KR20090087296A - Method for preparing ph measure means and the ph measure means prepared by the method - Google Patents

Abstract

A method for manufacturing pH measuring apparatus is provided to measure pH concentration at the pH range of 1 to 14 and use in a cosmetic field and food field. A method for manufacturing a pH measuring apparatus comprises: a step of cutting a red cabbage and boiling in the water for four to six minutes; a step of cooling and making a solution containing anthocyanin; a step of dipping pH material in the anthocyanin solution; and a step of drying the pH material at 20‹C-25‹C for 20-24 hours.

Description

Method for preparing pH measure means and the pH measure means prepared by the method

The present invention relates to a method for producing a pH measuring means and a pH measuring means prepared by the manufacturing method, and more particularly by a method for producing a novel pH measuring means by adsorbing purple cabbage to cellulose It relates to a manufactured pH measuring means.

pH refers to the hydrogen ion index of the solution, which means that the hydrogen ion concentration is expressed as an index. In general, the hydrogen ion concentration of the solution is very small value, which is inconvenient to handle. Therefore, the pH index is introduced to indicate the acidity of the solution in simple numbers. The pH meter and pH test paper are used to measure the pH of the solution.

pH meta is a machine for measuring pH using electricity, which can measure the pH of a solution more accurately, but it is expensive, it takes a long time to measure the pH, and has to manage continuously.

The pH test strip is made by infiltrating the universal indicator (indicator made of various indicators) into the filter paper (paper). Although the accuracy is inferior to pH meta, it has the advantage of easily measuring the pH of the solution.

The existing pH test papers are domestic and Japanese. Domestic products can measure up to pH (1 ~ 11), and Japanese products can measure pH up to pH (1 ~ 11) and pH (1 ~ 14). The method of use is to measure the pH by cutting the pH test paper wound on the roll, immersed in an unknown solution, and then taken out and compared to the color table for each pH attached to the case.

However, when the pH test paper was added to the solution and taken out, after several seconds, the color of the pH test paper was changed from the original color and stained, which made it difficult to measure the pH. In addition, the domestic pH test paper can only measure up to pH (1 ~ 11), there was a problem that the pH (12 ~ 14) which is a strong alkali region can not be measured.

The present invention is to solve the above problems, the pH measurement means that can maintain the color over time even after entering and taking out the test solution and can measure the pH of the solution in all pH range (pH 1-14) It aims to provide.

In order to solve the above problems, the present invention

Cutting the purple cabbage, putting it in boiling water and heating it for 4 to 6 minutes;

Removing the purple cabbage and cooling to room temperature to prepare an anthocyanin pigment solution;

Immersing a pH labeling material in the anthocyanin pigment solution and then adsorbing the pH labeling material;

Picking up the adsorbed pH labeling material in the range of 80% to 85%; And

It provides a method for producing a pH measuring means comprising the step of drying the anthocyanin pigment adsorbed pH labeling material at a temperature of 20 ℃ to 25 ℃ 20 to 24 hours.

The pH labeling material is preferably paper or cotton fibers.

When the concentration of the purple cabbage is measured by diluting 20 times, the absorbance is preferably 0.7.

In order to solve the above other problem, the present invention

After cutting the fine purple cabbage into boiling water and heated for 4 to 6 minutes, the purple cabbage is removed and cooled to room temperature to prepare an anthocyanin pigment solution, the pH labeling material is immersed in the anthocyanin pigment solution and adsorbed, Pick up the adsorbed pH labeling material in the range of 80% to 85%, and then measure the pH of the anthocyanin dye-adsorbed pH labeling material by drying at a temperature of 20 ° C to 25 ° C for 20 to 24 hours. Provide means.

The pH labeling material is preferably paper or cotton fibers.

The present invention relates to a method for producing a pH measuring means by a novel method, the natural pH measuring means prepared by the manufacturing method is more accurate than the existing pH test paper in various pH range (pH 1 ~ 14) pH can be measured.

Purple cabbage contains anthocyanin pigments. Anthocyanin is a kind of flavonoid compound consisting of 15 carbons. Atomic groups such as sugars (glucose, galactose), hydroxyl groups (-OH) or methyl groups (-CH ₃ ) are attached to this basic structure to produce various colors, and they also show various colors depending on the pH of the soil. . Anthocyanin pigments are mainly found in flowers and fruits, and it is due to the anthocyanin pigments that various colors appear in various plants and fruits. Plants containing anthocyanins can be used as indicators because their color changes with pH.

The present invention uses this property of anthocyanin, and when small cabbages are cut and boiled, anthocyanin pigment is released, and the purple cabbage liquid is adsorbed to a pH measuring means to prepare pH test paper and pH test cloth. By adsorbing an anthocyanin pigment to a pH labeling material (eg paper or cotton fiber), a new natural pH measuring means can be prepared, and pH can be measured in various pH ranges (pH 1-14). There is also no change in color immediately after immersion in the pH buffer or after a sufficient time after removal from the solution, allowing the user to measure pH more accurately.

