JP4133640B2 - Hydrogen sulfide gas detection material - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a gas detection material that supports a colorant and detects the gas concentration from the optical density of reaction traces caused by reaction with hydrogen sulfide gas.
[0002]
[Prior art]
Hydrogen sulfide needs to be detected from a very low concentration based on environmental standards to a very high concentration generated from crude oil in a hold.
In order to detect such a wide range of gas concentrations as a change in optical concentration due to a chemical reaction, a detection material tape in which a silver salt is supported on a carrier as shown in Patent Document 1 is used. It is also conceivable to adjust the concentration of the silver salt on the support so as to correspond to a certain concentration range.
[Patent Document 1]
Japanese Patent Laid-Open No. 06-18509
[Problems to be solved by the invention]
However, in addition to the problem that it takes time to manufacture a detection material suitable for each concentration range, if the concentration of the reaction reagent is lowered to cope with a high concentration gas, it is affected by the volatilization of the reaction reagent. There is a problem that the measurement accuracy is lowered.
The present invention has been made in view of such problems, and the object of the present invention is to measure a test gas in a wide concentration range with high accuracy while keeping the concentration of the reaction reagent on the carrier constant. It is to provide a hydrogen sulfide gas detection material that can be used.
[0004]
[Means for Solving the Problems]
In the present invention in order to achieve the above problems, a reaction reagent and the humectant to color reaction with the gas to be detected is supported on a carrier, the optical density due to reaction with the gas to be detected from the carrier In the hydrogen sulfide gas detection material to be detected based on the reflected light, the support supports copper nitrate as a reaction reagent, and at least the inflow surface side of the test gas of the support has a light-transmitting silicon rubber or polyethylene A film made of
According to this, the amount of permeation of the test gas is limited by the film, and even with a high concentration of the test gas, it is possible to reliably measure optically by suppressing the reaction amount of the reaction reagent. Further, since copper nitrate is less decomposed by light than silver salt, discoloration can be prevented and long-term storage is possible.
[0005]
BEST MODE FOR CARRYING OUT THE INVENTION
Therefore, details of the present invention will be described below based on the illustrated embodiment.
FIG. 1 shows one embodiment of the hydrogen sulfide detection material of the present invention, and in this embodiment, it is configured as a tab so as to be easily loaded into a detector.
The frame 2 constituting the tab 1 is configured to be engageable by an upper frame 21 having a through hole 21a, a lower frame 22 having a through hole 22b, a claw 21b, and a window 22b. A film 3 capable of transmitting a test gas is disposed at least on the gas inflow side so as to close, and a color reaction base material 4 that generates a reaction mark by a color reaction in a state where it is preferably in close contact with the lower surface thereof is laminated. ing. As such a film 3, a silicon rubber film, a polyethylene film, or the like is suitable.
[0006]
Note that idea to form the lower piece 3a to the end portion of the film 3 as shown in FIG. 2, the film 3 at the optical density measured easily removed from the color reaction substrate 4, enabling reliable measurements Become.
[0007]
When the tab 1 having such a configuration is set between the sampling head 11 and the measurement head 12 of the measuring apparatus 10 as shown in FIG. The test gas passes through the color reaction substrate 4 while receiving the ventilation resistance of the membrane 3. Thereby, even when the concentration of the test gas is extremely high, sampling can be performed for a specified time set in the measuring apparatus 10, and the gas can be detected with high accuracy.
[0008]
By the way, as the color reaction base material 4, a support made of a material that can be easily molded, such as cellulose, impregnated with silica gel fine particles is selected, and copper nitrate is added to the support 0.5 to 7.0 w / v. %, And an appropriate amount of a moisturizing agent such as glycerin is impregnated in a volatile solution, in this embodiment, a reaction reagent dissolved in methanol, and then the methanol is volatilized from the carrier.
As the carrier, it is desirable to use cellulose mixed with fine particles of silica gel to ensure the reaction between the hydrogen sulfide gas and the reaction reagent.
[0009]
When measuring a gas having a concentration of the environmental standard, the reaction reaction having an optical density corresponding to the gas concentration can be generated by using the color reaction base material 4 as it is. This reaction mark can be easily measured by an optical method, that is, a method of irradiating the reaction mark with a certain amount of light from the light emitting means 15 of the measuring head 12 and detecting the reflected light by the light receiving means 16.
[0010]
On the other hand, when the concentration of hydrogen sulfide in the hold containing a very high concentration of a test gas, for example, crude oil is to be measured, the above-described tab is set in the sampling device. Since the sample gas to be sampled is limited to a predetermined value, for example, 10 to the fifth power, due to the ventilation resistance of the membrane 3, the reaction amount of the reaction reagent is suppressed, and thus the apparatus Measurement at the sampling time set in 10 is possible.
[0011]
When the measurement is completed, the film is removed and the optical density of the reaction trace is measured by the above-described optical method, and the gas concentration can be obtained by multiplying by the rate of decrease in the air flow rate by the film 3.
[0012]
Silicon rubber and polyethylene have low light reflectivity, so even if the optical density is measured without removing the film 3 from the tab, the error is as low as 5% and the reduction rate of the amount of light is low. Since it is known, it can be easily corrected by multiplying by a coefficient.
[0013]
In addition, when measuring the medium concentration of hydrogen sulfide using the same colored reaction base material, the membrane is treated with a porous material to reduce the air flow resistance, thereby reducing the ventilation resistance in the same manner as described above. Can be measured.
[0014]
As described above, since the film 3 having ventilation resistance is present on at least the surface of the color reaction base material, not only the test gas having a high concentration can be detected by the color reaction base material of the same specification but also during storage. In this case, the color reagent is prevented from being volatilized, so that it can be stored for a long time. Furthermore, in the present invention, since copper nitrate is used as a reaction reagent, the light resistance is improved as compared with the case where a silver salt having optical reactivity described in Patent Document 1 is used. Saving is possible.
[0015]
In the above-described embodiment, the detection material is configured as a tab. However, as shown in FIG. 4, the film 3 is laminated on at least the side exposed to the test gas of the color reaction base material 4, or Even if it is formed and stored in a bag shape, the same effect is obtained.
[Brief description of the drawings]
FIGS. 1A and 1B are an assembled perspective view and a sectional view showing an embodiment of the hydrogen sulfide gas detection material of the present invention, respectively.
FIG. 2 is a cross-sectional view showing another embodiment of the detection material of the present invention.
FIG. 3 is a cross-sectional view showing an embodiment of measuring means suitable for the detection material.
FIGS. 4A and 4B are a top view and a cross-sectional view, respectively, showing another embodiment of the present invention.
[Explanation of symbols]
1 Tab 2 Frame 3 Membrane 4 Color Reaction Base

Claims (2)

A reaction reagent and the humectant to color reaction with the gas to be detected is supported on a carrier, wherein the hydrogen sulfide gas detecting material for detecting, based on the reflected light of the optical density from the carrier by reaction with the gas to be detected,
Hydrogen sulfide gas in which copper nitrate is supported as a reaction reagent on the carrier, and a film made of light-transmitting silicon rubber or polyethylene is laminated at least on the inflow surface side of the test gas of the carrier. Detection material. The hydrogen sulfide gas detection material according to claim 1, wherein the film is provided so as to be removable from the carrier .

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