartz tube B and the hollow quartz cylinder C, a plurality of through holes are uniformly distributed on the quartz wafer I along the circumferential direction at intervals, and a through hole is formed in the center of the quartz wafer I;

The diameter of the bottom of the hemispherical quartz ball bowl D is larger than that of the top, the diameter of the top of the hemispherical quartz ball bowl D is equal to that of the hollow quartz cylinder C, a cylindrical through cavity 41 is coaxially formed in the hemispherical quartz ball bowl D, and the cylindrical through cavity extends from the upper surface of the top of the hemispherical quartz ball bowl D to the lower surface of the bottom of the hemispherical quartz ball bowl D;

The hollow inner top of the hollow quartz cylinder C below the quartz wafer I is coaxially provided with a quartz filter membrane, the hollow inner of the hollow quartz cylinder C below the quartz filter membrane is coaxially provided with a hollow quartz cylinder, the hollow quartz cylinder is hollow with openings at the top and the bottom, the bottom of the hollow quartz cylinder is arranged at the top of a cylindrical through cavity of the hemispherical quartz ball bowl D, and the hollow inner of the hollow quartz cylinder is communicated with the cylindrical through cavity;

The lower collecting pipe component comprises a hemispherical quartz ball bowl E and a hollow quartz cylinder F which are arranged in a way of being connected up and down, the hemispherical quartz ball bowl E is coaxially provided with a hemispherical cavity 42 and a cylindrical cavity 47 which are arranged in a way of being closely communicated up and down, the hollow quartz cylinder F is in a hollow shape with openings at the top and the bottom, and the bottom of the cylindrical cavity of the hemispherical quartz ball bowl E is coaxially and closely communicated with the hollow interior of the hollow quartz cylinder F;

The lower bottom surface of the hemispherical quartz ball bowl D is upwards sunken to form a tetrafluoro O-shaped ring mounting annular groove, the upper bottom surface of the hemispherical quartz ball bowl E is downwards sunken to form a tetrafluoro O-shaped ring lower mounting annular groove, when the hemispherical quartz ball bowl D and the hemispherical quartz ball bowl E are connected, the tetrafluoro O-shaped ring mounting annular groove and the tetrafluoro O-shaped ring lower mounting annular groove form a tetrafluoro O-shaped ring mounting annular groove, the shape of the tetrafluoro O-shaped ring mounting annular groove is matched with that of the tetrafluoro O-shaped ring, and the tetrafluoro O-shaped ring can be tightly and detachably arranged in the tetrafluoro O-shaped ring mounting annular groove;

the upper part of the stainless steel passivation spring is arranged on the hollow quartz cylinder, and the bottom of the stainless steel passivation spring penetrates through the cylindrical through cavity of the hemispherical quartz ball bowl D and is arranged on the bottom of the hemispherical cavity of the hemispherical quartz ball bowl E in an extending manner;

Or the particle state trapping device further comprises a temperature control system, the particle state trapping pipe is connected with the temperature control system, the temperature control system comprises a heating furnace, an optical radiation heating rod, a heat tracing heating block, a stainless steel passivation reducing cutting sleeve joint, a temperature sensor, a temperature transmitter and a ceramic clamping seat, the optical radiation heating rod is arranged along the horizontal direction, the two horizontal ends of the optical radiation heating rod are detachably connected with each other and provided with the ceramic clamping seat, the temperature transmitter is connected with the temperature sensor, the temperature sensor is tightly wound on the outer side of the particle state trapping device, a probe of the temperature sensor and a quartz wafer I are positioned at the same horizontal and vertical positions, the temperature sensor can detect the temperature of a particle sample on a quartz filter membrane of the particle state trapping device in real time, and the temperature sensor can convey the temperature to the temperature transmitter;

The heating furnace comprises an aluminum box, an aluminum box cover plate, screws, stainless steel passivation reducing cutting sleeve connectors and reducing connector heat tracing heating blocks, wherein the aluminum box is arranged along the horizontal direction, the middle parts of the two horizontal ends of the aluminum box are symmetrically arranged in an inward concave manner, U-shaped grooves are formed in the side walls of the inward concave aluminum box, the shape of the U-shaped grooves is matched with the shape of the stainless steel passivation reducing cutting sleeve connectors, the stainless steel passivation reducing cutting sleeve connectors can be detachably and tightly arranged on the U-shaped grooves, and the two U-shaped grooves are symmetrically arranged along the horizontal direction; clamping seat mounting holes are symmetrically formed in the horizontal side walls of the aluminum box on the two longitudinal sides of the U-shaped groove along the longitudinal direction, and ceramic clamping seats can be mounted on the clamping seat mounting holes;

The shape of the stainless steel passivation reducing cutting sleeve joint is matched with the shape of an upper collecting pipe part of the particle collecting pipe, and the upper collecting pipe part is connected with the two stainless steel passivation reducing cutting sleeve joints;

The reducing joint heat tracing heating block is arranged in a shape matched with that of the stainless steel passivation reducing cutting sleeve joint, the stainless steel passivation reducing cutting sleeve joint is connected with the reducing joint heat tracing heating block, and the reducing joint heat tracing heating block can heat and preserve heat of the stainless steel passivation reducing cutting sleeve joint.

And the system also comprises a programmable logic controller which is connected with the gasification chamber, the electromagnetic three-way valve, the first two-position six-way valve, the second two-position six-way valve, the first mass flow controller, the second mass flow controller, the sampling pump, the enrichment-thermal analysis device and the heat tracing system through circuits, and the programmable logic controller can control the opening and closing of each component, the opening degree and monitor each system parameter.

The method for carrying out on-line enrichment of the gaseous and granular semi-volatile organic matters by utilizing the on-line enrichment system of the gaseous and granular semi-volatile organic matters comprises the following specific steps:

(1) Aging mode: in the mode, the heating mode is started by the primary trap, the secondary focusing and the enrichment-thermal analysis device of the particle state trapping device, and the temperature control systems of the primary trap, the secondary focusing trap and the particle state trapping device are all in high-temperature thermal analysis states. The carrier gas is subjected to aging purging on all pipelines and components among the particle state trapping device, the two-position six-way valve, the primary trapping trap, the secondary focusing trap, the first mass flow controller, the second mass flow controller and the sampling pump through the electromagnetic three-way valve after passing through the gas supply and pressure control system;

(2) Sampling mode: in the mode, the enrichment-thermal analysis device of the primary trap is started in a refrigeration mode, the primary trap is in a low-temperature enrichment state, the secondary trap and the enrichment-thermal analysis device of the particle state trap are closed, and the temperature control system is in a normal-temperature mode. Through the pumping action of the sampling pump, one path of the atmospheric sample sequentially passes through the particle state trapping device, the two-position six-way valve, the primary trapping trap and the two mass flow controllers and is discharged through the sampling pump; at the moment, the particulate organic matters are trapped by the particulate trapping device, and the target gaseous organic matters in the atmosphere are trapped by the primary focusing trap; if the calibration is needed, only the STD gasification chamber is connected to the inlet of the atmospheric sample, the sample inlet of the gasification chamber is filled with the standard liquid, the sampling time is shortened to 1min, and other relevant steps and operations of the device are the same;

(3) Purge mode: in the mode, the enrichment-thermal analysis device of the primary trap keeps a refrigeration mode, the primary trap is in a low-temperature enrichment state, the secondary trap and the enrichment-thermal analysis device of the particle state trap are closed, and the temperature control system is in a normal-temperature mode. The carrier gas passes through all pipeline components among the gas supply and pressure control system, the electromagnetic three-way valve, the particle state trapping device, the primary trapping trap, the two-position six-way valves, the two mass flow controllers and the sampling pump so as to remove residual redundant interference gas;

