Gas chromatography analysis method and gas chromatography analysis system

Abstract

To efficiently utilize hydrogen gas and oxygen gas generated by electrolysis of water in gas chromatography analysis.SOLUTION: A gas chromatography analysis method includes the steps of: introducing sample gas to a separation column (4) using carrier gas to separate components in the sample gas; and introducing the sample gas having passed through the separation column (4) to a detector (6) to detect the components in the sample gas. The detection step includes: individually taking out hydrogen gas and oxygen gas generated by electrolysis of water; and controlling flow rates of the taken out hydrogen gas and oxygen gas respectively and supplying the gases respectively to the detector as detector gas.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a gas chromatography analysis method and a gas chromatography analysis system. [Background technology]

[0002] In gas chromatography analysis, FID (flame ionization detector), FPD (flame photometric detector), FTD (thermal ionization detector), TCD (thermal conductivity detector), etc. can be used as detectors.

[0003] Incidentally, in detectors such as FIDs, it is necessary to supply hydrogen gas to the detector. Although hydrogen gas cylinders are generally used as a hydrogen gas supply source, in order to avoid the dangers of hydrogen gas cylinders, it has been proposed to generate hydrogen gas by a water electrolysis device and use the generated hydrogen gas as the working gas for the FID (see Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] US2002 / 054832A1 Summary of the Invention [Problem to be solved by the invention]

[0005] The system described in Patent Document 1 does not fully utilize the hydrogen gas and oxygen gas generated by the water electrolysis device.

[0006] An object of the present invention is to efficiently utilize hydrogen gas and oxygen gas produced by electrolysis of water in gas chromatography analysis. [Means for solving the problem]

[0007] The gas chromatography analysis method of the present invention includes the steps of introducing a sample gas into a separation column using a carrier gas to separate components in the sample gas, and introducing the sample gas that has passed through the separation column into a detector to detect the components in the sample gas, and the step of detecting includes separately extracting hydrogen gas and oxygen gas produced by electrolysis of water, and controlling the flow rates of the extracted hydrogen gas and oxygen gas to supply them to the detector as detector gases.

[0008] The gas chromatography analysis system of the present invention comprises a separation column for separating components in a sample gas, a detector fluidly connected downstream of the separation column for detecting the components separated in the separation column, a gas generator configured to generate hydrogen gas and oxygen gas by electrolysis of water and to individually extract the generated hydrogen gas and oxygen gas, a first flow path for guiding the hydrogen gas generated in the gas generator to the detector as a detector gas, a second flow path for guiding the oxygen gas generated in the gas generator to the detector as a detector gas, and a detector gas flow rate adjustment unit that adjusts the flow rate of hydrogen gas introduced to the detector via the first flow path and the flow rate of oxygen gas introduced to the detector via the second flow path.

[0009] That is, in the gas chromatography analysis method and system according to the present invention, hydrogen gas and oxygen gas generated by electrolysis of water are taken out separately, and are introduced into the detector as detector gas while controlling the flow rates of the hydrogen gas and oxygen gas. This makes it possible to control the ratio of hydrogen gas and oxygen gas introduced into the detector to a desired value. The ideal ratio of hydrogen gas and oxygen gas introduced into the detector varies depending on the type of detector, but in the present invention, the ratio of hydrogen gas and oxygen gas introduced into the detector can be controlled to a desired value, so that it can be used with a variety of detectors. On the other hand, in the method of introducing a mixed gas of hydrogen gas and oxygen gas generated by electrolysis of water into the detector as in Patent Document 1, the ratio of hydrogen gas and oxygen gas introduced into the detector is constant, and it cannot be used with a variety of detectors. Effect of the Invention

[0010] In the gas chromatography analysis method according to the present invention, the hydrogen gas and oxygen gas produced by the electrolysis of water are extracted separately, the flow rates of the extracted hydrogen gas and oxygen gas are controlled, and the hydrogen gas and oxygen gas are supplied to a detector as detector gases, respectively. Therefore, the hydrogen gas and oxygen gas produced by the electrolysis of water can be efficiently utilized in gas chromatography analysis.

[0011] In the gas chromatography analysis system according to the present invention, hydrogen gas and oxygen gas are generated by electrolysis of water and extracted separately, and the extracted hydrogen gas and oxygen gas are each configured to be introduced into a detector as detector gas while adjusting the flow rate of each of them, so that the hydrogen gas and oxygen gas generated by electrolysis of water can be efficiently utilized in gas chromatography analysis. [Brief description of the drawings]

[0012] [Figure 1] FIG. 1 is a schematic diagram showing an embodiment of a gas chromatography analysis system. [Diagram 2] FIG. 2 is a cross-sectional view showing an example of the structure of a detector according to the embodiment. [Diagram 3] 4 is a flowchart showing an example of the operation of the embodiment. [Figure 4] FIG. 2 is a principle diagram illustrating the gas generation principle in the gas generator of the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Hereinafter, an embodiment of a gas chromatography analysis method and system according to the present invention will be described with reference to the drawings.

