CN105004820A - Flow adjusting device and gas chromatograph comprising same - Google Patents

Abstract

The present invention provides a flow rate adjustment device that can be easily operated when setting the total flow rate of a carrier gas and the inlet pressure of a chromatography column, and a gas chromatograph equipped with the same. The pressure of the carrier gas flowing in the split channel (23) is controlled to a set value by a pressure control valve (231). Therefore, it is possible to prevent fluctuations in the pressure at the column inlet due to the adjustment of the flow rate of the carrier gas by the pressure control valve (221). That is, even when the flow rate of the carrier gas through the pressure control valve (221) is adjusted and the pressure on the upstream side of the flow resistance body (222) changes, the pressure on the downstream side of the flow resistance body (222) is also controlled by the pressure. Since the control valve (231) is kept constant, fluctuations in pressure at the column inlet can be prevented. Therefore, when setting the total flow rate of the carrier gas and the column inlet pressure, it is not necessary to alternately and repeatedly adjust them, and it is not necessary to set them while making fine adjustments.

Description

Flow adjustment device and gas chromatograph equipped with the device

technical field

The present invention relates to a flow adjustment device for adjusting the flow rate of carrier gas introduced into a chromatographic column, and a gas chromatograph equipped with the same.

Background technique

In a gas chromatograph, the sample is transported together with a carrier gas into a chromatography column, and the individual sample components are separated as the carrier gas passes through the column. The carrier gas is supplied from the gas supply path into the sample introduction part, mixed with the sample in the sample introduction part, and introduced into the column from the column inlet.

As an example of an analysis method using a gas chromatograph, split flow analysis and splitless analysis are well known. The sample introduction part of the gas chromatograph using this analysis method is connected with not only a supply path for supplying the carrier gas into the sample introduction part, but also a branch flow path for discharging a part of the sample together with the carrier gas from the sample introduction part. (For example, refer to the following Patent Document 1).

Fig. 4 is a schematic diagram showing a configuration example of a conventional gas chromatograph. The gas chromatograph has: a chromatographic column 101, a sample introduction part 102, a gas supply path 103, a split flow path 104, an exhaust flow path 105, a gas supply source 106, a pressure control valve 131, a pressure sensor 132, a flow rate adjustment valve 141, 151, and on-off valve 142 etc.

A sample vaporization chamber (not shown) is formed in the sample introduction part 102, and the sample vaporization chamber communicates with the chromatography column 101, the gas supply path 103, the split flow path 104, and the exhaust flow path 105, respectively. The gas supply path 103 is supplied with a carrier gas from a gas supply source 106 constituted by, for example, a gas cylinder. The pressure of the carrier gas flowing in the gas supply path 103 is controlled to a set value by the pressure control valve 131 . A liquid sample is injected into the sample vaporization chamber, and the vaporized sample in the sample vaporization chamber is introduced into the column 101 through the column inlet together with the carrier gas supplied from the gas supply path 103 .

In the split flow analysis, when the on-off valve 142 included in the split flow path 104 is opened, a part of the carrier gas in the sample introduction unit 102 is introduced into the split flow path 104 . Thereby, a part of the sample is discharged from the split channel 104 while the sample is introduced into the column 101 from the sample introduction part 102 , and analysis can be performed at high resolution. During split analysis, the flow rate of the carrier gas flowing in the split channel 104 can be arbitrarily set by adjusting the opening degree of the flow rate adjustment valve 141 composed of, for example, a needle valve.

On the other hand, in splitless analysis, the sample is introduced from the sample introduction unit 102 into the column 101 with the on-off valve 142 closed, and the on-off valve 142 is opened after a predetermined time elapses after the sample introduction. Thereby, all the samples in the sample introduction part 102 are introduced into the chromatography column 101, and a trace amount of samples can be analyzed with high efficiency.

Unnecessary components generated from the diaphragm and the like are exhausted through the exhaust flow path 105 together with the carrier gas. The flow rate of the carrier gas flowing in the exhaust flow path 105 can be arbitrarily set by adjusting the opening degree of the flow rate adjustment valve 151 composed of, for example, a needle valve.

