JP2000035385A - Gas sampling apparatus and gas analyzer and gas analyzing method using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gas sampling apparatus capable of collecting acidic gas and basic gas components low in water solubility in high collection efficiency and not lowering the collection efficiency of an analytical component even if used over a long period of time. SOLUTION: A gas sampling apparatus 2 is constituted so that an absorbing soln. is stored in a sampling container body 21 and a sample atmosphere is supplied from a sample atmosphere supply pipe 26 by sucking the body 21 from a sample atmosphere discharge pipe 27 by a suction pump (not shown in a drawing) and the atmosphere sample is blown in the absorbing soln. to absorb a component to be analyzed in the atmosphere sample by the absorbing soln. A photocatalyst membrane layer containing a photocatalyst optically excited upon the reception of light (e.g.; ultraviolet rays) having a specific wavelength to show strong oxidizing power is formed on the inner wall of the container body 21 and a mechanism ejecting the absorbing soln. to the inner wall of the container body 21 when the absorbing soln. is supplied to the container body 21, that is, a nozzle 24a is provided to the tip of an absorbing soln. supply pipe 24.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas sampling device for efficiently sampling a trace gas component or the like in order to continuously monitor a trace gas component or a trace volatile component in the atmosphere, and a gas using the gas sampling device. The present invention relates to an analyzer and a gas analysis method.

[0002]

2. Description of the Related Art Conventionally, for analysis of gas components in the atmosphere, a sample is taken on site and brought back to an analysis room for analysis by various analysis methods, or a specific component is sent to a site from a sensor and a recording device. A method of installing and monitoring an analyzer has been adopted. In most cases, on-site sampling is performed by absorbing the component to be analyzed with an absorbing solution or absorbent, and the analysis of the component is performed using the absorbing solution itself in the case of the absorbing solution and the absorbing solution itself in the case of the absorbing agent. Used an extract obtained by adding an extract to an absorbent to extract components.

[0003] Liquid chromatographs such as high-performance liquid chromatographs and ion chromatographs have the characteristic that multiple components in a liquid can be analyzed with high sensitivity by a single sample injection. In particular, ion chromatographs for the analysis of inorganic components have become widely used because other analysis methods can easily analyze anion components that require complicated analysis operations. In the method described above, a method of analyzing the absorption solution or the extract by ion chromatography after the sampling is performed as described above is also used.

[0004] In an analysis method for collecting gas by using an absorbing solution, ultrapure water or ultrapure water containing about 100 ppm of H ₂ O ₂ is put into a gas collecting device called a bubbler or an impinger as an absorbing solution, and is measured. A method of dissolving a component to be analyzed in an absorbing solution by suctioning a predetermined amount of air with a pump and bubbling the air is widely used. For example, as disclosed in JP-A-9-257777,
Automatic monitoring using this method has also been developed, and monitoring on site has become possible.

[0005] In the analysis apparatus and analysis method of Japanese Patent Application Laid-Open No. 9-257777, an impinger (absorber) shown in FIG. 10 is used for gas sampling. In FIG. 10, the impinger 104 has a structure in which an outer cylinder 140 and an inner cylinder 145 are detachably combined, and upper and lower ends of the outer cylinder 140 and the inner cylinder 145 are open. The lower end 141 of the outer cylinder 140 is connected to a valve 153 so as to be openable and closable.
5 is closed while maintaining airtightness by a lid 146 provided in the same. An opening 147 at the lower end of the inner cylinder 145 is immersed in pure water 160 as an absorbing solution stored in the outer cylinder 140, and the upper end is an inlet 148 for introducing the sample atmosphere into the impinger 104. . The lid 146 has an exhaust port 149 connected to an exhaust device (not shown).
It is provided so as to be located above the liquid level of pure water 160 stored in 40. On the side of the impinger 104, the light emitting element 1
A level sensor 108 including a light receiving element 80 and a light receiving element 181 is provided, and is controlled so that the amount of pure water 160 stored inside the impinger 104 becomes constant during analysis. The impinger 104 includes an electromagnetic three-way valve 15.
3, 154 and 155 are connected in series,
153, the outer cylindrical portion 140 of the impinger 104
Supplied from the opening 141 at the lower end of the impinger 10.
The suction port 1 is sucked into the pure water 160 stored inside the suction port 4 by an exhaust device (not shown) connected to the exhaust port 149.
The sample air introduced from 48 is blown into the sample air, and the analyte in the sample air is absorbed by pure water 160. Thereafter, the pure water 160 is sent to an analyzer main body (not shown) and analyzed by the analyzer main body. I do.

However, the prior art disclosed in Japanese Patent Application Laid-Open No. 9-257777 has a high trapping rate in the analysis of NH ₃ described as an example in the publication (gas components having a large solubility in water such as NH ₃ ). versa), but good measurement results are obtained, the collection rate of the small gas component solubility in water, such as of the NO _x were low. Collecting and measuring at a low collection rate reduces the reliability of the analytical values. If an alkali or the like is added to increase the collection rate, it becomes difficult to analyze components having a short retention time, and it is necessary to change the eluent for each component. In the case of automating the gas sampling device, changing the eluent for each component complicates the device and is not desirable in terms of maintenance.

[0007] Further, in the conventional gas sampling apparatus, while the gas sampling is repeatedly performed, organic substances in the atmosphere are adsorbed on the inner wall surface of the sampling vessel, and the inside of the gas sampling apparatus cannot be cleaned simply by rinsing with pure water. Will be enough. If the gas is collected with insufficient cleaning, the precision and accuracy of the measured values will decrease. When the gas sampling device is used for manual analysis, it is possible to clean contaminated components by washing with an appropriate cleaning solution.However, when automating the gas sampling device, it is only necessary to pass pure water. The ability to remove contaminants is desirable for maintenance.

[0008]

BRIEF Problems to be Solved] The prior art and that can be used as a guide for collecting a high collection rate of small gas component solubility in water, such as of the NO _x in the sample air, the sample in air The following prior art is referred to for preventing the attachment of organic components and the like.

[0009] The method as a technique for collecting NOx sample in air, in Japanese Laid-8-94502 Patent Publication, the NO and NO ₂ is changed to soluble chemical form in water by the action of the photocatalyst such as titanium oxide Is disclosed. JP-A-8-94
The method for measuring nitrogen oxides in gas described in Japanese Patent Publication No. 502 will be described with reference to FIG.

In the prior art, an ultraviolet lamp 2 is used as a means for irradiating ultraviolet rays to the film formation surface 214 in a glass tube 212 in which titanium oxide fine particles and hydroxyapatite are blended and fixed on the inner wall surface with a binder.
The nitrogen oxides in the gas sucked into the gas flow path are adsorbed and collected on the film formation surface by using the adsorption tube 210 provided with the gas channel 16, and then the film formation surface is washed with a certain amount of extracted water. The nitrogen oxides washed and collected on the wall surface of the adsorption tube are converted into nitrite ion NO ₂ ⁻ and nitrate ion NO ₃ ⁻ eluted in the extraction water.
And the nitric acid and nitrate ions in the extraction water are quantified to determine the concentration of nitrogen oxides in the gas. Further, based on the difference between the quantitative value of ions in the extraction water when the film forming surface of the adsorption tube 210 is irradiated with ultraviolet rays and the quantitative value of ions in the extraction water when light is not irradiated on the film forming surface. Thus, the concentration of nitric oxide in the gas is determined.

However, in the measuring method described in Japanese Patent Application Laid-Open No. Hei 8-94502, in order to perform the measurement again, after the measurement is completed, an ethanol treatment, a dry gas is introduced as a purge gas, or heating is performed. It is necessary to dry and regenerate the deposition surface of the tube. In order to analyze components that are not adsorbed on the adsorption tube 210 or that change their chemical form regardless of irradiation with ultraviolet rays when they are adsorbed by the adsorption tube, it is necessary to collect and measure with another gas sampling device. It is.

Therefore, the present invention is capable of collecting an acidic gas and a basic gas component having low solubility in water such as NOx at a high collection rate without switching an absorbing solution for each component to be analyzed. It is an object of the present invention to provide a gas sampling device having a function of preventing adsorption of organic components in the atmosphere to the inner wall surface of a sampling container, a gas analyzer using the gas sampling device, and a gas analysis method.

[0013]

The present invention has been made by applying the above-mentioned properties of the photocatalyst.

