Highly sensitive pH test paper and preparation method thereof

Abstract

The invention relates to a piece of highly sensitive pH test paper and a preparation method thereof, wherein a developing strip is in the form of a piece of pH body paper, which is dipped in a reagent solution and then dried by hot air at constant temperature; the reagent solution contains an indicator; the formula of the indicator contains bromothymol blue, thymol blue, metanil yellow, m-methyl red, bromocresol green, nitrazine yellow, cresol red, phenolphthalein, para-nitrophenylazosalicylate sodium, titan yellow, fluorescent pigment orange red, 5% 4-nitrobenzenediazo-1-naphthol-3.6-sodium disulfonate solution and 30% dissolved ethanol aqueous solution; and the formula of the indicator further contains an aqueous colour fixing agent, a cotton wooden fibre mildew preventive, a special paper mildew preventive and a buffer neutralizer formed by modulating sodium hydroxide and phosphoric acid. The preparation method comprises the following steps of: adjusting the reagent solution till a pH value is up to 6-7.5, uniformly wetting the pH body paper, and drying through hot air at constant temperature. According to the invention, the reagent solution can be adjusted, so that the pH value is up to 6-7.5; steady and precise high sensitivity of the pH1-14 test paper is effectively increased; and the test paper is convenient and simple to use.

Description

technical field [0001] The invention relates to pH test paper, in particular to a highly sensitive pH 1-14 test paper and a preparation method thereof. Background technique [0002] In the field of chemistry, the use of test paper is extremely frequent. It is a type of paper impregnated with chemicals and can be used to test the presence of certain substances in liquids or gases through its color change. [0003] pH test paper is impregnated with various acid-base indicators to test the acidity or alkalinity of the substance, or the approximate pH value of the solution to be tested. A test paper impregnated with potassium iodide for the detection of sulfides. The paper is soft, has good absorption performance, does not swell or break when soaked in water, and is made of cotton pulp or bleached and refined kraft wood pulp, which is free-form beating and copied under low pressure on a fourdrinier paper machine. After being impregnated with different chemicals and dried, it c...

AI Technical Summary

Problems solved by technology

[0005] The standard color plate of the existing test paper adopts artificial screen printing, and the toxicity of paint and solvent affects the health of operators

Due to the use of manual screen printing, human factors make the same batch of color plates have poor reproducibility, the color is difficult to be uniform, and the color accuracy is affected

The color block stability and accuracy of the test paper color strip are also poor