(4) Particle state focusing mode: in the mode, the temperature control system of the particle state trapping device is in a heating mode, the primary trapping well enrichment-thermal analysis device is closed, the temperature control system is in a normal temperature mode, the enrichment-thermal analysis device of the secondary focusing well is in a refrigerating mode, and the secondary focusing well is in a low-temperature enrichment state. The carrier gas is discharged through a gas supply and pressure control system, an electromagnetic three-way valve, a particle state trapping device, two-position six-way valves, a secondary focusing trap, a second mass flow controller and a sampling pump, and an object to be detected analyzed in the particle state trapping device is transferred to the secondary focusing trap in low-temperature enrichment through purging, so that the particle state sample is trapped for the second time;

(5) Particle sample injection mode: in the mode, the enrichment-thermal analysis device of the secondary focusing trap is in a heating mode, the secondary focusing trap is in a high-temperature thermal analysis state, the primary trapping trap and the enrichment-thermal analysis device of the particle state trapping device are closed, and the temperature control system is in a normal temperature mode. After carrier gas passes through a gas supply and pressure control system, an electromagnetic three-way valve, two-position six-way valves and a secondary focusing trap, carrying a substance to be measured which is thermally resolved by the secondary focusing trap in a high temperature state into a GC-MS for measurement, and completing primary granular SVOCs sampling and analysis;

(6) Gaseous sample focus mode: in the mode, the enrichment-thermal analysis device of the primary trapping well is in a heating mode, the enrichment-thermal analysis device of the secondary focusing well is in a refrigerating mode, the primary trapping well is in a high-temperature thermal analysis state, the secondary focusing well is in a low-temperature enrichment state, and the enrichment-thermal analysis device of the particle state trapping device is closed in a normal-temperature mode. The carrier gas is discharged through a gas supply and pressure control system, an electromagnetic three-way valve, two-position six-way valves, a primary trapping well, a secondary focusing well, a second mass flow controller and a sampling pump, and an object to be detected in the primary trapping well is transferred to the secondary focusing well in a low-temperature state to carry out secondary trapping on a gaseous sample;

(7) Gaseous sample injection mode: in the mode, the primary trap enrichment-thermal analysis device is closed, the temperature control system is in a normal temperature mode, the secondary trap is opened in a heating mode, the secondary focusing trap is in a high-temperature thermal analysis state, and the particulate trap enrichment-thermal analysis device is closed in a normal temperature mode. After carrier gas passes through a gas supply and pressure control system, an electromagnetic three-way valve and a secondary focusing trap, carrying a substance to be detected which is thermally resolved by the secondary focusing trap in a high temperature state into a GC-MS for separation and measurement, and thus completing once gaseous SVOCs sampling and analysis;

(8) Back-blowing cooling and blowing mode: in the mode, the enrichment-thermal analysis device of the primary trapping well and the secondary focusing well and the enrichment-thermal analysis device of the particle state trapping device are closed in a normal temperature mode, and the primary trapping well, the secondary focusing well and the particle state trapping device are in a normal temperature cooling state. The carrier gas is discharged into the atmosphere through an electromagnetic three-way valve, a first two-position six-way valve, a particle state trapping device, a primary focusing trap, a second two-position six-way valve, a secondary focusing trap, a first mass flow controller, a second mass flow controller and a sampling pump in sequence, and the sampling pump is closed after purging is completed, so that the whole cycle is completed;

(9) If the detection needs to be continued, the method can be circulated.

The use of an on-line enrichment system as described above in the measurement of gaseous, particulate semi-volatile organic compounds.

The invention has the advantages and positive effects that:

1. The system has simple gas circuit, can perform online enrichment measurement on the gaseous and granular SVOCs, has the time resolution of 85min, can perform online synchronous gaseous and granular trapping and analysis, avoids the error of the traditional indirect measurement and calculation method, has higher time resolution, low energy consumption, compact structure, small device, simple operation and reliable result, and can realize online accurate measurement on gaseous and granular semi-volatile organic matters. The system can realize the on-line monitoring of semi-volatile organic compounds within the span range of C ₁₂-C₃₀, and has larger measurement span and higher recovery rate compared with the traditional measurement technology.

2. The invention designs a direct online measurement system of the gaseous and granular SVOCs, realizes synchronous online sampling and enrichment of the gaseous and granular SVOCs, can measure the concentration and composition of the gaseous and granular SVOCs in the same space and at the same time, breaks through the technical barriers existing in indirect measurement, obtains accurate real-time gaseous and granular SVOCs data, and provides a data basis for research on generation, evolution, distribution and transmission of secondary organic pollutants in the atmosphere.

3. The invention adopts the passivated parts at the pipeline and the joints, adopts the whole set of electric heating wire heat tracing system, designs a special heat tracing device for each joint and the valve body, eliminates the cold point of the pipeline, solves the problem of residual SVOCs when the pipe wall is cold, and furthest reduces the loss of the sample to be tested in the pipeline.

4. The invention additionally provides a secondary trapping system to realize re-trapping and re-analyzing of low-concentration semi-volatile organic compounds, further concentrates SVOCs components in the sample, solves the problems of less SVOCs content in the atmosphere, small peak output and mess, reduces the detection limit of the system by multiple focusing, and improves the sensitivity of analysis and detection.

5. The invention improves the heating and refrigerating mode, the module adopts vortex refrigeration and optical radiation heating, and the heating and the refrigerating of the trap system can be realized in a short time, thereby trapping and heat analyzing the sample. The heating temperature is higher, the refrigerating temperature is lower, the refrigerating and heating time is shortened, the time resolution and the energy consumption of the instrument are increased, the final temperature control range is 0-300 ℃, the deviation is +/-0.1 ℃, the temperature control is more accurate compared with the traditional technology, and the reliability of quantitative adsorption is improved.

6. The invention designs a particle state trapping device, the device adopts optical radiation heating, and the core is a particle state trapping pipe which is designed by self, so that the accurate temperature control can be carried out, the thermal analysis effect of the particle state SVOCs is better, and the recovery rate is higher.

7. The invention realizes the innovation of the method, can realize the online simultaneous measurement of the ultra-low concentration gaseous and granular semi-volatile organic compounds in the atmosphere, and fills the technical blank.

8. The system only adopts the electromagnetic three-way valve and the two-position six-way valve, so that the gas path structure is simplified to the greatest extent, the sample conveying path is shortened, the dead volume is reduced, the loss of the sample in the sampling and analyzing processes is reduced to the minimum, and the accuracy of instrument measurement is improved.

Drawings

FIG. 1 is a schematic diagram of a structural connection of the system of the present invention;

FIG. 2 is a schematic diagram of a structural connection of the primary trap/secondary focusing trap, enrichment-thermal analysis device of FIG. 1;

FIG. 3 is a schematic front view of a structural connection of the enrichment-thermal analysis chamber of the enrichment-thermal analysis device of FIG. 1 (omitting the three-way heat tracing heating block);

FIG. 4 is a left side schematic view of FIG. 3;

FIG. 5 is a schematic bottom view of FIG. 3;

FIG. 6 is a perspective view of one structural attachment of FIG. 3;

FIG. 7 is a schematic front view of a structural connection of a three-way heat trace heating block of the enrichment-thermal analysis device of FIG. 1;

FIG. 8 is a left side schematic view of FIG. 7;

FIG. 9 is a schematic bottom view of FIG. 7;

FIG. 10 is a schematic rear view of FIG. 7;

FIG. 11 is a perspective view of one structural attachment of FIG. 7;

FIG. 12 is a front view of one structural attachment of the particulate collection header of FIG. 1;

fig. 13 is a cross-sectional view of the particulate trap taken along the direction H-H of fig. 12.

Detailed Description

The invention will now be further described in connection with specific examples which are intended to be illustrative only and not limiting in any way.