The method of preparing the pH measuring means by adsorbing the purple cabbage solution to the labeling material is cut purple cabbage, and then put into boiling water and heated. The heating time is preferably 4 to 6 minutes. If the heating time is less than 4 minutes, the anthocyanin pigment does not come out completely into the solution is not preferable, and if it exceeds 6 minutes, the anthocyanin pigment is excessive leaching is not suitable for use as a pH measuring means is not preferable. The purple cabbage is then removed and cooled to room temperature to prepare a solution containing the anthocyanin pigment. The temperature at which the heated solution is cooled is sufficient as a normal room temperature, preferably 18 ° C to 25 ° C.

After sufficiently immersing the pH labeling material in the solution containing the anthocyanin pigment, the treatment solution is padded to infiltrate the solution evenly. The pH measurement means is inserted between the upper and lower rollers and picked up to 80% to 85% through a mangling process of applying pressure. The ratio picked up is defined according to the following equation:

If the pick-up ratio is less than 80%, the purple cabbage liquid is not preferable because it is not sufficiently adsorbed by the measuring means, and if it exceeds 85%, it is not preferable because the purple cabbage liquid is excessively adsorbed by the measuring means.

Through this process, the pH measuring means adsorbed by the appropriate amount of anthocyanin pigment is dried for 20 to 24 hours at room temperature 20 ℃ ~ 25 ℃. Anthocyanin pigment in purple cabbage is sensitive to color depending on pH or temperature, so the drying temperature should be properly adjusted. In the present invention, the drying temperature is preferably 20 ° C ~ 25 ° C. If the drying temperature is less than 20 ℃ it becomes slightly blue is not preferable. If the drying temperature exceeds 25 ° C., the color of the pH measuring means is not purple but pink, which is not preferable.

The pH measuring means prepared by the manufacturing method according to the present invention can be used in school laboratories, cosmetics companies, etc., because it is using a material extracted from natural, so that the pH of the product can be easily measured even in food companies such as beverages, liquor, etc. Can be.

Hereinafter, the present invention will be described in more detail with reference to preferred embodiments of the present invention, but the present invention is not limited thereto.

Example

Example 1

The purple cabbage was chopped finely, put in boiling water, heated for 5 minutes, cooled to room temperature, and then cabbage was removed to prepare an anthocyanin pigment solution. At this time, the concentration of purple cabbage was measured by diluting 20 times using a spectrophotometer (UV-Vis Spectra Photometer, Shimadzu), the absorbance was measured as 0.7. Paper was immersed in the anthocyanin pigment solution to adsorb the anthocyanin pigment solution. Then, 80% of the paper was picked up through the mangle process, and the paper was dried at room temperature for 22 hours to prepare pH test paper.

Example 2

The purple cabbage was finely chopped and added to boiling water, heated for 5 minutes, cooled to room temperature, and then cabbage was removed to prepare an anthocyanin pigment solution. At this time, the concentration of purple cabbage was measured by diluting 20 times using a spectrophotometer (UV-Vis Spectra Photometer, Shimadzu), the absorbance was measured as 0.7. Cotton fibers were immersed in the anthocyanin pigment solution to adsorb the anthocyanin pigment solution. 80% cotton fibers were picked up through the mangle process, and the cotton fibers were dried at room temperature for 22 hours to prepare a pH test cloth.

Example 3

The purple cabbage was finely chopped and added to boiling water, heated for 5 minutes, cooled to room temperature, and then cabbage was removed to prepare an anthocyanin pigment solution. At this time, the concentration of purple cabbage was measured by diluting 20 times using a spectrophotometer (UV-Vis Spectra Photometer, Shimadzu), the absorbance was measured as 0.7. Paper was immersed in the anthocyanin pigment solution to adsorb the anthocyanin pigment solution. And 80% pick-up through the mangle process, the paper was dried for 24 hours at 23 ℃ to prepare a pH test paper.

Comparative Example 1

The purple cabbage was finely chopped and added to boiling water, heated for 5 minutes, cooled to room temperature, and then cabbage was removed to prepare an anthocyanin pigment solution. At this time, the concentration of purple cabbage was measured by diluting 20 times using a spectrophotometer (UV-Vis Spectra Photometer, Shimadzu), the absorbance was measured as 0.7. Paper was immersed in the anthocyanin pigment solution to adsorb the anthocyanin pigment solution. Then, 80% of the paper was picked up through the mangle process, and the paper was dried at 30 ° C. for 24 hours to prepare pH test paper.

Evaluation and Results

Figure 1 shows the results of the test at pH (1 ~ 14) prepared as a buffer using the pH test paper prepared according to Example 1. Referring to FIG. 1, various colors of pink in a strong acid region, pink in a weak acid region, purple in a neutral region, green in a basic region, and yellow in a strong basic region are illustrated.

Figure 2 shows the results of the test at pH (1 ~ 14) prepared as a buffer using a pH test cloth prepared according to Example 2. Referring to FIG. 2, various colors of pink in the strong acid region, pink in the weak acid region, violet in the neutral region, green in the basic region, and yellow in the strong basic region are shown.