On the downstream side of the pressure control valve 131 in the gas supply path 103, a pressure sensor 132 for detecting the pressure of the carrier gas is provided. The flow rate of the carrier gas can be set by adjusting the opening degree of the pressure control valve 131 while checking the pressure of the carrier gas detected by the pressure sensor 132 .

prior art literature

patent documents

Patent Document 1 Japanese Unexamined Patent Publication No. 9-127074

Contents of the invention

The problem to be solved by the invention

In the configuration shown in FIG. 4 , although the pressure of the carrier gas in the gas supply path 103 can be detected by the pressure sensor 132 , the flow rate of the carrier gas cannot be directly detected. Therefore, in order to detect the flow rate of the carrier gas, it is conceivable to adopt a configuration in which a flow resistor is provided in the gas supply path 103 and a pressure difference between the upstream side and the downstream side of the flow resistor is detected.

FIG. 5 is a schematic diagram showing a configuration example in which a flow resistor 134 is provided in the gas chromatograph of FIG. 4 . The flow resistor 134 is provided on the downstream side of the pressure sensor 132 in the gas supply path 103 . Another pressure sensor 135 is provided between the flow resistance body 134 and the sample introduction part 102 .

Accordingly, the pressure of the carrier gas on the upstream side of the flow resistor 134 can be detected by the pressure sensor 132 , and the pressure of the carrier gas on the downstream side of the flow resistor 134 can be detected by the pressure sensor 135 . Then, based on the pressure difference between the upstream side and the downstream side of the flow resistance body 134 , the flow rate measuring unit 107 can measure the flow rate of the carrier gas. In addition, since the structure other than the flow resistance body 134, the pressure sensor 135, and the flow measurement part 107 is the same as that of the example of FIG. 4, detailed description is abbreviate|omitted.

However, in the structure provided with the flow resistance body 134 as shown in FIG. 5, the following problems arise. First, there is a problem of complicated work when setting the full flow rate of the carrier gas and the pressure at the column inlet (column inlet pressure).

Specifically, in the case of the structure shown in FIG. 5 , after the full flow rate of the carrier gas is set by the pressure control valve 131 , the pressure at the inlet of the chromatographic column is set by adjusting the flow rate adjustment valve 141 . At this time, since the pressure control valve 131 controls to maintain the pressure upstream of the flow resistance body 134 at the set value, once the adjustment of the flow rate adjustment valve 141 causes the pressure on the downstream side of the flow resistance body 134 to change, the flow rate will be reduced. The pressure difference between the upstream side and the downstream side of the resistance body 134 changes, resulting in large fluctuations in the total flow rate.

Therefore, it is necessary to use the pressure control valve 131 to reset the full flow rate of the carrier gas after the pressure at the inlet of the chromatographic column is set by the flow rate adjustment valve 141 . However, if the adjustment of the pressure control valve 131 causes the pressure on the upstream side of the flow resistance body 134 to change, the pressure at the inlet of the chromatography column will fluctuate, making it necessary to adjust the flow adjustment valve 141 again. In this way, when setting the full flow rate of the carrier gas and the inlet pressure of the column, it is necessary to alternately and repeatedly adjust the pressure control valve 131 and the flow rate adjustment valve 141, or to set while making fine adjustments at the same time. It is cumbersome.

In addition, even after the start of the analysis, there is a problem that the reproducibility of the analysis is adversely affected. Specifically, the pressure directly controlled by the pressure control valve 131 is the pressure on the upstream side of the flow resistance body 134 detected by the pressure sensor 132, and the inlet pressure of the chromatographic column on the downstream side of the flow resistance body 134 detected by the pressure sensor 135 is the pressure detected by the pressure sensor 135. The flow resistance body 134 is indirectly controlled. Although the inlet pressure of the column is an important analysis condition, since the inlet pressure of the column cannot be directly controlled, when the sample is introduced, the followability of the inlet pressure of the column becomes poor, which adversely affects the reproducibility of the analysis.

Especially in splitless analysis, when the on-off valve 142 is opened and closed, the total flow rate of the carrier gas and the column inlet pressure fluctuate greatly. That is, when the on-off valve 142 is closed, the carrier gas cannot be discharged through the branch channel 104 , so the pressure detected by the pressure sensor 135 increases. As a result, the pressure difference between the upstream side and the downstream side of the flow resistance body 134 becomes smaller, and the total flow rate of the carrier gas becomes smaller. As a result, differences in characteristics such as resetting and flow rate characteristics of the pressure control valve 131 adversely affect the reproducibility of analysis. In addition, since the pressure of the carrier gas fluctuates greatly, it also adversely affects the durability of the pressure sensor 135 .