Structures of the present invention not specifically described in detail can be understood as conventional structures in the art.

The system comprises a gasification chamber 1, an electromagnetic three-way valve 2, a first two-position six-way valve 3, a particle state trapping device 5, a primary trapping well 6, a secondary focusing well 7, a second two-position six-way valve 8, a first mass flow controller 9, a second mass flow controller 17, a sampling pump 10, a gas chromatograph mass spectrum detection system 12, a vortex tube 13, an enrichment-thermal analysis device 14, an air supply and pressure control system 15, a sample injection tube 4 and a heat tracing system, wherein the electromagnetic three-way valve comprises an inlet end A, an outlet end B and an outlet end C, the outlet end of the air supply and pressure control system is connected with the inlet end A of the electromagnetic three-way valve, the inlet end B of the electromagnetic three-way valve is also connected with the inlet end of the particle state trapping device, the outlet end B of the electromagnetic three-way valve is also connected with the second two-position six-way valve, and the outlet end B of the particle state trapping device is also connected with the electromagnetic three-way valve, the secondary focusing well is also connected with the inlet end C of the electromagnetic three-way valve, and the secondary focusing well is also connected with the secondary trapping device; the enrichment-thermal analysis device comprises a vortex tube;

In this embodiment, the constant enrichment low temperature is a constant enrichment low temperature of 0 ℃, and the constant desorption high temperature is a constant thermal desorption high temperature of 300 ℃;

In this embodiment, the inlet end a of the electromagnetic three-way valve is connected with the air supply and pressure control system through a stainless steel pipeline, the outlet end B of the electromagnetic three-way valve is connected with the particulate state trapping device through a stainless steel pipeline, and the outlet end C of the electromagnetic three-way valve is connected with the first two-position six-way valve through a stainless steel pipeline.

In this embodiment, the first two-position six-way valve includes an a interface, a B interface, a C interface, a D interface, an E interface, and an F interface, the second two-position six-way valve 8 includes an a interface, a B interface, a C interface, a D interface, an E interface, and an F interface, the a interface of the first two-position six-way valve is connected with the outlet end C of the electromagnetic three-way valve through a passivated stainless steel pipeline, and the B interface of the first two-position six-way valve is connected with the a interface of the second two-position six-way valve through a passivated stainless steel pipeline; the C interface of the first two-position six-way valve is connected with the outlet end of the primary trap through a passivated stainless steel pipeline; the D interface of the first two-position six-way valve is connected with the E interface of the second two-position six-way valve through a passivated stainless steel pipeline; the E interface of the first two-position six-way valve is connected with one end of a quartz adapter (not shown in the figure) through a passivated stainless steel pipeline, the other end of the quartz adapter is connected with the inlet end of the particle state collecting pipe, and the F interface of the first two-position six-way valve is connected with the inlet of the primary collecting trap through the passivated stainless steel pipeline; typically, the first two-position six-way valve is connected at common positions A, B, C, D, E, F, and connected at second positions F, A, B, C, D, E.

The interface B of the second two-position six-way valve is connected with the gas chromatography mass spectrometry detection system through a passivated stainless steel pipeline, the interface C of the second two-position six-way valve is connected with the outlet end of the secondary focusing trap through the passivated stainless steel pipeline, the interface F of the second two-position six-way valve is connected with the inlet end of the secondary focusing trap through the passivated stainless steel pipeline, and the interface D of the second two-position six-way valve is connected with the inlet end of the second mass flow controller through the passivated stainless steel pipeline. Typically, the second two-position six-way valve 8 is connected at the normal position A, B, C, D, E, F, and is connected at the second position F, A, B, C, D, E.

In this embodiment, the gas supply and pressure control system is capable of providing helium, hydrogen, compressed air with a purity of not less than 99.999% and controlling the gas path pressure thereof.

In this embodiment, the heat tracing system is an electric heating wire heat tracing system, and the heat tracing temperature of the system is constant at 300 ℃;

In this embodiment, as shown in fig. 2, the primary trap includes a primary trap inner column 23, a primary trap stainless steel outer sleeve 24, an adsorbent 25, a stainless steel reducing tee joint 26 and a passivated quartz wool 30, where the primary trap inner column is disposed along a horizontal direction, two horizontal ends of the primary trap inner column are detachably disposed with the stainless steel reducing tee joint, two horizontal ends of the primary trap inner column are penetrated out of the stainless steel reducing tee joint, the outer surface of the primary trap inner column is coaxially and closely sleeved with the primary trap stainless steel outer sleeve at intervals, two horizontal ends of the primary trap stainless steel outer sleeve are detachably disposed with the stainless steel reducing tee joint, the adsorbent is disposed in the middle of the primary trap inner column, two sides of the adsorbent are connected with the passivated quartz wool, and the passivated quartz wool is also disposed in the primary trap inner column;

Preferably, the stainless steel reducing three-way joint is connected with the air compressor sequentially through the vortex tube and the proportional valve.

Preferably, the adsorbent is Tenax TA; or the primary trapping well inner column and the secondary focusing well inner column are all made of passivation 316L stainless steel tubes; the stainless steel outer sleeve of the primary trap and the stainless steel outer sleeve of the secondary focusing trap are all 316L stainless steel pipes.

Preferably, the diameter of the inner column of the primary trap is 1/4 inch, and the diameter of the stainless steel outer sleeve of the primary trap is 1/2 inch;

Or the diameter of the inner column of the secondary focusing well is 1/8 inch, and the diameter of the stainless steel outer sleeve of the secondary focusing well is 1/4 inch;

Or the two ends of the horizontal side of the stainless steel reducing tee joint are set to be 1/8 and 1/4, the vertical side joint is set to be 1/4, the primary trapping well inner column or the secondary focusing well inner column penetrates into one side from 1/8 of the stainless steel reducing tee joint and is fixed by a clamping sleeve, and the primary trapping well stainless steel outer sleeve or the secondary focusing well stainless steel outer sleeve is fixed by the clamping sleeve from the other side of the stainless steel reducing tee joint.

In this embodiment, as shown in fig. 2 to 11, the enrichment-thermal analysis device includes a heating and cooling device and an enrichment-thermal analysis chamber, where the heating and cooling device includes an optical radiation heating rod 31, a temperature sensor 27, a temperature transmitter (not shown in the figure), an air compressor 16, a vortex tube, a proportional valve 11, and a ceramic clamping seat 32, the optical radiation heating rod is disposed in a horizontal direction, and two horizontal ends of the optical radiation heating rod are detachably connected to each other to form a ceramic clamping seat;

The temperature sensor is arranged on the outer surface of the middle part of the primary trap inner column between the primary trap inner column and the primary trap stainless steel outer sleeve, or the temperature sensor is arranged on the outer surface of the middle part of the secondary focus inner column between the secondary focus inner column and the secondary focus inner sleeve; the temperature sensor is connected with the temperature transmitter and can receive and transmit the temperature detected by the temperature sensor; the temperature sensor is used for detecting the temperature of a sample in the primary trap inner column or the secondary focusing trap inner column, transmitting the temperature to the temperature transmitter, transmitting signals to the programmable logic controller by the temperature transmitter, controlling the heating time of the optical radiation heating rod, adjusting the opening of the proportional valve in the refrigerating system to carry out PID control so as to adjust and control the temperature, and finally controlling the temperature precision to be +/-0.1 ℃;

The enrichment-thermal analysis cavity comprises an aluminum box 33, screws 34, an aluminum box cover plate (not shown in the figure) and a three-way heat tracing heating block 35, wherein the aluminum box is arranged along the horizontal direction, the middle parts of the two horizontal ends of the aluminum box are symmetrically arranged in an inward concave manner, a U-shaped groove 36 is formed in the side wall of the inward concave aluminum box, the shape of the U-shaped groove is matched with the shape of a stainless steel reducing three-way joint, the stainless steel reducing three-way joint can be detachably and tightly arranged on the U-shaped groove, and the two U-shaped grooves are symmetrically arranged along the horizontal direction; clamping seat mounting holes 37 are symmetrically formed in the horizontal side walls of the aluminum box on the two longitudinal sides of the U-shaped groove along the longitudinal direction, and ceramic clamping seats can be mounted on the clamping seat mounting holes;

Preferably, the optical radiation heating rod is a ruby heating rod, adopts a radiation heating principle, and preferably adopts a ruby heating rod with the length of 120mm and 300w, and is fixed in a ceramic clamping seat of metal-clad ceramic of the enrichment-thermal analysis cavity. The two heating rods can be connected in series on a 220V circuit to be connected with a programmable logic controller so as to realize a heating function.

