How to detect the residual amount of hydrogen peroxide after disinfection of pure water storage tank

It is agreed that the new water quality conductivity index of 20 degrees is not necessary to repeat the detection when it comes to controlling the concentration of purified water, and the chloride, sulfate and calcium salts in key cities are stored in water.

In fact, there is a hydrogen peroxide residue test paper that is more convenient, but he can only measure one ppm

The chemical formula of hydrogen peroxide is H2O2, pure hydrogen peroxide is a light blue viscous liquid, which can be mixed with water in any proportion, and is a strong oxidant. Its aqueous solution is suitable for medical wound disinfection, environmental disinfection and food disinfection. In general, it will decompose into water and oxygen, but the decomposition rate is extremely slow, and the way to speed up the reaction is to add catalysts such as manganese dioxide or irradiate them with short-wave rays.

Hydrogen peroxide detection tubes.

Usage: Water hair products and aquatic products: Take 1ml of water hair products or soaked supernatant of water products in the detection tube, shake well for 1 3min to observe the color.

Solid food: take 10g of the sample and cut it into a colorimetric tube or beaker, add purified water or distilled water to 100ml, soak it for 10min after full shaking, take 1ml of sample soaking solution in the detection tube, shake it well for 1 3min and observe the color.

Blank control: Add 1ml of purified water or distilled water to the test tube for control test, and the normal blank control is light yellow.

Judgment of the result. The positive sample is orange-red, the higher the concentration, the darker the color, and the reference standard color plate can be used for semi-quantitative judgment.

Hydrogen peroxide rapid test discs:

How to use and how to determine the result.

1. Sample processing

Liquid sample: direct sampling as the sample to be tested;

Solid sample: take 10g of shredded sample in a colorimetric tube or beaker, add purified water or distilled water to 100ml, fully shake and soak for 10min, to be measured.

2. Detection: Insert the paper into the liquid to be tested, shake it for 5-10 times, take out the paper piece, shake off the excess water, react for 10s, compare with the standard color palette, and judge the result.

3. Scope of application.

It is suitable for the rapid determination of hydrogen peroxide in water, milk, beef shutters, sea cucumbers, fish skins, goose intestines, chicken feet and squid.

Heating, hydrogen peroxide decomposition can be removed.

At present, the detection method of starch slurry content on cloth surface includes visual inspection method with drops on the cloth surface, and the color depth of the cloth surface is observed with the naked eye, so as to judge the amount of starch residue, but this method cannot be quantitatively analyzed. The gravimetric method is to compare the weight loss of the cloth before and after desizing to calculate the accuracy of the original slurry quantity. The hydrolysis method is to hydrolyze the starch with acid or enzyme, and then use the iodine method to determine the content of the starch hydrolysate product on the sample before and after desizing, in order to obtain the desizing rate, this method needs to boil the cloth sample for a long time, and the improper operation is easy to cause fiber scattering and cellulose hydrolysis, which affects the measurement results The acid aqueous solution can dissolve the starch, the starch on the fabric is soaked in perchloric acid aqueous solution, and dissolved in the solution, and then acetic acid, potassium iodide, potassium iodate solution are added to form a blue complex, and its reaction formula is as follows, and it is necessary to make appropriate adjustments.

In addition, the influencing factors of color development conditions have not been reported in the literature. Therefore, the author has made relevant explorations, and the improved color development conditions are more conducive to the determination of starch content on fabrics.

Take a small amount of sample in the test tube, then add a small amount of mnO2 powder, if there is a large number of bubbles in the test tube, and then extend the wooden strip with sparks into the test tube, if the wooden strip rekindles, the original sample is hydrogen peroxide.

K2Cr2O7 reacts with hydrogen peroxide to form CRO5, which turns blue in color, but in a non-aqueous solvent.

Hydrogen peroxide, chemical formula H2O2. Pure hydrogen peroxide is a light blue viscous liquid, miscible with water in any proportion, is a strong oxidizing agent, aqueous solution is commonly known as hydrogen peroxide, is a colorless transparent liquid. Its aqueous solution is suitable for medical wound disinfection, environmental disinfection and food disinfection.

In general, it will slowly decompose into water and oxygen, but the decomposition rate is extremely slow, and the way to speed up the reaction is to add catalysts such as manganese dioxide or irradiate it with short-wave rays.

Hydrogen peroxide (H2O2), commonly known as hydrogen peroxide, is a strong oxidizing agent with functions such as disinfection, sterilization, bleaching, etc., and is widely used in industrial and medical fields. In the food industry, hydrogen peroxide is mainly used for the disinfection of flexible packaging paper, the disinfection of canning factories, the sterilization of milk and dairy products, the fermentation of bread, the decolorization of food fiber, etc., and is also used as an auxiliary material in the food industry, as a bleaching agent and antibacterial agent for wheat flour, edible oil, agar, egg white, cheese and other foods.

The National Standard of the People's Republic of China for the use of food additives clearly stipulates that in the process of processing food, the amount of hydrogen peroxide used should not exceed the limit used. The United States and other countries have also set standards for the use of hydrogen peroxide in different foods. However, neither China nor international organizations have developed methods for the determination of hydrogen peroxide in solid foods.

Therefore, it is necessary to establish a simple and accurate hydrogen peroxide detection method in food testing.

At present, the determination of hydrogen peroxide generally uses iodine and absorbance methods.

We generally only do disinfection tests for storage tanks and distribution systems, and we do it in combination with PQ verification of purified water systems, which is to see if regular disinfection will affect the test results of the water system and achieve the effect of removing microorganisms.

The disinfectant we use is a mixed solution of hydrogen peroxide and peracetic acid, and there are concentration test strips matched by the manufacturer, and each water point needs to be detected to reach the concentration before the disinfection time is calculated, and the final rinsing must be detected to reach a certain concentration before it is rinsed. The disinfection effect depends on the results of regular testing of purified water.