TW202331221A - Method and device for measuring concentration of trace gas component in water - Google Patents

Abstract

An object of the invention is to provide a method and a device for measuring the concentration of a trace gas component in water that avoids human complexity and is suitable for performing highly accurate measurement of trace gas components present in ultrapure water and other samples by using sample water collection methods, increasing sensitivity through concentration operations, and taking measures to prevent degradation of column separation performance due to large amounts of sample water. The device of the invention comprises: an introduction unit which introduces a predetermined amount of a water to be measured into the flow path of a measurement unit, a gas-water separation unit which uses a pre-column to separate the water to be measured that has been introduced into the flow path of the measurement unit into a trace gas component and a water component, a concentration unit which cools and concentrates the trace gas component separated from the water, and then heats the concentrated trace gas component and feeds the component into a main column section, a deoxygenation unit which removes oxygen from the trace gas component that has been fed into the main column section, a gas component separation unit which uses the main column section to separate the deoxygenated trace gas component into one or a plurality of gas components excluding the oxygen component, and a detection unit for detecting the separated one or plurality of gas components.

Description

Method and device for concentration determination of trace gas components in water

The present invention relates to a concentration measurement method and device for trace gas components in water, for example, a method and device for concentration measurement of trace gas components in water suitable for high-precision measurement of trace gas components present in ultrapure water.

Ultrapure water is generally used in semiconductor wafers, cleaning water for liquid crystals, steam generator water for power generation turbines required for stable operation of power plants, and water for injection in the pharmaceutical industry that requires safety in all situations. Use, even a very small amount of impurities must be removed. The impurity mentioned here refers to all target substances except H ₂ O, such as gases, fine particles, metal ions, inorganic substances, and organic substances.

Gas chromatography has been used as a method for measuring such trace impurities present in water by being mixed or dissolved, especially gas components.

Furthermore, various proposals have been made as measurement methods using gas chromatography (for example, refer to Patent Document 1). [Prior Art Literature] [Patent Document]

[Patent Document 1] Japanese Reexamination No. 2014-109410

[Problem to be Solved by the Invention]

However, there are problems in the determination of trace gas components in water using conventional gas chromatography.

In recent years, the gas concentration in water such as ultrapure water requiring management of dissolved gas may reach extremely low concentrations of tens of ppb to several ppb. If the existing gas chromatography is used to directly measure this concentration, it is not feasible in terms of sensitivity.

In addition, when, for example, a small amount (less than a few μL) of sample water containing trace gas components mixed in the water is directly injected into the analysis column with a microsyringe for measurement, water will gradually remain, When it is accumulated in the analysis column, when the amount of moisture that will affect the separation is accumulated, the temperature of the column is raised to mature, so that the activity of the column is restored, and analysis can be performed again. However, this method has the following inconvenience: the injection amount into the analysis column is small, so it cannot be measured when the mixed gas component is at the aforementioned trace concentration. Specifically, the measurable range is about a few ppm as the lower limit of the measurement, and the trace gas components in water below the ppm cannot be measured.

Also, concentration assays by headspace or purge-trap methods have been performed.

For example, in the concentration measurement of trace VOC (volatile organic compounds) in water by blowing and capturing, it is directly in the gas phase part in the step of filling the sample water into the small glass bottle for sample sampling. Seal it with a large amount of air mixed in. The gas phase or liquid phase containing this air is bubbled with an inert gas to drive out and capture the VOC components, and then GC-MS (gas chromatography-mass spectrometer) or GC-FID ( A gas chromatograph with a hydrogen flame ionization detector) is used for determination. For the GC-MS or GC-FID used in this measurement, it is impossible to detect the air components on the characteristic of the detector.

In addition, especially when measuring argon in gas components, if oxygen in the air is mixed, argon and oxygen cannot be separated under normal analysis conditions. important.

In addition, the method proposed in the aforementioned Patent Document 1 uses a vacuum gas sampling cylinder to sample dissolved gas with an airtight syringe through a diaphragm and introduces it into a gas chromatograph, which cannot avoid the mixing of air components, so it cannot be measured in water. Trace amounts of argon.

Therefore, such a measurement method that cannot avoid the mixing of ambient gas (air component) in the pretreatment has the inconvenience of being unable to apply to the measurement of trace amounts of argon in water when the mixed gas component in water is argon.