Preferably, the air compressor is connected with the stainless steel reducing tee joint through a polytetrafluoroethylene pipeline, outlets at two ends of the stainless steel reducing tee joint are respectively connected with a proportional valve through polytetrafluoroethylene pipelines, an outlet of the proportional valve is connected with an inlet of a vortex tube through polytetrafluoroethylene pipelines, an outlet of the vortex tube is connected with a vertical 1/4 joint of the stainless steel reducing tee joint, and the other proportional valve, the vortex tube and the stainless steel reducing tee joint are connected with one another. The proportional valve is connected with the programmable logic controller to realize the refrigeration function.

Specifically, at the time of production, the production may be as follows:

The 1/3 box volume part of the middle part of the left side and the right side of the aluminum box is wholly concave back and symmetrical on both sides. The concave parts on the left side and the right side are symmetrically provided with U-shaped grooves with the same diameter as the stainless steel reducing tee joint, and the U-shaped grooves are tightly matched with the stainless steel reducing tee joint. The left side and the right side are not recessed to form a round hole, the round hole is bilaterally symmetrical, the size of the round hole is tightly matched with the ceramic clamping seat, and the heating rod can provide required high temperature. After the stainless steel reducing tee joint is connected with the two ends of the primary trap inner column and the primary trap stainless steel outer sleeve or the two ends of the secondary focusing trap inner column and the two ends of the secondary focusing trap stainless steel outer sleeve, the stainless steel reducing tee joint is placed in a U-shaped groove, an aluminum box cover plate is covered, screws are screwed in, two tee heat tracing heating blocks which are tightly matched are sleeved on the stainless steel reducing tee joint after the connection is finished, the two heat tracing heating blocks are symmetrically arranged relative to the stainless steel reducing tee joint, preferably, the centers of the stainless steel reducing tee joint and the two heat tracing heating blocks are positioned at the same height, the two heat tracing heating blocks are tightly fixed on the stainless steel reducing tee joint by the screws, a temperature sensor is placed at the center of the horizontal direction of the stainless steel reducing tee joint of the primary trap and the inner sleeve of the primary trap, the temperature sensor is fixed on the primary trap, and the wire joint is connected with a temperature transmitter from the position of the stainless steel reducing tee joint vertical 1/4 joint of an unconnected refrigerating pipeline, so that the temperature of a sample in the 1/4 trap is detected and controlled in real time. The PTC heating plate can be placed in the heat tracing heating block to heat tracing at a constant temperature of 300 ℃, cold spots are removed, and SVOCs are prevented from being stuck on a filter membrane, a pipeline, a joint and a collecting pipe.

In this embodiment, as shown in fig. 12 and 13, the particle trap device includes a particle trap, where the particle trap includes an upper trap part, a lower trap part, a hollow quartz cylinder 43, a tetrafluoro O-ring 44, a stainless steel passivation spring 45, a quartz filter membrane 46, and a spherical interface clip (not shown in the drawings), where the tetrafluoro O-ring is tightly disposed between the upper trap part and the lower trap part, the upper trap part and the lower trap part are detachably disposed together by tightly connecting the spherical interface clip, the hollow quartz cylinder is disposed in the upper trap part, the stainless steel passivation spring is disposed between the hollow quartz cylinder and the lower trap part, and the quartz filter membrane is disposed in the upper trap part above the hollow quartz cylinder.

Preferably, the upper collecting pipe component comprises a hollow quartz cylinder A, a hollow quartz pipe B, a quartz wafer I, a hollow quartz cylinder C and a hemispherical quartz ball bowl D which are coaxially and tightly connected in sequence from top to bottom, wherein the hollow quartz cylinder A and the hollow quartz cylinder C are hollow cylinders with openings at the top and the bottom, the hollow quartz pipe B is in a hollow cone shape with openings at the top and the bottom, the diameter of the hollow quartz cylinder A is equal to the diameter of the top of the hollow quartz pipe B, the diameter of the bottom of the hollow quartz pipe B is equal to the diameter of the hollow quartz cylinder C, and the diameter of the hollow quartz cylinder C is larger than that of the hollow quartz cylinder A;

The top of the hollow interior of the hollow quartz cylinder C below the quartz wafer I is coaxially provided with a quartz filter membrane, the hollow interior of the hollow quartz cylinder C below the quartz filter membrane is coaxially provided with a hollow quartz cylinder 43, the hollow quartz cylinder is hollow with openings at the top and the bottom, the bottom of the hollow quartz cylinder is arranged at the top of a cylindrical through cavity of the hemispherical quartz ball bowl D, and the hollow interior of the hollow quartz cylinder is communicated with the cylindrical through cavity;

the upper part of the stainless steel passivation spring is arranged on the hollow quartz cylinder, and the bottom of the stainless steel passivation spring penetrates through the cylindrical through cavity of the hemispherical quartz ball bowl D and is arranged on the bottom of the hemispherical cavity of the hemispherical quartz ball bowl E in an extending mode.

When the particle state collecting pipe is used, the particle state collecting pipe is generally put down for use, namely, the particle state collecting pipe is rotated by 90 degrees clockwise for use.

Preferably, the interface clip is a stainless steel interface clip, or the interface clip is a spherical stainless steel interface clip with a diameter of 28 mm.

Preferably, the upper trapping pipe component and the lower trapping pipe component are both made of quartz.

Preferably, the diameter of the hollow quartz cylinder A is 6.35mm, the wall thickness is 1.5mm, and the length is 50mm;

The wall thickness of the hollow quartz tube B is 1.5mm;

the diameter of the hollow quartz cylinder C is 20mm, the wall thickness is 1.5mm, and the length is 80mm;

The thickness of the quartz wafer I is 3mm, the diameter is 17mm, 10 circular through holes with the diameter of 2mm are formed in the quartz wafer I, the circle centers of the 10 circular through holes are uniformly distributed on the circumference with the quartz wafer I as the circle center and the diameter of 17mm, and a circular through hole with the diameter of 3.35mm is formed in the circle center of the quartz wafer I.

Or the diameter of the hemispherical quartz spherical bowl D is 30mm, the diameter of the cylindrical through cavity of the hemispherical quartz spherical bowl D is 20mm, the depth of the groove of the tetrafluoro O-shaped ring mounting ring is 1mm, the width of the groove is 2.5mm, and the hemispherical quartz spherical bowl D is used as the center of a circle and the diameter of the groove is 22.5 mm;

The diameter of the hemispherical quartz spherical bowl E is 30mm, and the diameter of the hemispherical cavity of the hemispherical quartz spherical bowl E is 17mm; the length of the hollow quartz cylinder F is 20mm, the diameter is 6.35mm, and the wall thickness is 1.5mm.

Or the hollow quartz cylinder 43 has a diameter of 17mm and a wall thickness of 1mm. The other end of the hollow quartz cylinder is propped against a quartz filter membrane placed below the quartz wafer I, so that a closed environment is formed, and the quartz filter membrane is fixed to prevent the turnover damage of the quartz filter membrane and loss of the captured granular sample.