In order to achieve the above object, a gas sampling apparatus according to the present invention includes a gas sampling container main body, a sample atmosphere supply pipe for supplying a sample atmosphere to be measured into the gas sampling container main body, and an exhaust pipe. A gas sampling apparatus, wherein a predetermined amount of an absorbing solution is held in the sampling container main body, and an inner end of a sample atmosphere supply pipe is opened in the absorbing solution, and a sample contained in the sample atmosphere is contained. In the gas sampling device for absorbing an analysis component into the absorbing liquid, the sampling container main body is formed of a material that transmits light of a specific wavelength, and is specified at least on a surface of the sampling container inner wall and a part of a pipe in the sampling container. A photocatalyst thin film layer containing a photocatalyst that is photoexcited by light of a wavelength is formed, and an excitation light source that emits light containing a specific wavelength of light that excites the photocatalyst continuously or intermittently, and an absorbing liquid containing the vessel inner wall and And having a vessel the pipe absorbing liquid supply pipe which is suppliable disposed photocatalytic film layer provided on a part of the surface of the.

Further, the gas analyzer according to the present invention is characterized in that the gas collecting device, the capturing / concentrating means for capturing and concentrating the analyte to be analyzed absorbed in the absorbing solution in the main body of the collecting container, and the gas collecting device. A means for sending an absorbing solution to the capturing / concentrating means, a separating means for releasing the analyte trapped by the capturing / concentrating means from the capturing / concentrating means, and detecting an analyte separated from the capturing / concentrating means. It is a gas analyzer having component detection means.

A gas analysis method according to the present invention is a gas analysis method using the gas analyzer using the above-described gas analyzer according to the present invention, wherein the step of draining the absorption liquid remaining in the main body of the gas sampling container includes the steps of: A step of supplying the absorbing liquid from the liquid supply pipe so as to flow down the inner wall of the container main body from the upper part of the gas sampling container main body, and cleaning the inner wall of the container main body; A step of storing a predetermined amount of the absorbing liquid in the collection container main body, a sampling step of blowing a sample air to be measured into the absorbing liquid to absorb the analyte contained in the sample air, and absorbing the analyte Sending the absorbing solution to the capturing and concentrating means, concentrating the analyte component, removing the analyte component captured by the capturing and concentrating means from the capturing and concentrating means,
And analyzing the separated analyte component by means of component analysis means.

[0017]

DETAILED DESCRIPTION OF THE INVENTION Regarding a photocatalyst such as titanium oxide,
Japanese Patent Application Laid-Open No. 9-83005 discloses a technique of covering the surface of a solar cell with a transparent layer containing the photocatalyst.
This technology is a technology related to a protective cover for a solar cell.If the surface of the protective cover for a solar cell is covered with a photocatalytic layer as in this technology, the photocatalytic layer is photoexcited by sunlight, and the surface of the photocatalytic layer is The contact angle with water is about 0
It becomes superhydrophilic to the extent that it becomes ゜. When the solar cell is exposed to rain, dirt adhering to the surface of the protective cover is washed away by rainwater, and the surface is self-cleaned (self-cleaning).

In Japanese Patent Application Laid-Open No. Hei 8-99041, when a titanium oxide, which is a typical photocatalyst, having a crystal form of anatase is formed on a substrate surface so as to be transparent and porous, the titanium oxide film is obtained. Adsorbs environmental pollutants,
It is disclosed that the irradiation with light can rapidly and effectively decompose and remove the environmental pollutants.

Therefore, in the present invention, by utilizing such characteristics of the photocatalyst, the light from the excitation light source is irradiated to the main body of the gas collecting container to form the gas on the inner wall and a part of the surface of the pipe in the collecting container. and the photocatalytic film layer is activated, the collection in the container OH radicals and O ₂ ^- is generated strong oxidizing components such as an absorption liquid to the strong oxidizing component also being contained in the collection container body Allow to dissolve. When the sample atmosphere is blown into the absorbing solution, for example, the NO _x component in the sample atmosphere is oxidized, changes to a water-soluble chemical form (NO ₂ ⁻ or NO ₃ ⁻ ), and is absorbed by the absorbing solution. In addition, organic components and the like adhering to the surface of the photocatalytic thin film layer are oxidized and decomposed, and are easily washed away by the absorbing solution, so that the surface of the photocatalytic thin film layer is self-purified.

Next, an embodiment of the present invention will be described with reference to the drawings.

(First Embodiment) FIG. 1 is a block diagram showing a first embodiment of the gas analyzer of the present invention.

As shown in FIG. 1, a gas analyzer 1 of the present embodiment includes a gas sampling device 2 for sampling an analyte to be analyzed from a sample air, and a gas sampling device 2 for analyzing the analyte collected by the gas sampling device 2. An ion chromatograph 3 which is a component detection device for detection.

First, an outline of the gas sampling device 2 will be described with reference to FIGS. FIG. 2 is a conceptual perspective view showing a detailed configuration of the gas sampling device shown in FIG. FIG. 3 is a partially cutaway schematic sectional view.

As shown in FIGS. 1 and 2, the gas sampling apparatus 2 includes a sampling vessel main body 21, an excitation light source 22, and a reflection plate 23. In the collection container main body 21, an absorption liquid supply pipe 24 for supplying the absorption liquid, an absorption liquid discharge pipe 25 for discharging the absorption liquid from the collection container main body 21, and a gas collection container 21
Sample air supply pipe 26 for supplying the sample air into the inside, and sample air discharge pipe 2 for discharging the sample air from inside the collection container body 21
7 are provided.

As shown in FIG. 3, a photocatalytic thin film layer 21a is formed on the inner wall of the main body 21 of the collection container.

In the gas sampling apparatus 2 configured as described above, when ultrapure water is supplied to the absorption liquid supply pipe 24 as the absorption liquid by the liquid supply pump 15, the absorption liquid is supplied to the absorption liquid supply pipe 24. The nozzle 24 a provided at the tip squirts toward the inner wall of the collection container main body 21 and flows down along the inner wall of the collection container main body 2. When the drainage valve 28 is opened and the absorbing liquid flowing out of the absorbing liquid discharge pipe 25 by the liquid sending pump 12 is sequentially sent to the waste liquid side via the flow path switching valve 16,
The inner wall surface of the collection container main body 21 is washed with the absorbing liquid (cleaning step), the drainage valve 28 is closed, and the absorbing liquid flows down with the liquid supply pump 12 stopped, whereby the absorbing liquid is stored in the collecting container main body 21. (Storage process). At the time of the cleaning, the cleaning property is further improved by keeping the excitation light source 22 turned on.

After the cleaning, after a predetermined amount of absorbing liquid is stored in the collection container main body 21 in the water storage, the liquid supply pump 15 is stopped and the suction pump 13 is operated. A sample air is supplied into the sample 21, and the sample air is blown into the absorbing solution stored in the collection container main body 21, comes into contact with the absorbing solution, and is discharged from the sample air discharging pipe 27 (sampling step).
At this time, when the excitation light source 22 is lit, the activity of the formed on the inner wall of the collection container body 21 photocatalytic film layer 21a is very high, for example, NO and NO ₂ hardly soluble in the absorption liquid as it HNO _It is oxidized to ₂ and HNO ₃ and absorbed by the absorbing solution, but the organic acid is decomposed into carbon dioxide and water. On the other hand, if the excitation light source 22 is turned off, NO
And NO ₂ are discharged to the sample air discharge pipe 27 without being absorbed, and the organic acid is absorbed by the absorbing liquid without being oxidized and decomposed.

After the suction pump 13 is driven to supply a predetermined amount of sample air to the collection container main body 21, the suction pump 13 is stopped, the drain valve 28 is opened, and the flow path switching valve 16, the flow path switching valve 32 is switched to the flow path indicated by the broken line. When the liquid feed pump 11 is operated, the absorbent flowing out of the absorbent discharge pipe 25 is sent to the concentration column 33 of the ion chromatograph 3 via the flow path switching valve 16 (concentration step).

At the start-up and after the concentration, the flow path switching valve 1
6 is switched to the flow path indicated by the solid line, and the liquid feed pump 12 is operated, so that the absorbing liquid in the collecting container main body 21 (the absorbing liquid remaining in the collecting container main body at the time of starting or the absorbing liquid in the previous measurement).
Is sent to the waste liquid side (drainage process).

The flow rates of the liquid feed pumps 11, 12, and 15 are adjusted by a flow rate adjusting mechanism (not shown) of each liquid feed pump.
Is set to a predetermined value, and the flow rate of the suction pump 13 is set to a predetermined value by the flow rate controller 14.

Next, the outline of the ion chromatograph 3 will be described.

As shown in FIG. 1, the ion chromatograph 3 has a flow path switching valve 32 for switching the flow path of the supplied absorbent, and adsorbs the analyte to be collected in the absorbent. Concentration column 33 as capture concentration means for concentration
A liquid sending pump 31 for sending an eluent for eluting the analyte adsorbed to the concentration column 33; and a detecting means for separating the analyte from the eluent and detecting the analyte. It has a separation column 34 and a detector 35. The eluent removes the analyte from the concentration column 33 as a capturing and concentration means,
Functions as means for separating a plurality of analytes from each other. The eluent is constantly supplied by the liquid supply pump 31 throughout the entire measurement process. In addition, the liquid sending pump 31
Is set to a predetermined value by a flow rate adjusting mechanism (not shown).

