CN112345657A - Array sensing gas chromatography detector capable of realizing gas detection of various VOCs and detection method - Google Patents
Array sensing gas chromatography detector capable of realizing gas detection of various VOCs and detection method Download PDFInfo
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- G01N30/02—Column chromatography
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Abstract
The invention provides an array sensing gas chromatography detector capable of realizing gas detection of various VOCs (volatile organic compounds) and a detection method thereof2The first pipeline is connected with the first end of the six-way valve, and a gas sampling filter is arranged on the first pipeline; the second end of the six-way valve is connected with the air inlet of the gas preconcentration device, and the air outlet of the six-way valve is connected with the fifth end of the six-way valve; the second pipeline is connected with the first end of the first three-way valve, and the third end of the first three-way valve is connected with the third end of the six-way valve; the second end of the first three-way valve is connected with the second end of the second three-way valve through a switch valve; the third end of the second three-way valve is connected with the fourth end of the six-way valve through a switch valve; the first end of the second three-way valve is connected with a gas chromatographic column, and the gas chromatographic column is connected with an array sensing detector; the sixth end of the six-way valve is connected with a negative pressure pump; sample pre-concentration mode of detectorThe first end of the through valve is connected, the third end is connected, and the fifth end is connected; and under the analysis mode of the detector, the first six end of the six-way valve is connected, the second three end is connected, and the fourth five end is connected.
Description
Technical Field
The invention belongs to the technical field of gas detection, and particularly relates to an array sensing gas chromatography detector and a detection method capable of realizing gas detection of various VOCs.
Background
At present, for component detection of VOCs gas in air environment or at a chimney exhaust, a traditional detection method for separating single gas by using a chromatographic analysis method is generally adopted. However, because the components in the environment are complex and various, and there are not only permanent gases, but also volatile organic gases, etc., the above methods have great limitations to realize the detection of the components of the environmental gases.
For gas chromatographic analysis, a gas chromatographic column is divided into nonpolar, weak polar, medium polar, strong polar and the like, and a special chromatographic column can only be used for separating special substances, but cannot separate all gases. Different organic gases cannot be separated by using the same chromatographic column at the same time, for example, a nonpolar chromatographic column can be used for separating hydrocarbons and phenols, but cannot be used for separating alcohols. Therefore, the analysis of all components inevitably leads to the complex peripheral gas circuit system of the chromatographic detector, the complex operation and the long analysis time, and the wide application of the on-line monitoring is limited.
Disclosure of Invention
The technical problem to be solved by the invention is to overcome the defects in the prior art and provide an array sensing chromatographic detector capable of realizing gas detection of various VOCs.
The technical problem to be solved can be implemented by the following technical scheme.
The utility model provides a can realize gaseous array sensing gas chromatography detector that detects of multiple VOCs which characterized in that includes:
the gas inlet pipeline is connected with a first port of the six-way valve, and a gas sampling filter is arranged on the first gas inlet pipeline; the second port of the six-way valve is connected with the gas inlet of a gas preconcentration device, and the gas outlet of the gas preconcentration device is connected with the fifth port of the six-way valve; and
a will purge N2A second air inlet pipeline of the detector is introduced, the second air inlet pipeline is connected with a first port of a first three-way valve, and a third port of the first three-way valve is connected with a third port of the six-way valve; the second port of the first three-way valve is connected with the second port of a second three-way valve through a first switch valve; a third port of the second three-way valve is connected with a fourth port of the six-way valve through a second switch valve; the first port of the second three-way valve is connected with a gas chromatographic column, and the gas chromatographic column is connected with an array sensing detector; and
the negative pressure pump is connected with the sixth port of the six-way valve;
wherein,
the detector is in a sample pre-concentration mode, a first port of the six-way valve is communicated with a second port, a third port of the six-way valve is communicated with a fourth port of the six-way valve, and a fifth port of the six-way valve is communicated with a sixth port of the six-way valve;
when the detector is in an analysis mode, the first port of the six-way valve is communicated with the sixth port, the second port of the six-way valve is communicated with the third port of the six-way valve, and the fourth port of the six-way valve is communicated with the fifth port of the six-way valve; the first switch valve is opened, the second switch valve is closed, and the negative pressure pump is closed.
As a further improvement of the technical scheme, the gas pre-concentration device is a three-stage pre-concentration column with a cooling system and a heating system, and the packed adsorbate of each stage of the three-stage pre-concentration column is different.
