CN111751479A

CN111751479A - Gaseous and particle semi-volatile organic matter online enrichment system and method and application

Info

Publication number: CN111751479A
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: 2020-10-09

Abstract

The invention relates to an online enrichment system for gaseous and particle semi-volatile organic compounds, which comprises a gasification chamber, an electromagnetic three-way valve, a first two-position six-way valve, a particle state 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 chromatography-mass spectrometry detection system, an enrichment-thermal analysis device, an air supply and pressure control system, a sample inlet pipe and a heat tracing system. The system has simple gas circuit, can carry out online enrichment direct measurement on the gaseous and granular state SVOCs with the time resolution of 85min, carries out online trapping and measurement on the gaseous and granular state semi-volatile organic compounds, avoids the 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 online accurate measurement on the gaseous and granular state semi-volatile organic compounds.

Description

Gaseous and particle semi-volatile organic matter online enrichment system and method and application

Technical Field

The invention belongs to the technical field of environmental monitoring, and particularly relates to an online enrichment system and method for gaseous and granular semi-volatile organic compounds and application.

Background

In recent years, the problem of atmospheric environment is highlighted, wherein the problem of aerosol and ozone pollution is serious, and volatile organic compounds and semi-volatile organic compounds are not only important sources of secondary organic aerosol, but also important precursors for generating ozone. In addition to Volatile Organic Compounds (VOCs), Semi-Volatile Organic Compounds (SVOCs) with larger molecular weight and more complex molecular structure are also present. The semi-volatile organic compounds are important environmental pollutants, especially have great contribution to the generation of atmospheric Secondary Organic Aerosol (SOA), and cause harm to human health while polluting the environment, so that the realization of online monitoring of the atmospheric gaseous and particle semi-volatile organic compounds is the basis for quantitative research of pollution characteristics of generation, evolution, distribution, transmission and the like of the organic pollutants in the atmosphere, and has important significance for the research of the generation mechanism and the pollution distribution of the atmospheric Secondary organic aerosol.

At present, in domestic detection of SVOCs, an active sampler (such as a sampling gun) or an adsorption medium (such as polyurethane foam PUF and a quartz filter membrane) is generally adopted for sampling, then the SVOCs are extracted by technologies such as Soxhlet Extraction (SE), ultrasonic extraction (USE), Accelerated Solvent Extraction (ASE), microwave-assisted extraction (MAE) and the like, then a rotary evaporator and a concentrator are utilized for preconcentration, and the extracted SVOCs are sent to rear-end detection equipment such as GC-MS, GC-FID and the like for analysis. The method is the same as the method developed in China, and simultaneously, the method is developed in which an adsorbent, such as activated carbon, a molecular sieve and a high molecular polymer, is used for collecting samples, a thermal analyzer is used for heating an adsorption tube after collection, so that the adsorbed SVOCS is desorbed from the tube, and the SVOCS is sent to a rear-end detection device such as a GC-MS device for analysis.

At present, no document and patent at home and abroad publishes a commercial instrument which can directly measure the gaseous SVOCs and the particulate SVOCs on line at the same time, and only the particulate SVOCs exist off-line on-line measuring technology, such as TAG. In recent years, a technology for measuring gaseous semi-volatile organic compounds has been developed, for example, a two-channel SV-TAG appears, in which gaseous and particulate semi-volatile organic compounds are all captured by a metal filter membrane, the content of the gaseous semi-volatile organic compounds is calculated by subtracting the content of the total semi-volatile organic compounds from the content of the particulate semi-volatile organic compounds, and the content of the gaseous semi-volatile organic compounds obtained by a difference method has a problem of large gas particle distribution error, resulting in lack of scientificity of data.

The existing SVOCs measuring technology has the following problems: the method has the advantages that gaseous particle state semi-volatile organic compounds cannot be directly measured, offline sampling time is discontinuous, acquisition time is too long, direct analysis of low SVOCs content in a sample cannot meet the detection limit requirement of a detector, recovery rate is low, the size of an instrument is too large, and the like. Aiming at the problems, the invention provides the method and the device for enriching the gaseous and granular semi-volatile organic compounds on line, and realizes the direct on-line measurement of the atmospheric gaseous and granular semi-volatile organic compounds.

Through 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 provides a gaseous and granular semi-volatile organic matter online enrichment system, a method and application.

The technical problem to be solved by the invention is realized by adopting the following technical scheme:

the utility model provides an online enrichment system of gaseous state, half volatile organic compounds of particulate state, the system includes vaporizer, electromagnetism three-way valve, first two-position six-way valve, particulate state trapping device, once traps trap, secondary focus trap, second two-position six-way valve, first mass flow controller, second mass flow controller, sampling pump, gas chromatography mass spectrometry detecting system, enrichment-thermal analysis device, air feed and pressure control system, advances appearance pipe and heat tracing system, the electromagnetism three-way valve includes entry end A, exit end B and exit end C, the exit end of air feed and pressure control system is connected the setting with the entry end A of electromagnetism three-way valve, it is connected the setting with the entry end of particulate state trapping device to advance appearance pipe, exit end B of electromagnetism three-way valve also is connected the setting with the entry end of particulate state trapping device, the exit end of particulate state trapping device is connected the setting with 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 trap and the second two-position six-way valve, and the primary trap is also connected with the secondary focusing trap;

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 sequentially connected with a second mass flow controller and a sampling pump, 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 a first mass flow controller, and the outlet end of the first mass flow controller is connected with the inlet end of a second mass flow controller;

the gasification chamber and the sample inlet 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 trap and the secondary focusing trap 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 trap and the secondary focusing trap;

the sampling tube, the gasification chamber, the particle state trapping device, the primary trapping trap, the secondary focusing trap, the first two-position six-way valve, the second two-position six-way valve and the gas chromatography mass spectrometry detection system are all provided with heat tracing systems, and the heat tracing systems can heat the pipelines at constant temperature.