In this embodiment, the particulate capturing device further includes a temperature control system, where the particulate capturing tube is connected to the temperature control system (the structure of the temperature control system is similar to that of the enrichment-thermal analysis device, and thus not specifically shown), the temperature control system includes a heating furnace, an optical radiation heating rod, a heat tracing heating block, a stainless steel passivation reducing ferrule connector, a temperature sensor, a temperature transmitter, and a ceramic card holder, the optical radiation heating rod is disposed along a horizontal direction, two horizontal ends of the optical radiation heating rod are detachably connected to each other and provided with a ceramic card holder, the temperature transmitter is connected to a temperature sensor, the temperature sensor is tightly wound around the outside of the particulate capturing device, and a probe of the temperature sensor and a quartz wafer I are located at the same horizontal and vertical positions, the temperature sensor can detect the temperature of a particulate sample on a quartz filter membrane of the particulate capturing device in real time, the temperature sensor can transmit the temperature to the temperature transmitter, the temperature transmitter transmits a signal to a programmable logic controller, and the heating time of the optical radiation heating rod is controlled to control the final temperature of PID (PID) to be controlled to be within a temperature of ±0.1 ℃;

Specifically, at the time of production, the production may be as follows:

The 1/3 box volume part of the middle part of the left side and the right side of the thermal block aluminum shell is wholly concave back and symmetrical on both sides. The left side concave part is provided with a U-shaped groove with the diameter of 6.35mm, the right side concave part is provided with a U-shaped groove with the diameter of 20mm, and the U-shaped groove is tightly matched with the stainless steel passivation reducing cutting sleeve joint in size. The left side and the right side are not recessed to form a round hole, the round hole is bilaterally symmetrical, the size of the round hole is tightly matched with the ceramic clamping seat, and the heating rod can provide required high temperature. After the particle state collecting pipe is connected with the stainless steel passivation reducing cutting sleeve joint, the stainless steel passivation reducing cutting sleeve joint is placed into the U-shaped groove, two reducing joint heat tracing heating blocks which are tightly matched with the stainless steel passivation reducing cutting sleeve joint are sleeved after the particle state collecting pipe is connected, the two heat tracing heating blocks are symmetrically placed relative to the stainless steel passivation reducing cutting sleeve joint, the centers of the stainless steel passivation reducing cutting sleeve joint and the two heat tracing heating blocks are positioned at the same height, the two heat tracing heating blocks are tightly fixed on the stainless steel passivation reducing cutting sleeve joint by screws, a 5mm part left at the position of the particle state collecting pipe C is positioned outside the right side concave position, and a gap is reserved for fixing a quartz ball bowl D, E by the stainless steel interface clamp. PTC heating blocks can be arranged in the heat tracing heating blocks, so that cold points can be removed at the temperature of 300 ℃ through constant temperature heat tracing, and SVOCs can be prevented from being stuck to a filter membrane, a pipeline, a joint and a collecting pipe. After the assembly is completed, an aluminum box cover plate is covered, and screws are screwed in.

Preferably, the optical radiation heating rod is a ruby heating rod, adopts a radiation heating principle, adopts a ruby heating rod with the length of 120mm and 300w, and is fixed in a ceramic clamping seat of metal-clad ceramic of a heating furnace. The two heating rods are connected in series on a 220V circuit and connected with a programmable logic controller, the temperature transmitter is connected with a temperature sensor, the temperature sensor is placed on the outer side of the particle state collecting tube and is positioned at the same horizontal and vertical positions with the quartz wafer I, the temperature of a particle sample on a quartz filter membrane of the particle state collecting tube is detected in real time, the temperature is transmitted to the temperature transmitter, the temperature transmitter transmits signals to the programmable logic controller, the heating time of the optical radiation heating rod is controlled to carry out PID control so as to regulate and control the temperature, and finally the temperature precision is controlled to be +/-0.1 ℃.

In this embodiment, the system further includes a programmable logic controller, where the programmable logic controller is connected to the gasification chamber, the electromagnetic three-way valve, the first two-position six-way valve, the second two-position six-way valve, the first mass flow controller, the second mass flow controller, the sampling pump, the enrichment-thermal analysis device, and the heat tracing system through circuits, and the programmable logic controller can control opening and closing of each component, opening, and monitor each system parameter, such as a temperature parameter, a flow parameter, and the like.

Preferably, the proportional valve is connected to a programmable logic controller capable of controlling the opening and closing thereof and monitoring system parameters.

Preferably, the temperature transmitter is connected with a temperature sensor (K-type thermocouple) of the enrichment-thermal analysis device and a temperature sensor of a temperature control system of the particle state collection pipe, and meanwhile, the temperature transmitter is connected with a programmable logic controller, so that the control and monitoring of the constant high temperature 300 ℃ and the constant low temperature 0 ℃ of the enrichment-thermal analysis device can be realized, and the temperature control precision is +/-0.1 ℃.

In this embodiment, a complete measurement cycle mode of the online enrichment method of gaseous and particulate semi-volatile organic compounds using the online measurement system includes 8 processes: aging mode, sampling mode (calibration), purging mode, particle state focusing mode, particle state sample injection mode, gas state focusing mode, gas state sample injection mode and back blowing cooling purging mode. The gas supply and gas path pressure control system can provide helium, hydrogen and compressed air with purity not lower than 99.999 percent and can control the gas path pressure.

The method comprises the following specific steps:

(9) If the detection needs to be continued, the method can be circulated.

Preferably, the whole system and the components can be controlled in time sequence through a computer interaction control system, and the above 8 modes can be automatically and circularly operated without manual control and operation.

More specifically, the online measurement method of the online enrichment and measurement system for the gaseous and granular semi-volatile organic compounds is characterized in that the method is in a complete cycle mode and comprises the following steps: aging mode, sampling mode (calibration), purging mode, particle state focusing mode, particle state sample injection mode, gas state focusing mode, gas state sample injection mode and back blowing cooling purging mode, and the specific steps are as follows:

1. In an aging mode, an A-B port of the electromagnetic three-way valve is communicated, and the first mass flow controller, the second mass flow controller and the sampling pump are all opened; the first two-position six-way valve is used for enabling the A-B interface to be communicated, the C-D interface to be communicated and the E-F interface to be communicated, and the second two-position six-way valve is used for enabling the A-B interface to be communicated, the C-D interface to be communicated and the E-F interface to be communicated; the enrichment-thermal analysis device of the primary trapping well and the secondary focusing well and the temperature control system of the particle state trapping device are both in a heating mode, a heating rod is connected with a programmable logic controller, and the heating time is controlled by the logic controller to maintain the primary trapping well, the secondary focusing well and the particle state trapping device in a high-temperature thermal analysis state; the helium gas flows through the gas supply system and the electromagnetic three-way valve, and the particle trap is aged and flushed by controlling the flow of the first mass flow controller to be the same as that of the second mass flow controller; and by controlling the flow of the first mass flow controller to be smaller than the flow of the second mass flow controller, the particle trap, the primary trap and the secondary focusing trap are aged and washed, and substances possibly remained in the system device are brought out, so that the influence of the last sample on the detection is avoided.