During the next cycle of drainage, cleaning, water storage, and sampling after the concentration, the analyte to be concentrated in the concentration column 33 is eluted by the eluent.

The eluent containing a plurality of analytes which have been collectively concentrated in the concentration column 33 flows into the separation column 34 after passing through the flow path switching valve 32, and the plurality of analytes contained in the eluate. Are separated from each other by the difference in the retention time in the separation column 34, and together with the eluent, the detector 3
5 in turn. Quantitative analysis of each of the components to be analyzed is performed from the measurement value of the detector 35, and the concentration of the component to be analyzed in the sample air is calculated from the analysis value.

Here, the configuration of the gas sampling apparatus shown in FIG. 1 will be described in detail with reference to FIG. FIG. 3 is a partially enlarged cross-sectional view of the gas sampling device 2 shown in FIG. 1 and FIG.

The main body 21 of the collection container itself includes the photocatalytic thin film layer 2.
It is formed of a material capable of transmitting the excitation light for exciting the photocatalyst 1a with little attenuation. For example, it is preferable to use heat-resistant glass such as quartz or Pyrex (registered trademark) as the material. According to the result of verification by the present inventors, it was confirmed that the photocatalyst was photoexcited when the attenuation rate of the excitation light on the tube wall of the container body was 90% or less. Further, when the attenuation rate of the excitation light is 50% or less, the photocatalyst is more photoexcited, and the oxidation reaction of NO or NO ₂ in the sample atmosphere proceeds efficiently, and 80% or more of NO or NO ₂ becomes HNO ₂ or HNO. Oxidized to ₃ ,
It was confirmed that it was absorbed by the absorbing solution.

The photocatalytic thin film layer 21a can be photoexcited by light (for example, ultraviolet light) having a wavelength in the ultraviolet to visible range, and the same components as the components to be analyzed or components that interfere with the analysis are less eluted into the absorbing solution. The substance is used.
The photocatalytic substance, for example, anatase type titanium oxide,
Zinc oxide (excitation wavelength 378 nm), tin oxide (excitation wavelength 344 nm), rutile titanium oxide (excitation wavelength 413 n
m) and the like, it is desirable to use a substance that is efficiently activated by artificial light from a light source such as a UV lamp. In particular,
Titanium oxide such as anatase-type titanium oxide or rutile-type titanium oxide is harmless and chemically stable, and thus is suitable as a thin film layer material.

The photocatalytic thin film layer 21a may be formed as a single film using one of the photocatalytic materials described above, or may be formed as a composite film using two or more photocatalytic materials. The photocatalyst thin film layer 21a is transparent or translucent,
The thickness of the photocatalytic thin film layer 21a is preferably 0.01 μm to 5 μm, and more preferably 1 μm or less. Further, when the surface of the photocatalytic film layer 21a on the porous, photochemical reaction of the organic components such as soil the inner wall of the analyte and collection container 21, such as NO and NO ₂ adhering to the photocatalytic film layer 21a Efficiency is improved.

In order to form such a photocatalytic thin film layer 21a, for example, in the case of anatase-type titanium oxide, as disclosed in Japanese Patent Application Laid-Open No. Hei 8-99041, ultrafine titanium oxide is used. Polyethylene glycol or the like is added to the titania sol prepared by suspending in water or the like, coated on the inner wall of the collection container main body 21 by dip coating, spin coating, coating, spraying, etc., and then heated and baked. can get. In particular, by setting the firing temperature to 600 to 700 ° C., an anatase-type titanium oxide photocatalyst film having pores with uniform pore diameters can be obtained.

On the other hand, the nozzle 24a of the absorption liquid supply pipe 24
The end of the absorption liquid supply pipe 24 is sealed, and pores are formed on the side of the pipe near the sealed portion, so that the absorption liquid is dispersed in at least two directions, and It is structured to be supplied. The absorbing liquid supplied from the absorbing liquid supply pipe 24 is diffused over the entire inner wall surface of the collection container main body 21 to form a water film on the surface of the photocatalytic thin film layer 21a, and flows from the upper surface to the lower surface of the inner wall surface of the collection container main body 21. I do.
As a result, the analyte can be collected at a high reproducible collection rate. Note that the nozzle 24a may be configured so that most of the absorbing liquid ejected from each of the pores can reach the inner wall of the collection container main body.
The configuration such as the diameter of the pores and the position of the pores is arbitrary.

Further, a device (not shown) for controlling the temperature of the sampling container body 21 or the entire gas sampling device 2 is added, and the temperature of a part or the whole of the sampling container body 21 is reduced to 0 ° C.
By maintaining the above-mentioned room temperature or lower, preferably at 0 ° C. to 10 ° C., and suppressing the absorption liquid from evaporating and being discharged from the sample air discharge pipe 27 and disappearing from the collection container main body 21, the analysis accuracy can be improved.

Next, a gas analysis method using the above-described gas analyzer of the present embodiment will be described with reference to FIGS. 1, 4 and 5. FIG. FIG. 4 is a flowchart showing the analysis steps of the gas analysis method of the present embodiment, and FIG. 5 is a view showing the states of the valves and pumps in each analysis step.

The first step is drainage (S101). At startup and after concentration (S105) during continuous measurement, the absorbent remaining in the collection container main body 21 is discharged from the collection container main body 21. The flow path switching valve 16 shown in FIG. 1 is switched to the flow path shown by the solid line, the drain valve 28 is opened, the liquid supply pump 12 is operated, and the absorbent remaining in the collection container main body 21 is discharged to the waste liquid side of the liquid supply pump 12. Drain.

The second step is cleaning (S102). With the flow path switching valve 16, the drain valve 28, and the liquid sending pump 12 kept as they are, the liquid sending pump 15 is operated to supply ultrapure water from the absorbing liquid supply pipe 24 into the collection container main body 21. This supply state is continued for a predetermined time, and the inside of the collection container main body 21 is washed with ultrapure water. The ultrapure water that has flowed down to the bottom of the collection container main body 21 is drained to the waste liquid side via the absorption liquid discharge pipe 25, the drain valve 28, the flow path switching valve 16, and the liquid pump 12 in this order. As a result, the components to be analyzed in the pre-measurement remaining in the collection container are washed away. Further, when it is desired to activate the photocatalytic thin film layer 21a to react the analyte in the subsequent sampling (S104), the excitation light source 22 is turned on to bring the concentration of the reactive species in the collection container body 21 to a steady state. I do. If it is not desired to react the analyte, the excitation light source 22 is turned off, and the reactive species generated in the collection container main body 21 in the previous measurement cycle are also washed away. The on / off state of the excitation light source 21 remains the same from at least the second to fourth steps.

The third step is water storage (S103). The drain valve 28 is closed, and the liquid feed pump 12 is stopped. On the other hand, the supply of the ultrapure water from the absorbing liquid supply pipe 24 into the collection container main body 21 by the liquid feed pump 15 is continued. The supply of ultrapure water by the liquid feed pump 15 is continued for a predetermined time, and a predetermined volume of ultrapure water is stored in the collection container main body 21. The stored water is used for the absorbing solution.

The fourth step is sampling (S104). The liquid supply pump 15 is stopped, the suction pump 13 is operated, and the sample air is collected from the sample air supply pipe 2 of the collection container body 21.
The sample is ventilated into the absorbing solution through 6 and exhausted from the sample atmosphere exhaust pipe 27. The components to be analyzed in the sample atmosphere are collected
1 is absorbed by the absorbing liquid. At this time, the excitation light source 22
Is lit, NO and NO ₂ are absorbed as HNO ₂ or HNO ₃ in the absorbing solution. On the other hand, organic acids undergo oxidative decomposition or change in chemical form. Quantitative analysis is difficult. on the other hand,
When the excitation light source 22 is turned off, NO and NO ₂ are hardly absorbed by the absorbing solution, so that HNO ₂ , HNO ₃ and their salts originally existing in the sample atmosphere are absorbed by the absorbing solution. The organic acid is also absorbed by the absorbing solution in a chemical form that allows qualitative and quantitative analysis in the sample atmosphere. This ventilation state is continued for a predetermined period of time to quantitatively collect the components to be analyzed.

The fifth step is a pre-concentration treatment (S105a). First, a drain valve 28,
A suction pump 13 is provided to replace the inside of a pipe leading to the flow path switching valve 32 via the flow path switching valve 16 and the liquid sending pump 11 with the absorbing liquid having absorbed the analyte in the fourth step. The pump is stopped, and the liquid supply pump 11 is operated to drain a predetermined amount of the absorbing liquid from the waste liquid side of the flow path switching valve 32.

