JP3589265B2 - Nitrogen dioxide gas detection element, detection method and detection device - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a nitrogen dioxide gas detection element using an organic dye molecule as a gas-sensitive substance, a nitrogen dioxide gas detection method using the nitrogen dioxide gas detection element, and an optical nitrogen dioxide gas detection device including the nitrogen dioxide gas detection element. It relates to a device (sensor).
[0002]
[Prior art]
In recent years, exhaust gas from automobiles and nitric oxide gas contained in smoke from factories have become social problems as a cause of pollution. For this reason, in Japan, environmental standards are set for each harmful gas. The measurement methods specified in the environmental standards are all automatic measurement methods. The Atmosphere Monitoring Bureau constantly monitors nitrogen dioxide and the like in the environment using these methods. In addition to regular monitoring, air pollution surveys such as a survey of the distribution of harmful gas concentrations in the area, a preliminary survey and a follow-up survey when conducting a local environmental impact assessment are also conducted at any time. As a method of measuring harmful gases in such a case, since the automatic measurement method requires enormous cost and requires a power source and an installation place, a simple measurement method is usually used except for permanent measurement.
[0003]
In particular, nitrogen oxides are generated not only from stationary sources, but also in places where people live and in places very close to them, such as smoking, kitchens, exhaust heaters, and automobiles. Therefore, regarding nitrogen dioxide, it is considered necessary to monitor individual exposure and to grasp the actual status of pollution in living and working environments from the standpoint of impact on humans. Against such a background, a method that can easily and inexpensively detect the concentration of nitric oxide has been required.
[0004]
Conventionally, as a method for detecting the concentration of nitrogen oxide gas, a chemiluminescence method, a detection tube method, and the like are known. However, these methods use special devices and instruments, and cannot meet the demand for a simple and inexpensive method.
[0005]
As a simple measurement method using a passive sampler, a triethanolamine batch method is known. In this method, triethanolamine having high absorption efficiency of nitrogen dioxide soaked in a molecular sieve is exposed to a nitrogen dioxide atmosphere for a long time. At the time of analysis, the molecular sieve was washed with water to wash out the triethanolamine that had absorbed nitrogen dioxide, and a mixed solution of sulfinylamide and N- (1-naphthyl) ethylenediamine dihydrochloride, which were coloring reagents, was added. Nitrogen is quantified. This method has a problem that a special reagent is required to cause a color development reaction after the gas is collected, and it is difficult to perform the measurement on the spot.
[0006]
Further, a simple electrochemical measurement method using phthalocyanine or the like is known. However, this method has a problem that the sensitivity is on the order of ppm, and the concentration of nitrogen dioxide in the environment cannot be accurately measured.
[0007]
[Problems to be solved by the invention]
An object of the present invention is to provide an inexpensive detection element, a gas detection method, and a detection device that can easily detect nitrogen dioxide gas.
[0008]
[Means for Solving the Problems]
The nitrogen dioxide gas detection element of the present invention is characterized in that a transparent porous glass or a porous polymer film is impregnated with bis (aminophenyl) oxadiazole or dimethylnaphthidine .
The nitrogen dioxide gas detection method of the present invention is a nitrogen dioxide gas detection method using the nitrogen dioxide gas detection element, wherein bis (aminophenyl) oxadiazole or dimethyl is formed by contact of the gas detection element with the nitrogen dioxide gas. The irreversible color change of naphthidine is measured to detect nitrogen dioxide gas.
[0009]
The nitrogen dioxide gas detection device of the present invention is a nitrogen dioxide gas detection device including a light emitting element, a light receiving element, and a gas detection element, wherein the gas detection element is a porous glass or a porous glass transparent to a detection wavelength. A molecular film in which bis (aminophenyl) oxadiazole or dimethylnaphthidine is impregnated, and wherein the gas detection element is provided on a path from a light emitting element to a light receiving element. is there.
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
We have found that the diamine derivative selectively reacts with the nitrogen dioxide gas to form a colored product. The principle of the present invention is to detect nitrogen dioxide gas by measuring an irreversible color change of a diamine derivative caused by contact with the gas.