[0014] As shown in FIG. 1, the gas chromatography analysis system of this embodiment includes an injector 2, a separation column 4, a detector 6, a column oven 8, a gas generator 10, a control device 12, an AFC (advanced flow controller) 20, and an APC (advanced pressure controller).

[0015] The separation column 4 is, for example, a capillary coated or packed with a separation medium for separating components in the sample gas. The separation column 4 is fluidly connected at its inlet end to the injector 2 and at its outlet end to the detector 6. The separation column 4 is housed within a column oven 8 in which the temperature of the internal space is adjusted to a set temperature.

[0016] The injector 2 is for generating a sample gas and introducing the generated sample gas into the separation column 4 by means of a carrier gas. In this embodiment, hydrogen gas generated by a gas generator 10 is used as the carrier gas.

[0017] The detector 6 is for detecting components in the sample gas that has passed through the separation column 4. Any of an FID, FPD, FTD, and TCD can be used as the detector 6. When the detector 6 is an FID, FPD, or FTD, hydrogen gas and oxygen gas generated in the gas generator 10 are supplied to the detector 6 as detector gas. When the detector 6 is a TCD, only hydrogen gas generated in the gas generator 10 is supplied to the detector 6 as detector gas (i.e., the flow rate of oxygen gas introduced into the detector 6 is adjusted to zero).

[0018] Here, in addition to a capillary column, a packed column can also be used as the separation column 4. In particular, when the detector 6 is a TCD, it is preferable to use a packed column as the separation column 4.

[0019] The gas generator 10 is configured to generate hydrogen gas and oxygen gas by electrolysis of water, and to be able to extract the generated hydrogen gas and oxygen gas separately. FIG. 4 shows a schematic diagram of the gas generation principle in the gas generator 10. An anode electrode and a cathode electrode are provided in the gas generator 10 with an ion exchange membrane sandwiched therebetween, and by applying a DC voltage between the anode electrode and the cathode electrode, a current is generated on the anode electrode side according to the following formula: 2H2O-4e=O2+4H + Oxygen is generated by the electrolysis reaction of the following formula on the cathode side: 4H + +4e=2H2 Oxygen is generated by the electrolysis reaction of the above. The gas generator 10 is configured to be able to individually extract the oxygen gas generated at the anode electrode and the hydrogen gas generated at the cathode electrode. Note that electrolysis devices configured to be able to individually extract the hydrogen gas and oxygen gas generated by the electrolysis of water are known (see, for example, JP 2020-066796 A and JP 2018-178231 A).

[0020] The gas generator 10 has an outlet for hydrogen gas and an outlet for oxygen gas, with a flow path 13 connected to the hydrogen gas outlet and a flow path 18 connected to the oxygen gas outlet. The flow path 13 branches into a flow path 14 leading to the injector 2 and a flow path 16 leading to the detector 6. The flow path 18 leads to the detector 6. The flow path 16 constitutes a first flow path for guiding the hydrogen gas generated in the gas generator 10 to the detector 6 as a detector gas. The flow path 18 constitutes a second flow path for guiding the oxygen gas generated in the gas generator 10 to the detector 6 as a detector gas. The flow path 14 constitutes a third flow path for guiding the hydrogen gas generated in the gas generator 10 to the upstream of the separation column 4 as a carrier gas.

[0021] The AFC 20 is used to control the total flow rate of hydrogen gas introduced into the injector 2, the inlet pressure of the separation column 4, the split vent flow rate, and the purge vent flow rate during analysis. The flow rate obtained by subtracting the split vent flow rate and the purge vent flow rate from the total flow rate of hydrogen gas introduced into the injector 2 is the flow rate of hydrogen gas introduced as a carrier gas into the detector 6 via the separation column 4. In other words, the AFC 20 realizes a carrier gas flow rate adjustment unit for adjusting the flow rate of hydrogen gas introduced into the detector 6 as a carrier gas.