In this way, when the object of measurement is trace gas components in water, according to the prior art, there are the following inconveniences: it is difficult to prevent the mixing of ambient air, it is difficult to measure the correct concentration, and it is necessary to calculate the amount obtained by bubbling. The recovery rate, etc., and the operation is very cumbersome and complicated, so the operator's proficiency is also required.

The present invention is formed in view of these problems, and the purpose is to provide a method and device for concentration and measurement of trace gas components in water, which avoids manual and cumbersome operations, and improves the sensitivity by sampling water samples and concentration operations. It is suitable for measuring trace gas components present in water such as ultrapure water with high precision as a countermeasure to prevent the reduction of column separation performance caused by a large amount of sample water. [Means to solve the problem]

In order to solve the aforementioned problems, the concentration measurement method of trace gas components in water according to the first aspect of the present invention is to measure the concentration of trace gas components present in water by using a gas chromatography measurement means, which is characterized in that : by sequentially performing the introduction step, the gas-water separation step, the concentration step, the sending step, the oxygen removal step, the gas component separation step, and the detection step to measure the concentration of the aforementioned trace gas components present in the water; wherein, the introduction step, Introduce a predetermined amount of water to be measured containing the aforementioned trace gas components into the aforementioned measuring means; in the gas-water separation step, the aforementioned water to be measured that has been introduced into the aforementioned measuring means is separated into the aforementioned trace amounts by a pre-tubular column. Gas components and water; the concentration step, cooling and concentrating the aforementioned trace gas components separated from water; the sending step, heating and sending the concentrated aforementioned trace gas components to the main column; the oxygen removal step, Oxygen is removed from the aforementioned trace gas components that have been sent out; the gas component separation step is to separate one or more gas components other than the aforementioned oxygen components from the aforementioned trace gas components after deoxygenation through the aforementioned main column; In this detection step, one or more of the aforementioned gas components obtained through separation are detected.

The present invention is constituted in this way, so manual cumbersome operations can be avoided, and the sampling method of the water to be measured can be carried out by the sample water, the sensitivity of the concentration operation can be improved, and the column caused by a large amount of sample water can be prevented. As a countermeasure against the degradation of separation performance, it is possible to measure trace gas components present in water such as ultrapure water with high precision.

Also, the method for concentrating trace gas components in water according to the second aspect of the present invention is characterized in that: in the first aspect, in terms of the aforementioned introduction step, it is formed so that the metal sample cylinder or flexible The predetermined amount of the water to be measured in the chemical container is introduced into the aforementioned measuring means in the state of being separated from the outside air, and the purge gas is equipped with countercurrent flow in the aforementioned pre-column part to separate the water in the aforementioned gas-water separation step. The obtained moisture is discharged to a step outside the aforementioned measurement means.

The present invention is constituted in this way, so the introduction of the water to be measured into the measuring device can be carried out in a state isolated from the outside, and the residual moisture in the pre-column can be reliably discharged to the outside of the measuring device, which can be performed at a high Accurate determination of trace gas components existing in water such as ultrapure water.

Also, the concentration measurement method of trace gas components in water according to the third aspect of the present invention is characterized in that: in the first or second aspect, the aforementioned trace gas components measured in the aforementioned detection step are argon, methane, carbon monoxide , carbon dioxide, krypton, xenon in one or more.

The present invention is constituted in this way, so it is possible to reliably measure specific types of gas components such as argon with high precision.

The device for concentration and measurement of trace gas components in water according to the first aspect of the present invention is to measure the concentration of trace gas components existing in water by means of a gas chromatograph, and is characterized in that it has: introducing means, Introduce a predetermined amount of water to be measured into the flow path of the aforementioned measurement means; gas-water separation means, separate the water to be measured that has been introduced into the aforementioned flow path of the aforementioned measurement means into the aforementioned trace gas through a pre-tubular column Components and water; Concentrating means, cooling and concentrating the aforementioned trace gas components separated from water, and heating and sending the concentrated aforementioned trace gas components to the main column; Oxygen removal means, from the aforementioned trace gas components that have been sent Oxygen is removed from gas components; gas component separation means, the aforementioned trace gas components after oxygen removal are separated into one or more gas components other than the aforementioned oxygen components through the aforementioned main column; and detection means, for separated One or more of the aforementioned gas components are obtained for detection.

