JP4856866B2 - Test substance detector in gas and holder therefor - Google Patents

Description

  The present invention relates to a test substance detector in gas and a holder for the same.

  With the rapid development of the advanced technology industry, the types of chemical substances used are increasing, resulting in disasters and accidents. It has been reported that the concentration of gaseous harmful substances in the working environment atmosphere of factories, plants, laboratories, etc. is generally 2 to 4 times higher than the urban atmospheric level. In recent years, due to increasing interest in the environment and health, indoor environmental pollution in ordinary houses or schools has attracted attention. In addition to NOx and CO from combustion gas appliances, water heaters, heating devices, etc., building materials and Health damage (sick house syndrome or sick school syndrome) caused by formaldehyde and volatile organic compounds released from furniture is regarded as a problem.

  Conventional methods for measuring chemical substances in indoor air include standard measurement methods, detector tube methods, vapor diffusion analysis methods, chemiluminescence methods, and electrochemical analysis methods. While these methods are expected to provide accurate measurement results, i) requires precise analytical equipment and advanced technology, ii) takes some time to determine results, iii) It has also been pointed out that the substances used in the reaction (solvent, catalyst, etc.) are inappropriate for the environment. In particular, when looking at detector tubes that are widely used in simple analysis methods at present, i) poor detection sensitivity, ii) measurement errors due to poor selectivity, iii) glass fragments (detection at the start of measurement) It is dangerous to perform measurement after breaking the glass containing the agent).

  On the other hand, as a method for easily measuring a chemical substance in room air or the atmosphere, various methods using a test paper that reacts with or changes color when contacted with a chemical substance are known. For example, Patent Document 1 describes a formaldehyde detection test paper previously invented by the present inventors. However, such a method using a test paper is performed simply by leaving the test paper in the room or in the atmosphere. For this reason, when the density | concentration of a to-be-tested substance is low, there exists a problem that it cannot detect or requires a long time for detection. Further, the conventional test paper method has a problem that if the test paper surface is touched by hand before measurement, a measurement error is caused.

JP2003-207498

  An object of the present invention is to provide a detector that can detect a test substance in a gas simply, quickly, and with high sensitivity, and that can avoid errors caused by touching the test paper with a hand, and a test paper holder therefor Is to provide.

  As a result of earnest research, the inventors of the present application have stored a test paper for detecting a test substance in gas in a gastight manner in a holder, and forcibly distribute the test sample gas to the test paper. The present invention has been completed by conceiving that a test substance in a gas can be detected quickly and with high sensitivity, and that errors due to the hand touching the test paper can be avoided.

That is, the present invention comprises a lower main body having a gas flow hole, a porous test paper support plate supported on the lower main body with a gap between the lower main body and a test paper held on the lower main body, The upper body is connected to the lower body, at least its ceiling is formed of a transparent material, and has a gas flow hole. The lower body and the upper body are connected to each other, and the test paper support is provided therein. A plate is held, and when the test paper is held on the test paper support plate, a gap is formed between the test paper and the lower surface of the ceiling, for detecting a test substance in the gas There is provided a test paper holder for holding a test paper , wherein a loupe is detachably attached to the tubular protrusion provided on the upper body . The present invention also includes a lower main body having a gas flow hole, a porous test paper support plate supported on the lower main body with a gap between the lower main body and a test paper held on the lower main body, The upper body is connected to the lower body, at least its ceiling is formed of a transparent material, and has a gas flow hole. The lower body and the upper body are connected to each other, and the test paper support is provided therein. A plate is held, and when the test paper is held on the test paper support plate, a gap is formed between the test paper and the lower surface of the ceiling, for detecting a test substance in the gas A test substance detector in gas in which a test paper for detecting a test substance in gas is hermetically held on the test paper support plate in a test paper holder for holding the test paper. An O-ring is placed on the test paper support plate, and the test paper is Providing a test substance detector in the gas kept airtight inside the ring.

  According to the detector of the present invention, since the sample containing the test substance can be forced to flow through the test paper, the test substance in the gas can be detected simply, quickly and with high sensitivity. Since the test paper is stored in the holder in an airtight manner, errors due to the hand touching the test paper can be avoided.

  Hereinafter, a preferred specific example of the present invention will be described with reference to the drawings. FIG. 1 is a schematic exploded sectional view of one preferred specific example of the test substance detector of the present invention.