[0011]
The following are mentioned as a diamine derivative used in the present invention. For example, acriflavine hydrochloride, acriflavine neutral, 2-methyl-4,4 ′-{(4-imino-2,5-cyclohexadiene-1-ylidene) methylene} dianiline, benzoperpurine 4B, 1,1′- Dinaphthyl-2,2'-diamine, 2,5-bis (4-aminophenyl) -1,3,4-oxadiazole, N, N'-bis (3-aminophenyl) -3,4,9, 10-perylenecarboxylic diimide, 4,4 '-{(methyl-1,3-phenylene) bis (azo)} bis (6-methyl-1,3-benzenediamine) dihalide chloride, 4,4'-} m-phenylenebis (azo) @bis (m-phenylenediamine) dihydrochloride, 6'-butoxy-2,6-diamino-3,3'-azodipyridine, Chicago ska Blue 6B, 6-chloro-3,5-diamino-2-pyrazinecarbonitride, 6-chloro-3,5-diamino-2-pyrazinecarboxamide, 4-chloro-2,6-diaminopyrimidine, 2-chloro -4,6-diamino-1,3,5-triazine, chrysidine, 3,3 ′-{4,4′-biphenylenebis (azo)} bis (4-amino-1-naphthalenesulfonic acid) disodium salt , Cresyl violet acetate, 4 ', 6-diamidino-2-phenylindole dihydrochloride hydrate, diaminoacridine hemisulfate, diaminoanthraquinone, 3,3'-diaminobenzidine, 3,3'-diaminobenzidine tetrahydrochloride Dihydrate, 3,4-diaminobenzophenone, p-diaminoa Benzene, diaminobenzene acid, 4,4'-diaminobenzophenone, 5,6-diamino-2,4-dihydroxypyrimidine sulfate, 2,7-diaminofluorene, 3,4-diamino-5-hydroxypyrazole sulfate, 3 , 7-Diamino-2-methoxyfluorene, diaminonaphthalene, 9,10-diaminophenanthrene, 3,8-diamino-6-phenylphenanthridine, 2,4-diamino-6-phenyl-1,3,5-triazine , 3,3'-dimethylnaphthidine, dimidium bromide, direct red 75, direct yellow 62, Disperse blue 1, ethidium bromide, 6,6 '-{3,3'-dimethyl-4,4'-biphenylylene) Bis (azo) @bis (4-amino-5-hydroxy-1,3-na Phthalenedisulfonic acid) tetrasodium salt, fat brown RR, 2,4,6-triamino-s-triazine, new fuchsin, parasaniline base, 3,7-diamino-5-phenylphenazinium chloride, 2,3 -Pyrazinedicarboxamide, 3,4-pyridinedicarboxamide, o-tolidine, 2,4,7-triamino-6-phenylpteridine, 3,5,7-triamino-s-triazolo [4,3-a] -S-triazine, dianisidine, 4,4'-diaminodiphenylamine and the like.
[0012]
Among these diamine derivatives, for example, a diamine derivative having an amino group at a symmetric position such as o-triazine, bis (aminophenyl) oxadiazole, or dimethylnaphthidine is preferable.
[0013]
Examples of the support used in the present invention include transparent materials such as glass, quartz, a polymer film, a porous glass, and a porous polymer film. Preferably, it is excellent. The shape of the support may be plate-like or fiber-like. It is necessary that the support has no absorption in the absorption region of the coloring substance formed by the reaction of the diamine derivative with nitrogen dioxide.
[0014]
The gas detection element of the present invention is obtained by supporting a diamine derivative on a support. In this case, only the diamine derivative may be supported on the support, or a mixture of the diamine derivative and another suitable material may be supported on the support.
[0015]
The following method is used for producing the gas detection element of the present invention. For example, a gas detection element can be manufactured by dissolving a diamine derivative or a mixture thereof in water or an organic solvent (alcohol, ketone, aromatic solvent, petroleum-based solvent, or the like) and attaching it to a support such as porous glass. . Alternatively, a gas detection element may be manufactured by impregnating a support with a solution of a diamine derivative or a mixture thereof, and then removing the solvent. Further, a gas detection element may be manufactured by attaching a solution of a diamine derivative or a mixture thereof to a support by a general method such as a spin coating method or a doctor blade method.