The sixth step is concentration (S105b).
The liquid supply pump 11 is continuously operated, and the flow path switching valve 16 shown in FIG. 1 is switched to the flow path shown by the broken line. The fourth
The absorption liquid that has absorbed the analyte in the step (1) passes through the drain valve 28, the flow path switching valve 16, the liquid feed pump 11, and the flow path switching valve 32 in that order, and is sent to the concentration column 33. The analyte in the absorption solution is captured by the concentration column 33 while passing through the concentration column 33. The sixth step is continued for a predetermined time, but is performed in a pipe from the absorbent discharge pipe 25 to the concentration column 33 through the drain valve 28, the flow path switching valve 16, the liquid feed pump 11, and the flow path switching valve 32. The incorporation of air will hinder subsequent analysis,
At the end of this step, it is necessary to allow a small amount of the absorbing liquid to remain in the collection container main body 21. Therefore, the time of this step is expressed by (total volume (m
l) -Absorbed liquid amount (ml) consumed for liquid replacement in the pipe in the fifth step-Absorbed liquid amount (ml) remaining in sampling container 21 after completion of this step) / (Sending of liquid sending pump 11) The time must be set shorter than the liquid flow rate (ml / min). Therefore, to measure with the highest possible sensitivity,
It is necessary to minimize the amount of the absorbing liquid consumed for the liquid replacement in the fifth step and the amount of the absorbing liquid remaining in the collection container 21 after the end of this step. If the flow rate of the liquid sending pump 11 is set to a predetermined value or less, the analyte contained in the absorbing solution introduced into the concentration column is almost one.
00% can be captured in the concentration column 33.

The seventh step is a separation analysis (S106). The flow path switching valve 32 shown in FIG. 1 is switched to the flow path shown by the solid line, and the eluent sent by the liquid sending pump 31 is sent to the concentration column 33, and the concentration column 3 is supplied in the sixth step.
The plurality of analytes collectively captured in the column 3 are concentrated in the concentration column 3
Elute from 3. The eluent containing the plurality of analytes and flowing out of the concentration column 33 flows into the separation column 34, and the plurality of analytes are separated from each other by a difference in retention time in the separation column 34. You. Separation column 3
The effluent from 4 then flows into the detector 35 and the detector 35
In, a physical quantity is detected at an intensity corresponding to the type and concentration of the analyte contained in the liquid passing through the detection unit (not shown). The temporal change in the detected intensity is taken into a data processing / control unit (not shown). The data processing / control unit detects a change in the detected intensity caused by the component to be analyzed based on the captured data, and automatically calculates the concentration based on the calibration curve data input in advance.

By repeating the measurement using the first to seventh steps as one measurement cycle, continuous measurement of the sample atmosphere is possible. Further, the measurement cycle with the excitation light source 22 turned on and the measurement cycle with the excitation light source 22 turned off are continuously performed on the same sample atmosphere, that is,
By performing the combination of the seed measurement cycles as one measurement cycle, components that cannot be measured by the single measurement of turning on and off the excitation light source 22 can be complemented, and more analysis information on the sample atmosphere can be obtained.

Here, in the seventh step, if the flow path switching valve 32 shown in FIG. 1 is set to the flow path shown by the solid line,
Flow path switching valve 16, drain valve 28, liquid pump 1
This is a step in which the analysis processing in the ion chromatograph 3 can proceed independently, regardless of the state of the suction pump 13. Therefore, the seventh step is performed in parallel with the first to fourth steps of the next measurement cycle, and the separation analysis is performed so that the seventh step is completed between the first to fourth steps. By adjusting the above conditions, the measurement time can be reduced. FIGS. 4 and 5 used in the description of the present embodiment show examples in which the means for reducing the measurement time is applied. In FIG. 4, drainage, cleaning, water storage, and sampling are combined into a separate analysis. In the above, the operation status display of valves and pumps for separation analysis is omitted.

When only the measurement is performed in a state where the excitation light source 22 is turned off, an organic component or the like adheres to the surface of the photocatalytic thin film layer 21a. Therefore, after all the measurements, the excitation light source 22 is turned on and the first light source is turned on. After the third step, it is desirable to decompose the organic components and the like adhering to the surface of the photocatalytic thin film layer 21a, wash them away with the absorbing solution, and then stop the analyzer. Also, when starting the device, prior to all measurements,
It is desirable to perform the first and second steps by turning on the excitation light source 22.

As described above, the photocatalytic thin film layer 21a
By turning on the excitation light source 22, NO or NO _{2 that} is hardly dissolved in the absorbing solution as it is is converted into HNO ₂ or HNO _3.
It is oxidized to be absorbed by the absorbing solution and can be analyzed. Also,
When the excitation light source 22 is turned on, organic acids and the like that are oxidized and decomposed and cannot be analyzed can be analyzed by turning off the excitation light source. Conventionally, the analysis of acidic gas in the sample atmosphere, which had to use a different sampling method or an absorbing solution or an analyzer for each component, can be performed simply by controlling the turning on and off of the excitation light source by using the present invention. One sampling method, an absorbing solution, and an analyzer can be used.

Further, it is not possible to sufficiently wash just by passing water, and the contaminant components accumulated on the inner wall surface of the collection container main body 21 during continuous use in the conventional collection apparatus are reduced by the photocatalyst in the collection apparatus of the present invention. Since the thin film layer 21a is photoexcited and oxidatively decomposes the fouling component, adsorption of the fouling component can be prevented. In addition, the inner wall surface of the collection container main body 21 is kept highly hydrophilic due to the prevention of the attachment of fouling components, and the inner wall surface of the collection container main body is washed off evenly by the absorbing liquid jetted and supplied at the upper part of the collection container main body. Washed well.
Since it is not necessary to periodically perform maintenance cleaning of the collection container main body 21, the gas analyzer of the present invention can reduce the burden on the user.

Further, since the surface of the inner wall of the collection container body is highly hydrophilic, when the sample air is blown into the absorbing solution to perform sampling, even if the absorbing solution scatters to the upper portion of the collecting container, the liquid is retained at the upper portion. Without remaining as drops, a water film of the absorbing liquid is formed and flows down to the lower part of the collection container. The formation of the water film contributes to improving the collection rate of the analyte in the sample atmosphere. In the analyzer of the present invention, the collection rate hardly changes with time, and the concentration measurement accuracy of the analyte can be maintained.

In the gas sampling apparatus according to the present embodiment, as shown in FIG.
a, the absorption liquid is jetted from the nozzle 24a to the inner wall of the collection container main body 21. The purpose of the nozzle is to supply the absorption liquid from the upper portion to the lower portion of the collection container inner wall as uniformly as possible irrespective of the direction. Therefore, as long as the purpose is satisfied, the tip structure of the absorbing liquid supply pipe 24 may be other than that shown in FIG. For example, a structure in which the tip portion is branched may be used, or the absorption liquid supply pipe 2 may be used.
The tip of the absorption liquid supply pipe may be installed in the collection container main body 21 so that the absorption liquid flowing out from 4 flows spirally from the upper part to the lower part of the collection container main body 21. In these methods as well, since a water film is formed on the inner wall surface of the collection container main body 21 by the absorbing liquid, the analyte can be collected at a high reproducibility and high collection rate.

In this embodiment, the example in which the ion chromatograph 3 is used as the component detecting device for detecting the components of the gas collected by the gas collecting device 2 has been described. Is not limited to a liquid chromatograph such as an ion chromatograph 3, and it is desirable to use a component detection device corresponding to the component / component group to be analyzed.

(Second Embodiment) FIG. 6 is a block diagram showing a second embodiment of the gas analyzer of the present invention. The configuration of the gas sampling device 2 is the same as that of the first embodiment.

First, differences between the gas analyzer 51 of the present embodiment and the gas analyzer 1 of the first embodiment will be briefly described.