Also as a further improvement of this solution, said first stepA first flow regulating valve is arranged between a second port of the three-way valve and a second port of the second three-way valve; a second flow regulating valve is arranged between a third port of the first three-way valve and a third port of the second three-way valve; n flowing from the first three-way valve to the second three-way valve to the gas chromatography column through the first flow regulating valve2Relative to N flowing to the gas chromatography column through the second flow regulating valve2The flow ratio is 0:1 to 5: 1.
As a further improvement of the technical scheme, the adsorption material filled in the third-stage pre-concentration column concentrator is one or a combination of a plurality of molecular sieves, Tenax-TA and activated carbon Carbopack.
As one of the preferred embodiments of the present invention, the desorption temperature of the three-stage preconcentration column is 60 to 300 ℃.
Also as one of the preferred embodiments of the present invention, the array sensing detector is an array sensing detector composed of a semiconductor material VOCs gas sensor processed by MEMS, a chemical sensor, a micro ultraviolet light ion VOCs gas sensor, and a micro infrared laser VOCs gas sensor; the array sensor is connected with a sensing signal acquisition card which can convert physical signals into electric signals.
Furthermore, a single group of the array sensing detector consists of six sensors, and the sensing acquisition frequency of the single sensor is more than or equal to 10 times/second.
As a further aspect of the present disclosure, a first pressure maintaining valve and a second pressure maintaining valve are disposed on the first air intake pipeline; and a primary pressure stabilizing valve and a secondary pressure stabilizing valve are arranged on the second air inlet pipeline.
Also as one of the preferred embodiments of the present invention, the gas chromatography column is a micro MEMS gas chromatography column or a capillary gas chromatography column.
Similarly, an air filter membrane for filtering dust and water vapor in the air is arranged in the gas sampling filter.
Also as a preferred embodiment of the present invention, the negative pressure pump is a sampling diaphragm pump.
Another technical problem to be solved by the present invention is to provide a detection method capable of detecting multiple VOCs, which is characterized in that the array sensing gas chromatography detector is adopted, and the method comprises the following steps:
(1) pumping the gas to be detected through a negative pressure pump, sequentially entering a gas sample injection filter, a primary pressure stabilizing device and a secondary pressure stabilizing device, and then entering a pre-concentration device to concentrate the VOCs components to be detected in the sample gas; controlling sampling time through a prefabricated program, wherein the sampling time is in direct proportion to the concentration multiple and the detection precision;
(2) after the pre-concentration of the analysis sample gas is finished, entering an analysis mode through the switching of a six-way valve; in an analysis mode, a negative pressure pump serving as a sampling pump stops sampling, a temperature control system of the pre-concentration device is rapidly heated to a specified desorption temperature, the temperature interval is 60-300 ℃, and the second switch valve is in a closed state during the period;
(3) after reaching the specified temperature, N2The gas component to be detected is blown and desorbed from the pre-concentration device as blowing carrier gas, and the duration of the process can be adjusted; n is a radical of2The carrier gas carries gas to enter the gas chromatographic column for component separation; the working temperature of the gas chromatographic column is 50-180 ℃;
(4) and finally, the gas to be detected enters the array sensing detector with controllable temperature, and is analyzed in a form of a chromatographic chart after being collected according to the set collection frequency.
Further, step (4) of the method includes the step of determining the concentration and composition of the gaseous VOCs species by reference to a library of spectra.
Still further, the method may further comprise setting and adjusting bypass N2And a gas path, and mixing the gas path with a sample gas path to be analyzed and then feeding the mixture into the gas chromatographic column.
The array sensing gas chromatography detector and the detection method adopting the technical scheme have the following beneficial effects:
1. analysis of all gas components of the ambient gas can be achieved by the combination of the chromatographic columns with the array VOCs sensing units, without the need for multiple chromatographic columns.
2. The detection time is shortened, and the requirements on chromatographic columns are lower.
3. By adopting MEMS array sensing and micro-chromatography, the instrument has simpler design structure and low cost, can realize portable/handheld type and is easy to be widely used in multiple fields.
4. The integrated pre-concentration column can realize the detection of trace environmental gas, the detection limit can reach 0.01ppb, and the application range of the detector is improved.
