JP2009236591A - Gas chromatograph device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gas chromatograph device capable of using in common, a means for making sample gas and carrier gas flow, and detecting a component highly accurately. <P>SOLUTION: This gas chromatograph device 1 has a collection means 11 for collecting and concentrating the sample gas; a detection means 12 for detecting a sample gas component conveyed by the carrier gas; a channel 20 for connecting in series, the collection means 11 to the detection means 12; and a gas flow means 13 for making the sample gas and the carrier gas flow in the direction from the collection means 11 toward the detection means 12. The channel 20 has a gas cleaning means 21 for cleaning the sample gas, and a channel switching means 22 for switching selectively to either of a cleaning channel 20A in which the gas cleaning means 21 is interposed between the collection means 11 and the detection means 12 and a direct channel 20B for connecting directly the collection means 11 to the detection means 12. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a gas chromatograph apparatus for detecting a substance (component) contained in a sample gas.

  A gas chromatograph apparatus (hereinafter referred to as a GC apparatus) is an apparatus used for detecting a component to be detected such as a volatile organic compound contained in a sample gas such as a house atmosphere, and a trace amount component contained in the sample gas. In addition to detection devices such as a separation column and a detection sensor, a configuration having a collection device for collecting and concentrating a detection target component is generally used. .

  As shown in FIG. 7, the GC apparatus 100 proposed in Patent Document 1 includes a carrier gas source 108 such as a gas cylinder that generates a carrier gas for transporting a sample gas component, and a component of the sample gas transported by the carrier gas. , A sample introduction port 101 for introducing a sample gas, a suction pump 104 for sucking the sample gas introduced from the sample introduction port 101 and discharging it from the discharge port 115, and a component to be detected from the sample gas And a valve 105 for selectively connecting the collection tube 102 between the sample inlet 101 and the suction pump 104 or between the carrier gas source 108 and the analyzer 110. , Etc.

  In the GC apparatus 100, when collecting (concentrating) the detection target component, the valve 105 is switched so that the collection tube 102 is connected in series between the sample introduction port 101 and the suction pump 104, and the suction pump 104 is collected. As the sample gas is sucked, the sample gas introduced into the sample introduction port 101 flows in the collection tube 102 and the detection target component is collected. When detecting the component to be detected, the valve 105 is switched so that the collection tube 102 is connected in series between the carrier gas source 108 and the analyzer 110, and the carrier gas source 108 generates carrier gas. Then, the component to be detected is transported from the collection tube 102 to the analysis device 110 by the carrier gas, and introduced into the analysis device 110 by flowing in the collection tube 102.

  However, in the above-described GC device 100, when collecting the detection target component, the sample gas is flowed by the suction pump 104, and when detecting the detection target component, the carrier gas is flowed by the carrier gas source 108. That is, since a device for flowing the sample gas and the carrier gas is required separately, there is a problem that the device is enlarged and the manufacturing cost is increased. Therefore, the present inventor has studied to solve this problem and came up with a GC device having the configuration shown in FIG.

  The GC apparatus 200 shown in FIG. 8 collects a sample gas component according to the passage of the sample gas, and collects the collected sample gas component according to the passage of the carrier gas. A detection means 212 for detecting a sample gas component conveyed by the carrier gas from the means 211; and a gas flow means 213 for causing the sample gas and the carrier gas to flow in a direction from the collection means 211 toward the detection means 212. , Each is connected in series.

According to this GC apparatus 200, since the collection means 211, the detection means 212, and the gas flow means 213 are connected in series, the gas flow means 213 causes the sample gas and the carrier gas to flow in the same direction. It is possible to collect and detect sample gas components, and it is not necessary to provide gas flow means such as a pump or a gas cylinder for each gas, and it becomes possible to share the gas flow means, The GC device 200 can be reduced in size.
JP 2006-337158 A

  However, when the sample gas component is collected in the configuration of the GC apparatus 200, the sample gas flows to the detection means 212 together with the collection means 211. Therefore, the detection means 212 (specifically, the separation column constituting the detection means 212) Etc.), and the detection means 212 is contaminated before the sample gas component is detected, so that an accurate baseline (reference value) cannot be obtained, and detection with high accuracy is possible. It turns out that there is a new problem that cannot be done.