The present invention is constituted in this way, so by using the device of the first aspect of the present invention to implement the method of the present invention of the first aspect, manual cumbersome operations can be avoided, and water to be measured can be performed by sampling water. Sampling method, concentration operation to improve sensitivity, countermeasures to prevent column separation performance degradation caused by a large amount of sample water, and can measure trace gas components existing in ultrapure water and other water with high precision.

Also, the second aspect of the present invention is a device for concentration and measurement of trace gas components in water, which is characterized in that: in the first aspect, the aforementioned introduction means is a metal sample cylinder or a flexible tube that can be filled with a predetermined amount of the aforementioned water to be measured. and is formed so that it is connected to the aforementioned flow path and the aforementioned water to be measured is introduced into the aforementioned flow path in a state separated from the outside air, and the aforementioned gas-water separation means is formed so that the purge gas The pre-column part countercurrently discharges the separated moisture to the outside of the aforementioned measurement means.

The present invention is constituted in this way, so by performing the method of the present invention of the second aspect with the device of the present invention of the second aspect, the introduction of the water to be measured into the measuring device can be carried out in a state isolated from the outside , and the moisture remaining in the pre-column can be reliably discharged out of the measuring device, and the trace gas components existing in ultrapure water and other water can be measured with high precision.

Also, the third aspect of the present invention is a device for concentrating and measuring trace gas components in water, wherein in the first or second aspect, the flow path is formed by supplying from the outside of the measurement means to the aforementioned The working gas in the flow path and the switching valve installed in the middle of the flow path can deliver the water to be measured, the separated trace gas components, moisture, and the concentrated trace gas components.

The present invention is constituted in this way, so the connection state of the flow path can be switched by switching the valve according to the purpose, and the trace gas components can be measured with good working efficiency.

Also, the fourth aspect of the present invention is a device for concentrating and measuring trace gas components in water, which is characterized in that: in any one of the first to third aspects, the aforementioned trace gas components measured in the aforementioned detection means are One or more of argon, methane, carbon monoxide, carbon dioxide, krypton, and xenon.

The present invention is constituted in this way, so by executing the method of the present invention of the third aspect with the device of the present invention of the fourth aspect, it is possible to reliably measure specific types of trace gas components with high precision. [Effect of Invention]

As mentioned above, the present invention can provide a method and device for concentration and determination of trace gas components in water, which avoids manual and cumbersome operations, and improves the sensitivity by sampling water samples and concentration operations, and prevents a large number of samples from Countermeasures against column deterioration caused by water, and suitable for high-precision measurement of trace gas components present in water such as ultrapure water.

Hereinafter, an embodiment of the present invention will be described in detail with reference to FIGS. 1 to 2 .

Fig. 1 shows the overall structure of an embodiment of the device for concentration and measurement of trace gas components in water according to the present invention.

The concentration measurement device 1 of trace gas components in water according to the present embodiment is formed so that the water to be measured is introduced from the introduction unit 2 as the introduction means shown in the left part of Fig. 1 to the measurement device 3 as the measurement means, and the The gas chromatograph 4 of the device 3 is used to measure the concentration of trace gas components in the measured water. And it is formed to sequentially connect each part from the introduction unit 2 to the gas chromatograph 4 through the flow path F through which the water to be measured, the gas component, etc. to control the flow state.

Hereinafter, each component will be described in order from the upstream side to the downstream side.

The introduction unit 2 is formed so that the metal sample cylinder 5 for storing the water to be measured in which the component is mixed due to the incorporation of a trace gas component can be detachably installed in the flow path F1, and has a On the upstream and downstream sides of the flow path F1, stop valves ST1 to ST4 control the flow of water to be measured when it is introduced.