Drawings
FIG. 1 is a schematic diagram of a multi-sensor chromatographic detector in a pre-concentration mode;
FIG. 2 is a schematic diagram of a multisensor chromatography detector in an analysis mode according to an embodiment of the present invention;
fig. 3 is a schematic view of the structure of the deletion control section in fig. 1;
fig. 4 is a schematic view of the structure of the deletion control section in fig. 2;
in the figure: 1-gas sample introduction filter; 2/7/19/20-flow regulating valve; 3/8/30/31-flow meter; 4/9-primary pressure maintaining valve; 5/10-two-stage pressure maintaining valve; 6-six-way valve; 12/13-Pre-concentration column Cooling Fan; 14-three-stage pre-concentration column; 32-pre-concentration heater; 17/24-three-way valve; 16/18-switching valve; 21-column heater; 22-chromatographic column cooling temperature-regulating fan; 23-gas chromatography column; 25-sensor temperature control device; 26-array sensing detector; 27-sensing signal acquisition card; 28-check valve; 11-flow display module; 15-temperature control display module; 29-control Module; 33-sampling diaphragm pump.
Detailed Description
The following describes embodiments of the present invention in further detail with reference to the accompanying drawings.
Referring to fig. 1 to 4, the invention discloses an array sensing chromatographic detector capable of detecting various gases, which is divided into 4 subsystems, namely an online enrichment preconcentration system, a front-end micro chromatographic separation system, a micro sensor array detector system and a data acquisition and analysis system.
The array sensing chromatographic detector mainly comprises a gas sampling filter 1, a flow regulating valve 2/7/19/20, a primary pressure stabilizing valve 4/9, a secondary pressure stabilizing valve 5/10 and a six-way valve 6; the system comprises a pre-concentration column cooling system (a pre-concentration column cooling fan 12/13), a three-stage pre-concentration column 14, a pre-concentration heating system (a pre-concentration heater 32), a three-way valve 17/24, a switching valve 16/18, a chromatographic column temperature control system (a chromatographic column heater 21 and a chromatographic column cooling temperature-adjusting fan 22), a gas chromatographic column 23, an array sensing detector 26, a sensing signal acquisition card 27, a check valve 28, a flow display module 11, a temperature control display module 15, a control module 29 and a sampling diaphragm pump 33.
The online enrichment pre-concentration system is mainly characterized in that the concentration of VOCs gas in the environment is low, but the precision of the sensor cannot reach the lower limit of gas detection at the same time, and the pre-concentration of the sample gas is required to be carried out to reach the lower limit of detection, so that the multiple of the concentration of the VOCs of the sample gas is improved.
The front-end micro-chromatographic separation system is used for quickly separating certain characteristic gases of VOCs.
The micro sensor array detector system is a gas detector based on combination of a plurality of different micro gas sensors, and can be used for simultaneously distinguishing and identifying gas types and concentrations.
The data acquisition and analysis system is a software and hardware system for analyzing the acquired data.
The detector is divided into two working modes in the working process. The first is a sample pre-concentration mode, and the second is an analysis mode.
Each filtering, drying and purifying device is positioned in front of the quantitative ring and the chromatographic column and is used for filtering particles, moisture and other impurities in the sample gas, so that the stability and the dryness of the sample gas are ensured, and the main components of the sample gas are not damaged.
Each pressure stabilizing valve can be provided with an air pressure sensor for detecting the air pressure of the carrier gas so as to ensure that the carrier gas is stable and consistent.
The working principle is as follows: first, the sampling diaphragm pump 33 is turned on, and the sample pre-concentration mode is entered. At the moment, the sample gas sequentially enters a sample filter 1, a flow regulating valve 2, pressure stabilizing valves 4 and 5, and then enters a preconcentration system (a system consisting of components with the reference numbers of 12, 13, 14 and 32) through a six-way valve 6. All of the above regulating devices, pressure stabilizing devices and temperature control devices are equipped with associated sensors and are programmed via control module 29. In particular, the preconcentration heater 32 of the preconcentration column is required to have a fast heating rate, which is controlled to be between 10-50 ℃/s. After passing through the three-stage pre-concentration column 14, the sample gas is discharged out of the system through a sampling pump (i.e., a sampling diaphragm pump 33). The time of sampling can be set by a program. Generally, between 10s-5min is recommended.
