KR101229837B1 - Portable indicator for oxidizing gas and method for rapidly and simply measuring the level of oxidizing gas in the atmosphere - Google Patents

Abstract

The present invention wrist wrist coated band paper; Paper attached to the coating band paper and coated with an oxidizing gas sensing solution; Light blocking and moisture control tape covering the paper coated with the sensing solution; And a portable oxidizing gas indicator composed of a vacuum package and a method for quickly and simply measuring the concentration of an oxidizing gas in the atmosphere by using the indicator.

Description

Portable indicator for oxidizing gas and method for rapidly and simply measuring the level of oxidizing gas in the atmosphere

The present invention relates to a portable oxidizing gas indicator for measuring an oxidizing gas such as ozone (O ₃ ) or nitrogen dioxide (NO ₂ ) and a method for quickly and simply measuring the concentration of an oxidizing gas in the atmosphere using the same.

Ozone (O ₃ ) is a colorless, tasteless gas that causes odors and consists of three oxygen atoms. Originally, ozone (O ₃ ) is produced naturally. The concentration of ozone that can be naturally produced is known to be about 10-20 ppb, and is highly unstable and easily decomposed. The strong oxidizing power of ozone (O ₃ ) is used for sterilization and odor removal, and in the stratosphere, it forms an ozone layer and acts as a protective layer of the earth's atmosphere, but the high concentration of ozone (O ₃ ) produced on the surface of the earth affects the human body and property. Are classified as air pollutants.

About 90% of the total ozone (O ₃ ) is concentrated in the stratosphere, which is between 10 and 50 km above ground, which is why the stratosphere is also called the ozone layer. Ozone in the ozone layer absorbs ultraviolet rays harmful to life in the sun and protects the lives of humans and animals on earth.

However, when the surface ozone concentration increases, eyes and neck may feel itchy, the airways may contract and breathing may be difficult, and headaches and coughs may occur. Care should be taken because bronchial asthma, respiratory patients, children, the elderly are affected a lot.

Nitrogen compounds present in the atmosphere are present in the form of nitrogen (N ₂ ), ammonia (NH ₃ ), dinitrogen oxide (N ₂ O), nitrogen monoxide (NO), nitrogen dioxide (NO ₂ ), and the like. Among them, nitrogen oxide, called NOx, is mainly generated by human fuel use. In addition to dinitrogen oxide, nitrogen monoxide and nitrogen dioxide, there are also dinitrogen trioxide (N ₂ O ₃ ) and dinitrogen pentoxide (N ₂ O). Nitrogen oxides are commonly referred to as NO and NO ₂ because they are very unstable in the air and cause photochemical reactions with other substances to form substances such as peroxyacyl nitrate (PAN), peroxybutryl nitrate (PBN), and peroxy-propiony nitrate (PPN). There are two general mechanisms of generating nitrogen oxides, one called thermal NOx, which is mainly combined with nitrogen, which occupies about 78% of air and oxygen, which occupies about 21% of air when fuel burns at high temperature. It occurs in the place where the fuel is burned together with thermal power plant, boiler, etc., and also from internal combustion engines such as gasoline engine, diesel engine, etc. used in home oil, stove, gas range and automobile. do.

The other is called fuel NOx, which occurs when there is an organic compound including nitrogen in the fuel itself. In this case, the generated NO is proportional to the amount of nitrogen contained in the fuel. The content of coal and heavy oil differs depending on the producing region, but because the nitrogen contains a little nitrogen, fuel NOx is generated for thermal NOx.

The generation mechanism and characteristics of each gas are as follows. First, nitrogen monoxide is a colorless, odorless, and fragrance-free gas with relatively low toxicity. It occurs in soil or water by anaerobic biological reactions in the natural state, and also occurs by combustion processes and photochemical reactions in the stratosphere. Nitrogen dioxide is pale yellow at low concentrations, reddish brown at high concentrations, has an irritating odor, and is highly corrosive and very toxic due to its fast oxidation rate.