  The lower main body 10 has, for example, a thick disk shape, and is preferably provided with a gas flow hole 12 at the center or in the vicinity thereof. The shape of the lower main body 10 is not limited to a disc shape, and is not particularly limited as long as it has a portion that supports a test paper support plate described later and can be connected to the upper main body described later. The gas flow hole 12 preferably communicates with a tubular protrusion 14 formed in the lower body 10. The tubular protrusion 14 is convenient but not essential for connecting a rubber tube or the like. The side wall 10a of the lower body 10 is preferably threaded for connection to the upper body, which will be described later.

  A porous test paper support plate 16 is placed on the lower body 10. The test paper support plate 16 is made of, for example, a porous and rigid plastic. Here, “porous” means that the plate itself may be formed of a porous material, or a non-porous plate having a large number of through holes. The plane shape and size of the test paper support plate 16 are preferably the same as the upper surface of the lower main body 10. This is because when the upper main body and the lower main body 10 described later are connected, they are automatically positioned. On the periphery of the lower surface of the test paper support plate 16, a ridge 18 is provided. The ridges 18 are provided to provide a gap between the lower surface of the test paper support plate 16 and the upper surface of the lower main body 10. In addition, since this protrusion 18 is for giving the said space | gap, you may form in the upper surface peripheral part of the lower main body 10. FIG.

  An O-ring 20 is preferably placed on the test paper support plate 16 in order to hold a test paper described later in an airtight manner. The term “airtight” as used herein means that the gas tightness is achieved when the gas flow holes 12 and the gas flow holes of the upper main body described later are hermetically sealed. The shape and size of the O-ring are preferably the same as the peripheral shape and size of the test paper support plate 16. This is because when the upper main body and the lower main body 10 described later are connected, they are automatically positioned.

  A test paper 22 for detecting a test substance in the gas is supported on the test paper support plate 16 and inside the O-ring 20. The test paper 22 is discolored or colored when it comes into contact with a test substance in gas, and various known test papers can be used. In addition, it is preferable that the shape and size of the test paper are just the shape and size inscribed in the O-ring 20. By doing so, it is possible to prevent the test sample gas from flowing through the outer periphery of the test paper.

  A lid-like upper main body 24 is covered from the upper side of the structure described above. The upper body 24 has a ceiling portion 24a and a side wall portion 24b, and at least the ceiling portion 24a is formed of a transparent material. Inside the side wall portion 24b, a screw for screwing with a screw on the side portion 10a of the lower main body 10 is cut. A gas flow hole 26 is provided in the ceiling portion 24a. The gas flow hole 26 preferably communicates with a tubular protrusion 28 formed in the ceiling portion 24a. The tubular projection 28 is useful but not essential for connecting a rubber tube or the like or attaching a loupe described later. A step portion 24c is provided at the peripheral edge of the ceiling portion 24a. When the upper main body 24 and the lower main body 10 are connected, the O-ring 20 is pressed by the step portion 24c and airtightness is achieved. A sufficient gap is provided between the test paper 22 and the lower surface of the ceiling portion 24a. Since the thickness of the O-ring 20 is larger than the thickness of the test paper 22, a gap is formed between the test paper 22 and the lower surface of the ceiling portion 24a without the step 24c. It is not essential. However, by providing the stepped portion 24c, the gap is increased, and the airflow resistance between the lower surface of the ceiling portion 24a and the test paper 22 is reduced, so that the gas easily spreads uniformly to the peripheral portion of the test paper 22. preferable.

  In a preferred embodiment, a loupe (not shown) is attached to the tubular protrusion 28. For example, it can be mounted by providing a mounting hole in the center of the loupe and inserting a projection 28 into the mounting hole. When the loupe is attached, the discoloration or coloration of the test paper 22 can be observed more sensitively through the ceiling portion 24a.

  At the time of assembly, the upper body 24 is put on the lower body 10. In the above specific example, since the screws are cut on the side portion 10a of the lower main body 10 and the inner side of the side wall 24b of the upper main body 24, the lower main body 10 and the upper main body 24 can be screwed together. Then, the O-ring 20 is pressed by the stepped portion 24 c, and the test paper 22 is held airtight inside the O-ring 20. The gas flow holes 12 and 26 are preferably hermetically sealed until the detector is used. In the specific example described above, the gas flow holes 12 and 26 can be hermetically sealed by, for example, attaching an airtight seal to the outer ends of the tubular protrusions 14 and 28.

  The assembly is preferably performed by the manufacturer, since the test substance does not exist, for example, in a clean bench, etc., handling the test paper with clean tweezers and wearing a clean mask and gloves. It is preferable to sell the completed detector to the end user, but it is also possible for the end user to separately assemble the holder not including the test paper and the test paper separately. In any case, the test paper is preferably stored in a hermetically sealed state until assembly.