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

the heat tracing system can provide 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 provided with heat tracing systems which 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 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 trapping 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 a 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 a 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 a passivated stainless steel pipeline;

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

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 ℃;

alternatively, the enrichment thermal desorption system may provide a constant low temperature of 0 ℃ and a constant high temperature of 300 ℃.

The primary trapping trap comprises a primary trapping trap inner column, a primary trapping trap stainless steel outer sleeve, an adsorbent, a stainless steel reducing tee joint and passivated quartz cotton, wherein the primary trapping trap inner column is arranged along the horizontal direction, the horizontal two ends of the primary trapping trap inner column are detachably arranged with the stainless steel reducing tee joint, the stainless steel reducing tee joint penetrates through the horizontal two ends of the primary trapping trap inner column, the primary trapping trap stainless steel outer sleeve is coaxially and closely sleeved on the outer surface of the primary trapping trap inner column at intervals, the horizontal two ends of the primary trapping trap stainless steel outer sleeve are also detachably connected with the stainless steel reducing tee joint, the adsorbent is arranged in the middle of the primary trapping 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 primary trapping 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 stainless steel reducing tee joint penetrates through the horizontal two ends of the secondary focusing trap inner column, the secondary focusing trap stainless steel outer sleeve is coaxially and closely sleeved on the outer surface of the secondary focusing trap inner column at intervals, the horizontal two ends of the secondary focusing trap stainless steel outer sleeve are also 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 arranged on the two sides of the adsorbent in a connected mode, 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 constant temperature of 300 ℃.

The enrichment-thermal desorption device comprises heating and refrigerating equipment and an enrichment-thermal desorption 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 along the horizontal direction, and the horizontal two ends of the optical radiation heating rod can be detachably connected with 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 trap inner column between the secondary focus trap inner column and the secondary focus trap stainless steel outer 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 trapping trap inner column or the secondary focusing trap inner column and transmitting the temperature to the temperature transmitter;

the enrichment-thermal desorption cavity comprises an aluminum box, screws, an aluminum box cover plate and three-way 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 and inwards sunken, U-shaped grooves are formed in the side wall of the inwards sunken aluminum box, the shapes of the U-shaped grooves are matched with those 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 two horizontal side walls of the aluminum box on the two longitudinal sides of the U-shaped groove along the longitudinal direction, and a ceramic clamping seat can be mounted on each clamping seat mounting hole;

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

the shape phase-match setting of tee bend heat tracing heating piece and stainless steel reducing three way connection, this stainless steel reducing three way connection is connected the setting with tee bend heat tracing heating piece, and this tee bend heat tracing heating piece can carry out heating heat preservation operation to stainless steel reducing three way connection.

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

The upper collecting pipe part 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 from top to bottom, the hollow quartz cylinder A and the hollow quartz cylinder C are both in a hollow cylinder shape 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 that of the top of the hollow quartz pipe B, the diameter of the bottom of the hollow quartz pipe B is equal to that 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 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 at intervals along the circumferential direction, and a through hole is formed in the circle 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 of the hemispherical quartz ball bowl D, 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 quartz cylinder C below the quartz wafer I is hollow, the top and the bottom of the hollow quartz cylinder C are both open, the bottom of the hollow quartz cylinder is arranged on the top of the 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 lower collecting pipe part comprises a hemispherical quartz ball bowl E and a hollow quartz cylinder F which are connected up and down, wherein a hemispherical cavity 42 and a cylindrical cavity 47 which are communicated up and down tightly are coaxially manufactured by the hemispherical quartz ball bowl E, the hollow quartz cylinder F is hollow with an opening at the top and the bottom, and the bottom of the cylindrical cavity of the hemispherical quartz ball bowl E is coaxially communicated with the hollow interior of the hollow quartz cylinder F tightly;

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

or the particle state trapping device also 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 ferrule joint, a temperature sensor, a temperature transmitter and a ceramic clamping seat, wherein the optical radiation heating rod is arranged along the horizontal direction, the horizontal two ends of the optical radiation heating rod can be detachably connected and provided with a ceramic clamping seat, the temperature transmitter is connected and provided with a temperature sensor, the temperature sensor is tightly wound and arranged outside the granular state trapping device, a probe of the temperature sensor and the quartz wafer I are positioned at the same horizontal and vertical positions, the temperature sensor can detect the temperature of the particle sample on the quartz filter membrane of the particle state trapping device in real time, and the temperature sensor can transmit the temperature to the temperature transmitter;

the heating furnace comprises an aluminum box, an aluminum box cover plate, screws, stainless steel passivation reducing sleeve joints and reducing joint 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 and inwards sunken, U-shaped grooves are formed in the side walls of the inwards sunken aluminum box, the shapes of the U-shaped grooves are matched with those of the stainless steel passivation reducing sleeve joints, the stainless steel passivation reducing sleeve joints 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 two horizontal side walls of the aluminum box on the two longitudinal sides of the U-shaped groove along the longitudinal direction, and a ceramic clamping seat can be mounted on each clamping seat mounting hole;

the shape of the stainless steel passivation reducing ferrule connector is matched with that of an upper collecting pipe part of the particle state collecting pipe, and the upper collecting pipe part is connected with the two stainless steel passivation reducing ferrule connectors;

the reducing joint heat tracing heating block is matched with the stainless steel passivation reducing sleeve joint in shape, the stainless steel passivation reducing 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 sleeve joint.