The present invention is derived from the above demands, the air pollution of a large city is a serious level, when the concentration of ozone or nitrogen dioxide on the ground is higher than a certain standard seriously affects the human body, especially the elderly, children, students Big. Expensive equipment is needed to detect ozone or nitrogen dioxide present in the room as well as outdoors at present. Accordingly, the present invention provides an inexpensive and convenient portable oxidizing gas indicator and quickly and easily measures the concentration of ozone and nitrogen dioxide in the atmosphere. The purpose is to provide a method.

In order to solve the above problems, the present invention is a wrist-type coating band paper; Paper attached to the coating band paper and coated with an oxidizing gas sensing solution; Light blocking and moisture control tape covering the paper coated with the sensing solution; And it provides a portable oxidizing gas indicator composed of a vacuum package.

In addition, the present invention provides a method for quickly and simply measuring the concentration of oxidizing gas in the atmosphere using the indicator.

 According to the present invention, instead of the expensive equipment that requires a professional person, it is possible to find a reagent that reacts to a specific concentration of the oxidizing gas through various variable manipulations, and use it to measure the concentration of the oxidizing gas in an easy and inexpensive manner. . The portable oxidizing gas detector can measure the concentration of oxidizing gas through color change within a short time, if the measurement conditions are well established. Prediction of the range is possible. As a result, the simple oxidizing gas detector is very valuable in that it is easy to manufacture, inexpensive, and easily detects a certain concentration of oxidizing gas by color change.

Figure 1 shows the reaction route of the Salzman reagent.
Figure 2 shows the degree of reaction with the oxidizing gas of the coated paper according to the concentration of the potassium iodide aqueous solution and the Saltzmann reagent.
Figure 3 shows the color indicators according to the reaction degree of the potassium iodide aqueous solution coated paper according to the ozone concentration in the chamber.
Figure 4 shows the color index according to the reaction degree of the Salzman reagent coated paper according to the concentration of nitrogen dioxide in the chamber.
5 shows (1) a wrist band; (2) coated paper; (3) moisture adjusting tape; And (4) a portable oxidizing gas indicator consisting of a vacuum pack.
Figure 6 shows the color indicator according to the concentration of each of the potassium iodide aqueous solution and the Saltzmann reagent and the reaction time according to the exposure time.
Figure 7 compares the results measured using the oxidative indicator according to the present invention with the oxidizing gas measuring station specialized equipment, portable high-sensitivity measuring equipment.
8 is a graph showing a comparison of outdoor measurement results.

In order to achieve the object of the present invention, the present invention (1) wrist-type coated band paper; (2) paper attached to the coating band paper and coated with an oxidizing gas sensing solution; (3) light blocking and moisture control tape covering the paper coated with the sensing solution; And (4) a portable oxidizing gas indicator composed of a vacuum package.

In the portable oxidizing gas indicator of the present invention, (1) the wrist-shaped coating band paper maintains a band-shaped frame, and is not particularly limited to the wrist-type as long as it can be carried outside the body. (2) The coated paper is attached to the wrist-type coated band paper and coated with an oxidizing gas sensing solution, wherein the sensing solution is a 25% to 35% aqueous potassium iodide solution containing starch, preferably when the oxidizing gas is ozone (O ₃ ). 30% aqueous potassium iodide solution may be coated on coated paper, but is not limited thereto. When oxidizing gas is nitrogen dioxide (NO ₂ ), sulfanilic acid, phosphoric acid and NEDA (N- (1-naphthyl) may be used. Salzman reagent and / or methyl orange consisting of ethylene diamine) may be coated on coated paper, but is not limited thereto.

Mixing potassium iodide with starch and passing ozone gas causes the following reaction:

O ₃ + 2KI + H ₂ O → 2KOH + O ₂ + I ₂

At this time, when iodine molecules are produced by ozone, the iodine molecules and starch react to change color to reddish brown. This allows secondary detection of ozone.

The Saltsman reagent reacts specifically with nitrogen dioxide and the reaction proceeds as shown in FIG. 1.

(3) The moisture control tape covers the paper coated with the sensing solution to control the moisture of the coated paper and additionally blocks the light. The material of the tape is not particularly limited as long as it can perform the above function.