[0016]
The nitrogen dioxide gas detection device of the present invention has a configuration in which a gas detection element is provided on a path from a light emitting element to a light receiving element. As the light emitting element, a combination of various LEDs or a multi-color light source such as a mercury lamp and a filter can be used. Further, a semiconductor photodiode or the like can be used as the light receiving element. If these light emitting elements and light receiving elements are used, the size of the detection device can be reduced.
[0017]
By using the nitrogen dioxide gas detection device of the present invention, the concentration of nitrogen dioxide gas can be measured. In this case, a calibration curve is prepared by measuring the coloring density of the gas detection element in an atmosphere of a known nitrogen dioxide gas concentration in advance, and the calibration curve is compared with the actual measurement result to determine the nitrogen dioxide gas concentration. You can ask.
[0018]
【Example】
Hereinafter, the present invention will be described in more detail with reference to examples. It should be noted that the present invention is not limited to only these examples, and a wide variety of gas detection elements can be manufactured by changing the combination of materials and the support, and the like. Is shown.
[0019]
Example 1
FIG. 1 shows an example of an optical gas sensor using the nitrogen dioxide gas detection element of the present invention. This gas sensor detects a gas based on a change in the absorption wavelength of the transmitted light from the gas detection element. As shown in FIG. 1, a light-emitting element 1 in which a xenon lamp and a filter are combined, a gas detection element 2 in which a porous support is impregnated with a coloring substance containing a diamine derivative, and a light-receiving element 3 including a photodiode are arranged. ing. The gas detecting element 2 is disposed on a light path from the light emitting element 1 to the light receiving element 3, and the light receiving element 3 detects light transmitted through the gas detecting element 2.
[0020]
Example 2
0.028 g of 2,5-bis (4-aminophenyl) -1,3,4-oxadiazole was placed in an Erlenmeyer flask and dissolved in 10 ml of ethanol to prepare a solution of about 0.01 mol / L. A porous glass as a support was immersed in the solution to impregnate the solution. After impregnation for 24 hours, the porous glass was taken out into a Petri dish, air-dried for 24 hours to evaporate ethanol, and a gas detection element was obtained. The gas sensing element made of the dye-impregnated porous glass thus produced was colorless and transparent. FIG. 2 shows the absorption spectrum (initial).
[0021]
When this gas detection element was exposed to air having a NO ₂ concentration of 10 ppm, it was colored lemon yellow. FIG. 2 shows the absorption spectrum (after NO ₂ contact). This change was irreversible. Also, when the measurement was performed while changing the NO ₂ concentration in the range of 100 ppb to 100 ppm, the same spectrum change as in FIG. 2 was observed, although the intensity was different.
[0022]
Next, using a high-pressure mercury lamp and a blue filter as the gas detecting element and the light emitting element, and a photodiode having a sensitivity of 400 to 500 nm as the light receiving element, an optical gas sensor of the type shown in FIG. 1 was produced. When an output change was measured by this optical gas sensor, an output different from that of the reference sample not exposed to NO ₂ was obtained in an atmosphere having a NO ₂ concentration of 100 ppb to 100 ppm.
[0023]
Example 3
0.024 g of o-tolidine was placed in an Erlenmeyer flask and dissolved in 10 ml of ethanol to prepare a solution of about 0.01 mol / L. A porous glass as a support was immersed in the solution to impregnate the solution. After impregnation for 24 hours, the porous glass was taken out, air-dried for 24 hours to evaporate ethanol, and a gas detection element was obtained. The gas sensing element made of the dye-impregnated porous glass thus produced was transparent in reddish purple. FIG. 3 shows the absorption spectrum (initial).
[0024]
When this gas detection element was exposed to air having a NO ₂ concentration of 1 ppm, the gas detection element turned yellow-brown and transparent. FIG. 3 shows the absorption spectrum (after NO ₂ contact). This change was irreversible. Also, when the measurement was performed while changing the NO ₂ concentration in the range of 100 ppb to 100 ppm, the same spectrum change as in FIG. 3 was observed although the intensity was different.