And the system also comprises a programmable logic controller, the programmable logic controller 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 desorption device and the heat tracing system through circuits, and the programmable logic controller can control the opening and closing and the opening of each part and monitor each system parameter.

The method for on-line enrichment of the gaseous and granular semi-volatile organic compounds by using the gaseous and granular semi-volatile organic compound on-line enrichment system comprises the following specific steps:

(1) aging mode: in this mode, the enrichment-thermal desorption devices of the primary trap, the secondary focusing and particle state trapping devices all start a heating mode, and the temperature control systems of the primary trap, the secondary focusing trap and the particle state trapping devices are all in a high-temperature thermal desorption state. After passing through the gas supply and pressure control system, the carrier gas carries out aging purging on all pipelines and parts 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;

(2) sampling mode: in the mode, the enrichment-thermal analysis device of the primary trap starts a refrigeration mode, the primary trap is in a low-temperature enrichment state, the enrichment-thermal analysis device of the secondary trap and the particle state trap is closed, and the temperature control system is in a normal-temperature mode. One path of the atmospheric sample sequentially passes through the particle state trapping device, the two-position six-way valves, the primary trapping trap and the two mass flow controllers and then is discharged through the sampling pump under the pumping action of the sampling pump; at the moment, the particulate organic matter is trapped by a particulate trapping device, and the target gaseous organic matter in the atmosphere is trapped by a primary focusing trap; if calibration is needed, only an STD gasification chamber is connected to an atmospheric sample inlet, standard liquid is injected into a sample inlet of the gasification chamber, and the sampling time is shortened to 1min, wherein the related steps and operations of other devices are the same as those of the prior art;

(3) purging 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 enrichment-thermal analysis device of the secondary trap and the particle state trap is closed, and the temperature control system is in a normal-temperature mode. The carrier gas passes through the gas supply and pressure control system and the electromagnetic three-way valve, and is used for removing residual redundant interference gas from all pipeline parts among the particle state trapping device, the primary trapping trap, the two-position six-way valves, the two mass flow controllers and the sampling pump;

(4) particle state focusing mode: in this mode, the temperature control system of the particulate trap device is in a heating mode, the primary trap 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 trap is in a cooling mode, and the secondary focusing trap 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, the substance to be detected analyzed in the particle state trapping device is transferred to the secondary focusing trap in low-temperature enrichment through purging, and the particle state sample is secondarily trapped;

(5) particle state sample introduction mode: in this 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 enrichment-thermal analysis device of the primary trapping trap and the particle state trapping device is closed, and the temperature control system is in a normal-temperature mode. After the carrier gas passes through the gas supply and pressure control system, the electromagnetic three-way valve, the two-position six-way valves and the secondary focusing trap, the substance to be detected, which is thermally analyzed by the secondary focusing trap in a high-temperature state, is brought into the GC-MS for measurement, and the sampling and analysis of the particulate SVOCs are completed;

(6) gaseous sample focusing mode: in this mode, the enrichment-thermal analysis device of the primary trap is in a heating mode, the enrichment-thermal analysis device of the secondary trap is in a cooling mode, the primary trap is in a high-temperature thermal analysis state, the secondary trap is in a low-temperature enrichment state, and the enrichment-thermal analysis device of the particulate trap is closed and is 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 trap, a secondary focusing trap, a second mass flow controller and a sampling pump, the object to be detected in the primary trapping trap is transferred to the secondary focusing trap in a low-temperature state, and the gaseous sample is trapped secondarily;

(7) gas sample introduction 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 granular state trap enrichment-thermal analysis device is closed in the normal temperature mode. After the carrier gas passes through the gas supply and pressure control system, the electromagnetic three-way valve and the secondary focusing trap, the substance to be detected in the high-temperature state of the secondary focusing trap is thermally analyzed and brought into the GC-MS for separation and measurement, and thus, the sampling and analysis of the gaseous SVOCs are completed;

(8) a back flushing, cooling and purging mode: in this mode, the enrichment-thermal analysis device of the primary trap and the secondary focus trap and the enrichment-thermal analysis device of the particle state trap are closed to be in a normal temperature mode, and the primary trap, the secondary focus trap and the particle state trap 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 finished, so that the whole cycle is completed;

(9) if the detection is needed to be continued, the steps are circulated.

The application of the online enrichment system in the aspect of measuring gaseous and particle-state semi-volatile organic matters is disclosed.

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 with the time resolution of 85min, synchronously performs gaseous and granular trapping and analysis on line, avoids the 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 online accurate measurement on the gaseous and granular semi-volatile organic matters. The system can realize the control of C₁₂-C₃₀Compared with the traditional measurement technology, the on-line monitoring of the semi-volatile organic compounds in the span range has larger measurement span and higher recovery rate.