2. In a sampling mode, an A-C port of the electromagnetic three-way valve is communicated, and the first mass flow controller, the second mass flow controller and the sampling pump are all opened; maintaining the communication of the A-B interface, the C-D interface and the E-F interface of the first two-position six-way valve, and switching the second two-position six-way valve to ensure that the B-C interface, the D-E interface and the F-A interface are communicated; the enrichment-thermal analysis device of the primary trap is in a refrigeration mode, the proportional valve is connected with the programmable logic controller, the opening of the proportional valve is controlled by the logic controller, and the primary trap is maintained in a low-temperature trapping state; the temperature control systems of the particle state trapping device and the secondary focusing trap are closed, and the particle state trapping device and the secondary focusing trap are in a normal temperature mode; the environmental air sequentially passes through a particle state trapping device, a two-position six-way valve and a primary trapping trap, a particle state part is trapped by the particle state trapping device, a gaseous part is trapped by the primary trapping trap with the temperature stabilized at 0 ℃, and the gaseous part is discharged into the atmosphere through the two-position six-way valve, a first mass flow controller, a second mass flow controller and a sampling pump; if the calibration is needed, the STD gasification chamber is only connected to the inlet of the atmospheric sample, the standard liquid is pumped into the sample inlet of the gasification chamber, the sampling time is shortened to 1min, and other relevant steps and operations of the device are the same.

3. In the purging mode, the A-B port of the electromagnetic three-way valve is communicated, and the first mass flow controller, the second mass flow controller and the sampling pump are all opened; the communication of the A-B interface, the C-D interface and the E-F interface of the first two-position six-way valve are kept, and the communication of the B-C interface, the D-E interface and the F-A interface of the second two-position six-way valve are kept; the enrichment-thermal analysis device of the primary trap is in a refrigeration mode, the proportional valve is connected with the programmable logic controller, the opening of the proportional valve is controlled by the logic controller, and the primary trap is maintained in a low-temperature trapping state; the temperature control systems of the particle state trapping device and the secondary focusing trap are closed, and the particle state trapping device and the secondary focusing trap are in a normal temperature mode; helium is discharged into the atmosphere through an electromagnetic three-way valve, a particle state trapping device, a first mass flow controller, a two-position six-way valve, a primary trapping trap, a second mass flow controller and a sampling pump in sequence.

4. In the particle state focusing mode, the A-B port of the electromagnetic three-way valve is communicated, the first mass flow controller is closed, and the second mass flow controller and the sampling pump are both opened; switching the first two-position six-way valve to enable the B-C interface to be communicated, the D-E interface to be communicated and the F-A interface to be communicated, and switching the second two-position six-way valve to enable the A-B interface to be communicated, the C-D interface to be communicated and the E-F interface to be communicated; the temperature control system of the particle state trapping device is in a heating mode, the heating rod is connected with the programmable logic controller, and the heating time is controlled by the logic controller to maintain the particle state trapping device in a high-temperature thermal analysis state at 300 ℃; the primary trap and the secondary focusing trap are in a refrigerating mode, the proportional valve is connected with the programmable logic controller, the opening of the proportional valve is controlled by the logic controller, and the primary trap and the secondary focusing trap are maintained in a low-temperature trapping state; after helium passes through the air supply system and the A-B port of the electromagnetic three-way valve, the desorbed substances to be detected of the particle state trapping device at the high temperature are brought to the secondary focusing trap at the low temperature through the E-F port of the second two-position six-way valve to be enriched by the low-temperature adsorbent, and the helium is discharged into the atmosphere through the C-D port of the second two-position six-way valve and the sampling pump.

5. In the particle sample injection mode, the A-C port of the electromagnetic three-way valve is communicated, and the first mass flow controller, the second mass flow controller and the sampling pump are all closed; switching the first two-position six-way valve to enable the A-B interface to be communicated, the C-D interface to be communicated and the E-F interface to be communicated, and switching the second two-position six-way valve to enable the B-C interface to be communicated, the D-E interface to be communicated and the F-A interface to be communicated; GC-MS operates normally; the secondary focusing trap is in a heating mode, the heating rod is connected with the programmable logic controller, and the heating time is controlled by the logic controller, so that the secondary focusing trap is maintained in a high-temperature thermal analysis state at 300 ℃; the temperature control system of the enrichment-thermal analysis device of the particle state trapping device is disconnected; the temperature control system of the primary trap is in a refrigeration mode, the proportional valve is connected with the programmable logic controller, and the opening of the proportional valve is controlled by the logic controller to maintain the primary trap in a low-temperature trap state; helium enters a secondary focusing trap through an air supply system, an A-C port of an electromagnetic three-way valve and an A-F interface of a second two-position six-way valve, substances to be detected in the helium are desorbed, and enter a GC-MS through a B-C interface of the second two-position six-way valve, so that the substances to be detected are separated and detected by the GC-MS. The GC-MS automatically stores the detection data after the measurement is finished and continues to operate until the next detection is prepared after the operation is finished.

6. In the gaseous focusing mode, the A-B port of the electromagnetic three-way valve is communicated, the first mass flow controller is closed, the second mass flow controller and the sampling pump are both opened, and the A-B port of the first two-position six-way valve is communicated, the C-D port is communicated and the E-F port is communicated; switching the A-B interface communication, the C-D interface communication and the E-F interface communication of the second two-position six-way valve; the primary trap is in a heating mode, the heating rod is connected with the programmable logic controller, and the heating time is controlled by the logic controller to maintain the primary trap in a high-temperature thermal analysis state; the temperature control system of the enrichment-thermal analysis device of the secondary focusing trap is in a refrigeration mode, the proportional valve is connected with the programmable logic controller, and the opening of the proportional valve is controlled by the logic controller to maintain the secondary focusing trap in a low-temperature trapping state; the temperature control system of the enrichment-thermal analysis device of the particle state trapping device is disconnected; after helium passes through the air supply system, the A-B port of the electromagnetic three-way valve and the two-position six-way valves, the desorbed substances to be detected of the primary trapping well at the high temperature are brought to the secondary focusing well at the low temperature through the E-F port of the second two-position six-way valve, are enriched by the low-temperature adsorbent, and are discharged through the C-D port of the second two-position six-way valve, the second mass flow controller and the sampling pump.

7. In a gaseous sample injection mode, an A-C port of the electromagnetic three-way valve is communicated, and the first mass flow controller, the second mass flow controller and the sampling pump are all closed; switching the B-C interface communication, the D-E interface communication and the F-A interface communication of the first two-position six-way valve, and switching the second two-position six-way valve to enable the B-C interface communication, the D-E interface communication and the F-A interface communication; GC-MS operates normally; the secondary focusing trap is in a heating mode, the heating rod is connected with the programmable logic controller, and the heating time is controlled by the logic controller, so that the secondary focusing trap is maintained in a high-temperature thermal analysis state at 300 ℃; the temperature control system of the enrichment-thermal analysis device of the primary focusing trap and the particle state trapping device is disconnected and is in a normal temperature mode; helium enters a secondary focusing trap through a gas supply system, an A-C port of an electromagnetic three-way valve, a B-C port of a first two-position six-way valve and an A-F port of a second two-position six-way valve, substances to be detected in the helium are desorbed, and the helium enters a GC-MS through a B-C port of the second two-position six-way valve, so that the substances to be detected are separated and detected by the GC-MS. The GC-MS automatically stores the detection data after the measurement is finished and continues to operate until the next detection is prepared after the operation is finished.

8. In the back-blowing cooling mode, the A-B port of the electromagnetic three-way valve is communicated, and the first mass flow controller, the second mass flow controller and the sampling pump are all opened; switching the first two-position six-way valve to enable the A-B interface to be communicated, the C-D interface to be communicated and the E-F interface to be communicated, and switching the A-B interface to be communicated, the C-D interface to be communicated and the E-F interface to be communicated; GC-MS operates normally; the enrichment-thermal analysis device of the primary trapping well and the secondary focusing well and the temperature control system of the particle state trapping device are in a normal temperature mode, the proportional valve is connected with the programmable logic controller, the proportional valve is controlled to be closed by the logic controller, and the primary trapping well, the secondary focusing well and the particle state trapping device are in a normal temperature cooling state; the carrier gas is discharged through the electromagnetic three-way valve, the particle state trapping device, the primary focusing trap, the two-position six-way valve, the secondary focusing trap, the first mass flow controller, the second mass flow controller and the sampling pump in sequence, and the sampling pump is closed after the purging is finished, so that the whole cycle is completed.