[0025]
Next, using a high-pressure mercury lamp and a blue filter as the gas detecting element and the light emitting element, and a photodiode having a sensitivity of 400 to 500 nm as the light receiving element, an optical gas sensor of the type shown in FIG. 1 was produced. When an output change was measured by this optical gas sensor, an output different from that of the reference sample not exposed to NO ₂ was obtained in an atmosphere having a NO ₂ concentration of 100 ppb to 100 ppm.
[0026]
Example 4
0.034 g of 3,3′-dimethylnaphthidine was placed in an Erlenmeyer flask and dissolved in 10 ml of ethanol to prepare a solution of about 0.01 mol / L. A porous glass as a support was immersed in the solution to impregnate the solution. After impregnation for 24 hours, the porous glass was taken out, air-dried for 24 hours to evaporate ethanol, and a gas detection element was obtained. The gas sensing element made of the dye-impregnated porous glass thus produced was yellow and transparent. FIG. 4 shows the absorption spectrum (initial).
[0027]
When this gas detection element was exposed to air having a NO ₂ concentration of 1 ppm, the color changed to pink transparent. FIG. 4 shows the absorption spectrum (after NO ₂ contact). This change was irreversible. Also, when the measurement was performed while changing the NO ₂ concentration in the range of 100 ppb to 100 ppm, the same spectrum change as in FIG. 3 was observed although the intensity was different.
[0028]
Next, using a high-pressure mercury lamp and a blue filter as the above-mentioned gas detection element and light emitting element, and a photodiode having a sensitivity of 400 to 600 nm as a light receiving element, an optical gas sensor of the type shown in FIG. 1 was produced. When an output change was measured by this optical gas sensor, an output different from that of the reference sample not exposed to NO ₂ was obtained in an atmosphere having a NO ₂ concentration of 100 ppb to 100 ppm.
[0029]
【The invention's effect】
As described in detail above, the gas detection element of the present invention can detect the approximate concentration of NO ₂ gas only by exposing it to an atmosphere containing nitrogen dioxide gas and observing the coloring state thereof. Since there is no need to use an instrument, it is simple and inexpensive. Further, according to the present invention, a calibration curve is prepared by measuring the coloring concentration of the gas detection element in an atmosphere of a known nitrogen dioxide gas concentration in advance, and the calibration curve is compared with an actual measurement result. The nitrogen dioxide gas concentration can be easily measured.
[Brief description of the drawings]
FIG. 1 is a diagram showing a schematic configuration of a nitrogen dioxide gas detection device of the present invention.
FIG. 2 is a diagram showing absorption spectra before and after exposure to nitrogen dioxide when 2,5-bis (4-aminophenyl) -1,3,4-oxadiazole is used as a diamine derivative.
FIG. 3 shows absorption spectra before and after exposure to nitrogen dioxide when o-tolidine is used as a diamine derivative.
FIG. 4 is a diagram showing absorption spectra before and after exposure to nitrogen dioxide when 3,3′-dimethylnaphthidine is used as a diamine derivative.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Light emitting element 2 ... Nitrogen dioxide gas detecting element 3 ... Light receiving element

Claims (3)

An element for detecting a nitrogen dioxide gas, wherein a transparent porous glass or a porous polymer film is impregnated with bis (aminophenyl) oxadiazole or dimethylnaphthidine . 2. A nitrogen dioxide gas detection method using the nitrogen dioxide gas detection element according to claim 1 , wherein bis (aminophenyl) oxadiazole or dimethylnaphthidine generated by contact of the gas detection element with the nitrogen dioxide gas is irreversible. A method for detecting nitrogen dioxide gas, comprising measuring a color change and detecting nitrogen dioxide gas. In a nitrogen dioxide gas detection device comprising a light-emitting element, a light-receiving element, and a gas detection element, the gas detection element includes bis (aminophenyl) oxadiazole or bis (aminophenyl) oxadiazole on a porous glass or a porous polymer film transparent to a detection wavelength. A nitrogen dioxide gas detection device impregnated with dimethylnaphthidine , wherein the gas detection element is provided on a path from a light emitting element to a light receiving element.

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