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

3. The invention adopts the passivated components at the pipeline and the joints, adopts the complete set of electric heating wire heat tracing system, designs the special heat tracing device for each joint and valve body, eliminates the cold point of the pipeline, solves the problem of cold residue of SVOCs on the pipe wall, and reduces the loss of the sample to be measured in the pipeline to the maximum extent.

4. The invention is additionally provided with a secondary trapping system to realize recapture and reanalysis of low-concentration semi-volatile organic compounds, further concentrate SVOCs components in the sample, solve the problems of low SVOCs content in the atmosphere, small peak and disorder, reduce the detection limit of the system by multiple focusing and improve the sensitivity of analysis and detection.

5. The invention improves the heating and refrigerating mode, and the module adopts vortex refrigeration and light radiation heating, so that the heating and refrigeration of the trap system can be realized in a short time, and the sample can be trapped and thermally analyzed. The heating temperature is higher, the refrigerating temperature is lower, meanwhile, 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 granular state trapping device is designed, the granular state trapping device is heated by light radiation, the core of the granular state trapping device is a set of granular state trapping pipe which is designed by self, and accurate temperature control can be performed, so that the granular state SVOCs thermal desorption effect is better, and the recovery rate is higher.

7. The invention realizes the innovation of the method, can realize the on-line simultaneous measurement of gaseous and granular semi-volatile organic compounds with ultralow concentration 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, thereby simplifying the gas path structure to the maximum extent, shortening the sample conveying path, reducing the dead volume, reducing the loss of the sample in the sampling and analyzing process to the minimum and improving the accuracy of the measurement of the instrument.

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 focus trap, enrichment-thermal analysis apparatus of FIG. 1;

FIG. 3 is a schematic view of a structural connection of the enrichment-thermal desorption chamber of the enrichment-thermal desorption apparatus of FIG. 1 (the three-way heat tracing heating block is omitted);

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 view of the structure connection of the three-way heat tracing heating block of the enrichment-thermal desorption apparatus shown in FIG. 1;

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

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

FIG. 10 is a 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 a structural attachment of the particulate trap of FIG. 1;

fig. 13 is a sectional view in the direction of H-H of the particulate trap of fig. 12.

Detailed Description

The present invention will be further described with reference to specific examples, which are intended to be illustrative, not limiting and are not intended to limit the scope of the invention.

Structures not specifically described in detail herein are to be understood as conventional in the art.

An online enrichment system for gaseous and particulate semi-volatile organic compounds, as shown in fig. 1, comprises a gasification chamber 1, an electromagnetic three-way valve 2, a first two-position six-way valve 3, a particulate trapping device 5, a primary trapping trap 6, a secondary focusing trap 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 chromatography-mass spectrometry detection system 12, a vortex tube 13, an enrichment-thermal desorption device 14, a gas supply and pressure control system 15, a sample inlet 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 gas supply and pressure control system is connected with the inlet end a of the electromagnetic three-way valve, the sample inlet tube is connected with the inlet end of the particulate trapping device, and the outlet end B of the electromagnetic three-way valve is also connected with the inlet end of the particulate, the outlet end of the particle state trapping device is connected with a 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, a primary trapping trap and a second two-position six-way valve, and the primary trapping trap is also connected with a secondary focusing trap; the enrichment-thermal desorption apparatus comprises a vortex tube;

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

the heat tracing system can provide a constant temperature of 300 ℃;

in this embodiment, the entry end A of electromagnetism three-way valve is connected the setting through stainless steel pipeline and air feed and pressure control system, the exit end B of electromagnetism three-way valve is connected the setting through stainless steel pipeline and granule attitude entrapment device, the exit end C of electromagnetism three-way valve is connected the setting through stainless steel pipeline and first two-position six-way valve.

In this embodiment, the first two-position six-way valve includes 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 8 includes 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 to 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 to 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 trapping 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; an 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 an 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; normally, the normally-open positions of the first two-position six-way valve are A, B, C, D, E and F connected, and the second positions are F, A, B, C, D and E connected.

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 a 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 a 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 a passivated stainless steel pipeline. Normally, the normally open positions of the second two-position six-way valve 8 are a, B, C, D, E, and F connected, and the second positions are F, a, B, C, D, and E connected.

In this embodiment, the gas supply and pressure control system can provide helium, hydrogen and compressed air with purity not lower than 99.999%, and can control the pressure of the gas path.

In the 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 comprises a primary trap inner column 23, a primary trap stainless steel outer sleeve 24, an adsorbent 25, a stainless steel reducer union 26 and passivated quartz wool 30, 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, and the horizontal two ends of the primary trap inner column penetrate through the stainless steel reducing tee joint, the outer surface of the inner column of the primary trap is coaxially and closely sleeved with a stainless steel outer sleeve of the primary trap at intervals, the horizontal two ends of the stainless steel outer sleeve of the primary trap are also detachably connected with a stainless steel reducing tee joint, an adsorbent is arranged in the middle of the inner column of the primary trapping well, passivated quartz wool is connected and arranged on two sides of the adsorbent, and the passivated quartz wool is also arranged in the inner column of the primary trapping well;

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

Preferably, the adsorbent is Tenax TA; or, the primary trap inner column and the secondary focus trap inner column both adopt 316L stainless steel pipes subjected to passivation treatment; the stainless steel outer sleeve of the primary trap and the stainless steel outer sleeve of the secondary focusing trap are both made of 316L stainless steel pipes.