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a flow rate adjustment device that can be easily operated when setting the full flow rate of the carrier gas and the inlet pressure of the column, and a gas chromatograph equipped with the device. . Another object of the present invention is to provide a flow rate adjustment device capable of improving analysis reproducibility, and a gas chromatograph including the same.

means of solving problems

The flow adjustment device according to the present invention is a flow adjustment device for adjusting the flow rate of carrier gas introduced into the chromatographic column. Measuring section, flow adjustment section, and pressure control valve. The sample introduction part introduces a sample together with a carrier gas into the chromatography column. The gas supply path supplies a carrier gas into the sample introduction part. The split channel discharges a part of the sample together with the carrier gas from the sample introduction part. The flow resistance body is provided in the gas supply path, and acts as a flow resistance of the carrier gas flowing in the gas supply path. The upstream side pressure sensor detects the pressure of the carrier gas on the upstream side of the flow resistor. The downstream side pressure sensor detects the pressure of the carrier gas on the downstream side of the flow resistor. The flow rate measurement unit measures the flow rate of the carrier gas based on detection signals from the upstream pressure sensor and the downstream pressure sensor. The flow adjustment unit is provided upstream of the upstream pressure sensor, and adjusts the flow rate of the carrier gas flowing in the gas supply path. The pressure control valve controls the pressure of the carrier gas flowing in the split channel to a set value.

According to such a structure, the pressure of the carrier gas flowing in the split flow path is controlled to the set value by the pressure control valve, so it is possible to prevent pressure fluctuations at the column inlet caused by adjusting the flow rate of the carrier gas by the flow rate regulator. change. That is, even when the flow rate of the carrier gas is adjusted through the flow rate adjustment part to change the pressure on the upstream side of the flow resistance body, the pressure on the downstream side of the flow resistance body is kept constant by the pressure control valve, so Prevents pressure fluctuations at the column inlet.

Therefore, when setting the total flow rate of the carrier gas and the column inlet pressure, it is not necessary to alternately and repeatedly adjust them, and it is not necessary to set them while making fine adjustments. Therefore, it is easy to work when setting the full flow rate of the carrier gas and the column inlet pressure.

In addition, the column inlet pressure on the downstream side of the flow resistance body detected by the downstream side pressure sensor can be directly controlled by the pressure control valve without passing through the flow resistance body. Thereby, it is possible to prevent deterioration of followability when the column inlet pressure fluctuates during sample introduction, and improve the reproducibility of analysis.

The flow control device may further include a multi-way valve and a bypass flow path. The multi-way valve is provided on an upstream side of the pressure control valve in the split flow path. The bypass channel bypasses the sample introduction part and communicates the gas supply channel with the multi-way valve. The multi-way valve is capable of switching between a first communication state and a second communication state, the first communication state is a state in which the sample introduction part communicates with the pressure control valve via the split channel. The second communication state is a state in which the gas supply path communicates with the pressure control valve via the bypass flow path.

According to such a configuration, the pressure control valve can allow the carrier gas to flow regardless of the first communication state or the second communication state. Therefore, not only in the first communication state in which the carrier gas is introduced into the split flow channel from the sample introduction part, but also in the second communication state in which the carrier gas is not introduced from the sample introduction part into the split flow channel, it is always possible to A pressure control valve is used to control the pressure at the inlet of the chromatographic column. In addition, since the carrier gas always flows through the pressure control valve, the pressure control valve can be kept clean, and the durability of the pressure control valve can be improved.

Also, since the bypass flow path is branched from the gas supply path. Therefore, it is possible to make the bypass flow path function as a buffer during analysis, and suppress pressure fluctuations of the carrier gas. Thus, the stability of the inlet pressure of the chromatographic column is improved, and the reproducibility of analysis is improved.

The flow rate adjustment device may further include a selection receiving unit and a valve control unit. The selection receiving unit receives a selection of split analysis or splitless analysis. When the selection receiver receives the split analysis, the valve control unit sets the multi-way valve to the first communication state, and introduces the sample into the chromatographic column; In a case where the multi-way valve is in the second communication state, the multi-way valve is switched to the first communication state after introducing the sample into the chromatographic column.

According to such a configuration, split analysis can be performed in the first communication state in which the carrier gas is introduced into the split channel from the sample introduction portion. On the other hand, in the case of splitless analysis, in the second communication state in which the carrier gas is not introduced into the split channel from the sample introduction part, the sample can be switched to the first communication state after introducing the sample into the chromatography column.