  Accordingly, an object of the present invention is to provide a gas chromatograph apparatus that can share a means for causing a sample gas and a carrier gas to flow and can detect components with high accuracy.

  In order to solve the above problems, the gas chromatograph according to claim 1 made according to the present invention collects a sample gas component according to the passage of the sample gas and carries a carrier gas as shown in the basic configuration diagram of FIG. Collecting means 11 for desorbing the collected sample gas component in response to the passage of gas, detection means 12 for detecting the sample gas component conveyed by the carrier gas from the collecting means 11, and the collecting A flow path 20 that connects the means 11 and the detection means 12 in series, and a gas flow means 13 that causes the sample gas and the carrier gas to flow in a direction from the collection means 11 toward the detection means 12. In the gas chromatograph apparatus 1, a gas cleaning unit 21 that cleans the sample gas so that the flow path 20 removes a sample gas component detected by the detection unit 12; Which of the cleaning flow path 20A in which the gas cleaning means 21 is interposed between the collection means 11 and the detection means 12 and the direct flow path 20B in which the collection means 11 and the detection means 12 are directly connected A flow path switching means 22 that selectively switches to either one of the flow paths. The flow path switching means 22 switches to the cleaning flow path 20A according to the flow of the sample gas, and the flow of the carrier gas. Accordingly, it is a means for switching to the direct flow path 20B accordingly.

  According to the gas chromatograph apparatus of the present invention as set forth in claim 1, since the gas cleaning means is interposed between the collecting means and the detection means when the sample gas flows, the gas cleaning means is located in front of the detection means. Since the sample gas component is removed, the detection means is not contaminated before the component detection, and when the carrier gas flows, the collection means and the detection means are directly connected. The sample gas component is not removed, and therefore, in the configuration in which the gas flow means is made common, the contamination of the detection means before the component detection can be prevented, so that the size can be reduced and the high accuracy can be achieved. A gas chromatograph apparatus capable of component detection can be obtained.

  Hereinafter, an embodiment of a gas chromatograph apparatus according to the present invention will be described with reference to the drawings of FIGS.

  As shown in FIG. 2, the gas chromatograph apparatus (hereinafter, GC apparatus) 1 includes a collection device 11 that concentrates a sample gas, a detection device 12 that detects a sample gas component contained in the sample gas, and a collection device 11. And a flow path 20 connecting the detection device 12 in series, a pump 13 for flowing the sample gas and the carrier gas, a buffer 31 for stabilizing the flow of gas by the pump 13, and an outlet 32 for discharging each gas, An air suction port 33 for sucking air, a sample introduction part 34 for introducing sample gas, an activated carbon filter 41 for filtering the air to generate carrier gas, and a gas introduced into the collection device 11 and the detection device 12 An introduction gas switching valve 42 for switching and a control device 51 for controlling the GC device 1 are provided.

  The collection device 11 corresponds to the collection means of the claims, and is a device for collecting and concentrating the sample gas component so as to enable detection of a trace amount component contained in the sample gas. 11a and a collection tube heating / cooling device 11b.

  The collection tube 11a is, for example, a glass tube having an inner diameter of about 5 mm and a length of about 20 to 30 cm filled with a collection agent corresponding to a detection target component such as a heat resistant resin or carbon black. Then, the sample gas component is adsorbed (collected) to the collection agent by passing the sample gas through the collection tube 11a that has been cooled to low temperature, and then the collected sample gas component is heated to a high temperature. Desorbed from the collection agent can generate a high concentration of sample gas. In addition, the collection tube 11a generally has a property of adsorbing more sample gas components on the end side where the sample gas is introduced.

  The collection tube heating / cooling device 11b cools the collection tube 11a according to the collection of the sample gas component and heats the collection tube 11a according to the desorption of the sample gas component. This is an existing apparatus that includes a heater such as a heat wire and a Peltier element as a cooling means. The collection tube heating / cooling device 11 b is connected to a control device 51 described later, and is controlled in conjunction with other members constituting the GC device 1.