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

or the diameter of the inner column of the secondary focusing trap is 1/8 inches, and the diameter of the stainless steel outer sleeve of the secondary focusing trap is 1/4 inches;

or the joints at the two ends of the horizontal side of the stainless steel reducing tee joint are set to be 1/8 and 1/4, the joint at the vertical side of the stainless steel reducing tee joint is set to be 1/4, the primary trap inner column or the secondary focusing trap inner column penetrates through one side of the stainless steel reducing tee joint from 1/8 and is fixed by a clamping sleeve, and the primary trap stainless steel outer sleeve or the secondary focusing trap stainless steel outer sleeve is fixed by a 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 desorption apparatus includes a heating and cooling device and an enrichment-thermal desorption chamber, 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 along a horizontal direction, and both horizontal ends of the optical radiation heating rod are detachably connected to 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 trap inner column between the secondary focus trap inner column and the secondary focus trap stainless steel outer 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 focus trap inner column, transmitting the temperature to the temperature transmitter, transmitting a signal to the programmable logic controller by the temperature transmitter, controlling the heating time of the optical radiation heating rod, and adjusting the opening degree of a proportional valve in the refrigeration 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 desorption cavity comprises an aluminum box 33, screws 34, an aluminum box cover plate (not shown in the figure) and three-way heat tracing heating blocks 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 and inwards sunken, U-shaped grooves 36 are formed in the side walls of the inwards sunken aluminum box, the shapes of the U-shaped grooves are matched with those of a stainless steel reducing tee joint, the stainless steel reducing tee 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 37 are longitudinally and symmetrically formed in the two horizontal side walls of the aluminum box on the two longitudinal sides of the U-shaped groove, and a ceramic clamping seat can be mounted on each clamping seat mounting hole;

Preferably, the optical radiation heating rod is a ruby heating rod, the radiation heating principle is adopted, and preferably, the ruby heating rod with the length of 120mm and the weight of 300w is fixed in a ceramic clamping seat of the metal outer-wrapping ceramic of the enrichment-thermal desorption cavity. Two heating rods can be connected in series on a 220V circuit and connected with a programmable logic controller to realize the 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 the polytetrafluoroethylene pipeline, an outlet of the proportional valve is connected with an inlet of a vortex tube through the polytetrafluoroethylene pipeline, an outlet of the vortex tube is connected with a vertical 1/4 joint of the stainless steel reducing tee joint, and similarly, the other proportional valve, the vortex tube and the stainless steel reducing tee joint are connected and arranged on the same way. The proportional valve is connected with the programmable logic controller to realize the refrigeration function.

Specifically, in the manufacturing, the manufacturing may be as follows:

the box volume parts of the middle parts 1/3 at the left and right sides of the aluminum box are integrally sunken back and are symmetrical at two sides. The left and right side concave parts 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 and right sides do not sunken department respectively open a round hole, bilateral symmetry, and the round hole size closely cooperates with the ceramic cassette, and this heating rod can provide the high temperature of needs. Connecting two ends of a primary trap inner column and a primary trap stainless steel outer sleeve or a secondary trap inner column and a secondary trap stainless steel outer sleeve with stainless steel reducing tee joints, putting the stainless steel reducing tee joints into a U-shaped groove, covering an aluminum box cover plate, screwing screws, sleeving two three-way heat tracing heating blocks which are tightly matched on the stainless steel reducing tee joints after connection, symmetrically arranging the two heat tracing heating blocks relative to the stainless steel reducing tee joints, preferably, the stainless steel reducing tee joints and the two heat tracing heating blocks are positioned at the same height, tightly fixing the two heat tracing heating blocks on the stainless steel reducing tee joints by using the screws, placing a temperature sensor at the horizontal center of the inner side sleeve of the primary trap and fixing on the primary trap, connecting an electric wire joint from the position of the stainless steel reducing tee joint which is not connected with a refrigeration pipeline and perpendicular to 1/4 joints, and connecting the temperature of a transmitter, real-time detection and control 1/4 traps the temperature of the sample within the trap. The PTC heating plate can be arranged in the heat tracing heating block, the constant temperature heat tracing is carried out at 300 ℃, cold spots are removed, and SVOCs are prevented from being adhered to the filter membrane, the pipeline, the joint and the collecting pipe.

In the present embodiment, as shown in fig. 12 and 13, the particulate trap device includes a particulate trap pipe including an upper trap pipe member, a lower trap pipe member, a hollow quartz cylinder 43, a tetrafluoro O-ring 44, a stainless steel deactivating spring 45, a quartz filter 46, and a ball joint clamp (not shown), the tetrafluoro O-ring is tightly disposed between the upper trap pipe member and the lower trap pipe member, the upper trap pipe member and the lower trap pipe member are detachably disposed together by the ball joint clamp dense phase connection, the hollow quartz cylinder is disposed in the upper trap pipe member, the stainless steel deactivating spring is connected and disposed between the hollow quartz cylinder and the lower trap pipe member, and the quartz filter is disposed in the upper trap pipe member above the hollow quartz cylinder.