The flow path F1 of the introduction unit 2 is connected to the flow path F2 of the measuring device 3, and the flow path F2 is connected to the flow path F2 through the switching valve V1 to measure the amount of water to be measured introduced. On the downstream side of the switching valve V1, a gas-water separation unit 8 is connected through the flow path F3 and the switching valve V2. The gas-water separation unit 8 is equipped with a pre-column 7 and separates the measured water into moisture and trace gas components. means of separation. The switching valve V2 is connected to the flow path FPG1 for supplying the purge gas PG1, and the discharge flow path P1 for discharging moisture. gas. Also, a discharge flow path P2 for discharging excess water to be measured when the water to be measured is measured in the metering tube 6 is connected to the switching valve V1. On the downstream side of the gas-water separation unit 8, a capture pipe 9 is connected through the switch valve V2, the flow path F4, and the switch valve V3. The capture tube 9 is used to cool and concentrate the trace gas components separated from water and to Concentration means that the concentrated trace gas components are heated and sent to the main column part 4a. A heater 10 for heating is wound around the capture pipe 9 . A Dewar bottle 11 storing liquid nitrogen is disposed on the catch tube 9 so as to be able to move up and down freely.

The gas chromatograph 4 is connected to the downstream side of the capture pipe 9 through the switching valve V3, the flow path F5, the switching valve V4, and the flow path F6. The switching valve V4 is connected to a flow path FCG for supplying a carrier gas CG as a working gas for sending the concentrated trace gas components in the capture tube 9 to the gas chromatograph 4 .

An aerobic trap 12 serving as oxygen removal means for removing oxygen from trace gas components is connected to the flow path F6.

On the downstream side of the oxygen trap 12 is connected the main pipe column part 4a, which serves as a gas component separation means for separating various gas components other than the oxygen component from the trace gas components after deoxygenation. A detector 13 is connected to the downstream side of the main pipe column portion 4a, and this detector 13 is used as a detection means for detecting a plurality of separated gas components.

Furthermore, the chromatography signal is transmitted from the detector 13 to a PC (personal computer) 15 (hereinafter referred to as "PC 15") which is a data processing device 14 . The concentration of the gas components calculated by PC15 is displayed on a display device (not shown) or printed. Moreover, the PC 15 transmits sequence control signals to the control unit 16 to control the up and down motions of the switching valves V1 - V4 , the catch tube 9 , the heater 10 and the Dewar bottle 11 .

Next, the concentration measurement method of trace gas components in water according to this embodiment will be described.

In this embodiment, the gas present in the water by being mixed in will be described as argon.

＜Import procedure＞ In the introducing step, a predetermined amount of water to be measured in which the component is present due to the mixing of a trace gas component is introduced into the measuring device 3 as a measuring means.

Specifically, first, water to be measured is sealed in a metal sample cylinder 5 with an inner volume of about 1 L so as not to allow air components to enter, and then it is connected to the flow path F1 of the introduction unit 2 .

Then, the sample cylinder 5 is placed in the vertical direction, and the purge gas PG2 (high-purity helium (He)) is connected to the upper stop valve ST1. While maintaining the closed state of the stop valve ST3, the two stop valves ST1 and ST2 are alternately opened and closed several times or more to replace the air component in the flow path F1 with helium. Then, fine-tune the two stop valves ST1 and ST2 so that about 100-500ml/min of helium flows through.

Then, the other stop valves ST3 and ST4 are carefully opened and adjusted so that the water to be measured flows into the metering pipe 6 through the flow paths F1 and F2 in the lower stage. The amount of water to be measured in the metal sample cylinder 5 will be filled with helium, so the metal sample cylinder 5 will not become negative pressure. Alternatively, the water to be measured may be squeezed out by slightly pressurizing helium, and introduced into the metering tube 6 .

Next, the switching valve V1 is operated, and the water to be measured in the metering tube 6 is driven out with the purge gas PG1 (high-purity helium (He)), and then introduced into the pre-column 7 .

Here, the metering tube 6 has an internal volume of about 200 μL, which is relatively large in terms of the amount of liquid introduced into the gas chromatograph. It is directly connected with the metering tube 6 and passed through water, so as to prevent contamination by air components during sampling, and the amount of water to be measured is about 100 times the normal measurement level, so high sensitivity measurement can be realized.

＜Gas-water separation step＞ In the gas-water separation step, the measured water introduced into the gas-water separation unit 8 is separated into trace gas components and water by the pre-column 7 .

Specifically, the gas components containing argon and water are separated in the pre-column 7 , and the argon is introduced into the capture tube 9 cooled by the liquid nitrogen in the Dewar bottle 11 . On the other hand, when moisture remains in the pre-column 7, the switching valve V2 is operated to reverse the flow direction of the purge gas PG1 in the pre-column 7, so that the moisture passes through the switching valve V2 and The flow path P1 is discharged to the outside of the pre-column 7 .