It can be seen that Example 2 (pH test cloth) is more vivid in color than Example 1 (pH test paper). Since paper contains cellulose impurities such as lignin, the vividness of color is lowered compared to cotton fibers. Therefore, pH test cloth is superior to pH test paper in color clarity.

The pH test paper and pH test cloth prepared according to Examples 1 and 2 were immersed in pH buffers (1 to 14), and then the colors shown on the two samples were measured using a spectrophotometer (Macbath Color eye 3100, USA). It was converted into the value of Munsell color system and the results are shown in Table 1.

pH Example 1 Example 2 One 2.89PR 4.78R 2 9.85PR 0.61R 3 2.44R 2.55R 4 2.33R 2.63R 5 9.46RP 9.64RP 6 5.21PB 7.68RB 7 4.52 PB 4.96PB 8 6.23B 7.18B 9 5.23RP 5.44RP 10 5.12RP 5.81RP 11 3.11B 3.14B 12 5.37BG 6.40BG 13 7.98G 9.37G 14 1.56Y 2.35Y

As shown in Table 1, it was confirmed that the paper has a lower color value than the cotton fiber in all pH ranges.

Figure 3 shows the results of the test at pH (1 ~ 14) using a pH test paper prepared according to Example 3. That is, it shows the color according to the pH (1 ~ 14) when drying for 24 hours at a drying temperature of 23 ℃. Figure 4 shows the test results at pH (1 ~ 14) using a pH test paper prepared according to Comparative Example 1. That is, it shows the color according to the pH (1 ~ 14) when the drying temperature for 30 hours at 30 ℃.

Comparing the color of Figures 3 and 4, the color is not clear when the drying temperature is high (Comparative Example 1) compared with the case where the drying temperature is low (Example 3). Therefore, when the drying temperature exceeds 25 ℃ it can be seen that the color of the pH measuring means is not clear.

5a shows the color of the pH measuring means prepared according to Example 1 immediately after being immersed in a solution of pH (1-14), 5 minutes after 1 minute after being taken out of the solution, and FIG. 5b shows the pH (1-14). ) 10 minutes after removal from the solution, 15 minutes later, and 30 minutes later.

6a shows the color of the pH measuring means prepared according to Example 2 immediately after being immersed in a solution of pH (1-14), 5 minutes after 1 minute after being taken out of the solution, and FIG. 6b shows the pH (1-14). ) 10 minutes after removal from the solution, 15 minutes later, and 30 minutes later.

5A and 5B, and 6A and 6B, even if there is a time difference in pH measurement due to no change in color immediately after immersion in the buffer or after a sufficient time after taking out of the solution (after 30 minutes), It can be seen that the pH can be measured more accurately.

Figure 1 shows the color of the results of the test at the pH (1 ~ 14) prepared as a buffer using the pH test paper prepared according to Example 1.

Figure 2 shows the color of the results of the test at the pH (1 ~ 14) prepared as a buffer using a pH test cloth prepared according to Example 2.

Figure 3 shows the color of the results of the test at pH (1 ~ 14) using a pH test paper prepared according to Example 3.

Figure 4 shows the test results at pH (1 ~ 14) using a pH test paper prepared according to Comparative Example 1.

Figures 5a and 5b is the color and time immediately after immersing the pH test paper prepared according to Example 1 in the pH (1 ~ 14) solution (after 1 minute, after 5 minutes, after 10 minutes, after 15 minutes, after 30 minutes ) Is the color.

6a and 6b are the color and time immediately after immersing the pH test fabric prepared in Example 2 in the pH (1-14) solution (after 1 minute, after 5 minutes, after 10 minutes, after 15 minutes, after 30 minutes) It shows the color of.

Claims (5)

Cutting the purple cabbage, putting it in boiling water and heating it for 4 to 6 minutes; Removing the purple cabbage and cooling to room temperature to prepare a solution containing anthocyanin pigment; Immersing a pH labeling material in the anthocyanin pigment solution and then adsorbing the pH labeling material; Picking up the adsorbed pH labeling material in the range of 80% to 85%; And Method for producing a pH measuring means comprising the step of drying the anthocyanin pigment adsorbed pH labeling material at a temperature of 20 ℃ to 25 ℃ 20 to 24 hours. The method of claim 1, wherein the pH labeling material is paper or cotton fiber. The method of claim 1, wherein the concentration of the purple cabbage has a absorbance of 0.7 when measured by diluting 20 times. After cutting the fine purple cabbage into boiling water and heated for 4 to 6 minutes, the purple cabbage is removed and cooled to room temperature to prepare a solution containing an anthocyanin pigment, immersed pH labeling material in the anthocyanin pigment solution After adsorbing, the adsorbed pH labeling material is picked up in the range of 80% to 85%, and then the pH labeling material adsorbed by the anthocyanin pigment is dried at a temperature of 20 ° C to 25 ° C for 20 to 24 hours. PH measuring means, characterized in that. 5. The pH measuring means according to claim 4, wherein the pH labeling material is paper or cotton fiber.

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