Preferably, the upper collecting pipe part comprises a hollow quartz cylinder A, a hollow quartz tube B, a quartz wafer I, a hollow quartz cylinder C and a hemispherical quartz ball bowl D which are coaxially and tightly connected from top to bottom, the hollow quartz cylinder A and the hollow quartz cylinder C are both in a hollow cylinder shape with openings at the top and the bottom, the hollow quartz tube 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 that of the top of the hollow quartz tube B, the diameter of the bottom of the hollow quartz tube B is equal to that 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 in a hollow shape with openings at the top and the bottom, the bottom of the hollow quartz cylinder is arranged on 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 portion 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 extends to be arranged on the bottom of the hemispherical cavity of the hemispherical quartz ball bowl E.

When the particle state collecting pipe is used, the particle state collecting pipe is generally used in an inverted mode, namely the particle state collecting pipe is rotated by 90 degrees in a clockwise direction.

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

Preferably, the upper collecting pipe part and the lower collecting pipe part 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 50 mm;

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

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

the thickness of quartz disk I is 3mm, and the diameter is 17mm, be equipped with 10 circular through-holes that the diameter is 2mm on the quartz disk I, 10 circular through-hole centre of a circle evenly distributed use quartz disk I is the centre of a circle, and the diameter is on 17 mm's circumference, just quartz disk I centre of a circle department is equipped with a circular through-hole of diameter 3.35 mm.

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

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

Alternatively, the hollow quartz cylinder 43 has a diameter of 17mm and a wall thickness of 1 mm. The other end of the hollow quartz cylinder is propped against a quartz filter membrane arranged below the quartz wafer I to form a closed environment and simultaneously fix the quartz filter membrane to prevent the quartz filter membrane from turning over, damaging and losing the trapped granular sample.

In this embodiment, the particle state collecting device further includes a temperature control system, the particle state collecting tube is connected to the temperature control system (the structure of the temperature control system is similar to that of the enrichment-thermal desorption device, and therefore 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 joint, a temperature sensor, a temperature transmitter, and a ceramic ferrule, the optical radiation heating rod is disposed along a horizontal direction, both horizontal ends of the optical radiation heating rod are detachably connected to the ceramic ferrule, the temperature transmitter is connected to the temperature sensor, the temperature sensor is tightly wound outside the particle state collecting device, a probe of the temperature sensor and the quartz wafer I are located at the same horizontal and vertical positions, and the temperature sensor can detect the temperature of the particle sample on the quartz filter membrane of the particle state collecting device in real time, the temperature sensor can transmit the temperature to a temperature transmitter, the temperature transmitter transmits a signal to a programmable logic controller, the heating time of the light radiation heating rod is controlled to carry out PID control, so that the temperature is regulated and controlled, and the final temperature precision is controlled to be +/-0.1 ℃;

Specifically, in the manufacturing, the manufacturing may be as follows:

the box volume parts in the middle 1/3 at the left and right sides of the aluminum shell of the hot block are integrally sunken back and are symmetrical at two sides. The left side depressed part is provided with a U-shaped groove with the diameter of 6.35mm, the right side depressed part is provided with a U-shaped groove with the diameter of 20mm, and the size of the U-shaped groove is tightly matched with the stainless steel passivation reducing ferrule connector. The left and right sides do not sunken department respectively open a round hole, bilateral symmetry, and the round hole size closely cooperates with the ceramic cassette, and this heating rod can provide the high temperature of needs. After the granular state collecting pipe is connected with the stainless steel passivated reducing sleeve joint, the stainless steel passivated reducing sleeve joint is placed in a U-shaped groove, two reducing joint heat tracing heating blocks which are tightly matched with the stainless steel passivated reducing sleeve joint are sleeved on the connected pipe, the two heat tracing heating blocks are symmetrically placed relative to the stainless steel passivated reducing sleeve joint, the stainless steel passivated reducing sleeve joint and the two heat tracing heating blocks are located at the same height, the two heat tracing heating blocks are tightly fixed on the stainless steel passivated reducing sleeve joint through screws, and a gap is reserved at the position of the granular state collecting pipe C, located at the position of a right side recess, of 5mm and located outside the position of the right side recess to fix a quartz ball bowl D, E for the stainless steel interface clamp. The PTC heating blocks can be arranged in the heat tracing heating blocks, and can carry out constant-temperature heat tracing at 300 ℃ to remove cold spots, so that SVOCs are prevented from being adhered to the filter membrane, the pipeline, the joint and the collecting pipe. After the assembly is completed, the aluminum box cover plate is covered, and the screw is screwed in.

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

In this embodiment, the system further includes a programmable logic controller, 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 a circuit, and the programmable logic controller is capable of controlling the opening and closing and the opening of each component and monitoring each system parameter, such as a temperature parameter, a flow parameter, and the like.

Preferably, the proportional valve is connected with a programmable logic controller, and the programmable logic controller can control the opening and closing of the proportional valve and monitor 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 collecting pipe, and is connected with the programmable logic controller, so that the control and monitoring of the enrichment-thermal analysis device at a constant high temperature of 300 ℃ and a constant low temperature of 0 ℃ can be realized, and the temperature control precision is +/-0.1 ℃.

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

The method comprises the following specific steps:

(9) if the detection is needed to be continued, the steps are circulated.