Here, the water is discharged to the outside of the pre-column 7, which can protect the pre-column 7 from the reduction of separation performance caused by a large amount of water remaining in the pre-column 7, and can shorten the analysis time.

＜Concentration procedure＞ In the concentration step, the trace gas components separated from the water are cooled and concentrated using liquid nitrogen.

Specifically, the Dewar flask 11 is raised to immerse the trap tube 9 in liquid nitrogen, thereby condensing and collecting trace gas components in the trap tube 9 .

Here, since the trace gas component separated from the moisture by the pre-column 7 is injected in a large amount, the peak tends to widen in the main tube column 4a. Therefore, if the trace gas components are introduced into the capture tube 9 cooled with liquid nitrogen and concentrated and collected, the bandwidth of the measured components will be narrowed, and when they are introduced into the main pipe column 4a, they will be collected in a sharp peak shape. detected.

The capture tube 9 is obtained by forming a Sulfinert tube with passivation treatment on the inner surface into a U-shape, winding it with a heater 10, and filling it with an adsorption filler. Before the start of the measurement, the small Dewar bottle 11 containing liquid nitrogen was raised to cool the capture tube 9 by immersing it in the liquid nitrogen, and after collecting trace gas components as the measurement components, the Dewar bottle 11 was lowered to capture The tube 9 is extracted from the liquid nitrogen, heated by the heater 10 energized, and the collected trace gas components are driven out by the carrier gas CG and sent to the main pipe column 4a.

＜Sending procedure＞ In the sending step, the trace gas components concentrated in the capture tube 9 are heated and sent to the main column part 4a.

Specifically, when the concentration and collection by the capture pipe 9 is completed, the connected state of the switching valves V3 and V4 is operated, and the gas chromatography carrier gas (He)CG is passed through the flow path FCG, the switching valve V4, and the flow path F5a. , switch the valve V3 to send to the capture pipe 9, and then switch to the flow paths F5 and F6 toward the gas chromatograph 4 through the capture pipe 9 and the switching valve V3.

Next, the Dewar flask 11 filled with liquid nitrogen was lowered to lift the capture tube 9 from the liquid nitrogen, and then the heater 10 was energized to heat the capture tube 9 .

Thereby, argon, the trace gas component obtained by cooling and capturing with liquid nitrogen, is driven out while heating the capture tube 9, and is sent through the switching valve V3, the flow path F5, the switching valve V4, and the flow path F6 in sequence. To the gas chromatograph 4.

<Oxygen removal step> In the oxygen removal step, oxygen is removed from the trace gas components that have been sent out from the capture pipe 9 .

Specifically, oxygen is adsorbed and captured from the trace gas components introduced into the oxygen trap 12 by the carrier gas CG through the flow path F6 and removed.

Here, regarding the separation of oxygen and argon by the oxygen trap 12, a trace gas component is passed through the oxygen trap 12 to adsorb and remove oxygen, and only argon is detected. Oxygen trap 12 is a general commercial product, and its effectiveness will deteriorate if it absorbs a large amount of oxygen, but its oxygen adsorption capacity is L (liter) level. On the other hand, the oxygen in the trace gas component that is the object of the present invention is a trace amount of ppm level. Therefore, it is almost unnecessary to perform aging regeneration of the oxygen trap 12 .

＜Gas Component Separation Procedure＞ In the gas component separation step, the trace gas components after deoxygenation are separated into multiple gas components except oxygen components through the main column.

Specifically, trace gas components from which oxygen has been removed are separated into argon, nitrogen, and other gas components in the main pipe column portion 4a.

Here, under normal conditions, the gas components introduced into the main pipe column portion 4a are separated into argon+oxygen and nitrogen, and argon and oxygen are not separated and are detected as one peak. On the other hand, in the present invention, the oxygen trap 12 is provided before the main pipe column portion 4a, so oxygen is adsorbed and captured by the oxygen trap 12, so argon is detected as a single peak in terms of the result.

＜Detection procedure＞ In the detection step, various gas components are detected after removing oxygen in the preceding stage.

Specifically, various gas components are detected by the detector 13 constituted by a thermal conductivity detector or the like. The gas used for this detection is discharged to the outside of the concentration measuring device 1 after being detected.