In the gas analyzer 1 of the first embodiment shown in FIG. 1, the liquid supply pump 15 has a function of supplying ultrapure water as an absorbing liquid into the collection container main body 21, and the liquid supply pump 11 has The function of sending the absorbing solution having absorbed the above to the ion chromatograph 3 was provided. In addition, the absorption liquid that has absorbed the analyte in the collection container main body 21 from the gas collection device 2 was sent to the concentration column 33 by the liquid sending pump 11, passed through the concentration column, and was discarded. In contrast,
In the gas analyzer 51 of the present embodiment shown in FIG. 6, by providing the flow path switching valve 17 between the flow path switching valve 16 and the liquid sending pump 11, the liquid sending pump 15 is omitted, and the liquid sending pump 11 It has two functions: a function of supplying ultrapure water as the absorbing liquid into the collection container main body 21 and a function of sending the absorbing liquid having absorbed the analyte to the ion chromatograph 3. In the analyzer according to the first embodiment shown in FIG. 1, a flow switching valve is provided at the connection port of the flow switching valve 32 on the waste liquid side of the absorbing liquid sent by the liquid sending pump 11. 18 is connected, and the absorption liquid having absorbed the analyte in the collection container main body 21 is concentrated by the liquid sending pump 11 into the concentration column 3.
3, the liquid was passed through the concentration column 33, and then supplied again from the absorbing liquid supply pipe 24 to the collection container main body 21. This makes it possible to circulate the absorbent through the absorbent circulation system between the collection container main body 21 and the concentration column 33. The supply of fresh absorbing liquid (ultra pure water) to the absorbing liquid circulation system between the collection container main body 21 and the concentration column 33 is performed via the flow path switching valve 17. Other components are the gas analyzer 1 shown in FIG.
Since the configuration is the same as that described above, the description is omitted.

Further, the gas analyzer 51 of the present embodiment
Will be described in detail with respect to differences from the gas analyzer 1 of the first embodiment.

In the gas sampling device 2 incorporated in the gas analyzer 51, in cleaning and water storage, ultrapure water as an absorbing liquid is sequentially passed through the flow path switching valves 17, 32, and 18 by the liquid sending pump 11. When the liquid is sent to the absorbing liquid supply pipe 24, the absorbing liquid is ejected from a nozzle 24 a provided at the tip of the absorbing liquid supply pipe 24 toward the inner wall of the collection container main body 21, and downward along the inner wall of the collection container main body 21. Flow down. The other operations of the valve and the pump are the same as those described for the cleaning and the water storage in the gas analyzer 1 of the first embodiment, and the description is omitted.

After a predetermined amount of the absorbing liquid is stored in the sampling container main body 21 in the water storage, the liquid sending pump 11 is stopped and the suction pump 13 is operated to perform sampling. The other operations of the valve and the pump are the same as those described for the sampling in the gas analyzer 1 described in the first embodiment, and the description is omitted.

After a predetermined amount of sample air is supplied to the collection container main body 21 by the suction pump 13, the suction pump is stopped, the drain valve 28 is opened, and the flow path switching valves 16 and 1 are opened.
7 and 32 are switched to flow paths indicated by broken lines. Liquid pump 1
When 1 is operated, the absorbent flowing out of the absorbent discharge pipe 25 is sent to the concentration column 33 of the ion chromatograph 3 via the flow path switching valves 16 and 17 sequentially. At this time, if the flow path switching valve 18 shown in FIG. 6 is set to the flow path shown by the solid line, the absorbent flowing out of the concentration column 33 is returned to the collection container main body 21 (concentration 2), and the flow path switching valve 1
When the flow path 8 is set to the flow path indicated by the broken line, the absorbent flowing out of the concentration column 33 is drained to the waste liquid side of the flow path switching valve 18 (concentration 1).

At the start-up and after the concentration 1 and the concentration 2, the flow path switching valves 16 and 17 are switched to flow paths shown by solid lines,
When the liquid sending pump 12 is operated, the absorbing liquid in the collecting container main body 21 (the absorbing liquid remaining in the collecting container main body at the time of starting or the pre-measured absorbing liquid) is sent to the waste liquid side (drainage).

The outline of the ion chromatograph 3 is also described in the ion chromatograph 3 in the first embodiment.
Only the differences from the description will be described.

In the cleaning and water storage, the flow path switching valve 32 is set to a flow path shown by a solid line in FIG. 6, and the absorption liquid sent to the ion chromatograph 3 flows through the concentration column 33 without passing through the concentration column 33. Switching valve 3
The liquid is sent to the collection container main body 21 sequentially through 2 and 18. In the concentration 1 and the concentration 2, the flow path switching valve 3
2 is set in a flow path indicated by a broken line in FIG. 6, and the absorbing solution sent to the ion chromatograph 3 is sent to the concentration column 33. In the concentration column 33, the analyte component is concentrated by capturing the analyte component contained in the absorption liquid. The absorbent flowing out of the concentration column 33 passes through the flow path switching valves 32 and 18 sequentially, and when the flow path switching valve 18 is set to the flow path shown by the broken line in FIG. When the flow path switching valve 18 is set to the flow path indicated by the solid line, the liquid is returned to the collection container main body 21.

Next, FIG. 6 and a flowchart showing the analysis steps of the gas analysis method according to the present embodiment in that the analysis method using the gas analysis device 51 is different from the analysis method using the gas analysis device 1. 7 and FIG. 8 showing the states of valves and pumps in each analysis step of the gas analysis method of the present embodiment.

The first step is drainage (S101). Since this step is performed in the same manner as the first step of the first embodiment, the description is omitted.

The second step is cleaning (S102). With the flow path switching valves 16 and 28 and the liquid pump 12 kept as they are, the liquid pump 11 is operated to supply ultrapure water from the absorbent supply pipe 24 into the collection container body 21. This supply state is continued for a predetermined time, and the collection container body 21
Wash the inside with ultrapure water. The ultrapure water that has flowed down to the bottom of the collection container main body 21 is drained to the waste liquid side via the absorption liquid discharge pipe 25, the drain valve 28, the flow path switching valve 16, and the liquid pump 12 in this order. As a result, the components to be analyzed in the pre-measurement remaining in the collection container are washed away. Further, when it is desired to activate the photocatalytic thin film layer 21a to react the analyte in the subsequent sampling (S104), the excitation light source 22 is turned on to bring the concentration of the reactive species in the collection container body 21 to a steady state. I do. If it is not desired to cause the analyte to react, the excitation light source 22 is turned off, and the reactive species generated in the collection container body 21 in the previous measurement are also washed away. The on / off state of the excitation light source 21 remains the same from at least the second to fourth steps.

The third step is water storage (S103). The drain valve 28 is closed, and the liquid feed pump 12 is stopped. On the other hand, the supply of the ultrapure water from the absorption liquid supply pipe 24 into the collection container main body 21 by the liquid feed pump 11 is continued. The supply of ultrapure water by the liquid sending pump 11 is continued for a predetermined time, and a predetermined volume of ultrapure water is stored in the collection container main body 21. The stored water is used for the absorbing solution.

The fourth step is sampling (S104). Since this step is performed in the same manner as the fourth step of the first embodiment, the description is omitted.

The fifth step is concentration 1 (S105a). The suction pump 13 is stopped, the liquid supply pump 11 is operated, and the flow path switching valves 16, 17, 18, 32 shown in FIG.
Is switched to the flow path indicated by the broken line. The absorption liquid that has absorbed the analyte in the fourth step passes through the drain valve 28, the flow switching valves 16 and 17, the liquid feed pump 11, and the flow switching valve 32, and is sent to the concentration column 33. Is done. The analyte in the absorption solution is captured by the concentration column 33 while passing through the concentration column. The absorbent flowing out of the concentration column 33 is drained to the waste liquid side of the flow path switching valve 18.
The sixth step is continued for a predetermined time, and the time of this step is (the total volume (ml) of the absorbent in the collection container body 21).
It must be set to a time shorter than ÷ (liquid flow rate of liquid pump 11 (ml / min)). After this step, it is desirable to set the time of this step so that about 10% of the total volume of the absorbing solution remains in the collection container main body 21.

The sixth step is concentration 2 (S105b). The liquid supply pump 11 is continuously operated, and the flow path switching valve 18 shown in FIG. 6 is switched to the flow path shown by the solid line. The absorption liquid having absorbed the analyte in the fourth step is supplied to the drain valve 28, the flow path switching valves 16 and 17,
1. Passing sequentially through the flow path switching valve 32, the concentration column 33
Liquid. The analyte in the absorption solution is captured by the concentration column 33 while passing through the concentration column. The absorbent flowing out of the concentration column 33 is returned to the collection container main body 21 via the flow path switching valve 18. Sampling container body 21
When returning the absorbent to the nozzle 2 of the absorbent supply pipe 24,
By spraying from 4a onto the inner wall of the collection container main body 21, the absorbent scattered on the upper part of the collection container main body 21 in the fourth step is washed down on the lower part of the collection container main body 21, and the components to be analyzed contained in the scattered absorbent are also reduced. to recover. Thereby, the collection rate can be improved. The fifth step is continued for a predetermined time. The time of the sixth step is set to (the volume (ml) of the absorbent remaining in the collection container main body 21 after the fifth step) ÷
If the time is set to 5 times or more of (liquid flow rate of the liquid pump 11 (ml / min)), the analyte contained in the absorption liquid remaining in the collection container main body 21 after the fifth step is substantially reduced. It can be captured on the 100% concentration column 33.