[0022] The APC 22 is for adjusting the flow rate of hydrogen gas flowing through the flow path 16 and the flow rate of oxygen gas flowing through the flow path 18. In other words, the APC 22 realizes a detector gas flow rate adjuster for adjusting the flow rates of hydrogen gas and oxygen gas introduced as detector gases to the detector 6. Note that the detector gas flow rate adjuster does not need to be realized by a single flow rate adjuster such as the APC 22, and the flow rate of hydrogen gas flowing through the flow path 16 and the flow rate of oxygen gas flowing through the flow path 18 may be adjusted by different flow rate adjusters.

[0023] Here, the structure of the detector 6 will be described using an FID as an example.

[0024] When the detector 6 is an FID, as shown in Fig. 2, a nozzle 102 for generating a hydrogen flame is provided in the internal space of a cell 100 of the detector 6. A pipe 104 forming an outlet of the separation column 4 passes through the inside of the nozzle 102. A pipe 108 forming a part of the flow path 16 is fluidly connected to the nozzle 102, and hydrogen gas generated in the gas generator 10 is introduced as a detector gas into a gap between the outer circumferential surface of the pipe 104 and the inner surface of the nozzle 102. The hydrogen gas introduced into the nozzle 102 as the detector gas merges with the carrier gas from the separation column 4 at the tip of the nozzle 102 and is ejected from the tip of the nozzle 102.

[0025] A pipe 110 forming a part of the flow path 18 communicates with the internal space of the cell 100, and oxygen gas generated in the gas generator 10 is introduced into the internal space of the cell 100 as a detector gas. The oxygen gas introduced into the internal space of the cell 100 is used as a supporting gas for burning the hydrogen gas ejected from the tip of the nozzle 102, thereby forming a hydrogen flame at the tip of the nozzle 102. The pipe 110 may also communicate with the inside of the nozzle 2, so that the hydrogen gas and the oxygen gas are mixed inside the nozzle 2.

[0026] Returning to FIG. 1, the description of the analysis system will continue. The control device 12 has a function of controlling the operation of the gas generator 10, the AFC 20, and the APC 22, and is realized by an electronic circuit having at least a CPU (Central Processing Unit) and a data storage device. The control device 12 includes a control unit 24 and an information storage unit 26. The control unit 24 is a function realized by the CPU executing a program, and the information storage unit 26 is a function realized by a partial storage area of ​​the data storage device.

[0027] The control unit 24 is configured not only to operate the gas generator 10 so as to obtain the amounts of hydrogen gas and oxygen gas required for analysis, but also to control the operation of the AFC 20 and APC 22 to adapt the ratio of the flow rates of hydrogen gas and oxygen gas introduced to the detector 6 to the detector 6.

[0028] The flow rate ratio of hydrogen gas to oxygen gas required for the detector 6 to operate normally varies depending on the type of detector 6 (FID, FPD, etc.). Information storage unit 26 stores information on the flow rate ratio of hydrogen gas to oxygen gas that is suitable for various detectors. As another embodiment, detector 6 itself may hold information on the flow rate ratio of hydrogen gas to oxygen gas that is suitable for detector 6.

[0029] An example of the operation of the gas chromatography analysis system realized by the control unit 24 will be described with reference to the flowchart of FIG. 3 together with FIG.

[0030] First, the control unit 24 recognizes the type of the detector 6 based on information input by the user or based on information read from the detector 6, and calculates the flow rate ratio of hydrogen gas and oxygen gas that is suitable for the type of the detector 6 from the information stored in the information storage unit 26 (step 101). Then, the control unit 24 calculates the flow rates of hydrogen gas and oxygen gas required to make the ratio of the total flow rate of hydrogen gas introduced into the detector 6 as a carrier gas through the separation column 4 and the hydrogen gas introduced into the detector 6 as a detector gas through the flow path 16, to the flow rate of oxygen gas introduced into the detector 6 through the flow path 18, the ratio calculated from the information in the information storage unit 26 (step 102). Based on the calculation result, the control unit 24 operates the gas generation unit 10 so that the required amount of hydrogen gas and oxygen gas are generated (step 103), and controls the operation of the AFC 20 and the APC 22 so that the ratio of the flow rates of hydrogen gas and oxygen gas introduced into the detector 6 is suitable for the detector 6 (step 104).

[0031] With the flow rates of hydrogen gas and oxygen gas introduced into detector 6 controlled by the above operations, a sample is injected into injector 2 and gas chromatography analysis is started. The sample injected into injector 2 becomes sample gas, which is introduced into separation column 4 by carrier gas and the components in the sample are separated (step 105). The components in the sample separated in separation column 4 are introduced into detector 6 together with carrier gas and detected (step 106).