  The detection device 12 corresponds to the detection means in the claims, and is connected in series to the collection device 11, and a high-concentration sample gas generated by the collection device 11 is introduced to detect its component (analysis). This is a device for performing separation, and includes a separation column 12a, a column heating / cooling device 12b, and a detection sensor 12c.

  The separation column 12a is for separating components contained in the sample gas, and is a packed column in which a tube having a diameter of 2 to 6 mm and a length of several meters is filled with a granular stationary phase, an inner diameter of about 0.5 mm or less, Existing columns such as capillary columns with a liquid stationary phase held directly on the wall of a thin tube of several tens of meters, or microcolumns in which fine column grooves are formed in a glass plate by etching are used. .

  The column heating / cooling device 12b adjusts the temperature of the separation column 12a according to the introduction of the sample gas into the separation column 12a and the separation of the sample gas components, and includes a heater such as a heating wire as a heating means, and a cooling means It is an existing device equipped with a Peltier element. The column heating / cooling device 12b is connected to a control device 51, which will be described later, and is controlled in conjunction with other members constituting the GC device 1.

  The detection sensor 12c is for detecting the component of the sample gas that has been transported by the carrier gas after being separated in the separation column 12a. For example, a flame ionization detector, a thermal conductivity detector, etc. The existing sensor is used, and the detection sensor 12c is connected to a control device 51, which will be described later, and is controlled in conjunction with other members constituting the GC device 1. Since the configuration and operation of the detection sensor 12c are not related to the essence of the present invention, the details are omitted.

  The flow path 20 connects the sample gas and the carrier gas in series so that the sample gas and the carrier gas can flow from the collection device 11 to the detection device 12, and a gas scrubber 21 that removes unnecessary components by washing the passing gas. And a flow path switching valve 22 for switching the connection order of the collection device 11, the detection device 12, and the gas scrubber 21.

  The gas scrubber 21 corresponds to the gas scrubbing means of the claims, and cleans the gas passing through the gas scrubber 21 to remove unnecessary components. There are known water-type gas scrubbers that are washed through, and ion-exchange-type gas scrubbers that adsorb contaminants in the gas with an ion-exchange resin. In the present embodiment, the gas scrubber 21 is used as the gas cleaning means. However, the gas scrubber 21 is not limited to this. For example, components that contaminate the detection device 12 such as an activated carbon filter can be removed from the sample gas. Any material can be used.

  The flow path switching valve 22 corresponds to the flow path switching means in the claims, and, for example, a six-way electromagnetic valve or the like is used, and each connection (that is, the flow of the scrubber 21, the detection apparatus 12, and the gas scrubber 21). Road). Specifically, when the sample gas flows, the collection device 11, the gas scrubber 21, and the detection device 12 are connected in series in this order from the upstream side in the flow direction of the sample gas (hereinafter referred to as a cleaning flow path 20A). When the carrier gas flows, the gas scrubber 21, the collection device 11, and the detection device 12 are connected in series in this order from the upstream side in the flow direction of the carrier gas (hereinafter referred to as a direct flow path 20B) to switch the flow path. It is.

  The pump 13 corresponds to the gas flow means of the claims, and is connected in series to the detection device 12 via the buffer 31, and discharges the gas sucked from the pump suction port 13a from the pump discharge port 13b and flows. The sample gas and the carrier gas are caused to flow in the direction from the collection device 11 toward the detection device 12, and the flow rate and flow rate of the gas are appropriately changed depending on the situation so that each gas can be appropriately flowed. It is an existing one that can be finely controlled. The pump 13 is connected to a control device 51 to be described later, and is controlled in conjunction with other members constituting the GC device 1. In addition, the connection position of the pump 13 is arbitrary as long as the sample gas and the carrier gas can flow in the direction from the collection device 11 to the detection device 12.