The test results are output by the data processing device 14 ie the PC 15 along the thick arrows, and displayed on a display not shown in the figure, or printed out.

The above-mentioned measurement method is carried out through automatic control by the PC 15 and the control unit 16 . In addition, it can also be performed by manual operation.

The measurement method according to this embodiment can avoid manual and cumbersome operations, and can improve the sensitivity by the sampling method and concentration operation of the water to be measured as the sample water, and prevent the occurrence of errors caused by a large amount of sample water. Countermeasures against column deterioration, and can measure with high precision the trace gas components that exist in water such as ultrapure water.

Next, the embodiment shown in FIG. 2 will be described.

Fig. 2 shows the overall structure of another embodiment of the device for concentration and measurement of trace gas components in water according to the present invention.

This embodiment is compared with the embodiment shown in FIG. 1, and the introduction unit 2 which is the introduction means which introduces the water to be measured into the measuring apparatus 3 is changed. The other configurations are unchanged, so the same symbols are attached.

In this embodiment, a flexible container 25 (such as a medical infusion bag, etc.) is used instead of the metal sample cylinder 5 of the foregoing embodiment. Air components are avoided from entering this flexible container 25 and only the water to be measured is sampled. Furthermore, the flexible container 25 is connected to the flow path F1 communicating with the flow path F2 of the measurement device 3 and housed in the pressurized case 26 to be installed. The flow paths F1 upstream and downstream of the flexible container 25 are respectively equipped with stop valves ST1 and ST2.

Next, the measuring method according to this embodiment will be described.

＜Import procedure＞ In the introduction step, a predetermined amount of water to be measured, in which the component exists due to the mixing of trace gas components, is introduced into the measuring device 3 as the measuring means.

Specifically, first, the water to be measured is sealed in a flexible container 25 with an inner volume of about 1 L so as not to allow air components to enter, and then it is connected to the flow path F1 of the introduction unit 2 .

Then, carefully open the stop valves ST1 and ST2, and squeeze the flexible container 25 with a slight pressure from the outside by the purge gas PG2 (the type of purge gas is not limited, but He is recommended to prevent contamination) to be measured. The water is extruded to the downstream side of the flow path F1, and introduced into the metering tube 6 through the flow path F2.

In addition to the above, it can also be adjusted as follows: the flexible container 25 is arranged above the measuring device 3, and the water to be measured passes through the flow paths F1 and F2 on the downstream side due to its own weight, and passes into the metering tube 6.

<Gas-water separation step> to <Detection step> It is carried out in exactly the same manner as the <gas-water separation step> to the <detection step> of the aforementioned embodiment, so the description is omitted.

In addition, according to this embodiment, the same function and effect as those of the above-mentioned embodiment can be exhibited, so description thereof will be omitted.

<Example> Next, an embodiment of concentration measurement performed by the concentration measurement device 1 for trace gas components in water according to the present invention shown in FIG. 1 or FIG. 2 will be described. These two figures are executed in the same manner, so in the following description, an embodiment of the concentration measurement performed by the concentration measurement device 1 for trace gas components in water shown in FIG. 1 will be described.

＜Measurement of Standard Gas＞ Before measuring the water to be measured, the aforementioned <introduction step> to <detection step> are performed with respect to the standard gas containing predetermined amounts of argon and helium.

Specifically, the standard gas Ar1000ppm/He was connected to the flow path F2, filled into the metering tube 6 of the switching valve V1, and then all the steps from <introduction step> to <detection step> were sequentially performed to perform measurement. In addition, the standard gas Ar1000ppm/He is 0.3324μg in 200μL of a metering tube at 20°C and 1 atm.

The measurement results obtained by the detector 13, that is, the chromatographic data, are processed by the data processing device 14, that is, the PC (personal computer) 15, and then displayed on the display device in the form of the chromatographic data of the standard gas shown in FIG. 3 (not shown) or print out. As shown in FIG. 3 , 0.3324 μg of argon was measured at a height of 2518 μV at a position with a residence time of 6.062 minutes. The peak position of oxygen will overlap with the peak position of argon, but the standard gas does not contain oxygen, so the reliability of the measurement result of argon shown in Figure 3 becomes extremely high. In addition, even if oxygen is contained in the standard gas, oxygen is surely removed in the <oxygen removal step> in this embodiment, so the peak of oxygen is not measured, and the reliability of the measurement result of argon is maintained at a high level. The measurement result of this argon is used as the measurement standard of the argon of the water to be measured later.