(4) the vacuum packaging is the (1) wrist-type coating band paper; (2) coated paper; And (3) a package for packing the moisture control tape, and preferably vacuum packed to prevent contamination of surrounding oxidizing gas and to store for a long time.

The oxidizing gas may be ozone (O ₃ ) or nitrogen dioxide (NO ₂ ), but is not limited thereto.

The present invention also provides a method for quickly and simply measuring the oxidizing gas in the atmosphere using the oxidizing gas indicator of the present invention.

Specifically, the method

(a) removing the package and the moisture control tape of the oxidizing gas indicator of the present invention at the place to be measured;

(b) exposing the indicator to air in a state of blocking direct sunlight to induce color development of the sensing solution; And

(c) comparing the color indicator prepared in advance by the concentration and the measurement time of the oxidizing gas and the degree of color development induced in the step (b) may include determining the concentration of the oxidizing gas in the atmosphere.

In the method of the present invention, the oxidizing gas to be measured may be ozone or nitrogen dioxide, but is not limited thereto.

In the step (b), when the oxidizing gas is ozone, the indicator of the present invention may be exposed to the oxidizing gas for 1 minute to 10 minutes in the case of nitrogen dioxide, and preferably 5 minutes when the oxidizing gas is ozone. The exposure may be performed within minutes, and in the case of nitrogen dioxide, exposure may be performed within 3 minutes, but is not limited thereto.

Step (c) is a step of determining the concentration of the oxidizing gas in the atmosphere, the concentration of the oxidizing gas such as ozone or nitrogen dioxide (for example, 0.01ppm, 0.03ppm, 0.05ppm, 0.1ppm) and the measurement time (for example For example, 1 minute, 2 minutes, 3 minutes, 4 minutes, 5 minutes, 10 minutes) by measuring the color indicators prepared in advance (see FIGS. 3 and 4) and the degree of color development induced in step (b) is compared The concentration of the oxidizing gas in it can be determined. The concentration of the oxidizing gas determined in step (c) is not accurate than that measured with a precision instrument, but has the advantage of being able to measure quickly and simply.

Hereinafter, the embodiment of the present invention will be described in detail. However, the following examples are merely to illustrate the invention, but the content of the present invention is not limited to the following examples.

Example  One: Saltzmann  reagent( Color ) Recipe

Fill a 1 L volumetric flask with medium ultrapure water (distilled water), add 5 g of sulfanilic acid, 30 mL of phosphoic acid, and 0.05 g of NEDA (N- (1-naphthyl) ethylene diamine). After dissolving, add ultrapure water until 1L is reached. Note that the three reagents must be added in sequence.

Example  2: reaction of oxidizing gas and indicator

end. Experimental Method

Prepare methyl orange and phenol red indicators that react with oxidizing gases and methyl orange indicators at 5%, 10% and 15% concentrations. Ozone and nitrogen dioxide gas are each passed for 5 seconds through the indicator of this concentration, and the color change of the indicator is observed.

I. Experiment result

Ozone reacted with KI aqueous solution containing starch and turned reddish brown, but nitrogen dioxide did not react. Nitrogen dioxide turned yellow in the reaction with methyl orange but did not react with ozone. Saltzmann reagent reacts mainly with nitrogen dioxide to turn pink and does not react with sulfur dioxide.

Reaction of oxidizing gas with indicator Indicator Ozone and Reaction Reaction with Nitrogen Dioxide Methyl Orange × ○ Starch-potassium iodide ○ × Saltsman Reagent △ ○

Example  3: with potassium iodide Saltzmann  Reactivity of Oxidizing Gases with Reagent Concentration

end. Experimental Method

Make an aqueous potassium iodide solution by concentration and expose it to a certain concentration of ozone (0.1 ppm) in the acrylic chamber and measure the start time of color change. In the case of nitrogen dioxide, the same method is used.