In this way, in splitless analysis, since the multi-way valve can be switched from the second communication state to the first communication state, the full flow rate of the carrier gas and the inlet pressure of the chromatographic column before and after switching can be kept constant through the function of the pressure control valve. . In this way, it is possible to prevent the reproducibility of the analysis from being adversely affected by the difference in characteristics such as the resetting of the pressure control valve and the flow rate characteristic, and at the same time, since the carrier gas pressure does not fluctuate greatly, it is possible to prevent the downstream side pressure from being affected. adverse effects on the durability of the sensor.

A gas chromatograph according to the present invention includes a chromatography column and the flow rate adjustment device.

The effect of the invention

According to the present invention, since it is possible to prevent fluctuations in column inlet pressure due to adjustment of the flow rate of the carrier gas by the flow regulator, it is possible to easily perform work when setting the full flow rate of the carrier gas and the column inlet pressure. In addition, it is possible to prevent poor followability when the column inlet pressure fluctuates during sample introduction, thereby improving the reproducibility of analysis.

Description of drawings

FIG. 1 is a schematic diagram showing a configuration example of a gas chromatograph according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration example of a control unit.

FIG. 3 is a flowchart showing an example of processing performed by the control unit during analysis.

Fig. 4 is a schematic diagram showing a configuration example of a conventional gas chromatograph.

Fig. 5 is a schematic diagram showing a configuration example in which a flow resistor is provided in the gas chromatograph of Fig. 4 .

Detailed ways

Embodiments are described below based on the drawings.

FIG. 1 is a schematic diagram showing a configuration example of a gas chromatograph according to an embodiment of the present invention. The gas chromatograph includes a column 1 and a flow rate adjusting device 2 for adjusting the flow rate of a carrier gas introduced into the column 1 . The flow adjustment device 2 has, for example, a sample introduction part 21, a gas supply path 22, a split flow path 23, an exhaust flow path 24, a bypass flow path 25, a gas supply source 26, pressure control valves 221, 231, and a flow rate adjustment valve 241. Flow resistance body 222, pressure sensors 223, 224, three-way valve 232, control unit 27, operation unit 28, display unit 29, and the like.

A sample vaporization chamber (not shown) is provided in the sample introduction part 21 , and the sample vaporization chamber is connected to an inlet (column inlet) formed at one end of the column 1 . In addition, a gas supply path 22 , a split flow path 23 , and an exhaust flow path 24 are connected to the sample introduction part 21 , and each communicates with the sample vaporization chamber.

The gas supply channel 22 is a gas supply flow channel for supplying the carrier gas to the sample introduction part 21 , and a gas supply source 26 is connected to the end on the side opposite to the sample introduction part 21 . The gas supply source 26 is constituted by a gas cylinder in which a carrier gas such as nitrogen or helium is sealed, and the carrier gas is supplied from the gas supply source 26 into the sample introduction part 21 through the gas supply path 22 .

The pressure of the carrier gas flowing in the gas supply path 22 is controlled to a set value by the pressure control valve 221 provided on the gas supply path 22 . The operator can set the pressure of the carrier gas in the gas supply path 22 to an arbitrary set value by adjusting the opening degree of the pressure control valve 221 . A liquid sample is injected into the sample vaporization chamber of the sample introduction part 21 , and the vaporized sample in the sample vaporization chamber is introduced into the column 1 from the column inlet together with the carrier gas supplied from the gas supply path 22 .

The split channel 23 is a channel for discharging a part of the sample together with the carrier gas from the sample introduction part 21 . The pressure of the carrier gas flowing in the branch channel 23 is controlled to a set value by the pressure control valve 231 provided on the branch channel 23 . The operator can adjust the opening degree of the pressure control valve 231 to set the pressure of the carrier gas in the split channel 23 to an arbitrary set value. A three-way valve 232 is provided upstream of the pressure control valve 231 in the branch flow path 23 .

The three-way valve 232 is connected to the gas supply path 22 through the bypass flow path 25 . Thereby, the gas supply path 22 and the three-way valve 232 can be connected by bypassing the sample introduction part 21 . That is, by switching the three-way valve 232, it is possible to switch between the first communication state in which the sample introduction part 21 and the pressure control valve 231 communicate through the branch flow path 23 and the second communication state. The second communication state is a state in which the gas supply path 22 and the pressure control valve 231 are in communication through the bypass flow path 25 .

