CN217846208U - Volatile organic compound analysis system - Google Patents

Abstract

The application provides a volatile organic compound analysis system. The volatile organic compound analysis system includes: the sampling module (1) is used for providing a gas phase sample of the volatile organic compounds to be detected for the volatile organic compound analysis system; a chromatography column (2) for separating components in the gas phase sample; and the shunt pipeline (3) is communicated with a pipeline between the sample feeding module (1) and the chromatographic column (2) and is used for adjusting the amount of the gas phase sample entering the chromatographic column (2). This application is through setting up the reposition of redundant personnel pipeline, has controlled the flow of the sample that lets in the chromatographic column effectively, does benefit to the chromatographic peak of volatile organic compounds and parts for the chromatographic column can realize the detection analysis to multiple component in the sample.

Description

Volatile organic compound analysis system

Technical Field

The application belongs to the technical field of chromatographic separation and analysis of volatile organic compounds, and particularly relates to a volatile organic compound analysis system.

Background

The detection and analysis method of Volatile Organic Compounds (VOCs) includes gas chromatography, which utilizes carrier gas (such as argon or other inert gas) to drive the VOCs to enter a detector after separation by a chromatographic column, so as to measure the content and other information of the VOCs.

The existing detection and analysis capability of volatile organic compounds is limited. For example, in the chemical industry, printing industry, coating industry, etc., only styrene, ethylbenzene, and cyclohexanone are generally analyzed from the discharged volatile organic compounds. In addition, indexes such as response repeatability, linearity and the like of styrene and cyclohexanone are poor, and the analysis accuracy is not high. In addition, the peak patterns of the chloroethylene and the methanol discharged in the chemical industry coincide, and the analysis and the measurement are difficult.

When volatile organic compounds are analyzed through gas chromatography, a chromatographic column and a column incubator for providing proper temperature for the chromatographic column are selected according to the components and the quantity of the volatile organic compounds and the industry type of the volatile organic compounds to be measured.

Many times, simultaneous measurement of a plurality of components in a volatile organic compound is required, and thus, it is necessary to use a plurality of chromatography columns depending on the combination of components. The increase of the number of chromatographic columns causes the problems of complex system, inconvenient maintenance, increased cost and the like.

SUMMERY OF THE UTILITY MODEL

To improve or solve the problems of the background art, the present application provides a volatile organic compound analysis system.

The volatile organic compound analysis system includes:

the sample injection module is used for providing a gas phase sample of the volatile organic compounds to be detected for the volatile organic compound analysis system;

a chromatographic column for separating components of the gas phase sample; and

and the shunt pipeline is communicated with a pipeline between the sample injection module and the chromatographic column and is used for adjusting the amount of the gas phase sample entering the chromatographic column.

In at least one embodiment, the voc analysis system further includes a column oven in which the chromatographic column is disposed, the temperature of the column oven being controllable.

In at least one embodiment, the sample introduction module comprises a sample pipeline for introducing a sample and a carrier gas pipeline for introducing a carrier gas, and a carrier gas control valve is arranged in the carrier gas pipeline and used for controlling the flow rate of the carrier gas in the carrier gas pipeline.

In at least one embodiment, a control valve is disposed in the diversion conduit for controlling the flow of gas in the diversion conduit.

In at least one embodiment, the control valve is a shunt regulator valve.

In at least one embodiment, the voc analysis system further includes a three-way adapter, and the diversion conduit is connected to the conduit between the sample introduction module and the chromatographic column through the three-way adapter.

In at least one embodiment, the volatile organic analysis system includes a detector for detecting the sample separated by the chromatography column, the detector being a flame ionization detector or a thermal conductivity detector.

In at least one embodiment, the detector is a flame ionization detector, and the volatile organic analysis system further comprises:

an air supply duct connected to the detector;

a hydrogen supply pipe and a tail purge gas supply pipe, the hydrogen supply pipe being connected to the tail purge gas supply pipe, and the hydrogen supply pipe and the tail purge gas supply pipe being connected together to the detector.

In at least one embodiment, the voc analysis system includes a conduit and a fitting, and an interior wall of the conduit and an interior wall of the fitting are inerted.

In at least one embodiment, the number of chromatography columns is one.

This application is through setting up the reposition of redundant personnel pipeline, has controlled the flow of the sample that lets in the chromatographic column effectively, does benefit to the chromatographic peak of volatile organic compounds and parts for the chromatographic column can realize the detection analysis to multiple component in the sample.

Drawings

Fig. 1 shows a schematic structural diagram of a volatile organic compound analysis system according to an embodiment of the present application.