  At the time of use, the gas flow holes 12 and 26 are unsealed, and the gas flow holes 26 and the test paper 22 are connected, for example, by connecting a rubber tube to the tubular protrusion 14 and pulling it with a pump or connecting a vacuum container. The gas is circulated through the test paper support plate 16 and the gas flow hole 12. The gas flowing in from the gas circulation hole 26 spreads into the gap between the test paper 22 and the ceiling portion 24 a and passes through the entire surface of the test paper 22. When measuring chemical substances in room air or air, the room air or air is forced to pass through the test paper 22 as described above. If the concentration of the test substance is sufficiently high, the detector may simply be left in the room or atmosphere without forcing the room air or atmosphere to pass through. For this purpose, it is preferable to force the passage. Further, when detecting a test substance in the gas in the sealed container, a rubber tube connected to the sealed container is connected to the tubular protrusion 28 to compress the sealed container or to form the tubular protrusion 14. A rubber tube is connected to the gas and the gas in the sealed container is passed through the test paper 22 by pulling it with a pump or connecting a vacuum container.

  Next, the discoloration or coloration of the test paper 22 is observed through the ceiling portion 24a. If the test paper 22 is discolored or colored, since the test substance exists in the gas, the test substance can be detected. Note that the amount of the test substance can be quantified or semi-quantified based on the degree of color change or coloration, and such quantification or semi-quantification is also included in “detection” in the present invention. As described above, when a loupe is attached, the degree of color change or coloration can be observed more sensitively.

  Various test papers and chemical reactions for detecting various chemical substances are known, and any of these can be used for the test paper 22. For example, formaldehyde (Patent Document 1), acetaldehyde (Document Analytical Letters, 24 (5), 857-869 (1991)), glutaraldehyde (Document Analytical Letters, 24 (5), 857-869 (1991)), toluene ( Literature Abstracts of the 52nd Annual Meeting of the Analytical Society of Japan), Xylene (Abstracts of the 52nd Annual Meeting of the Analytical Society of Japan), Ammonia (Reference Bayer Medical Co., Ltd. Aqua Check Series Simple Water Quality Test Paper, 2002), Ichi Test papers and chemical reactions for detecting carbon oxide, nitric oxide, nitrogen dioxide, hydrogen chloride, chlorine (literature Bayer Medical Co., Ltd. Aqua Check Series Simple Water Quality Test Paper, 2002) and the like are known. The “test paper” is not necessarily limited to paper such as filter paper, but is made of porous plastic, fibers such as woven fabric or nonwoven fabric made of synthetic fibers, and the like. The “test paper” used in the present invention includes those using a substrate other than such paper.

  Various modifications can be made to the specific example shown in FIG. 1 within the scope of the present invention. For example, in the above specific example, the O-ring 20 is used, but the step 24c of the upper main body 24 is formed of an elastic material such as elastic plastic so that the function of the O-ring is shared and the O-ring is omitted. Is possible. Further, as shown in FIG. 2, the upper main body 24 can be divided into a ceiling portion 24a + step portion 24c and a side wall portion 24b, and can be constituted by independent parts. In this case, in order to hold down the ceiling portion 24a from above, a horizontal portion 24d connected to the side wall portion 24b is further required. Moreover, as shown in FIG. 3, you may form the ceiling part 24a diagonally so that a center part may become high. By doing in this way, the space | gap between the lower surface of the ceiling part 24a and the test paper 22 can be enlarged more. In this case, a sufficient gap can be provided between the lower surface of the ceiling portion 24a and the test paper 22 even if the step portion 24c is a simple horizontal portion without forming a step. Similarly, the lower body 10 can also be formed with an upper surface that is inclined so that the center portion is lowered, thereby increasing the gap between the test paper support plate 16. In this case, the protrusion 18 can be omitted.

  Hereinafter, the present invention will be described more specifically based on examples. However, the present invention is not limited to the following examples.

Example 1 Detection of Formaldehyde A holder of the above-described specific example was prepared based on FIG. 1, and a test paper for formaldehyde detection described in Patent Document 1 was prepared as described below as a test paper and incorporated in the holder. . When this test paper comes into contact with formaldehyde, the following chemical reaction occurs, and the white test paper turns yellow.

1.1 Stock Solution Preparation Stock 1: Dissolve KD-XA01 (0.1 g) in 10 ml of methanol.
Stock 2: 1 ml of phosphate buffer solution (pH 2.5, manufactured by Nacalai Tesque) is dissolved in 10 ml of methanol.
Stock 3: Mix Stock 1 and Stock 2 so that the volume ratio is 1: 1.

1.2 Preparation of test paper A filter paper (No. 2 manufactured by Advantec) was immersed in Stock 3 and then vacuum-dried for 15 minutes.