The seventh step is a separation analysis (S106). Since this step is performed in the same manner as the sixth step of the first embodiment, the description is omitted.

By the way, in the analyzer of the first embodiment shown in FIG. 1, at the end of the fourth step (sampling), the drain valve 28, the flow path switching valve 16, After the pump 11, the flow path switching valve 3
The pipe leading to No. 2 was filled with the absorbing solution from the pre-measurement cycle, and it was essential to perform a pre-concentration treatment as the fifth step. However, in the analyzer according to the present embodiment,
At the end of the fourth step (sampling), all of the pipes except for the pipe between the flow path switching valve 16 and the flow path switching valve 17 have been liquid-replaced with ultrapure water. As long as the piping capacity during this period is as small as possible, the influence of the contamination of the pre-measurement cycle is negligible as long as the difference from the concentration of the analyte contained in the sample atmosphere in the pre-measurement cycle does not exceed two orders of magnitude. Therefore, before this step, the first
Although the pre-concentration treatment, which is the fifth step in the embodiment, may be performed, in the present embodiment, the absorbing solution in which the analyte is absorbed in the fourth step is efficiently concentrated, and the sensitivity is increased. As a method that can be analyzed by the method described above, an analysis method in which the pretreatment for concentration was omitted was described. In the analysis method according to the present embodiment, unlike the first embodiment, the absorbing solution is not consumed for the pre-concentration treatment, and the absorbing solution remains in the collection container main body 21 after the concentration. In the fifth and sixth steps, the collection container main body 2 in the fourth step is unnecessary.
Almost 100% of the analyte absorbed in the absorbing solution in 1
It can be subjected to analysis by ion chromatography,
Analysis with higher sensitivity is possible. In addition, in the analysis method of the first embodiment, fluctuations in the flow rate of the liquid sending pump 11 result in fluctuations in the amount of concentration, which may lower the analysis accuracy.
However, in the analysis method according to the present embodiment, by providing a margin for the set time in the sixth step, the liquid sending pump 11
The influence of the flow rate fluctuation can be neglected, and a decrease in analysis accuracy can be prevented.

The measurement of the sample atmosphere can be continuously performed by repeating the measurement using the first to seventh steps as one measurement cycle. Further, the measurement cycle with the excitation light source 22 turned on and the measurement cycle with the excitation light source 22 turned off are continuously performed on the same sample atmosphere, that is,
By performing the combination of the seed measurement cycles as one measurement cycle, components that cannot be measured by the single measurement of turning on and off the excitation light source 22 can be complemented, and more analysis information on the sample atmosphere can be obtained.

Here, in the seventh step, if the flow path switching valve shown in FIG. 6 is set to the flow path shown by the solid line, the flow path switching valves 16, 17, 18, the drain valve 28, the liquid feed pump This is a step in which the analysis process in the ion chromatograph 3 can be independently performed regardless of the state of the suction pump 13. Therefore, the sixth step is performed in parallel with the first to fourth steps of the next measurement cycle, and the separation analysis is performed so that the sixth step is completed between the first to fourth steps. By adjusting the above conditions, the measurement time can be reduced. 7 and 8 used in the description of the present embodiment show examples in which the means for reducing the measurement time is applied. In FIG. 7, drainage, cleaning, water storage, and sampling are combined for separation analysis. In the above, the operation status display of valves and pumps for separation analysis is omitted.

When only the measurement is performed in a state where the excitation light source 22 is turned off, an organic component or the like adheres to the surface of the photocatalytic thin film layer 21a. Therefore, after all the measurements, the excitation light source 22 is turned on and the first light source is turned on. After the third step, it is desirable to decompose the organic components and the like adhering to the surface of the photocatalytic thin film layer 21a, wash them away with the absorbing solution, and then stop the analyzer. Also, when starting the device, prior to all measurements,
It is desirable to perform the first and second steps by turning on the excitation light source 22.

The technical features of this embodiment compared to the prior art are the same as those described in the first embodiment, and will not be described. If only the features that are different from those of the first embodiment are noted, a flow path switching valve 18 is added and the concentration column 3 is added.
A function of returning the absorbing liquid flowing out of the concentration column 3 to the collection container main body 21 is added. By performing concentration in two steps of concentration 2 which is returned to the container main body 21 and circulated, the absorption liquid having absorbed the analyte in the sample air is efficiently subjected to analysis by ion chromatography, and highly sensitive and highly accurate. Can analyze the components in the sample air.

[0081]

Next, an embodiment of the gas analyzer of the present invention will be described with reference to the drawings.

(First Example) First, an example of the gas analyzer 1 in the first embodiment shown in FIG. 1 and the like will be described.

The gas analyzer 1 according to the present embodiment includes a separation column 34 (“IonPac CS1” manufactured by Dionex).
2 ": trade name, a concentration column 33 (manufactured by Dionex," Ion Pac CG12 ": trade name), a suppressor (not shown, downstream of the separation column 34, detector 35).
Connected to the upstream side of Dionex, "CSRS-
I ": trade name" and an ion chromatograph 3 (manufactured by Dionex, "DX120": trade name) with a detector 35 (built-in ion chromatograph, "DX120": trade name) Was used as the detection device,
This is a gas analyzer that analyzes ammonia components in the atmosphere.

Ultrapure water was used for the absorbing solution, and 20 mm for the eluent.
ol methanesulfonic acid solution was used. Sampling container body 21
Is a cylinder made of heat-resistant glass (registered trademark "Pyrex") having an inner diameter of 12 mm, an outer diameter of 16 mm, a length of 350 mm, and a conical bottom, and the photocatalytic thin film layer 21a is made of a transparent porous material made of anatase type titanium oxide. The film was formed to a thickness of 0.7 μm. The collection container main body 21 is
4. The sample atmosphere supply pipe 26 and the sample atmosphere discharge pipe 27 were installed vertically with the upper part provided up, and a 10 W low-pressure mercury lamp was installed in parallel with the collection vessel main body 21. The flow rates of the liquid sending pumps 11, 12, and 15 are 2
ml / min, and the flow rate of the liquid sending pump 31 is 1 ml / mi.
The flow rate of the suction pump 13 was adjusted to 1 l / min by adjusting the flow rate controller 14.

In the evaluation of the collection rate performed using a standard gas whose ammonia component concentration was adjusted in advance, the suction pump 1
When the flow rate of No. 3 was 2 l / min or less, the concentration of the ammonia component contained in the standard gas could be reproduced at a collection rate of 100%.

The gas analysis is performed in accordance with the first to seventh steps described with reference to FIG. 4. The drainage time of the residual absorbent in the collection vessel main body 21 in the first step (drainage) is 2.5.
Minute, the cleaning time in the second step (cleaning) is 10 minutes, the supply of the absorbing liquid into the collection container body 21 in the third step (water storage), the water storage time is 2.5 minutes, and the fourth step (sampling). ) Is 5 minutes, the liquid replacement time of the flow channel in the fifth step (concentration pretreatment) is 0.5 minutes, and the absorption in the sixth step (concentration) is performed. The concentration time of the liquid was set to 1.5 minutes, and the time of component analysis in the seventh step (separation analysis) was set to 10 minutes. When the apparatus is started, the excitation light source 22 is turned on, only the first and second steps are performed first, the inside of the collection container body 21 is washed, and then the excitation light source is turned off and the normal measurement from the first to the seventh is performed. The cycle was performed. The sixth step of the first measurement cycle was performed in parallel with the first and second steps of the second measurement cycle (the same applies to the following measurement cycles). The time required for one measurement cycle is 22
Minutes.

The lower limit of detection of the concentration of ammonia component using the gas analyzer 1 was 0.02 ppbv. Some amines are actually detected as ammonia, but under the above conditions, the amines cannot be separated from ammonia and detected. However, the separation column 34 of the ion chromatograph 3
It is also possible to detect amines by optimizing the eluent and the eluent. Note that the above device configuration, measurement conditions, measurement cycle, and detection lower limit have been optimized and obtained by study of the present inventors, but their device configuration, measurement conditions, and the like are not limited to the above. Not something.

(Second Example) Next, an example of the gas analyzer 51 according to the second embodiment shown in FIG. 6 and the like will be described.

The gas analyzer 51 of this embodiment is also a gas analyzer for analyzing the ammonia component in the atmosphere. The ion chromatograph 3 has the same separation column 3 as that of the first embodiment.
4, a concentration column 33, and a suppressor (not shown, connected downstream of the separation column 34 and upstream of the detector 35). In addition, the configurations of the collection container main body 21, the absorbing solution, and the eluent are the same as those in the first embodiment.