When the sample pre-concentration mode is completed, the six-way valve 6 is automatically switched to the analysis mode. In the analysis mode, the sampling pump stops operating, and the pre-concentration heater 32 of the pre-concentration column rapidly rises to the prescribed desorption temperature of 300 ℃, during which the on-off valve 18 is closed. After reaching the specified temperature, N2The carrier gas passes through the flow regulating valve 7, the primary pressure stabilizing valve 9 and the secondary pressure stabilizing valve 10 in sequence, enters the three-stage pre-concentration column 14 at a fixed flow and pressure, the switch valve 18 is opened, and N is2And the purging carrier gas is used for purging and desorbing the VOCs component to be detected from the pre-concentration column, and the duration of the process can be adjusted by a program. The preconcentration column is filled with three materials, which are respectively as follows: the first-stage adsorbing material Carbopack B, the second-stage adsorbing material Carbopack X and the third-stage adsorbing material carbopen 1000. The pre-concentration tube is designed to have an inner diameter<5 mm; the length is 8-15 cm; the stainless steel shell ensures good temperature resistance and thermal conductivity.
N2The carrier gas carries the VOCs gas into the gas chromatography column 23 for separation of the components. The chromatographic column used in the method is a benzene series capillary chromatographic column, and the working temperature is between 50 and 180 ℃. The temperature for this example was 80 ℃. To better separate each peak, we designed a bypass N2The gas circuit can be mixed with a sample gas circuit to be analyzed and then enters the chromatographic column together, so that the separation degree is improved, and the flow and the pressure of the gas circuit can be adjusted. The flow rate is varied by adjusting the flow rate control valves 19 and 20, the flow rate in this embodiment being variedThe quantity ratio is 1: 1. The gas to be detected finally enters an array sensing detector, and the temperature of the detector is controlled at 40 ℃. The array sensing monitor consists of a photoion VOCs gas sensor, an EtOH chemical gas sensor, an ETO chemical gas sensor and 3 MOS gas sensors. The sensing acquisition frequency is acquired at least 10 times per second for a total of>60 times/s. And the sensed data enters an analysis system for analysis after being collected, a related atlas is drawn, and finally the identification of concentration and components is realized.
That is, in the sample pre-concentration mode, the gas to be measured (for example, the ambient air containing a small amount of VOCs) is pumped by the sampling diaphragm pump 33 to enter the gas sample filter 1 (for filtering a small amount of water vapor and fine particles), the first-stage pressure-stabilizing valve 4, and the second-stage pressure-stabilizing valve 5 in sequence, and then the components of the VOCs to be measured in the sample gas are concentrated in the third-stage pre-concentration column 14. The two-stage pressure stabilizing valve is mainly suitable for ensuring that gas enters the pre-concentration column to maintain certain pressure, and the flow regulating valve in the gas path is used for regulating, controlling and collecting the flow of the gas path for subsequent calculation and analysis. The pre-concentration column adopts three-stage pre-concentration, and filling and adsorbing materials of each stage have difference and are used for ensuring that all effective components to be detected can be enriched. The temperature of the inlet air during concentration can be adjusted and controlled, and enrichment is generally carried out under normal temperature adjustment.
The pre-concentration mode is switched into the analysis mode by switching of the six-way valve 6. In the analysis mode, the sampling pump stops sampling, and the temperature control system (pre-concentration heater 32) of the pre-concentration column is rapidly heated to a specified desorption temperature, wherein the temperature interval is 60-300 ℃, and the switch valve 18 is closed during the period. After reaching the specified temperature, N2And the purging carrier gas is used for purging and desorbing the VOCs component to be detected from the pre-concentration column, and the duration of the process can be adjusted by a program. N is a radical of2The carrier gas carries the VOCs gas into the chromatography column for separation of components. To better separate each peak, we designed a bypass N2The gas path (i.e. the path from the three-way valve 17 to the three-way valve 24 via the on-off valve 16, the flow regulating valve 20 and the flow meter 30) can be mixed with the sample gas path to be analyzed and then enter the gas chromatographic column 23, so that the separation degree is improved, and the flow rate and the pressure of the gas path can be adjusted.Accordingly, the gas chromatography column 23 is provided with a column heater 21 for adjusting the temperature and a column cooling tempering fan 22.
The gas to be detected finally enters an array sensing detector 26, the temperature of the detector can be controlled through a sensor temperature control device 25, 6 sensors are preliminarily designed, and the sensing acquisition frequency is acquired at least 10 times per second, and the total time is more than 60 times/s. The sensed data is collected by the sensing signal acquisition card 27 and then enters an analysis system for analysis, and a related spectrum is drawn, so that the identification of concentration and components is finally realized. In which an array sensing detector 26 is connected to a check valve 28.