Fig. 2 shows a chromatogram of a set of volatile organics measured by the volatile organic analysis system according to an embodiment of the present application.

Description of the reference numerals

1, a sample introduction module; 11 a sample conduit; 12 a carrier gas conduit; a 121-carrier gas control valve;

2, a chromatographic column;

3 a shunt pipeline; 31 a shunt regulating valve; a 32-way crossover sub;

4 column oven;

5, a detector; 51 an air supply duct; 52 a hydrogen supply line; 53 tail blow supply lines.

Detailed Description

Exemplary embodiments of the present application are described below with reference to the accompanying drawings. It should be understood that the detailed description is only intended to teach one skilled in the art how to practice the present application, and is not intended to be exhaustive or to limit the scope of the application.

Referring to fig. 1, embodiments of the present application provide a volatile organic compound analysis system, which may include a sample introduction module 1, a chromatography column 2, a flow distribution conduit 3, a column oven 4, and a detector 5.

The sample introduction module 1 is used for providing a gas phase sample to be detected for the volatile organic compound analysis system. In one embodiment of the present application, the sample introduction module 1 may include a sample pipe 11 for introducing a sample and a carrier gas pipe 12 for introducing a carrier gas. The carrier gas pipe 12 may be provided with a carrier gas control valve 121, and the carrier gas control valve 121 may be a flow rate adjusting valve, which can adjust the concentration of the sample introduced into the chromatographic column 2 by adjusting the flow rate of the carrier gas.

Can set up reposition of redundant personnel pipeline 3 between advancing kind module 1 and chromatographic column 2, can set up the control valve in the reposition of redundant personnel pipeline 3, for example reposition of redundant personnel governing valve 31, the control is to the flow of reposition of redundant personnel pipeline 3 reposition of redundant personnel, and then the flow of the sample that the control got into in chromatographic column 2. For example, the more split the flow splitting conduit 3, the less sample enters the chromatography column 2. Accordingly, in the chromatogram, the chromatographic peaks of the components of the sample become small, but the chromatographic peaks close to each other are easily separated, and the separation effect is better. That is, the flow dividing pipe 3 provided in the present application can control the flow rate of the sample introduced into the column 2, and in cooperation with the carrier gas control valve 121, can control the entry of the sample into the column 2, and can improve the separation effect of each component in the sample.

In one embodiment of the present application, the voc analysis system may include a three-way adapter 32, and the diversion conduit 3 may be connected to the conduit between the sample injection module 1 and the chromatographic column 2 through the three-way adapter 32. As an example, a three-way valve (not shown in the figure) may be further provided, and the diversion pipeline 3 is connected to the pipeline between the sample injection module 1 and the chromatographic column 2 through the three-way valve, and the flow rate of the diversion pipeline 3 is directly controlled through the three-way valve. In embodiments using a three-way valve, the split regulating valve 31 may not be used.

Furthermore, flow monitoring devices (not shown in the figure) can be arranged in the shunt pipeline 3 and the pipeline between the sample injection module 1 and the chromatographic column 2, so that the flow conditions in each pipeline can be obtained more accurately, and reference basis is provided for flow adjustment and valve control.

Further, the chromatographic column 2 may be disposed in a column oven 4. Unlike the constant temperature column oven common in the prior art, the column oven 4 proposed in the present application can be set such that the temperature can vary with the program setting, for example, the temperature can be set to gradually increase.

Overall, the peak velocity of the sample is positively correlated to the temperature in the column 2. The volatile organic compounds are various in types, cover different boiling point temperatures of high, medium and low, the activity of the volatile organic compounds with low boiling points is high, if the column temperature is too high, the peak of a sample is fast, and the components of the sample with low boiling points cannot be effectively separated in a chromatogram, so that the column temperature required by the organic compounds with low boiling points is also low. Organic matters with high boiling points need higher column temperature, otherwise, the activity is insufficient, so that the peak-producing time is too long and even the organic matters are retained in a chromatographic column, and the analysis result is influenced. This application is through the temperature that progressively improves column incubator 4 for the different volatile organic compounds of boiling point can effectively be separated to single chromatographic column, and the reposition of redundant personnel effect of reposition of redundant personnel pipeline is deuterogamied, can realize the effective separation of multiple component in the sample.

The detector 5 is used to detect the sample separated by the chromatographic column 2. The application does not limit the specific type of detector 5, which may be, for example, a Flame Ionization Detector (FID) or a Thermal Conductivity Detector (TCD).