[0032] In the above embodiment, the hydrogen gas generated by the gas generator 10 is used as the carrier gas, but a carrier gas supply source may be provided separately from the gas generator 10. In that case, a gas other than hydrogen gas, such as helium gas or nitrogen gas, may be used as the carrier gas. When a gas other than hydrogen gas is used as the carrier gas, the control unit 24 controls the operation of the APC 22 so that the ratio of the flow rate of hydrogen gas and the flow rate of oxygen gas introduced as detector gases to the detector 6 is adapted to the detector 6.

[0033] The above-described examples are merely illustrative of the embodiments of the gas chromatography analysis method and system according to the present invention. The embodiments of the gas chromatography analysis method and system according to the present invention are as follows.

[0034] One embodiment of the gas chromatography analysis method according to the present invention includes the steps of introducing a sample gas into a separation column using a carrier gas to separate components in the sample gas, and introducing the sample gas that has passed through the separation column into a detector to detect the components in the sample gas, and the detection step includes separately extracting hydrogen gas and oxygen gas produced by electrolysis of water, and controlling the flow rates of the extracted hydrogen gas and oxygen gas, respectively, and supplying them to the detector as detector gases.

[0035] In a specific aspect of the analytical method according to the above embodiment, the detecting step includes adjusting the ratio of hydrogen gas and oxygen gas introduced into the detector to a ratio suitable for the detector. This aspect allows various types of detectors to be used in gas chromatography analysis using hydrogen gas generated by electrolysis of water.

[0036] In the above specific embodiment, the separating step includes supplying hydrogen gas generated by electrolysis of water as the carrier gas upstream of the separation column, and in the detecting step, the flow rates of the hydrogen gas and the oxygen gas may be controlled so that the ratio of the total flow rate of the hydrogen gas introduced into the detector as the detector gas and the hydrogen gas introduced into the detector as the carrier gas to the flow rate of the oxygen gas introduced into the detector is a ratio suitable for the detector. In this embodiment, when gases other than hydrogen gas and oxygen gas are not used as makeup gases, all gases used in the gas chromatography analysis are generated by electrolysis of water, so that gas chromatography analysis without using a gas cylinder can be realized. Make-up gas can be made unnecessary by making the shape of the detector suitable for the flow rate when using a capillary column to suppress the broadening of peaks in the chromatogram. And, since the ratio of the total flow rate of the hydrogen gas introduced into the detector to the flow rate of the oxygen gas introduced into the detector is controlled to be suitable for the detector, various types of detectors can be used in gas chromatography analysis without using a gas cylinder.

[0037] One embodiment of a gas chromatography analysis system according to the present invention comprises a separation column for separating components in a sample gas, a detector fluidly connected downstream of the separation column for detecting the components separated in the separation column, a gas generator configured to generate hydrogen gas and oxygen gas by electrolysis of water and to individually extract the generated hydrogen gas and oxygen gas, a first flow path for guiding the hydrogen gas generated in the gas generator to the detector as a detector gas, a second flow path for guiding the oxygen gas generated in the gas generator to the detector as a detector gas, and a detector gas flow rate regulator for regulating the flow rate of hydrogen gas introduced to the detector via the first flow path and the flow rate of oxygen gas introduced to the detector via the second flow path.

[0038] In a first aspect of the analysis system according to the above embodiment, a control unit is further provided that is configured to control the detector gas flow rate regulator to adjust the ratio of the flow rate of hydrogen gas and the flow rate of oxygen gas introduced into the detector to a ratio suitable for the detector. This aspect enables the use of various types of detectors in a gas chromatography analysis system that generates hydrogen gas and oxygen gas by electrolysis of water and uses the gas as detector gas.

[0039] In the first aspect, the gas chromatography analysis system may further include a third flow path for guiding the hydrogen gas generated by the gas generator as a carrier gas to the upstream of the separation column, and a carrier gas flow rate regulator for regulating the flow rate of the hydrogen gas introduced to the detector as the carrier gas, and the control unit may be configured to control the detector gas flow rate regulator and the carrier gas flow rate regulator to regulate the ratio of the total flow rate of the hydrogen gas introduced to the detector as the detector gas and the hydrogen gas introduced to the detector as the carrier gas to the flow rate of the oxygen gas introduced to the detector to a ratio suitable for the detector. With this aspect, when gases other than hydrogen gas and oxygen gas are not used as makeup gases, all of the gases used in the analysis are generated by the gas generation unit, so that a gas chromatography analysis system that does not use a gas cylinder can be realized. Make-up gas can be made unnecessary by making the shape of the detector suitable for the flow rate when using a capillary column to suppress the broadening of peaks in a chromatogram. Furthermore, since the ratio of the total flow rate of hydrogen gas introduced to the detector to the flow rate of oxygen gas introduced to the detector is controlled to suit the detector, various types of detectors can be used in gas chromatography analysis systems that do not use gas cylinders.