<Measurement of water to be measured 1> A liquid containing a trace amount of argon in ultrapure water without degassing treatment is prepared as water to be measured 1, and the aforementioned <introduction step> to <detection step> are carried out.

Specifically, the water 1 to be measured is prepared and supplied to the metal sample cylinder 5, and then all the steps from <introduction step> to <detection step> are sequentially performed to perform measurement.

The measurement results obtained by the detector 13, that is, the chromatographic data, are calculated and processed by the data processing device 14, that is, the PC (personal computer) 15, and the layer of the trace gas present in the measured water 1 shown in FIG. The format of the analysis data is displayed on a display device (not shown) or printed out. As shown in FIG. 4 , argon was detected as a peak at a retention time of 5.897 minutes and a height of 360 μV, and the measured concentration was 0.0407 μg (203.5000 ppb in terms of concentration in water). The retention time of the argon peak of the measured water 1 is 5.897 minutes and the retention time of the argon peak of the standard gas is 6.062 minutes. The reliability of the measurement results of argon shown in Figure 4 is high. Furthermore, the argon content was reliably measured even though it was in a trace order of ppb. In addition, since the oxygen present in the water to be measured 1 is reliably removed in the <oxygen removal step> in this embodiment, the peak of oxygen is not measured, and the reliability of the measurement result of high argon is maintained. . In Fig. 4, the peak to the right of argon represents nitrogen.

<Measurement of water to be measured 2> Prepare a liquid containing a trace amount of argon in ultrapure water that has undergone degassing treatment as water to be measured 2, and perform the aforementioned <introduction step> to <detection step>.

Specifically, the water 2 to be measured is prepared and supplied to the metal sample cylinder 5, and then all the steps from <introduction step> to <detection step> are sequentially performed to perform measurement.

The measurement results obtained by the detector 13, that is, the chromatographic data, are calculated and processed by the data processing device 14, that is, the PC (personal computer) 15, and the layer of the trace gas present in the measured water 2 as shown in FIG. The format of the analysis data is displayed on a display device (not shown) or printed out. As shown in FIG. 5 , argon was detected as a peak at a retention time of 5.925 minutes and a height of 44 μV, and the measured concentration was 0.0047 μg (23.5000 ppb in terms of concentration in water). The retention time of the argon peak of the measured water 2 is 5.925 minutes and the retention time of the argon peak of the standard gas is 6.062 minutes. The reliability of the measurement results of argon shown in Fig. 5 is high. Furthermore, the argon content was reliably measured even though it was in a trace order of ppb. In addition, the oxygen present in the water to be measured 2 is reliably removed in the <oxygen removal step> in this embodiment, so the peak of oxygen is not measured, and the reliability of the measurement result of high argon is maintained. . In Fig. 5, the peak to the right of argon represents nitrogen.

As shown in the measurement results of the various embodiments in Fig. 4 and Fig. 5, according to the concentration measurement device 1 of trace gas components in water according to the present invention, it can accurately measure the concentration in the measured water 1 and 2 without being affected by oxygen. The trace gas contained is argon (ppb level content), and the reliability is also very high.

In addition, this invention is not limited to the said embodiment, Various changes are possible. For example, instead of using the metal sample cylinder 5 and the flexible container 25 as the introduction means, it may be formed as a flow path F2 for sending the water to be measured to the measurement device 3 through the flow path F1 on the line.

1: Concentration and determination device for trace gas components in water 2: import unit 3: Measuring device 4: Gas Chromatograph 4a: Main column 5: Metal sample cylinder 6:Metering tube 7: Pre-column 8: Gas-water separation unit 9: capture tube 10: heater 11: Dewar bottle 12: Oxygen trap 13: Detector 14: Data processing device 15: PC (personal computer) 16: Control unit 25: Flexible container 26: Pressurized housing CG: carrier gas F, F1, F2, F3, F4, F5, F5a, F6, FCG, FPG1: flow path P1, P2: discharge flow path PG1, PG2: purge gas ST1, ST2, ST3, ST4: stop valve V1, V2, V3, V4: switching valve

[ Fig. 1 ] is a block diagram showing the overall configuration of one embodiment of the present invention. [ Fig. 2 ] is a block diagram showing the overall configuration of another embodiment of the present invention. [ Fig. 3 ] is a characteristic diagram showing the chromatographic data of the standard gas measured by the present invention. [ Fig. 4 ] is a characteristic diagram showing the chromatographic data of the gas present in the measured water 1 measured by the present invention. [ Fig. 5 ] is a characteristic diagram showing the chromatographic data of the gas present in the measured water 2 measured by the present invention.