Prepare samples according to the concentration of the potassium iodide aqueous solution and the Saltzman reagent as shown in Table 2 and Table 3. The container containing 10 mL of each aqueous solution is previously put in the chamber. Each sample solution is exposed to the same concentration of ozone for 1 minute. Measure and record the time the color changes. Each sample was cut into circles and immersed in a circle, and then coated several times to produce coated paper by concentration. As with each sample solution, the coated paper is exposed to a constant concentration of ozone for 1 minute to observe the color change. In the case of the reaction between the Saltzman reagent and nitrogen dioxide, five saltsman reagents of different concentrations are prepared, 0.1 ppm nitrogen dioxide is mixed with nitrogen dioxide and dry air in a container, and the five samples are exposed for 1 minute and the color change is observed.

Samples by concentration of aqueous potassium iodide Sample 1 (10%) Solution 1 (KI 1g + Water 9g + Starch 0.5g) Sample 2 (20%) Solution 2 (KI 2g + Water 8g + Starch 0.5g) Sample 3 (30%) Solution 3 (KI 3g + Water 7g + Starch 0.5g) Sample 4 (40%) Solution 4 (KI 4g + Water 6g + Starch 0.5g) Sample 5 (50%) Solution 5 (KI 5g + Water 5g + Starch 0.5g)

Samples by concentration of saltsman reagent Sample 1 (Legacy) Solution 1 (distilled water + sulfanic acid 5g + phosphoric acid 30mL + NEDA 0.05g) Sample 2 (NEDA 2x) Solution 2 (distilled water + sulfanic acid 5g + phosphoric acid 30mL + NEDA 0.1g) Sample 3 (double sulfanic acid) Solution 3 (distilled water + 10 g of sulfanic acid + 30 mL of phosphoric acid + 0.05 g of NEDA) Sample 4 (all twice) Solution 4 (distilled water + sulfanilic acid 10 g + phosphoric acid 30 mL + NEDA 0.1 g) Sample 5 (all three times) Solution 5 (distilled water + sulfanilic acid 15g + phosphoric acid 30mL + NEDA 0.15g)

I. Experiment result

The 50% aqueous KI solution had the fastest color change. The aqueous solution reacts on the surface and changes color faster than coated paper. In the case of saltsman reagent, when the amount of sulfanilic acid and NEDA was tripled, color change occurred rapidly and pink was dark (FIG. 2).

Example  4: Coated paper  Effect of Air and Light on Discoloration

end. Experimental Method

Filter paper of the same size is coated in a predetermined amount of time, in aqueous potassium iodide solution having different concentrations. Saltsman's reagent coated paper is also manufactured in the same manner. In order to find out the relationship between air and light, the degree of discoloration was observed in units of time while blocking air and light using a vacuum pack and aluminum foil. Humidity was 70% and temperature was performed on 24 degreeC conditions.

Cut the sample paper into circles of constant size. It is made by dipping several times in 30% KI coating solution. Prepare four samples with or without vacuum and light blocking. Observe the color change over time.

I. Experiment result

Wrapping in vacuum packs and aluminum foil did not cause any color change. Exposure to air and light causes the most color change. In the case of nitrogen dioxide, Saltzmann coated paper is more prone to color change when exposed to air than light.

Example  5: chamber  Depending on the oxidizing gas concentration To color change  Impact and Color indicator

end. Experimental Method

Put an automatic ozone meter (model name: high sensitivity type AQ-200) in a volume 10L acrylic chamber in advance, adjust the concentration of ozone with an ozone generator, insert 30% potassium iodide coated paper, and observe the degree of discoloration in units of time. Prepare a 10L acrylic square chamber in the hood and make 8mm small holes on both sides. Put digital temperature and humidity meter and automatic ozone meter (model name: high sensitivity type AQ-200) in advance and measure temperature, humidity and ozone concentration. Inject ozone gas into household ozone generator. Make ozone concentrations of 0.01, 0.05 and 0.1 ppm. Insert 30% potassium iodide coated paper over time (first, minute, hourly), remove, record macro photography. Organize close-up files with digital camera and make color index by density. The control group was tested indoors without direct sunlight in the open space. Considering that the ozone concentration decreases with time in the chamber, a certain amount of ozone is injected after a certain time to maintain the concentration continuously. In the case of nitrogen dioxide, the saltsman color indicator, which tripled the amount of sulfanilic acid and NEDA, was placed in a reaction vessel prepared in 1 minute units and allowed to react for 10 minutes.