Preferably, the whole system and the components can be subjected to time sequence control through a computer interactive control system, and the above 8 modes can be subjected to automatic cycle operation without manual control and operation.

More specifically, the online measurement method using the above gaseous and particulate semi-volatile organic compound online enrichment and measurement system is a complete cycle mode including: the method comprises the following steps of aging mode, sampling mode (calibration), purging mode, particle state focusing mode, particle state sampling mode, gas state focusing mode, gas state sampling mode and back flushing cooling purging mode, and specifically comprises the following steps:

1. in the aging mode, the A-B ports of the electromagnetic three-way valve are communicated, and the first mass flow controller, the second mass flow controller and the sampling pump are all started; the first two-position six-way valve enables the A-B interface to be communicated, the C-D interface to be communicated and the E-F interface to be communicated, and 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 systems of the enrichment-thermal desorption device and the particle state trapping device of the primary trapping trap and the secondary focusing trap are in heating modes, the heating rod is connected with the programmable logic controller, the heating time is controlled by the logic controller, and the primary trapping trap, the secondary focusing trap and the particle state trapping device are maintained in a high-temperature thermal desorption state; the helium passes through the gas supply system and the electromagnetic three-way valve, and aging washing is carried out on the particle trap by controlling the flow of the first mass flow controller to be the same as that of the second mass flow controller; through 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 subjected to aging washing, substances possibly remaining in a system device are taken out, and the influence of a previous sample on the detection is avoided.

2. In the sampling mode, the A-C ports of the electromagnetic three-way valve are communicated, and the first mass flow controller, the second mass flow controller and the sampling pump are all started; keeping the A-B interface, the C-D interface and the E-F interface of the first two-position six-way valve communicated, 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 degree of the proportional valve is controlled through the logic controller, and the primary trap is maintained in a low-temperature trapping state; closing the temperature control systems of the particle state trapping device and the secondary focusing trap, and enabling the particle state trapping device and the secondary focusing trap to be in a normal-temperature mode; the ambient air sequentially passes through the particle state trapping device, the two-position six-way valve and the primary trapping trap, the particle state part is trapped by the particle state trapping device, the gas state part is trapped by the primary trapping trap with the temperature stabilized at 0 ℃, and the gas state part is exhausted into the atmosphere through the two-position six-way valve, the first mass flow controller, the second mass flow controller and the sampling pump; if the calibration is needed, only the STD gasification chamber is connected to the atmospheric sample inlet, the standard liquid is injected into the sample inlet of the gasification chamber, the sampling time is shortened to 1min, and the related steps and operation of other devices are the same as those in the above.

3. In the purging mode, the ports A-B of the electromagnetic three-way valve are communicated, and the first mass flow controller, the second mass flow controller and the sampling pump are all opened; keeping the A-B interface, the C-D interface and the E-F interface of the first two-position six-way valve communicated, and keeping the B-C interface, the D-E interface and the F-A interface of the second two-position six-way valve 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 degree of the proportional valve is controlled through the logic controller, and the primary trap is maintained in a low-temperature trapping state; closing the temperature control systems of the particle state trapping device and the secondary focusing trap, and enabling the particle state trapping device and the secondary focusing trap to be in a normal-temperature mode; helium is exhausted to 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 a particle state focusing mode, the A-B ports of the electromagnetic three-way valve are 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, the heating time is controlled by the logic controller, and the particle state trapping device is maintained in a 300 ℃ high-temperature thermal desorption state; the primary trapping trap and the secondary focusing trap are in a refrigeration mode, the proportional valve is connected with the programmable logic controller, and the opening degree of the proportional valve is controlled through the logic controller to maintain the primary trapping trap and the secondary focusing trap in a low-temperature trapping state; and after passing through the gas supply system and the A-B ports of the electromagnetic three-way valve, helium brings the desorbed substances to be detected of the particle state trapping device at the high temperature to the secondary focusing trap at the low temperature through the E-F port of the second two-position six-way valve, and the substances are 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 state sampling mode, the A-C ports of the electromagnetic three-way valve are communicated, and the first mass flow controller, the second mass flow controller and the sampling pump are all closed; switching a 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 a 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; normal operation of GC-MS; the secondary focusing trap is in a heating mode, the heating rod is connected with the programmable logic controller, the heating time is controlled by the logic controller, and the secondary focusing trap is maintained in a 300 ℃ high-temperature thermal desorption state; disconnecting a temperature control system of the enrichment-thermal desorption device of the particle state trapping device; 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 degree of the proportional valve is controlled by the logic controller to maintain the primary trap in a low-temperature trapping state; helium enters the secondary focusing trap through the air supply system, the A-C port of the electromagnetic three-way valve and the A-F port of the second two-position six-way valve, substances to be detected in the secondary focusing trap are desorbed, the substances enter the GC-MS through the B-C port of the second two-position six-way valve, and the substances to be detected are separated and detected by the GC-MS. And 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 a gaseous focusing mode, the A-B ports of the electromagnetic three-way valve are 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, the C-D port and the E-F port of the first two-position six-way valve are 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, the heating time is controlled by the logic controller, and the primary trap is maintained in a high-temperature thermal desorption state; the temperature control system of the enrichment-thermal desorption device of the secondary focusing trap is in a refrigeration mode, the proportional valve is connected with the programmable logic controller, and the opening degree of the proportional valve is controlled by the logic controller to maintain the secondary focusing trap in a low-temperature trapping state; disconnecting a temperature control system of the enrichment-thermal desorption device of the particle state trapping device; and helium passes through the air supply system, the A-B port of the electromagnetic three-way valve and the two-position six-way valves, then the desorbed substances to be detected of the primary trap 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, 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 the gaseous sample injection mode, the A-C ports of the electromagnetic three-way valve are communicated, and the first mass flow controller, the second mass flow controller and the sampling pump are all closed; B-C interface communication, D-E interface communication and F-A interface communication of the first two-position six-way valve are switched, and B-C interface communication, D-E interface communication and F-A interface communication are realized by switching the second two-position six-way valve; normal operation of GC-MS; the secondary focusing trap is in a heating mode, the heating rod is connected with the programmable logic controller, the heating time is controlled by the logic controller, and the secondary focusing trap is maintained in a 300 ℃ high-temperature thermal desorption state; 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 the secondary focusing trap through the gas supply system, the A-C port of the electromagnetic three-way valve, the B-C port of the first two-position six-way valve and the A-F port of the second two-position six-way valve, substances to be detected in the secondary focusing trap are desorbed, the substances enter the GC-MS through the B-C port of the second two-position six-way valve, and the substances to be detected are separated and detected by the GC-MS. And 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 a back flushing cooling mode, the A-B ports of the electromagnetic three-way valve are 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; normal operation of GC-MS; the temperature control systems of the enrichment-thermal desorption device and the particle state trapping device of the primary trapping trap and the secondary focusing trap are in a normal temperature mode, the proportional valve is connected with the programmable logic controller and is controlled to be closed by the logic controller, and the primary trapping trap, the secondary focusing trap and the particle state trapping device are in a normal temperature cooling state; and 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 purging is finished, so that the whole cycle is completed.