In the gas chromatograph according to this embodiment, split analysis or splitless analysis can be selected and executed. In the split flow analysis, the sample is introduced from the sample introduction part 21 into the column 1 by setting the three-way valve 232 to the first communication state, and a part of the carrier gas in the sample introduction part 21 is guided to the split channel 23 . Thereby, while a sample is introduced into the column 1 from the sample introduction part 21 , a part of the sample is discharged from the split channel 23 , so that analysis can be performed at high resolution.

On the other hand, in the splitless analysis, the three-way valve 232 is placed in the second connection state, and the sample is introduced into the column 1 from the sample introduction part 21 . In this case, the carrier gas cannot be guided from the sample introduction part 21 to the split channel 23 when the sample is introduced, and all the samples in the sample introduction part 21 are introduced into the chromatographic column 1, so that a trace amount of sample can be efficiently processed. analyze.

The exhaust flow path 24 is a flow path for exhausting unnecessary components generated from a diaphragm (not shown) etc. provided on the sample introduction part 21 together with the carrier gas. The flow rate of the carrier gas flowing in the exhaust flow path 24 can be set arbitrarily by adjusting the opening degree of the flow rate adjustment valve 241 constituted by, for example, a needle valve. In addition, while the pressure control valves 221 and 231 have a pressure control mechanism such as a spring to control the pressure of the carrier gas to a set value, the flow rate adjustment valve 241 can only set the amount of carrier gas corresponding to the opening degree. The flow rate does not have the function of controlling the pressure of the carrier gas.

In the present embodiment, a flow resistance body 222 serving as a flow resistance of the carrier gas flowing in the gas supply path 22 is provided on the downstream side of the pressure control valve 221 in the gas supply path 22 . By the action of the flow resistance body 222 , a pressure difference can be generated between the upstream side and the downstream side of the flow resistance body 222 .

A pressure sensor 223 is provided between the pressure control valve 221 and the flow resistance body 222 in the gas supply path 22 . The pressure sensor 223 constitutes an upstream side pressure sensor that detects the pressure of the carrier gas on the upstream side of the flow resistor 222 . The pressure control valve 221 constitutes a flow adjustment unit that adjusts the flow rate of the carrier gas flowing in the gas supply path 22 , and can directly control the upstream pressure of the flow resistor 223 detected by the pressure sensor 223 .

On the other hand, a pressure sensor 224 is provided between the flow resistor 222 in the gas supply path 22 and the sample introduction part 21 . The pressure sensor 224 constitutes a downstream side pressure sensor for detecting the pressure of the carrier gas on the downstream side of the flow resistor 222 . The pressure control valve 231 can directly control the pressure on the downstream side of the flow resistance body 222 detected by the pressure sensor 224 .

The control unit 27 is composed of, for example, a computer, and performs processing for controlling the operation of the flow rate regulator 2 . The control unit 27 may be a device that controls not only the flow rate adjustment device 2 but also the operation of the entire gas chromatograph. The operation unit 28 is composed of, for example, a keyboard and a mouse, and an operator can perform an input operation by operating the operation unit 28 . The display unit 29 is composed of, for example, a liquid crystal display, and can display the result of processing by the control unit 27 .

In this embodiment, since the pressure of the carrier gas flowing in the split channel 23 is controlled to a set value by the pressure control valve 231, it is possible to prevent the pressure of the carrier gas from being adjusted by the pressure control valve 221 from increasing the column inlet pressure. changes. That is, the flow rate of the carrier gas is adjusted by the pressure control valve 221. Even if the pressure on the upstream side of the flow resistance body 222 changes, the pressure on the downstream side of the flow resistance body 222 is kept constant by the pressure control valve 231. , so it is possible to prevent fluctuations in the column inlet pressure.

Therefore, when setting the total flow rate of the carrier gas and the column inlet pressure, it is not necessary to alternately and repeatedly adjust them, and it is not necessary to set them while making fine adjustments. Therefore, it is easy to work when setting the full flow rate of the carrier gas and the column inlet pressure.

In addition, the column inlet pressure on the downstream side of the flow resistance body 222 detected by the pressure sensor 224 can be directly controlled by the pressure control valve 231 without passing through the flow resistance body 222 . Thereby, it is possible to prevent deterioration of followability when the column inlet pressure fluctuates during sample introduction, and improve the reproducibility of analysis.