1: Concentration and determination device for trace gas components in water

2: import unit

3: Measuring device

4: Gas Chromatograph

4a: Main column

5: Metal sample cylinder

6:Metering tube

7: Pre-column

8: Gas-water separation unit

9: capture tube

10: heater

11: Dewar bottle

12: Oxygen trap

13: Detector

14: Data processing device

15: PC (personal computer)

16: Control unit

CG: carrier gas

F1, F2, F3, F4, F5, F5a, F6, FCG, FPG1: flow path

P1, P2: discharge flow path

PG1, PG2: purge gas

ST1, ST2, ST3, ST4: stop valve

V1, V2, V3, V4: switching valve

Claims (7)

A method for concentrating and measuring trace gas components in water, which is to measure the concentration of trace gas components existing in water by means of a gas chromatograph, and is characterized by: Determining the concentration of the trace gas component present in the water by sequentially performing the introduction step, the gas-water separation step, the concentration step, the sending step, the oxygen removal step, the gas component separation step, and the detection step; in, In the introducing step, introducing a predetermined amount of water to be measured containing the trace gas component into the measuring means; In the gas-water separation step, the water to be measured that has been introduced into the measuring means is separated into the trace gas component and water through a pre-column; In the concentrating step, the trace gas components separated from water are cooled and concentrated; In the sending step, the concentrated trace gas components are heated and sent to the main column; The oxygen removal step removes oxygen from the trace gas component that has been sent; In the gas component separation step, the trace gas component after deoxygenation is used to separate one or more gas components except the oxygen component through the main column part; In the detecting step, one or more of the gas components obtained through separation are detected. Such as the concentration determination method of trace gas components in water according to claim 1, wherein, In the introduction step, a predetermined amount of the water to be measured is introduced into the measurement means in a state separated from the outside air, and The purge gas is made to flow countercurrently in the pre-column part, and the moisture separated in the gas-water separation step is discharged out of the measuring means. The concentration determination method of trace gas components in water as claimed in claim 1 or 2, wherein the trace gas components measured in the detection step are one or more of argon, methane, carbon monoxide, carbon dioxide, krypton, and xenon. A device for concentration and measurement of trace gas components in water, which measures the concentration of trace gas components existing in water by means of a gas chromatograph, and is characterized by: Introduction means, which introduces a predetermined amount of water to be measured into the flow path of the measurement means; A gas-water separation means, which separates the measured water introduced into the flow path of the measurement means into the trace gas component and water through a pre-column; Concentration means, cooling and concentrating the trace gas components separated from water, and heating the concentrated trace gas components and sending them to the main column; Oxygen removal means to remove oxygen from the trace gas component that has been sent; Gas component separation means, which separates the trace gas component after deoxygenation into one or more gas components other than the oxygen component through the main column part; and The detection means is to detect one or more of the gas components obtained through separation. The device for concentration and measurement of trace gas components in water as claimed in item 4, wherein, The introduction means is a metal sample cylinder or flexible container that can be filled with a predetermined amount of the water to be measured, and is formed so that it is connected to the flow path and the water to be measured is introduced in a state separated from the outside air. into the flow path, The gas-water separation means is formed so that the purge gas flows countercurrently in the pre-column part to discharge the separated moisture to the outside of the measurement means. The concentration measurement device for trace gas components in water as claimed in item 4 or 5, wherein, The flow path is formed so that the water to be measured and the separated trace gas components can be transported by the working gas supplied into the flow path from the outside of the measuring means and the switching valve installed in the middle of the flow path. , moisture, trace gas components after concentration. The concentration measurement device for trace gas components in water as claimed in item 4 or 5, wherein, The trace gas components measured in the detection means are one or more of argon, methane, carbon monoxide, carbon dioxide, krypton, and xenon.

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