Taking a flame ionization detector as an example, the detector 5 of one embodiment of the present application may include an air supply pipe 51, a hydrogen supply pipe 52, and a tail-blown gas (makeup gas) supply pipe 53. Wherein the air supply pipe 51 is directly connected to the detector 5, and the tail blow supply pipe 53 may be connected to the hydrogen supply pipe 52 and then connected to the detector 5. The organic matter produces ionization reaction in hydrogen-air flame to produce many ion pairs, and ion flow is formed between two poles with certain voltage, and the component of organic matter can be detected by measuring the intensity of ion flow.

For example, the material of the pipe in the present application may be stainless steel. Furthermore, the inner wall of each pipeline and the inner wall of each joint are subjected to inerting treatment, for example, silanization treatment, vulcanization treatment and the like can be carried out on the inner wall, so that the adsorption effect of the inner wall on a gas sample is reduced, the concentration change of the sample is reduced, and the repeatability performance and the analysis accuracy of an analysis system are improved.

It will be understood that the direction of the arrows in the duct in fig. 1 indicates the direction of flow of the gas.

For example, the working principle of the volatile organic compound analysis system provided by the present application may be: the flow rate and the concentration of the sample introduced into the chromatographic column 2 are controlled by adjusting the shunt adjusting valve 31 and the carrier gas control valve 121; gradually increasing the set temperature of the column oven 4 (for example, keeping the time period of T1 under the state of T1, rapidly increasing the temperature, then keeping the time period of T2 under the state of T2 \8230;, when the chromatogram map detects the volatile organic compound with the lowest set temperature, continuing the above-mentioned temperature increasing step, and separating and detecting other volatile organic compounds with higher boiling points. The split flow control and temperature control can be combined to play a role, and a plurality of components in a sample can be effectively separated through a single chromatographic column.

Illustratively, referring to FIG. 2, the present application provides a chromatogram of 10 volatile organic compounds detected by an analytical system. The peak patterns of vinyl chloride and methanol are effectively separated, and the peak patterns of styrene and cyclohexanone are effectively separated, so that the good separation effect of the method is reflected. In addition, the single chromatographic column can also effectively separate and analyze ethanol, acetone, tertiary butanol, acrylonitrile, normal hexane and ethyl acetate, and the wide applicability of the application is embodied. The application utilizes a single chromatographic column to complete the separation of various volatile organic compounds, and the analysis system with the single chromatographic column has the advantages of simple structure, convenient maintenance and lower cost.

While the foregoing is directed to the preferred embodiment of the present application, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention.

Claims (9)

1. A volatile organic analysis system, comprising:

the sample injection module is used for providing a gas phase sample of the volatile organic compounds to be detected for the volatile organic compound analysis system;

a chromatographic column for separating components in the gas phase sample; and

a shunt pipeline communicated with the pipeline between the sample feeding module and the chromatographic column and used for adjusting the amount of the gas phase sample entering the chromatographic column,

the volatile organic compound analysis system further comprises a column incubator, the chromatographic column is arranged in the column incubator, and the temperature of the column incubator can be controlled.

2. The volatile organic compound analysis system according to claim 1, wherein the sample injection module comprises a sample pipeline for introducing a sample and a carrier gas pipeline for introducing a carrier gas, and a carrier gas control valve is disposed in the carrier gas pipeline for controlling a flow rate of the carrier gas in the carrier gas pipeline.

3. The voc analysis system of claim 1 wherein a control valve is disposed in the diversion conduit for controlling the flow of gas in the diversion conduit.

4. The voc analysis system of claim 3, wherein the control valve is a shunt regulator valve.

5. The voc analysis system of claim 3, further comprising a three-way adapter, wherein the flow diversion conduit communicates with a conduit between the sample injection module and the chromatographic column via the three-way adapter.

6. The voc analysis system of claim 1, wherein the voc analysis system includes a detector for detecting the sample separated by the chromatographic column, the detector being a flame ionization detector or a thermal conductivity detector.

7. The voc analysis system of claim 6, wherein the detector is a flame ionization detector, the voc analysis system further comprising:

an air supply duct connected to the detector;

a hydrogen supply pipe and a tail purge gas supply pipe, the hydrogen supply pipe being connected to the tail purge gas supply pipe, and the hydrogen supply pipe and the tail purge gas supply pipe being connected together to the detector.

8. The voc analysis system according to claim 1, wherein the voc analysis system comprises a pipe and a fitting, and an inner wall of the pipe and an inner wall of the fitting are inerted.

9. The voc analysis system of claim 1, wherein the number of chromatographic columns is one.

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