1.3 Mounting on Holder A detector was assembled using the prepared test paper as test paper 22 shown in FIG.

1.4 Gas used
Measurement was performed by flowing 0.1 ppm formaldehyde gas through the detector.

1.5 Results It was confirmed that the surface of the test paper was changed from white to yellow by contact with formaldehyde gas.

Example 2 Detection of Aldehydes A detector similar to that of Example 1 was produced except that the test paper was replaced with a test paper for detection of aldehydes produced as follows. In this test paper, when it comes into contact with aldehydes, the following chemical reaction occurs, and the yellow test paper turns blue.

2.1 Preparation of stock solution Stock 1: Dissolve MBTH (0.1 g) in 10 ml of methanol.
Stock 2: FeCl ₃ (0.1 g) is dissolved in 10 ml of methanol.
Stock 3: 1 ml of phosphate buffer solution (pH 2.5, manufactured by Nacalai Tesque) is dissolved in 10 ml of methanol.
Stock 4: Mix Stock 1, Stock 2, and Stock 3 so that the volume ratio is 1: 1: 1.

2.2 Preparation of test paper A filter paper (No. 2 manufactured by Advantec) was immersed in Stock 4 and then vacuum-dried for 15 minutes.

2.3 Attachment to Holder The detector was assembled using the prepared test paper as the test paper 22 shown in FIG.

2.4 Gas used
Measurement was performed by flowing 0.1 ppm formaldehyde gas, acetaldehyde gas or glutaraldehyde gas through the detector.

2.5 Results It was confirmed that the surface of the test paper was changed from yellow to blue by contact with various aldehyde gases.

Example 3 Detection of Carbon Monoxide A detector similar to that of Example 1 was produced, except that the test paper was replaced with a test paper for carbon monoxide detection prepared as follows. In this test paper, when it comes into contact with carbon monoxide, the following chemical reaction occurs, and the yellow test paper turns brown.

3.1 Preparation of Stock Solution Tetrakis (acetonitrile) palladium (II) tetrafluoroborate (100 mg), acetamide (200 mg), and 5.0 ml of water were placed in a screw tube and dissolved at room temperature.

3.2 Preparation of test paper A filter paper (No. 2 manufactured by Advantec) was immersed in the stock solution and then vacuum-dried at room temperature for 15 minutes.

3.3 Mounting on Holder A detector was assembled using the prepared test paper as the test paper 22 shown in FIG.

3.4 Gas used
Measurement was performed by flowing 1.0 ppm of carbon monoxide gas through a sampler.

3.5 Measurement results The surface of the test paper quickly changed from yellow to brown.

It is a typical exploded sectional view showing one desirable example of a detector of the present invention. FIG. 6 is a schematic exploded cross-sectional view showing another preferred embodiment of the upper main body of the detector of the present invention. FIG. 6 is a schematic exploded cross-sectional view showing another preferred embodiment of the upper main body of the detector of the present invention.

Claims (6)

A lower test body having a gas flow hole, a porous test paper support plate supported on the lower main body with a gap between the lower main body and a test paper held thereon, and connected to the lower main body , At least the ceiling portion is formed of a transparent material, and includes an upper body having a gas flow hole, the lower body and the upper body are connected, and the test paper support plate is held therein, A gap is formed between the test paper and the lower surface of the ceiling when the test paper is held on the test paper support plate, in order to hold the test paper for detecting the test substance in the gas A test paper holder , wherein a loupe is detachably attached to the tubular protrusion provided on the upper body .   The holder according to claim 1, wherein the gas flow hole of the upper body communicates with a tubular protrusion provided in the upper body. The holder according to claim 1 or 2 , wherein the gas flow hole of the lower body communicates with a tubular protrusion provided in the lower body. It said lower body and said upper body holder according to any one of claims 1 to 3 are connected by screwing. A lower test body having a gas flow hole, a porous test paper support plate supported on the lower main body with a gap between the lower main body and a test paper held thereon, and connected to the lower main body , At least the ceiling portion is formed of a transparent material, and includes an upper body having a gas flow hole, the lower body and the upper body are connected, and the test paper support plate is held therein, A gap is formed between the test paper and the lower surface of the ceiling when the test paper is held on the test paper support plate, in order to hold the test paper for detecting the test substance in the gas A test substance detector in gas in which a test paper for detecting a test substance in gas is hermetically held on the test paper support plate in the test paper holder, wherein the test paper support plate An O-ring is placed on top, and the test paper is placed inside the O-ring. Analyte detector in the gas tightly held. The detector according to claim 5 , wherein the test paper has a size and a shape just inscribed in the O-ring.

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