Preferably, the array sensing detector 26 is an array sensing integration composed of several micro-VOCs gas sensors, including a semiconductor material VOCs gas sensor processed by MEMS, a chemical sensor, a micro-uv light ion VOCs gas sensor, a micro-infrared laser VOCs gas sensor, and the like, and particularly, the MEMS structure ensures a small volume of the array sensing detector.
An air filter membrane is arranged in the gas sampling filter 1 and used for filtering dust and water vapor in air and preventing pollution to a chromatographic column and a detector.
The flow regulating valve is used for controlling the subsequent airflow speed to be constant and consistent, and the stability and the test precision of the detector are improved.
The gas chromatography column 23 is preferably a micro-MEMS gas chromatography column or a capillary gas chromatography column.
The three-stage pre-concentration column 14 is a traditional concentrator or an MEMS micro concentrator, and the adsorbent material filled in the concentrator is a combination of a molecular sieve, Tenax-TA and activated carbon Carbopack, wherein the molecular sieve, the Tenax-TA and the activated carbon Carbopack are single or multiple.
Wherein the bypass N2The flow ratio of the gas path and the analysis sample gas path can be adjusted to optimize the chromatographic peak separation degree. The method of adjustment is specifically to effect a change in flow by adjusting the flow control valves 19 and 20. The optimal flow ratio is between 0:1 and 5: 1.
The detection method comprises the following steps:
1. gas to be detected (for example, ambient air containing a small amount of VOCs) sequentially enters the gas sampling filter 1 (for filtering a small amount of water vapor and fine particles), the flow regulating valve 2, the flow meter 3, the primary pressure stabilizing valve 4 and the secondary pressure stabilizing valve 5 through the suction force of the sampling diaphragm pump 33, and then enters the three-stage pre-concentration column 14 through the six-way valve 6 to concentrate the components of the VOCs to be detected in the sample gas. The timing of the sampling can be controlled by a pre-programmed program. The longer the time, the greater the corresponding subsequent concentration factor, which also means that the detection accuracy can be higher.
2. After the pre-concentration of the analysis sample gas is completed, the detector enters an analysis mode through the switching of the six-way valve 6. In the analysis mode, the sampling pump stops sampling, the temperature control system of the pre-concentration column is rapidly heated to the specified desorption temperature, the temperature interval is 60-300 ℃, and the switch valve 18 is closed during the period.
3. After reaching the specified temperature, N2The gas component to be detected is blown and desorbed from the pre-concentration column as a blowing carrier gas, and the duration of the process is adjustable. N is a radical of2The carrier gas carries the gas into the gas chromatography column 23 for separation of components. To better separate each peak, we designed a bypass N2And the gas circuit can be mixed with a sample gas circuit to be analyzed and then enters the chromatogram together, so that the separation degree is improved.
4. The gas to be detected finally enters the array sensing detector 26, the temperature of the detector can be controlled, 6 sensors are preliminarily designed, and the sensing acquisition frequency is acquired at least 10 times per second, and the total time is more than 60 times/s. And the sensed data enters an analysis workstation for analysis after being collected. Six chromatograms will appear in the analysis results. Because the sensors of each VOCs have certain differences, response spectrums measured by different sensors in the same time period can be learned by a machine to form a set of spectrum library. Through the difference of six chromatograms, the concentration and the component of VOCs substances can be finally judged.
The array sensing chromatographic detector capable of realizing the detection of various VOCs gases and the detection method thereof greatly reduce the number of chromatographic columns when various qualitative and quantitative gases need to be measured. The concentration of various gases is detected, and the separated VOCs gases can be qualitatively and quantitatively measured by adopting the array type sensor unit without independently separating each gas. The quantity of chromatographic columns is reduced, and qualitative and quantitative measurement of various VOCs gases can be realized.