9. If the detection is needed to be continued, the steps are circulated.

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

Although the 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 embodiments disclosed.

Claims

1. The utility model provides a gaseous state, online enrichment system of semi-volatile organic compounds of particulate state which 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 trap, a secondary focusing trap, a second two-position six-way valve, a first mass flow controller, a second mass flow controller, a sampling pump, a gas chromatography mass spectrometry detection system, an enrichment-thermal desorption device, a gas supply and pressure control system, a sample inlet 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 sample inlet 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, and the first two-, The primary trap and the second two-position six-way valve are connected, and the primary trap is also connected with the secondary focusing trap;

2. The on-line enrichment system for gaseous and particulate semi-volatile organic compounds according to claim 1, characterized in that: the constant enrichment low temperature is a constant 0 ℃ enrichment low temperature, and the constant desorption high temperature is a constant 300 ℃ thermal desorption high temperature;

the heat tracing system can provide a constant temperature of 300 ℃;

3. The on-line enrichment system for gaseous and particulate semi-volatile organic compounds according to claim 1, characterized in that: 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 trapping 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;

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

5. The on-line enrichment system for gaseous and particulate semi-volatile organic compounds according to claim 1, characterized in that: the enrichment-thermal desorption device comprises heating and refrigerating equipment and an enrichment-thermal desorption 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 along the horizontal direction, and the horizontal two ends of the optical radiation heating rod can be detachably connected and provided with the ceramic clamping seat;

6. The on-line enrichment system for gaseous and particulate semi-volatile organic compounds according to claim 1, characterized in that: the particle state trapping device comprises a particle state trapping pipe, the particle state trapping pipe comprises an upper trapping pipe part, a lower trapping pipe part, a hollow quartz cylinder, a tetrafluoro O-shaped ring, a stainless steel passivation spring, a quartz filter membrane and a spherical interface clamp, the tetrafluoro O-shaped ring is tightly arranged between the upper trapping pipe part and the lower trapping pipe part, the upper trapping pipe part and the lower trapping pipe part are detachably arranged together through clamping dense-phase connection of the spherical interface clamp, the hollow quartz cylinder is arranged in the upper trapping pipe part, the stainless steel passivation spring is connected and arranged between the hollow quartz cylinder and the lower trapping pipe part, and the quartz filter membrane is arranged in the upper trapping pipe part above the hollow quartz cylinder.

7. The on-line enrichment system for gaseous and particulate semi-volatile organic compounds according to claim 6, wherein: the upper collecting pipe part 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 from top to bottom, the hollow quartz cylinder A and the hollow quartz cylinder C are both in a hollow cylinder shape 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 that of the top of the hollow quartz pipe B, the diameter of the bottom of the hollow quartz pipe B is equal to that 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;

8. The on-line enrichment system for gaseous and particulate semi-volatile organic compounds as claimed in any one of claims 1 to 7, further comprising a programmable logic controller, wherein the programmable logic controller is electrically 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, and the programmable logic controller can control the opening and closing of each component and control the opening degree and monitor each system parameter.

9. The method for the online enrichment of gaseous and particulate semi-volatile organic compounds by using the online enrichment system of gaseous and particulate semi-volatile organic compounds as claimed in any one of claims 1 to 8, wherein the online enrichment system comprises: the method comprises the following specific steps:

(9) if the detection is needed to be continued, the steps are circulated.

10. Use of the on-line enrichment system according to any of the claims 1 to 8 for the measurement of gaseous, particulate semi-volatile organic compounds.