  The buffer 31 is connected in series to the pump 13 and is an existing one for suppressing the disturbance of the flow caused by the pump 13 and keeping the flow amount constant. The buffer 31 is arranged on the path to flow. Since the amount is stable, the detection accuracy can be increased. Further, the buffer 31 may be omitted if the error due to the disturbance of the flow of the pump 13 is within an allowable range.

  The discharge port 32 is connected to the pump discharge port 13 b and is a part for discharging the sample gas and the carrier gas to the outside of the GC device 1. The air suction port 33 is connected to the activated carbon filter 41, and is a part that sucks air into the activated carbon filter 41 by the operation of the pump 13.

  The sample introduction unit 34 is an introduction unit for introducing a sample gas into the GC device 1.

  The activated carbon filter 41 operates the pump 13 and sucks in the direction from the collection device 11 toward the detection device 12, thereby removing impurities contained in the atmosphere sucked from the atmosphere suction port 33 with activated carbon and generating a carrier gas. To do.

  For example, an existing three-way solenoid valve is used as the introduction gas switching valve 42 and includes three ports a, b, and c. The activated carbon filter 41 is provided in the port a, and the sample introduction unit 34 is provided in the port b. The flow path switching valve 22 is connected to the port c. The introduction gas switching valve 42 switches the gas introduced into the GC device 1, that is, the activated carbon filter 41 and the channel switching valve 22 (ac connection), or the sample introduction unit 34 and the channel switching valve. 22 (bc connection) is selectively connected.

  The control device 51 includes a collection tube heating / cooling device 11b (a), a column heating / cooling device 12b (b), a detection sensor 12c (c), a pump 13 (d), and a flow path switching valve 22 (e). ), And an introductory gas switching valve 42 (f), and a microcomputer (MPU) (not shown) that controls each of them in conjunction with each other. As is well known, the MPU is a central processing unit (CPU) that performs various processes and controls according to a predetermined program, a ROM that is a read-only memory storing programs for the CPU, and various data. An I / O unit that includes a RAM that is a readable / writable memory having an area necessary for CPU processing operations and a serial interface for transmitting / receiving control information to / from the above-described control target portion, etc. It consists of

  The CPU of the control device 51, based on a program stored in the ROM, collects the collection tube heating / cooling means for heating / cooling the collection tube 11a so that the temperature of the collection tube 11a becomes an appropriate temperature, and the separation column 12a. The column heating / cooling means for heating / cooling the separation column 12a so that the temperature becomes an appropriate temperature, the component detecting means for detecting the sample gas component contained in the sample gas, and flowing in the collection device 11 and the detection device 12 Flow rate control means for controlling the flow rate and flow rate of the sample gas and carrier gas, flow path switching means for switching to the cleaning flow path 20A according to the introduction of the sample gas, and for switching directly to the flow path 20B according to the introduction of the carrier gas, and The sample introduction unit 34 and the flow path switching valve 22 are connected according to the introduction of the sample gas, and the activated carbon filter 41 and the flow path switching valve 2 according to the introduction of the carrier gas. It operates as an introducing gas-switching means, for connecting and.

  Next, an example of the processing according to the present invention executed by the control device 51 (i.e., CPU) of the gas chromatograph apparatus 1 will be described with reference to the flowchart shown in FIG. 3 and the schematic operations corresponding to the steps shown in FIGS. This will be described with reference to the drawings.

  When the CPU of the control device 51 is activated by turning on the power of the GC device 1, it switches directly to the flow channel 20 </ b> B by the flow channel switching valve 22, and switches between the activated carbon filter 41 and the flow channel switching valve 22 by the introduction gas switching valve 42. After performing a predetermined initialization operation such as connection (ac connection), the process proceeds to step S110.

  In step S110, the collection tube 11a and the column heating / cooling device 12b heat the collection tube 11a and the separation column 12a to a high temperature to take out impure components, and then start the flow by the pump 13. As a result, the carrier gas flows so as to pass through the collection tube 11a and the separation column 12a, and the impure components are discharged out of the GC apparatus 1 by the carrier gas (the cleaning operation in FIG. 4). After discharging the impure components, the process proceeds to step S120.