9. If the detection needs to be continued, the method can be circulated.

In the system operation period, 8 working modes can be continuously and automatically switched by controlling a time sequence of a computer interaction control system and the like, the time resolution of the whole operation period is 85min, the aging time is 10min, the sampling time is 10min (the calibration sample injection time is 1 min), the purging time is 1min, the particle state focusing time is 5min, the particle state sample injection time is 2min (35 min analysis time exists), the gas state focusing time is 5min, the gas state sample injection time is 2min, and the back-flushing cooling time is 15min. In the whole working cycle, the two-position six-way valve and the whole system pipeline are both provided with heat tracing to keep the high temperature of 300 ℃ unchanged so as to prevent the uneven loss of the temperature of high-carbon organic matters in the system device.

Although embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that: various substitutions, changes and modifications are possible without departing from the spirit and scope of the invention and the appended claims, and therefore the scope of the invention is not limited to the disclosure of the embodiments.

Claims

1. An online enrichment system for gaseous and granular semi-volatile organic compounds, which is characterized in that: the system comprises a gasification chamber, an electromagnetic three-way valve, a first two-position six-way valve, a particle state trapping device, a primary trapping well, a secondary focusing well, a second two-position six-way valve, a first mass flow controller, a second mass flow controller, a sampling pump, a gas chromatography mass spectrum detection system, an enrichment-thermal analysis device, an air supply and pressure control system, a sample injection pipe and a heat tracing system, wherein the electromagnetic three-way valve comprises an inlet end A, an outlet end B and an outlet end C, the outlet end of the air supply and pressure control system is connected with the inlet end A of the electromagnetic three-way valve, the air supply pipe is connected with the inlet end of the particle state trapping device, the outlet end B of the electromagnetic three-way valve is also connected with the inlet end of the particle state trapping device, the outlet end of the particle state trapping device is connected with the first two-position six-way valve, the first two-position six-way valve is also connected with the outlet end C of the electromagnetic three-way valve, the primary trapping well and the second two-position six-way valve, and the primary trapping well is also connected with the secondary focusing well;

The device comprises a gas chromatography mass spectrometry detection system, a particle state trapping device, a primary trapping trap, a secondary focusing trap, a first two-position six-way valve, a second two-position six-way valve and a gas chromatography mass spectrometry detection system, wherein the gas chromatography mass spectrometry detection system is connected with the gas chromatography mass spectrometry detection system through a pipeline;

The constant enrichment low temperature is constant 0 ℃ enrichment low temperature, and the constant desorption high temperature is constant 300 ℃ thermal desorption high temperature;

The inlet end A of the electromagnetic three-way valve is connected with the air supply and pressure control system through a stainless steel pipeline, the outlet end B of the electromagnetic three-way valve is connected with the particle state trapping device through a stainless steel pipeline, and the outlet end C of the electromagnetic three-way valve is connected with the first two-position six-way valve through a stainless steel pipeline;

The particle state trapping device comprises a particle state trapping pipe, wherein the particle state trapping pipe comprises an upper trapping pipe component, a lower trapping pipe component, a hollow quartz cylinder, a tetrafluoro O-shaped ring, a stainless steel passivation spring, a quartz filter membrane and a spherical interface clamp, wherein the tetrafluoro O-shaped ring is tightly arranged between the upper trapping pipe component and the lower trapping pipe component, the upper trapping pipe component and the lower trapping pipe component are tightly connected and detachably arranged together through the spherical interface clamp, the hollow quartz cylinder is arranged in the upper trapping pipe component, the stainless steel passivation spring is connected between the hollow quartz cylinder and the lower trapping pipe component, and the quartz filter membrane is arranged in the upper trapping pipe component above the hollow quartz cylinder.

2. The gaseous, particulate semi-volatile organic compound on-line enrichment system according to claim 1, wherein: the first two-position six-way valve comprises an A interface, a B interface, a C interface, a D interface, an E interface and an F interface, the second two-position six-way valve comprises an A interface, a B interface, a C interface, a D interface, an E interface and an F interface, the A interface of the first two-position six-way valve is connected with the outlet end C of the electromagnetic three-way valve through a passivated stainless steel pipeline, and the B interface of the first two-position six-way valve is connected with the A interface of the second two-position six-way valve through a passivated stainless steel pipeline; the C interface of the first two-position six-way valve is connected with the outlet end of the primary trap through a passivated stainless steel pipeline; the D interface of the first two-position six-way valve is connected with the E interface of the second two-position six-way valve through a passivated stainless steel pipeline; the E interface of the first two-position six-way valve is connected with one end of a quartz adapter through a passivated stainless steel pipeline, the other end of the quartz adapter is connected with the inlet end of the particle state collecting pipe, and the F interface of the first two-position six-way valve is connected with the inlet of the primary collecting trap through the passivated stainless steel pipeline;

the air supply and pressure control system can provide helium, hydrogen and compressed air with purity not lower than 99.999%, and can control the air path pressure;

the heat tracing system is an electric heating wire heat tracing system.

3. The gaseous, particulate semi-volatile organic compound on-line enrichment system according to claim 1, wherein: the primary trap comprises a primary trap inner column, a primary trap stainless steel outer sleeve, an adsorbent, a stainless steel reducing tee joint and passivated quartz cotton, wherein the primary trap inner column is arranged along the horizontal direction, the horizontal two ends of the primary trap inner column are detachably arranged with the stainless steel reducing tee joint, the horizontal two ends of the primary trap inner column penetrate through the stainless steel reducing tee joint, the outer surface of the primary trap inner column is coaxially and closely sleeved with the primary trap stainless steel outer sleeve at intervals, the horizontal two ends of the primary trap stainless steel outer sleeve are detachably connected with the stainless steel reducing tee joint, the adsorbent is arranged in the middle of the primary trap inner column, the passivated quartz cotton is arranged on the two sides of the adsorbent in a connecting mode, and the passivated quartz cotton is also arranged in the primary trap inner column;

4. The gaseous, particulate semi-volatile organic compound on-line enrichment system according to claim 1, wherein: the enrichment-thermal analysis device comprises heating and refrigerating equipment and an enrichment-thermal analysis cavity, wherein the heating and refrigerating equipment comprises an optical radiation heating rod, a temperature sensor, a temperature transmitter, an air compressor, a vortex tube, a proportional valve and a ceramic clamping seat, the optical radiation heating rod is arranged in the horizontal direction, and the two horizontal ends of the optical radiation heating rod are detachably connected with each other to form the ceramic clamping seat;

5. The gaseous, particulate semi-volatile organic compound on-line enrichment system according to claim 1, wherein: the upper collecting pipe component comprises a hollow quartz cylinder A, a hollow quartz pipe B, a quartz wafer I, a hollow quartz cylinder C and a hemispherical quartz bowl D which are coaxially and tightly connected in sequence from top to bottom, wherein the hollow quartz cylinder A and the hollow quartz cylinder C are hollow cylinders with openings at the top and the bottom, the hollow quartz pipe B is in a hollow cone shape with openings at the top and the bottom, the diameter of the hollow quartz cylinder A is equal to the diameter of the top of the hollow quartz pipe B, the diameter of the bottom of the hollow quartz pipe B is equal to the diameter of the hollow quartz cylinder C, and the diameter of the hollow quartz cylinder C is larger than the diameter of the hollow quartz cylinder A;

The diameter of the bottom of the hemispherical quartz ball bowl D is larger than that of the top, the diameter of the top of the hemispherical quartz ball bowl D is equal to that of the hollow quartz cylinder C, a cylindrical through cavity (41) is coaxially formed in the hemispherical quartz ball bowl D, and the cylindrical through cavity extends from the upper surface of the top of the hemispherical quartz ball bowl D to the lower surface of the bottom of the hemispherical quartz ball bowl D;