FIG. 2 is a block diagram showing a configuration example of the control unit 27 . The control unit 27 is configured to include, for example, a CPU (Central Process Unit), and functions as a flow measurement unit 271, a selection receiving unit 272, a valve control unit 273, and the like by running a program on the CPU.

The flow measurement unit 271 performs a process of measuring the flow rate of the carrier gas based on the detection signals of the pressure sensors 223 and 224 . That is, based on the pressure difference between the upstream pressure of the flow resistance body 134 detected by the pressure sensor 223 and the pressure on the downstream side of the flow resistance body 134 detected by the pressure sensor 224, the flow rate measurement unit 271 measures The flow rate of the carrier gas in the gas supply path 22. The measured flow rate of the carrier gas is displayed on, for example, the display unit 29 so that the operator can check it in real time.

The selection accepting unit 272 receives processing to select split analysis or non-shunt analysis based on an operation performed by the operator on the operation unit 28 . The operator can select either of split analysis or non-split analysis by operating the operation unit 28 before starting the analysis.

The valve control unit 273 performs processing for switching the three-way valve 232 to the first communication state or the second communication state. Specifically, depending on whether the selection receiving unit 272 receives split analysis or splitless analysis, the ON state of the three-way valve 232 is switched differently by the valve control unit 273 at the time of sample introduction and at the time of analysis.

In the present embodiment, the pressure control valve 231 can allow the carrier gas to flow regardless of the state of the first communication state or the second communication state. Therefore, not only in the first communication state in which the carrier gas is introduced into the split channel 23 from the sample introduction part 21, but also in the second communication state in which the carrier gas is not introduced from the sample introduction part 21 into the split channel 23, The pressure at the inlet of the chromatographic column can always be controlled by the pressure control valve 231 . In addition, since the carrier gas always flows through the pressure control valve 231 , the pressure control valve 231 can be kept clean, and the durability of the pressure control valve 231 can be improved.

Furthermore, since the bypass flow path 25 is branched from the gas supply path 22 . Therefore, it is possible to make the bypass channel 25 function as a buffer during the analysis, and suppress the pressure fluctuation of the carrier gas. Thus, the stability of the inlet pressure of the chromatographic column is improved, and the reproducibility of analysis is improved.

FIG. 3 is a flowchart showing an example of processing performed by the control unit 27 at the time of analysis. When the analysis starts, when the selection of the split analysis is accepted by the selection receiving unit 272 (Yes in step S101), the valve control unit 273 sets the three-way valve 232 to the first communication state (step S102), and introduces the flow into the chromatography column 1. sample.

Thereby, while the sample is introduced into the column 1 from the sample introduction part 21 , a part of the sample can be discharged from the split channel 23 . Thereafter, the three-way valve 232 is maintained in the first communication state until the end of the analysis (until YES in step S103 ).

On the other hand, when the selection receiving unit 272 has accepted the selection of splitless analysis (No in step S101), the valve control unit 273 sets the three-way valve 232 to the second communication state (step S104), and introduces the sample into the chromatogram. Inside column 1. At this time, the carrier gas is not introduced from the sample introduction part 21 to the split channel 23 , and all the sample in the sample introduction part 21 is introduced into the column 1 .

After the sample is introduced into the chromatographic column 1 in this way, when the predetermined time has elapsed (Yes in step S105), the three-way valve 232 is switched to the first communication state by the valve control part 273, and the carrier gas is supplied from the sample introduction part 21. Lead to the branch channel 23. As a result, the residue left on the gasket (not shown) in the sample introduction part 21 can be discharged from the split channel 23 . Thereafter, the three-way valve 232 is maintained in the first communication state until the end of the analysis (until YES in step S103 ).

In this way, in splitless analysis, although the three-way valve 232 is switched from the second communication state to the first communication state, due to the effect of the pressure control valve 231, the full flow of the carrier gas and the inlet pressure of the chromatographic column before and after switching can be maintained. must. In this way, it is possible to prevent the reproducibility of the analysis from being adversely affected by the difference in characteristics such as the resetting of the pressure control valve 231 and the flow rate characteristic, and at the same time, since the carrier gas pressure does not fluctuate greatly, it is possible to prevent the pressure sensor from being damaged. 224's durability has adverse effects.

In the above embodiments, the configuration in which the first communication state and the second communication state are switched by the three-way valve 232 has been described. However, it is not limited to such a configuration, and a multi-way valve other than the three-way valve 232 may be used to switch the first communication state and the second communication state. In this case, the multi-way valve is not limited to one valve, but may be a combination of a plurality of valves.