In this embodiment, the flow rates of the liquid sending pumps 11 and 12 are 2 ml / min, and the flow rate of the liquid sending pump 31 is 1 ml / min.
/ Min, and the flow rate of the suction pump 13 was set to 1 l / min by adjusting the flow rate controller 14. The gas analysis is performed in accordance with the first to seventh steps described with reference to FIG. 7. The drainage time of the residual absorbent in the collection container body 21 in the first step (drainage) is 2.5 minutes, The cleaning time in the step (cleaning) is 10 minutes, the supply of the absorbing liquid into the collection container body 21 in the third step (water storage), the water storage time is 2.5 minutes, and the sample air in the fourth step (sampling). The supply time to the collection container main body 21 is 5 minutes, the concentration time of the absorbent in the fifth step (concentration 1) is 2.25 minutes, and the concentration time of the absorbent in the sixth step (concentration 2) is At 2.75 minutes, the time of component analysis by the seventh step (separation analysis) was set at 10 minutes. When the apparatus is started, the excitation light source 22 is turned on, and the first and second excitation light sources are turned on.
Only the first step was performed to clean the inside of the collection container main body 21, and then the excitation light source was turned off, and the first to seventh normal measurement cycles were performed. Sixth of first measurement cycle
Was performed in parallel with the first and second steps of the second measurement cycle (the same applies to the following measurement cycles). 1
The time required for each measurement cycle was 25 minutes.

In addition, the analysis results of the gas analyzer 51 such as the lower limit of detection were the same as in the first embodiment.

(Third Example) Next, another example of the gas analyzer 1 in the first embodiment shown in FIG. 1 and the like will be described.

[0093] The gas analyzer 1 of the present example is provided with a separation column 34 ("IonPac AS1" manufactured by Dionex).
4 ": trade name, concentration column 33 (manufactured by Dionex," Ion Pac AG14 ": trade name), suppressor 22 (not shown, downstream of separation column 34, upstream of detector 35, dionex) ASRS-
I ": trade name" and an ion chromatograph 3 (manufactured by Dionex, "DX120": trade name) with a detector 35 (built-in ion chromatograph, "DX120": trade name) Was used as the detection device,
This is a gas analyzer that analyzes acidic gas components in the atmosphere.

In this embodiment, ultrapure water was used as the absorbing solution, 4 mmol sodium carbonate-1.5 mmol sodium hydrogencarbonate solution was used as the eluent, and the flow rate of the liquid sending pump 31 was 1.5 ml / min ( The flow rates of the other pumps are the same as in the first embodiment). The gas analysis is performed using the first method described with reference to FIG.
To the seventh step, the drainage time of the residual absorbent in the collection container body 21 in the first step (drainage) is 2.5 minutes, the cleaning time in the second step (cleaning) is 10 minutes, and the third step is Supply of the absorbing liquid into the collection container main body 21 in the step (water storage) in the step (water storage), and the water storage time is 2.5 minutes;
The supply time of the sample air to the collection container main body 21 in the step (sampling) in step (5) is 5 minutes, the liquid replacement time in the flow path in the fifth step (concentration pretreatment) is 0.5 minutes, and the sixth step ( The concentration time of the absorbing solution by the concentration (concentration) was set to 1.5 minutes, and the time of the component analysis by the seventh step (separation analysis) was set to 20 minutes. At the start of the apparatus, the excitation light source 22 is turned on, only the first and second steps are performed first, the inside of the collection container body 21 is washed, and then the excitation light source is continuously turned on and the first to seventh normal operations are continued. The measurement cycle was performed (measurement cycle a), and the excitation light source was turned off and turned on for the same sample atmosphere, and the first to seventh normal measurement cycles were performed (measurement cycle b). The combination of the measurement cycle a and the measurement cycle b was defined as one measurement cycle. The sixth step in the first measurement cycle a is performed in parallel with the first to fourth steps in the first measurement cycle b, and the sixth step in the first measurement cycle b is performed in the second measurement cycle. First of cycle a
To the fourth step (the same applies to the following measurement cycles). The time required for one measurement cycle was 44 minutes.

As a result of the measurement by the gas analyzer 1 of this embodiment, in the measurement cycle a, ions of fluoride, chloride, nitrous acid, nitric acid, and sulfuric acid were detected. The detected ions are mainly these acids and some of them are salts.
In particular, nitrite ions are chemically changed from NO ₂ , and sulfate ions are chemically changed from SO ₂ .
Only a few organic acids such as formic acid and acetic acid were detected.
As a result of the evaluation using the standard gas, the collection rate of hydrofluoric acid, hydrochloric acid, nitric acid, NO ₂ and SO ₂ was almost 100%.
%Met. On the other hand, in the measurement cycle b, formic acid, acetic acid, and sulfite ions were detected in addition to fluoride, chloride, nitrite, nitric acid, and sulfuric acid ions. The detected ions are mainly these acids and some of them are salts. Compared with the measurement cycle a, the detected amount of nitrite ion was reduced to about 1/2, and the detected amount of nitrate ion and sulfate ion was reduced to about 3/4. SO ₂ was detected as two kinds of ions, sulfuric acid and sulfurous acid. As a result of evaluation using a standard gas, the collection rate of hydrofluoric acid, formic acid, acetic acid, hydrochloric acid, and nitric acid was almost 100%, but NO ₂ was 20%.
% And SO ₂ were 80%. By combining measurement cycle a and measurement cycle b into one measurement cycle,
Most acid gases can be measured.

FIG. 9 shows that the analysis method of this embodiment shows that NO ₂
It is a chromatogram obtained by analyzing a standard gas. The broken line indicates when the excitation light source is turned off, and the solid line indicates when the excitation light source is turned on. The unlit NO ₂ ^-, NO ₃ ^- peak of disappeared. NO ₂ ^-,
NO ₃ ^- other peak (not attributable) is an impurity contained in the air used for diluting the standard gas, a device blank analyzer, off the excitation light source, significance due to differences in lighting conditions There was no difference.

A gas analyzer 1 according to the first embodiment shown in FIG. 1 and the like has a gas analyzer for analyzing ammonia in the atmosphere as a first embodiment, and an acid analyzer in the atmosphere as a third embodiment. Similarly to the gas analyzer for analyzing gas components, the gas analyzer 51 according to the second embodiment shown in FIG. 6 and the like also analyzes the ammonia in the atmosphere as the second embodiment. The present invention can be applied not only to gas analyzers that perform analysis but also to gas analyzers that analyze acidic gas components in the atmosphere by changing columns, eluents, and measurement conditions used.

When the gas analyzer 51 according to the second embodiment shown in FIG. 6 or the like is applied to a gas analyzer for analyzing acidic gas components in the atmosphere, the time required for the measurement cycles a and b is 25, respectively. Therefore, the time required for one measurement cycle was 50 minutes.

[0099]

As described above, the gas sampling apparatus according to the present invention receives light of a specific wavelength on the inner wall of a sampling vessel into which a predetermined amount of absorbing liquid is put and the sample air to be measured is blown into the absorbing liquid. A photocatalytic thin film layer containing a photocatalyst that is photoexcited to generate a component having a strong oxidizing power is formed, and the gas sampling device continuously or intermittently emits light containing light of a specific wavelength for photoexciting the photocatalyst. By having the light source, components that are hardly dissolved in the absorbing solution as they are, such as NO and NO ₂ , can be collected. Further, organic components and the like adhering to the surface of the photocatalytic thin film layer are oxidized and decomposed and easily washed away by the absorbing solution, whereby the surface of the photocatalytic thin film layer is self-purified. Further, since the uniform wettability of the absorbing liquid on the inner wall surface of the collection container is maintained, the collection rate of the analyte is hardly changed with time, and the concentration measurement accuracy of the analyte can be maintained.

[0100] The function is that the excitation light source and the main body of the gas sampling device are installed adjacent to each other in a container whose inner wall surface is processed so as to efficiently reflect the light of the specific wavelength, or both of them are specified. The height can be increased by surrounding the display with a reflector that efficiently reflects the light of the wavelength.

The above function can also be improved by forming the photocatalytic thin film layer to be porous.

Further, by maintaining the temperature of a part or the whole of the collection container at room temperature or lower, preferably at 0 ° C. to 10 ° C., and suppressing the absorption liquid from evaporating and disappearing, the analysis accuracy can be improved.

In addition, means for miniaturizing bubbles in the sample atmosphere to be passed through the absorbing solution at the inner end portion of the gas sampling container main body of the sample atmosphere supply pipe, for example, do not elute substances having a bad influence on the analysis into the absorbing solution. By attaching a member made of a porous material, the sample air passing through the absorbing solution is miniaturized, and the absorption efficiency is improved.