  In step S120, the flow path switching valve 22 switches to the cleaning flow path 20A, the introduction gas switching valve 42 connects the sample introduction part 34 and the flow path switching valve 22 (bc connection), and column heating. The separation column 12a is continuously heated by the cooling device 12b, the collection tube 11a is cooled by the collection tube heating / cooling device 11b, and the sample gas is introduced from the sample introduction unit 34. Thus, after the sample gas is introduced into the collection device 11 and the sample gas component is collected, the sample gas component that has passed through the collection device 11 and has been washed by the gas scrubber 21 and remains. , And the cleaned sample gas is discharged from the discharge port 32 via the detection device 12 (the sampling operation in FIG. 5 above). Then, after the collection of the sample gas component is completed, the process proceeds to step S130.

  In step S130, the flow path switching valve 22 switches directly to the flow path 20B again, the introduction gas switching valve 42 reconnects the activated carbon filter 41 and the flow path switching valve 22 (ac connection), and the column The separation column 12a is cooled to a temperature suitable for gas component separation by the heating / cooling device 12b, and the collection tube 11a is heated to a high temperature by the collection tube heating / cooling device 11b. As a result, the high-concentration sample gas desorbed and staying in the collection device 11 is pushed out (ie, purged) by the carrier gas and introduced into the detection device 12 (ie, the separation column 12a). (End of FIG. 4 driving operation). At this time, the amount of the carrier gas that is flowed by the pump 13 is small enough to convey the sample gas from the collection device 11 to the detection device 12. Then, after the high-concentration sample gas is introduced into the separation column 12a, the process proceeds to step S140. Note that the temperature of the separation column 12a is maintained until the detection operation.

  In step S140, the sample gas component contained in the sample gas introduced into the separation column 12a is separated in the separation column 12a by the carrier gas, and each sample gas component is transported to the detection sensor 12c with a time difference. Each component is detected (the detection operation shown in FIG. 4). Then, after all the detection target components have been conveyed, the processing of this flowchart is terminated.

  Next, an example of the operation when performing the component detection of the sample gas in the gas chromatograph apparatus 1 described above will be described with reference to FIGS.

  In the component detection in the GC device 1, first, the collection tube 11a and the separation column 12a are heated to a high temperature to extract impure components, and then the carrier gas is switched to the flow path 20B directly to flow the collection device 11. Then, the detection device 12 is cleaned (FIG. 4 cleaning operation).

  When the cleaning is completed, the collection tube 11a is cooled to a temperature suitable for gas component separation, and is switched to the cleaning channel 20A by the channel switching valve 22, and the sample gas introduced from the sample introduction unit 34 is collected. 11, the gas scrubber 21 and the detection device 12 are made to flow in order, and the sample gas component is collected (concentrated) by the collection device 11 (FIG. 5 sampling operation).

  After the collection of the sample gas component is completed, the collection tube 11a is heated, the separation column 12a is cooled, and the flow path switching valve 22 is directly switched to the flow path 20B. The carrier gas generated by the activated carbon filter 41 is The gas scrubber 21, the collection device 11, and the detection device 12 are made to flow in order, and the desorbed sample gas component is introduced into the detection device 12 (that is, the separation column 12a) (FIG. 4 driving operation).

  Then, by continuously flowing the carrier gas, the sample gas component contained in the sample gas introduced into the separation column 12a is separated in the separation column 12a and conveyed to the detection sensor 12c to detect the sample gas component. (Fig. 4 Detection operation).

  As described above, according to the present embodiment, the sample gas component is collected by switching to the cleaning flow path 20A by the flow path switching valve 22, that is, the gas scrubber 21 is interposed between the collection apparatus 11 and the detection apparatus 12. Therefore, the gas scrubber 21 removes the sample gas component from the sample gas before the detection device 12, so that the detection device 12 is not contaminated before the component detection, and when the cleaning operation and the sample gas component are detected. Is directly switched to the flow path 20B by the flow path switching valve 22, that is, the collection device 11 and the detection device 12 are directly connected, so that the necessary sample gas component is not removed by the gas scrubber 21. In the configuration in which the pump 13 is shared, it is possible to prevent the detection device 12, that is, the separation column 12a from being contaminated before the component detection. , Thus, together it can be miniaturized, it is possible to obtain a gas chromatograph apparatus 1 capable of high precision components detected.