The above-mentioned embodiments, objects, technical solutions and advantages of the present invention are further described in detail, it should be understood that the above-mentioned embodiments are only specific embodiments of the present invention, and are not intended to limit the present invention, and any modifications, equivalent substitutions, improvements and the like made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (14)
1. The utility model provides a can realize gaseous array sensing gas chromatography detector that detects of multiple VOCs which characterized in that includes:
the gas inlet pipeline is connected with a first port of the six-way valve, and a gas sampling filter is arranged on the first gas inlet pipeline; the second port of the six-way valve is connected with the gas inlet of a gas preconcentration device, and the gas outlet of the gas preconcentration device is connected with the fifth port of the six-way valve; and
a will purge N2A second air inlet pipeline of the detector is introduced, the second air inlet pipeline is connected with a first port of a first three-way valve, and a third port of the first three-way valve is connected with a third port of the six-way valve; the second port of the first three-way valve is connected with the second port of a second three-way valve through a first switch valve; a third port of the second three-way valve is connected with a fourth port of the six-way valve through a second switch valve; the first port of the second three-way valve is connected with a gas chromatographic column, and the gas chromatographic column is connected with an array sensing detector; and
the negative pressure pump is connected with the sixth port of the six-way valve;
wherein,
the detector is in a sample pre-concentration mode, a first port of the six-way valve is communicated with a second port, a third port of the six-way valve is communicated with a fourth port of the six-way valve, and a fifth port of the six-way valve is communicated with a sixth port of the six-way valve;
when the detector is in an analysis mode, a first port of the six-way valve is communicated with a sixth port, a second port of the six-way valve is communicated with a third port, and a fourth port of the six-way valve is communicated with a fifth port of the six-way valve; the first switch valve is opened, the second switch valve is closed, and the negative pressure pump is closed.
2. The array sensing gas chromatography detector according to claim 1, wherein the gas preconcentration device is a three-stage preconcentration column having a cooling system and a heating system, and the packed adsorbents in each stage of the three-stage preconcentration column are different.
3. The array sensing gas chromatography detector capable of detecting multiple kinds of VOCs according to claim 1, wherein a first flow regulating valve is arranged between the second port of the first three-way valve and the second port of the second three-way valve; a second flow regulating valve is arranged between a third port of the first three-way valve and a third port of the second three-way valve; n flowing from the first three-way valve to the second three-way valve to the gas chromatography column through the first flow regulating valve2Relative to N flowing to the gas chromatography column through the second flow regulating valve2The flow ratio is 0:1 to 5: 1.
4. The array sensing gas chromatography detector capable of detecting multiple VOCs according to claim 2, wherein the adsorbing material filled in the three-stage pre-concentration column concentrator is one or a combination of multiple of molecular sieve, Tenax-TA and activated carbon Carbopack.
5. The array sensing gas chromatography detector capable of detecting multiple VOCs according to claim 2, wherein the desorption temperature of the three-stage preconcentration column is 60-300 ℃.
6. The array-sensing gas chromatography detector capable of detecting multiple VOCs gases according to claim 1, wherein the array-sensing detector is an array-sensing detector consisting of a semiconductor material VOCs gas sensor processed by MEMS, a chemical sensor, a micro ultraviolet light ion VOCs gas sensor and a micro infrared laser VOCs gas sensor; the array sensor is connected with a sensing signal acquisition card which can convert physical signals into electric signals.
7. The array sensing gas chromatography detector capable of detecting multiple VOCs according to claim 6, wherein a single group of the array sensing detector consists of six sensors, and the sensing acquisition frequency of the single sensor is more than or equal to 10 times/second.
8. The array sensing gas chromatography detector capable of realizing gas detection of multiple VOCs according to claim 1, wherein a primary pressure stabilizing valve and a secondary pressure stabilizing valve are arranged on the first air inlet pipeline; and a primary pressure stabilizing valve and a secondary pressure stabilizing valve are arranged on the second air inlet pipeline.
9. The array sensing gas chromatography detector according to claim 1, wherein the gas chromatography column is a micro-MEMS gas chromatography column or a capillary gas chromatography column.
10. The array sensing gas chromatography detector capable of detecting multiple VOCs according to claim 1, wherein an air filter membrane for filtering out dust and water vapor in air is arranged in the gas sampling filter.
11. The array sensing gas chromatography detector according to claim 1, wherein the negative pressure pump is a sampling diaphragm pump.