The gas analyzer according to the present invention includes a gas sampling device according to the above-described invention, a component detector for detecting an analyte contained in a solution sample, and a gas sampling device. the absorbent sample air is blown, a gas analyzer and means for feeding to the component detecting means, a gas collecting device, by lighting an excitation light source, as it as NO and NO ₂ In addition to being able to analyze components that are hardly soluble in the absorbing solution, the surface of the photocatalytic thin film layer is self-purified, so that the uniform wettability of the absorbing solution on the inner wall surface of the tubular member is maintained and the collection rate of the analyte Can be prevented from changing over time, and the accuracy of measuring the concentration of the analyte can be maintained. Further, since it is not necessary to periodically perform maintenance cleaning of the gas sampling device, the burden on the user of the gas analyzer can be reduced.

Needless to say, if the excitation light source is turned off, it becomes possible to analyze components which are decomposed by the action of the photocatalyst and difficult to detect. By analyzing the excitation light source in two states, a light-on state and a light-off state, analysis of many components contained in the sample atmosphere can be performed by one apparatus.

Further, the component detecting device includes a capturing / concentrating means for capturing and concentrating the analyte contained in the absorbing solution;
Since the system has a separation unit for separating the analyte from the capture and concentration unit and a detection unit for detecting the analyte, the analyte is detected in a concentrated state, and thus the detection of the analyte is performed. The strength is increased, and the analysis accuracy can be improved.

Further, by adopting a configuration in which a part or all of the absorbing solution from which the analyte has been removed by passing through the capturing / concentrating means can be circulated and sent to a gas sampling device, All the components to be analyzed contained in the liquid can be supplied to the component detection device, and the analysis sensitivity can be improved.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a first embodiment of a gas analyzer according to the present invention.

FIG. 2 is a schematic perspective view showing a detailed configuration of the gas sampling device shown in FIG.

FIG. 3 is a partially cutaway sectional view of a part of the gas sampling device shown in FIGS. 1 and 2;

FIG. 4 is a flowchart illustrating an analysis process of the gas analysis method according to the first embodiment.

FIG. 5 is a diagram showing operation states of a valve and a pump in each analysis step of the gas analysis method according to the first embodiment.

FIG. 6 is a configuration diagram showing a second embodiment of the gas analyzer of the present invention.

FIG. 7 is a flowchart illustrating an analysis process of the gas analysis method according to the second embodiment.

FIG. 8 is a diagram showing operation states of a valve and a pump in each analysis step of the gas analysis method according to the second embodiment.

FIG. 9 is a chromatogram obtained by analyzing a standard gas of NO ₂ by the gas analysis method shown in the third embodiment of the present invention.

FIG. 10 is a cross-sectional view of an impinger (absorber) in a conventional gas analyzer.

FIG. 11 is a cross-sectional view of a gas sampling device using a photocatalyst in a conventional gas analyzer.

[Explanation of symbols]

 Reference Signs List 1,51 Gas analyzer 2 Gas sampling device 3 Ion chromatograph 11, 12, 15, 31 Liquid feed pump 13 Suction pump 14 Flow controller 16, 17, 18, 32 Flow path switching valve 21 Sampling container main body 21a Photocatalytic thin film layer 22 Excitation light source 23 Reflector 24 Absorbing liquid supply pipe 24 a Nozzle 25 Absorbing liquid discharge pipe 26 Sample air supply pipe 27 Sample air discharge pipe 28 Drain valve 33 Concentration column 34 Separation column 35 Detector

Claims (20)

[Claims] 1. A gas sampling apparatus comprising: a gas sampling container main body, a sample air supply pipe for supplying a sample atmosphere to be measured into the gas sampling container main body, and an exhaust pipe, wherein the gas sampling container includes: In a gas sampling device, a predetermined amount of the absorbing solution is held, and the inner end of the container of the sample atmosphere supply pipe is opened in the absorbing solution, and the analyte contained in the sample atmosphere is absorbed by the absorbing solution. The collection container body is formed of a material that transmits light of a specific wavelength, and a photocatalytic thin film layer including a photocatalyst that is photo-excited by light of a specific wavelength on at least a part of the inner surface of the collection container inner wall and the collection container piping. Is formed, an excitation light source that continuously or intermittently emits light including light of a specific wavelength that optically excites the photocatalyst, and a photocatalytic thin film layer provided with an absorbing liquid on a part of the inner wall of the container and a part of the piping in the container. To A gas collection device comprising: an absorption liquid supply pipe arranged so as to be able to supply the gas. 2. The gas according to claim 1, wherein the excitation light source and the gas sampling container main body are contained in a space surrounded by a reflector that efficiently reflects the light of the specific wavelength. Sampling equipment. 3. The gas collection device according to claim 2, wherein the reflection material is processed so that an inner wall of the jacket of the gas collection device is efficiently reflected by the light having the specific wavelength. 4. The gas collection device according to claim 2, wherein the reflection member is a reflection plate inserted between the gas collection device outer jacket, the excitation light source, and the gas collection container main body. 5. The photocatalyst is composed of a substance that is so small that elution of the same component as the analysis component or a component that hinders the analysis of the analysis component into the absorbing solution does not affect the analysis accuracy of the analysis component. The gas sampling device according to any one of claims 1 to 4. 6. The gas sampling apparatus according to claim 1, wherein the photocatalyst is an anatase type titanium oxide or a rutile type titanium oxide. 7. The photocatalytic thin film layer is transparent and has a thickness of 0.01 μm to 5 μm.
7. The gas sampling device according to any one of 6. 8. The gas sampling device according to claim 1, wherein the photocatalytic thin film layer is formed porous. 9. The collection container main body according to claim 1, wherein an attenuation rate of the light of the specific wavelength on the inner wall of the container is 90% or less.
The gas sampling apparatus according to any one of claims 1 to 8. 10. The gas collection device according to claim 9, wherein the collection container main body has an attenuation rate of light of the specific wavelength on the inner wall of the container of 50% or less. 11. A temperature control device for controlling the temperature of a part or the whole of the collection container main body or the gas collection device is provided.
The gas sampling device according to Item. 12. The gas sampling device according to claim 11, wherein a temperature of a part or the whole of the inside of the sampling container body by the temperature control device is 0 ° C. to room temperature. 13. A sample air supply pipe further comprising means for miniaturizing air bubbles in the sample atmosphere to be ventilated into the absorbing solution, at an inner end of the gas sampling apparatus main body of the sample atmosphere supply pipe.
The gas sampling device according to any one of the above. 14. A gas collecting apparatus according to claim 1, wherein said gas is collected and concentrated in said main body of said collecting container by capturing and concentrating a component to be analyzed absorbed by said absorbing solution. Means for sending an absorbing solution from the collection device to the capture and concentration means, separation means for separating the analyte to be captured by the capture and concentration means from the capture and concentration means, and analyte to be removed from the capture and concentration means A gas analyzer comprising: 15. The capturing and concentrating means of the component detecting device,
The gas analyzer according to claim 14, wherein the gas analyzer is a concentration column filled with an adsorbent for adsorbing the analyte contained in the absorbing solution. 16. The gas analyzer according to claim 14, further comprising a mechanism that circulates and sends the absorption liquid from which the analyte has been removed by passing through the trapping / concentrating means to the gas sampling device. 17. The gas analyzer according to claim 14, wherein said component detecting means is a liquid chromatograph or an ion chromatograph. 18. A gas analysis method using the gas analyzer according to claim 14, wherein the step of draining the absorption liquid remaining in the gas collection container main body includes the steps of: A step of supplying the absorbing liquid from the upper part of the gas sampling container main body so as to flow down the inner wall of the container main body and cleaning the inner wall of the container main body; Storing a predetermined amount of the absorbing solution, sampling a sample air to be measured into the absorbing solution to absorb the analyte contained in the sample air, and capturing the absorbing solution having absorbed the analyte. Sending to the concentration means, concentrating the analyte component, removing the analyte component captured by the capture / concentration means from the capture / concentration means, and separating the separated analyte component from the capture / concentration means. Analyzing by gas analysis means. 19. The method according to claim 19, wherein a part or all of the absorbing solution from which the analyte has been removed by passing through the capturing / concentrating means is circulated and sent to a gas sampling device, and the concentration step is repeated. Item 19. The gas analysis method according to Item 18. 20. After the analyte to be analyzed is collected from the atmosphere of the sample to be measured in the absorption liquid by the gas sampling device in a state where the excitation light source is turned off, the absorption liquid is subjected to the component detection. A first component analysis step of analyzing by means, and after collecting the analyte to be analyzed from the sample atmosphere to be measured in the absorption liquid by the gas sampling device from the sample atmosphere to be measured with the excitation light source turned on, 20. The gas analysis method according to claim 18, further comprising: a second component analysis step of analyzing the absorption liquid by the component detection device.