  Further, by switching directly to the flow path 20B with the flow path switching valve 22, the gas scrubber 21 is connected upstream from the collection device 11 when the GC device 1 is cleaned or the sample gas component is detected. , The air filtered by the activated carbon filter 41) can be further washed, and a carrier gas with less impurities can be supplied to the collection device 11 and the detection device 12. Therefore, it becomes possible to detect the component with higher accuracy.

  In addition, since the end of the sample tube 11a into which the sample gas is introduced is connected to the detection device 12 at the time of component detection by switching the connection by the flow path switching valve 22, there are many in the vicinity of the end. The sample gas component is adhering and stays in a location near the detection device 12 from the sample gas having a higher concentration due to the desorption, and the sample gas having a higher concentration can be introduced in a short time. Detection peaks can be clarified, and more accurate component detection is possible.

  In the present embodiment, a six-way valve is used for the flow path switching valve 22, but the present invention is not limited to this. For example, as shown in FIG. From the upstream side of the flow direction of the sample gas, the collection device 11, the gas scrubber 21, and the detection device 12 are connected in series in this order (FIG. 6 df connection, that is, connected to the cleaning flow path 20A), When the carrier gas flows, the collection device 11 and the detection device 12 are connected in series in this order from the upstream side in the flow direction of the carrier gas (FIG. 6 ef connection, ie, directly connected to the flow path 20B). It may be.

  In the present embodiment, a method of performing separation of sample gas components (constant temperature method) while maintaining the temperature of the separation column 12a at a constant temperature during the detection operation is used. The method may be changed according to the sample gas to be detected, such as a method of separating the sample gas components while raising the temperature of the separation column 12a (temperature raising method).

  The above-described embodiments are merely representative examples of the present invention, and the present invention is not limited to the embodiments. That is, various modifications can be made without departing from the scope of the present invention.

It is a basic lineblock diagram of the gas chromatograph device of the present invention. It is a block diagram which shows embodiment of the gas chromatograph apparatus of this invention. It is a flowchart which shows an example of the process which concerns on this invention which CPU of the gas chromatograph apparatus in FIG. 2 performs. FIG. 3 is a diagram illustrating states of a cleaning operation, a driving operation, and a detection operation of the gas chromatograph apparatus in FIG. 2. It is a figure which shows the state of the sampling operation | movement of the gas chromatograph apparatus in FIG. It is a block diagram which shows other embodiment of the gas chromatograph apparatus of this invention. It is a block diagram of the conventional gas chromatograph apparatus. It is a basic block diagram of the gas chromatograph apparatus which shared the gas flow means.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Gas chromatograph apparatus 11 Collection means (collection apparatus)
12 Detection means (detection means)
13 Gas flow means (pump)
20 channel 20A cleaning channel 20B direct channel 21 gas cleaning means (gas scrubber)
22 Channel switching means (channel switching valve)

Claims (1)

Sample gas components are collected according to the passage of the sample gas and are collected by the carrier gas from the collection means for collecting the sample gas components collected according to the passage of the carrier gas. Detection means for detecting the sample gas component, a flow path connecting the collection means and the detection means in series, and flowing the sample gas and the carrier gas in a direction from the collection means to the detection means A gas chromatograph device comprising:
Gas cleaning means for cleaning the sample gas so that the sample gas component detected by the detection means is removed by the flow path, and cleaning in which the gas cleaning means is interposed between the collection means and the detection means A flow path switching means for selectively switching to any one of the direct flow path directly connecting the flow path and the collecting means and the detection means,
The gas chromatograph apparatus, wherein the flow path switching means is a means for switching to the cleaning flow path according to the flow of the sample gas and switching to the direct flow path according to the flow of the carrier gas.

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