Preparation method of accurate pH test paper

A test paper and sophisticated technology, applied in the direction of material analysis by observing the influence of chemical indicators, and analysis by chemical reaction of materials, etc., can solve problems such as error, poor precision, uneven color, etc., to ensure accurate stability and stability, factors that reduce test values, the effect of high sensitivity

Active Publication Date: 2013-04-10
杭州特种纸业有限公司
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  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the precision of the pH precision test papers currently on the market is relatively poor. The error of the general precision test paper pH measurement is about ±1, and it is easily affected by the indoor environment, especially the time. When the test paper leaves the test solution, it will Rapid changes, if not judged quickly, are likely to introduce large errors
[0003] A high-sensitivity pH test paper and its preparation method (CN102519959A) are disclosed on the website of the Intellectual Property Office of the People's Republic of China. This method solves the human factor by using digital advanced offset printing technology instead of manual screen printing to print standard color plates. Caused the same batch of color plates to reappear, uneven color, and then affect the accuracy of the test, but the sensitivity and accuracy of the pH test paper itself has not been well resolved
Moreover, the above-mentioned literature records that in order to ensure that the pH base paper is not affected by acid and alkali corrosion and improve the stability of the pH test paper, water-based color-fixing agent, cotton wood fiber anti-mold agent, and special paper anti-mold agent are added to the indicator formula. , and a buffer neutralizer prepared by sodium hydroxide and phosphoric acid, which not only makes the production process complicated, but also may affect the accuracy of the test when determining certain substances

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0018] (1) Preparation of indicators: 200g of saponin yellow, 50g of malachite green, 650g of acid lake blue, 1200g of bromophenol blue, 126g of cresol red, 54g of m-cresol violet, 680g of bromocresol green, dissolved in 30% of 700kg ethanol solution;

[0019] (2) Impregnation: The pH test paper base paper of the reel enters the impregnation machine successively through the unwinding frame and the paper guide roller. The speed passes through the dipping tank on the dipping machine, and the indicator is evenly coated on the base paper, then squeezed by the rubber guide roller, and then enters the drying device;

[0020] (3) Drying: dry with hot steam under normal pressure, the steam temperature is 100°C, and the time is 1.5 minutes;

[0021] (4) Test: Take a small piece of test paper and put it on the peeling Petri dish, dip a clean and dry glass rod into the middle of the test paper, and observe the color after the change is stable. Compared with the standard color card, the ...

Embodiment 2

[0023] (1) Preparation of indicators: 198g of saponin yellow, 48g of malachite green, 648g of acid lake blue, 1190g of bromophenol blue, 124g of cresol red, 52g of m-cresol violet, and 678g of bromocresol green were dissolved in 700kg of 30% ethanol solution;

[0024] (2) Impregnation: The pH test paper base paper of the reel enters the dipping machine successively through the unwinding frame and the paper guide roller, adjust the unwinding frame guide roller and the paper guide roller, so that the base paper is in a state of tension and flatness, and the base paper is 2.5m / The speed of s passes through the dipping tank on the dipping machine, and the indicator is evenly coated on the base paper, then squeezed by rubber guide rollers, and enters the drying device;

[0025] (3) Drying: dry with hot steam under normal pressure, the steam temperature is 105°C, and the time is 1 minute;

[0026] (4) Test: First wet the test paper with distilled water, stick it to one end of the ...

Embodiment 3

[0028] (1) Preparation of indicators: 202g of saponin yellow, 52g of malachite green, 653g of acid lake blue, 1210g of bromophenol blue, 128g of cresol red, 56g of m-cresol violet, and 682g of bromocresol green were dissolved in 700kg of 30% ethanol solution;

[0029] (2) Impregnation: The pH test paper base paper of the reel enters the impregnation machine successively through the unwinding frame and the paper guide roller, and the unwinding frame guide roller and the paper guide roller are adjusted so that the base paper is in a tensioned and flat state. The base paper is 3.5m / The speed of s passes through the dipping tank on the dipping machine, and the indicator is evenly coated on the base paper, then squeezed by rubber guide rollers, and enters the drying device;

[0030] (3) Drying: dry with hot steam under normal pressure, the steam temperature is 95°C, and the time is 2 minutes;

[0031] (4) Test: Take a small piece of test paper on a glass slide, dip a clean and dr...

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PUM

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Abstract

The invention relates to a preparation method of accurate pH test paper. An indicator is prepared by dissolving Metanil yellow, malachite green, acid turquoise blue, bromphenol blue, cresol red, m-cresol purple and bromocresol green in a 30% ethanol water solution. The preparation method comprises the following steps: previously impregnating base paper of pH test paper in the prepared indicator solution, and drying with heating steam of 95-105 DEG C at normal pressure. The preparation method of accurate pH test paper is simple in process, stable in product quality and higher in sensitivity and accuracy in comparison with the common accurate test paper, and the accuracy can be up to 0.2 level. Thus, the preparation method can be widely used in the fields of scientific research, industry, agriculture, environmental protection, medicine and food.

Description

technical field [0001] The invention belongs to the technical field of detection test papers, and in particular relates to a preparation method of pH precision test papers for testing the pH values ​​of liquids and gases. Background technique [0002] pH test paper is widely used in scientific research, industry, agriculture, environmental protection, medicine and food fields to determine the pH value of liquids and gases. The reaction principle of pH is based on the pH indicator method. At present, the general pH analysis test paper contains methyl red [pH4.2 (red) ~ 6.2 (yellow)], bromocresol green [pH3.6 (yellow) ~ 5.4 (green)], bromothymol blue [pH6.7 (yellow) ~ 7.5 (blue)], these mixed acid-base indicators can reflect the variation range of pH 4.5 ~ 9.0. However, the precision of the pH precision test papers currently on the market is relatively poor. The error of the general precision test paper pH measurement is about ±1, and it is easily affected by the indoor envir...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): G01N21/80
Inventor 吴安波
Owner 杭州特种纸业有限公司
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