12. A method for detecting gases containing multiple VOCs, comprising the steps of:
(1) pumping the gas to be detected through a negative pressure pump, sequentially entering a gas sample injection filter, a primary pressure stabilizing device and a secondary pressure stabilizing device, and then entering a pre-concentration device to concentrate the VOCs components to be detected in the sample gas; controlling sampling time through a prefabricated program, wherein the sampling time is in direct proportion to the concentration multiple and the detection precision;
(2) after the pre-concentration of the analysis sample gas is finished, entering an analysis mode through the switching of a six-way valve; in an analysis mode, a negative pressure pump serving as a sampling pump stops sampling, a temperature control system of the pre-concentration device is rapidly heated to a specified desorption temperature, the temperature interval is 60-300 ℃, and the second switch valve is in a closed state during the period;
(3) after reaching the specified temperature, N2The gas component to be detected is blown and desorbed from the pre-concentration device as blowing carrier gas, and the duration of the process can be adjusted; n is a radical of2The carrier gas carries gas to enter the gas chromatographic column for component separation; the working temperature of the gas chromatographic column is 50-180 ℃;
(4) and finally, the gas to be detected enters the array sensing detector with controllable temperature, and is analyzed in a form of a chromatographic chart after being collected according to the set collection frequency.
13. The detection method according to claim 12, wherein step (4) further comprises the step of determining the concentration and composition of the gaseous VOCs species by comparison to a library of spectra.
14. The method of claim 12, further comprising setting and adjusting bypass N2And a gas path, and mixing the gas path with a sample gas path to be analyzed and then feeding the mixture into the gas chromatographic column.
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Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1701233A (en) * | 2002-09-27 | 2005-11-23 | 霍尼韦尔国际公司 | Phased micro analyzer V, VI |
| CN101713770A (en) * | 2008-10-06 | 2010-05-26 | 索尼株式会社 | a sensor for thiol analytes |
| WO2013119719A1 (en) * | 2012-02-06 | 2013-08-15 | Ludwig, Lester, F. | Microprocessor-controlled microfluidic platform for pathogen, toxin, biomarker, and chemical detection with removable updatable sensor array for food and water safety, medical, and laboratory apllications |
| CN104297389A (en) * | 2014-10-23 | 2015-01-21 | 佛山市南海区环境保护监测站 | Chromatographic analysis system |
| CN106596782A (en) * | 2016-12-22 | 2017-04-26 | 汇众翔环保科技河北有限公司 | On-line monitoring system and analysis method for volatile organic compounds |
| CN107727774A (en) * | 2017-11-28 | 2018-02-23 | 中国科学院电子学研究所 | More sensing chromatogram detectors and detection method |
| WO2018183929A1 (en) * | 2017-03-30 | 2018-10-04 | Progenity Inc. | Treatment of a disease of the gastrointestinal tract with an immune modulatory agent released using an ingestible device |
| CN109891233A (en) * | 2016-04-27 | 2019-06-14 | 量子生物有限公司 | The system and method for measurement and sequencing for biomolecule |
-
2019
- 2019-08-08 CN CN201910729991.XA patent/CN112345657B/en active Active
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1701233A (en) * | 2002-09-27 | 2005-11-23 | 霍尼韦尔国际公司 | Phased micro analyzer V, VI |
| CN101713770A (en) * | 2008-10-06 | 2010-05-26 | 索尼株式会社 | a sensor for thiol analytes |
| WO2013119719A1 (en) * | 2012-02-06 | 2013-08-15 | Ludwig, Lester, F. | Microprocessor-controlled microfluidic platform for pathogen, toxin, biomarker, and chemical detection with removable updatable sensor array for food and water safety, medical, and laboratory apllications |
| CN104297389A (en) * | 2014-10-23 | 2015-01-21 | 佛山市南海区环境保护监测站 | Chromatographic analysis system |
| CN109891233A (en) * | 2016-04-27 | 2019-06-14 | 量子生物有限公司 | The system and method for measurement and sequencing for biomolecule |
| CN106596782A (en) * | 2016-12-22 | 2017-04-26 | 汇众翔环保科技河北有限公司 | On-line monitoring system and analysis method for volatile organic compounds |
| WO2018183929A1 (en) * | 2017-03-30 | 2018-10-04 | Progenity Inc. | Treatment of a disease of the gastrointestinal tract with an immune modulatory agent released using an ingestible device |
| CN107727774A (en) * | 2017-11-28 | 2018-02-23 | 中国科学院电子学研究所 | More sensing chromatogram detectors and detection method |
Non-Patent Citations (2)
| Title |
|---|
| 徐永红等: "纳米金-卟啉复合传感阵列快速识别肺癌患者呼气中的有机小分子", 《高等学校化学学报》 * |
| 郭伟清等: "传感器阵列结合化学计量学方法快速评估烟用包装材料中挥发性有机物", 《分析化学》 * |
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