[0040] In the first aspect, the apparatus may further include an information storage unit that stores information on the correlation between the type of the detector and the ratio of flow rates of hydrogen gas and oxygen gas that is suitable for that type. In this case, the control unit may be configured to recognize the type of the detector based on information input by a user or information obtained from the detector, calculate the ratio of hydrogen gas to oxygen gas that is suitable for the type of the detector from the information storage unit, and use the calculated ratio of hydrogen gas to oxygen gas as the ratio suitable for the detector. In this way, the analysis system can automatically calculate the hydrogen gas flow rate and oxygen gas flow rate suitable for the detector without the user having to set the flow rates of hydrogen gas and oxygen gas.

[0041] The separation column in the present invention may be a capillary column. [Explanation of symbols]

[0042] 2 Injectors 4. Separation column 6. Detector 8 Column oven 10 Gas Generator 12 Control device 13,14,16,18 Flow path 20 A.F.C. 22 APC 24 Control Unit 26 Information storage section

Claims

1. introducing a sample gas into a separation column using a carrier gas to separate components in the sample gas; and introducing the sample gas that has passed through the separation column into a detector to detect components in the sample gas. The detecting step includes: Separately extracting hydrogen gas and oxygen gas produced by electrolysis of water; and controlling the flow rates of the extracted hydrogen gas and oxygen gas to be supplied to the detector as detector gases. The step of separating includes supplying a portion of the hydrogen gas produced by electrolysis of the water and separately extracted as the carrier gas upstream of the separation column; The detecting step includes: A gas chromatography analysis method comprising: controlling the flow rates of hydrogen gas and oxygen gas so that a ratio of a total flow rate of hydrogen gas introduced into the detector as the detector gas and hydrogen gas introduced into the detector as the carrier gas to a flow rate of oxygen gas introduced into the detector is a predetermined ratio.

2. a separation column for separating components in the sample gas; a detector fluidly connected downstream of the separation column for detecting components separated in the separation column; A gas generator configured to generate hydrogen gas and oxygen gas by electrolysis of water and to extract the generated hydrogen gas and oxygen gas separately; a first flow path for guiding the hydrogen gas generated by the gas generator to the detector as a detector gas; a second flow passage for guiding the oxygen gas generated by the gas generator to the detector as a detector gas; a detector gas flow rate adjuster that adjusts a flow rate of hydrogen gas introduced to the detector via the first flow path and a flow rate of oxygen gas introduced to the detector via the second flow path; a third flow path for guiding the hydrogen gas generated by the gas generator as a carrier gas to an upstream of the separation column; a carrier gas flow rate regulator that regulates the flow rate of hydrogen gas introduced into the detector as the carrier gas; a control unit configured to control the detector gas flow rate adjusting unit and the carrier gas flow rate adjusting unit to adjust a ratio of a total flow rate of hydrogen gas introduced to the detector as the detector gas and hydrogen gas introduced to the detector as the carrier gas to a flow rate of oxygen gas introduced to the detector to a predetermined ratio.

3. The gas chromatography analysis system of claim 2 , wherein the separation column is a capillary column.

4. a separation column for separating components in the sample gas; a detector fluidly connected downstream of the separation column for detecting components separated in the separation column; A gas generator configured to generate hydrogen gas and oxygen gas by electrolysis of water and to extract the generated hydrogen gas and oxygen gas separately; a first flow path for guiding the hydrogen gas generated by the gas generator to the detector as a detector gas; a second flow passage for guiding the oxygen gas generated by the gas generator to the detector as a detector gas; a detector gas flow rate adjuster that adjusts a flow rate of hydrogen gas introduced to the detector via the first flow path and a flow rate of oxygen gas introduced to the detector via the second flow path; a control unit configured to control the detector gas flow rate regulator to adjust a ratio of a flow rate of hydrogen gas and a flow rate of oxygen gas introduced into the detector to a ratio suitable for the detector; and an information storage unit that stores information regarding a correlation between the type of the detector and a flow rate ratio of hydrogen gas to oxygen gas that is compatible with the type of the detector, The control unit is configured to recognize the type of the detector based on information input by a user or information obtained from the detector, calculate a ratio of hydrogen gas to oxygen gas that is suitable for the type of detector from the information storage unit, and use the calculated ratio of hydrogen gas to oxygen gas as a ratio suitable for the detector.

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