I. Experiment result

Humidity was 66% and temperature was 26 ℃, and it was found that color indicators showing the difference according to ozone concentration could be produced. The darker the ozone concentration, the darker the color and the more blue-blue. Ozone can be easily decomposed, so a measurement within 5 minutes would be appropriate. Nitrogen dioxide in confined spaces would be adequate within 3 minutes in terms of color indicator discrimination. It was found that the error of the Saltzmann color index was affected by moisture.

Example  6: Color indicator  Portable oxidizing gases Indicator  making

end. Experimental Method

The band can be made according to the conditions of the oxidizing gas indicator found in the above experiment. (1) the coated band paper for the wrist to maintain the band-shaped frame; (2) Potassium iodide coated paper, Saltzmann coated paper, attached as a key component of the sense band, which reacts with an oxidizing gas to cause color change; (3) attached thereon a moisture control tape of a sensing solution that prevents contamination of surrounding gas, maintains moisture in the initial state and blocks light; (4) It is packed in a vacuum pack that prevents contamination of surrounding oxidizing gas and enables long-term storage (FIG. 5). To use a band, wear a coated band on your wrist. Remove the vacuum pack after going to a place without direct sunlight or blocking sunlight. Peel off the moisture control tape. Cover with direct sunlight, expose for 5 minutes in the air, and visually determine the concentration compared to the color indicator.

I. Experiment result

Coating bands can be prepared for each concentration (FIGS. 6 and 7). In the absence of oxidizing gases other than ozone and in direct sunlight, it is recommended to observe the color change by exposure within 5 minutes to 1 hour after opening the 30% potassium iodide coating band.

Example  7: portable oxidizing gas Indicator  Concentration measurement

end. Experimental Method

The direct oxidizing gas indicator went to Cheonan-si measuring station about 5-6 pm and observed the color change. Go to Cheonan Baekseok Agricultural Industrial Complex and expose the indicator. It was about 5 pm with clear weather, less direct sunlight and heavy traffic. The indicator was observed for color change accumulated for the first 5 minutes.

I. Experiment result

Accurate measurement is difficult because it is not the same as the conditions in the chamber, but when compared with the color indicator, the concentration of nitrogen dioxide was found to be 0.01 ppm or less. In the case of the outdoors, the big error is light, other oxidizing gases, and other factors (humidity, temperature), so the reaction time should be increased. The portable oxidizing gas indicator is less accurate than the professional equipment and the portable measuring device in the outdoor, but shows the difference of the color change and it can be seen that the prediction of the specific concentration range is possible (FIGS. 7 and 8).

1: wrist band
2: coated paper
3: moisture control tape
4: vacuum pack

Claims (6)

delete delete delete (a) at the location to be measured (1) wrist coated band paper; (2) 25% to 35% aqueous potassium iodide solution containing starch when the oxidizing gas is ozone (O ₃ ) or sulfanilic acid when the oxidizing gas is nitrogen dioxide (NO ₂ ). Paper coated with a Salzman reagent consisting of phosphoric acid and NEDA (N- (1-naphthyl) ethylene diamine) or a sensing solution consisting of Saltzman reagent and methyl orange; (3) light blocking and moisture control tape covering the paper coated with the sensing solution; And (4) removing the package and the moisture control tape of the portable oxidizing gas indicator composed of a vacuum package.
(b) exposing the indicator to within 5 minutes when the oxidizing gas to be measured is ozone in the air in a state of being blocked by direct sunlight and within 3 minutes when it is nitrogen dioxide to induce color development of the sensing solution; And
(c) Concentration of the oxidizing gas in the atmosphere comprising the step of determining the concentration of the oxidizing gas in the atmosphere by comparing the color indicator prepared in advance by the concentration and the measurement time of the oxidizing gas and the degree of color development induced in step (b) To quickly and easily. delete delete

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