The lower collecting pipe component comprises a hemispherical quartz ball bowl E and a hollow quartz cylinder F which are arranged in a way of being connected up and down, wherein the hemispherical quartz ball bowl E is coaxially provided with a hemispherical cavity (42) and a cylindrical cavity (47) which are arranged in a way of being closely communicated up and down, the hollow quartz cylinder F is hollow, the top and the bottom of the hollow quartz cylinder F are both open, and the bottom of the cylindrical cavity of the hemispherical quartz ball bowl E is coaxially and closely communicated with the hollow interior of the hollow quartz cylinder F;

The particle state trapping device further comprises a temperature control system, the particle state trapping pipe is connected with the temperature control system, the temperature control system comprises a heating furnace, an optical radiation heating rod, a heat tracing heating block, a stainless steel passivation reducing clamp sleeve joint, a temperature sensor, a temperature transmitter and a ceramic clamping seat, the optical radiation heating rod is arranged along the horizontal direction, the two horizontal ends of the optical radiation heating rod are detachably connected with each other and provided with the ceramic clamping seat, the temperature transmitter is connected with the temperature sensor, the temperature sensor is tightly wound on the outer side of the particle state trapping device, a probe of the temperature sensor and a quartz wafer I are positioned at the same horizontal and vertical positions, the temperature sensor can detect the temperature of a particle sample on a quartz filter membrane of the particle state trapping device in real time, and the temperature sensor can convey the temperature to the temperature transmitter;

6. The gaseous, particulate semi-volatile organic compound on-line enrichment system as claimed in any one of claims 1-5, further comprising a programmable logic controller in electrical communication with the vaporization chamber, the electromagnetic three-way valve, the first two-way six-way valve, the second two-way six-way valve, the first mass flow controller, the second mass flow controller, the sampling pump, the enrichment-thermal analysis device, and the heat tracing system, the programmable logic controller being capable of controlling the opening and closing of the individual components, the opening and monitoring the individual system parameters.

7. A method for on-line enrichment of gaseous, particulate semi-volatile organic compounds using the on-line enrichment system of gaseous, particulate semi-volatile organic compounds as claimed in any one of claims 1 to 6, characterized in that: the method comprises the following specific steps:

(1) Aging mode: in the mode, the heating mode is started by the enrichment-thermal analysis device of the primary trap, the secondary focusing device and the particle state trapping device, and the temperature control systems of the primary trap, the secondary focusing device and the particle state trapping device are all in a high-temperature thermal analysis state; the carrier gas is subjected to aging purging on all pipelines and components among the particle state trapping device, the first two-position six-way valve, the second two-position six-way valve, the primary trapping trap, the secondary focusing trap, the first mass flow controller, the second mass flow controller and the sampling pump through the electromagnetic three-way valve after passing through the gas supply and pressure control system;

(2) Sampling mode: in the mode, the enrichment-thermal analysis device of the primary trap is started in a refrigeration mode, the primary trap is in a low-temperature enrichment state, the secondary trap and the enrichment-thermal analysis device of the particle state trap are closed, and the temperature control system is in a normal-temperature mode; through the pumping action of the sampling pump, one path of the atmospheric sample sequentially passes through the particle state trapping device, the two-position six-way valve, the primary trapping trap and the two mass flow controllers and is discharged through the sampling pump; at the moment, the particulate organic matters are trapped by the particulate trapping device, and the target gaseous organic matters in the atmosphere are trapped by the primary focusing trap; if the calibration is needed, only the STD gasification chamber is connected to the inlet of the atmospheric sample, the sample inlet of the gasification chamber is filled with the standard liquid, the sampling time is shortened to 1min, and other relevant steps and operations of the device are the same;

(3) Purge mode: in the mode, the enrichment-thermal analysis device of the primary trap keeps a refrigeration mode, the primary trap is in a low-temperature enrichment state, the secondary trap and the enrichment-thermal analysis device of the particle state trap are closed, and the temperature control system is in a normal-temperature mode; the carrier gas passes through all pipeline components among the gas supply and pressure control system, the electromagnetic three-way valve, the particle state trapping device, the primary trapping trap, the two-position six-way valves, the two mass flow controllers and the sampling pump so as to remove residual redundant interference gas;

(4) Particle state focusing mode: in the mode, a temperature control system of the particle state trapping device is in a heating mode, the primary trapping well enrichment-thermal analysis device is closed, the temperature control system is in a normal temperature mode, the enrichment-thermal analysis device of the secondary focusing well is in a refrigerating mode, and the secondary focusing well is in a low-temperature enrichment state; the carrier gas is discharged through a gas supply and pressure control system, an electromagnetic three-way valve, a particle state trapping device, two-position six-way valves, a secondary focusing trap, a second mass flow controller and a sampling pump, and an object to be detected analyzed in the particle state trapping device is transferred to the secondary focusing trap in low-temperature enrichment through purging, so that the particle state sample is trapped for the second time;

(5) Particle sample injection mode: in the mode, the enrichment-thermal analysis device of the secondary focusing trap is in a heating mode, the secondary focusing trap is in a high-temperature thermal analysis state, the primary trapping trap and the enrichment-thermal analysis device of the particle state trapping device are closed, and the temperature control system is in a normal temperature mode; after carrier gas passes through a gas supply and pressure control system, an electromagnetic three-way valve, two-position six-way valves and a secondary focusing trap, carrying a substance to be measured which is thermally resolved by the secondary focusing trap in a high temperature state into a GC-MS for measurement, and completing primary granular SVOCs sampling and analysis;

(6) Gaseous sample focus mode: in the mode, the enrichment-thermal analysis device of the primary trapping well is in a heating mode, the enrichment-thermal analysis device of the secondary focusing well is in a refrigerating mode, the primary trapping well is in a high-temperature thermal analysis state, the secondary focusing well is in a low-temperature enrichment state, and the enrichment-thermal analysis device of the particle state trapping device is closed in a normal-temperature mode; the carrier gas is discharged through a gas supply and pressure control system, an electromagnetic three-way valve, two-position six-way valves, a primary trapping well, a secondary focusing well, a second mass flow controller and a sampling pump, and an object to be detected in the primary trapping well is transferred to the secondary focusing well in a low-temperature state to carry out secondary trapping on a gaseous sample;

(7) Gaseous sample injection mode: in the mode, the primary trap enrichment-thermal analysis device is closed, the temperature control system is in a normal temperature mode, the secondary trap is opened in a heating mode, the secondary focusing trap is in a high-temperature thermal analysis state, and the particulate trap enrichment-thermal analysis device is closed in a normal temperature mode; after carrier gas passes through a gas supply and pressure control system, an electromagnetic three-way valve and a secondary focusing trap, carrying a substance to be detected which is thermally resolved by the secondary focusing trap in a high temperature state into a GC-MS for separation and measurement, and thus completing once gaseous SVOCs sampling and analysis;

(8) Back-blowing cooling and blowing mode: in the mode, the enrichment-thermal analysis device, the particle state trapping device and the enrichment-thermal analysis device of the primary trapping well and the secondary focusing well are closed and are in a normal temperature mode, and the primary trapping well, the secondary focusing well and the particle state trapping device are in a normal temperature cooling state; the carrier gas is discharged into the atmosphere through an electromagnetic three-way valve, a first two-position six-way valve, a particle state trapping device, a primary focusing trap, a second two-position six-way valve, a secondary focusing trap, a first mass flow controller, a second mass flow controller and a sampling pump in sequence, and the sampling pump is closed after purging is completed, so that the whole cycle is completed;

(9) If the detection needs to be continued, the method can be circulated.