In addition, the flow rate adjustment device 2 may not have a structure including the bypass channel 25 and the three-way valve (multi-way valve) 232 . That is, the pressure control valve 231 may not always be in communication with the sample introduction part 21 through the branch channel 23 . In this case, an on-off valve may be provided on the downstream side of the pressure control valve 231 in the branch channel 23 . Thus, in the split analysis, the sample can be introduced while a part of the carrier gas in the sample introduction part 21 is guided to the split channel 23 by opening the on-off valve. In the splitless analysis, the sample is introduced into the column 1 from the sample introduction part 21 with the on-off valve closed, and the on-off valve may be opened after a predetermined time elapses after the sample is introduced.

The flow adjustment unit that adjusts the flow rate of the carrier gas flowing in the gas supply path 22 is not limited to the pressure control valve 221, and may be composed of, for example, a needle valve, a flow adjustment valve, or the like. That is, the flow rate regulator is not limited to a device having a function of controlling the pressure of the carrier gas to a set value, and may be a device capable of setting only the flow rate of the carrier gas corresponding to the degree of opening.

In the above embodiment, the structure in which the liquid sample is vaporized in the sample introduction part 21 (sample vaporization chamber) has been described, but it is not limited to this structure, and the vaporized gas sample may be supplied to the The structure inside the sample introduction part 21. In this case, the sample vaporization chamber may not be formed inside the sample introduction part 21 .

Explanation of symbols

1 column

2 flow adjustment device

21 Sample introduction department

22 Gas supply department

23 Split flow path

24 Exhaust flow path

25 bypass flow path

26 gas supply source

27 Control Department

28 Operation Department

29 Display

221 pressure control valve

222 flow resistance body

223 pressure sensor

224 pressure sensor

231 pressure control valve

232 three-way valve

241 flow adjustment valve

271 Flow Measurement Department

272 Select Receiving Department

273 Valve Control Section.

Claims (4)

1. a flow adjuster, it is the flow adjuster adjusted the flow of the carrier gas imported in chromatographic column, it is characterized in that having:

Sample introduction portion, sample imports in described chromatographic column by described Sample introduction portion together with carrier gas;

Gas supply road, supply carrier gas in Sample introduction portion described in described gas supply road direction;

Shunting stream, a part for sample is discharged by described shunting stream in described Sample introduction portion together with carrier gas;

Flow resistance body, described flow resistance body is arranged at described gas supply road, becomes the flow resistance of the carrier gas of flowing in this gas supply road;

Upstream side pressure sensor, the pressure of described upstream side pressure sensor to the carrier gas of the upstream side of described flow resistance body detects;

Downstream pressure transducer, the pressure of described downstream pressure transducer to the carrier gas in the downstream of described flow resistance body detects;

Flow measurement portion, described flow measurement portion, based on the detection signal of described upstream side pressure sensor and described downstream pressure transducer, measures the flow of carrier gas;

Flow adjustment part, described flow adjustment part is arranged on the upstream side of described upstream side pressure sensor, adjusts the flow of the carrier gas of flowing in described gas supply road; And

Pressure control valve, described pressure control valve by the Stress control of carrier gas that flows in described shunting stream in setting value.

2. flow adjuster according to claim 1, is characterized in that,

Also there is banked direction control valves and bypass stream further,

Described banked direction control valves is arranged on the upstream side of the described pressure control valve in described shunting stream,

Described bypass stream walks around described Sample introduction portion, makes described gas supply road and is communicated with described banked direction control valves,

Described banked direction control valves can switch between the first connected state and the second connected state, described first connected state is the state described Sample introduction portion being communicated with via described shunting stream with described pressure control valve, and described second connected state is the state described gas supply road being communicated with via described bypass stream with described pressure control valve.

3. flow adjuster according to claim 2, is characterized in that,

Also have and select acceptance division and valve control part,

Described selection acceptance division receives point flow analysis or the selection regardless of flow analysis,

Described valve control part, when described selection acceptance division have received the selection of point flow analysis, makes described banked direction control valves for described first connected state and by chromatographic column described in Sample introduction; When described selection acceptance division have received the selection regardless of flow analysis, making described banked direction control valves for described second connected state and by after in chromatographic column described in described Sample introduction, switch to described first connected state.

4. a gas chromatograph, is characterized in that,

Possesses the flow adjuster described in any one of claim 1-3.