The main component of the Filin reagent is that it can react with the Filin reagent

Feilin reagent is generally composed of sodium hydroxide and copper sulfate solution, which was invented by German chemist Hermann von Ferring in 1849; Filin reagent is often used to identify the presence of soluble reducing sugars, which can react with reducing sugars to form brick-red precipitates.

The Filin reagent is a potassium sodium tartrate complex of divalent copper ions that can be reduced to cuprous oxide by fatty aldehydes or reducing sugars. The reagent is a dark blue solution, and when it is coheated with aliphatic aldehydes or reducing sugars, the blue color disappears, and a red cuprous oxide precipitate is precipitated. During the precipitation of cuprous oxide, the color of the reaction solution may gradually change from blue, green, yellow, and red precipitates, and the red precipitate is directly observed when the reaction is fast.

The Filin reagent is formulated from a solution of sodium hydroxide with a mass fraction of g ml and a solution of copper sulfate with a mass fraction of g ml. It is combined with soluble reducing sugars (glucose, fructose and maltose) under heated conditions to produce brick-red cuprous oxide precipitates. For this reason, Filin reagents are often used to identify the presence or absence of soluble reducing sugars.

Preparation of Filin reagents:

Liquid A solution with a mass fraction of sodium hydroxide in g ml.

Liquid B A solution with a mass fraction of g ml of copper sulfate.

To use, drop 4 5 drops of solution B into 2 ml of solution A and use immediately after mixing.

For a solution with a mass fraction of sodium hydroxide of g ml and a solution of copper sulfate with a mass fraction of g mL, three to four drops of both solutions can be mixed.

The reagents that can react with the Filin reagent are reducing sugars such as glucose, fructose, and disaccharides except sucrose. The reducing sugar contains an aldehyde group, and the Feilin reagent, that is, the copper hydroxide in the new system, has weak oxidation, and in the case of water bath heating, it reacts with the aldehyde group to oxidize the aldehyde group to a carboxyl group, and the copper hydroxide is reduced to a brick-red cuprous oxide, so there is a brick-red precipitate.

Extension: Fehling's reagent (Fehling'S solution) is a reagent that can identify reducing substances, generally composed of sodium hydroxide and copper sulfate solution, invented by German chemist Hermann von Ferling in 1849. Filin reagent is often used to identify the presence of soluble reducing sugars, which can react with reducing sugars to form brick-red precipitates.

The preparation of liquid A is to dissolve 50g of sodium hydroxide and 137g of potassium sodium tartrate in 500ml of distilled water;

The preparation of liquid B is to dissolve crystalline copper sulfate and sulfuric acid in 500ml of water.

Filin reagent A and Filin reagent B react to form Filin reagent. When detecting reducing sugar, liquid A and liquid B must be added to the sample to be tested after the dust reaction is completed, and they must be used and prepared.

Because copper sulfate and sodium hydroxide together will produce copper hydroxide precipitation, the current configuration of Filin reagent can prevent the two from reacting completely, and it will become a precipitation after a long time.

1.Feilin reagent is generally composed of sodium hydroxide and copper sulfate solution and was invented by the German synchotomy chemist Hermann von Ferling in 1849; Filin reagent is often used to identify the presence of soluble reducing sugars, which can react with reducing sugars to form brick-red precipitates.

2.Fijianwanglin reagent is a potassium sodium tartrate complex of divalent copper ions, which can be reduced to cuprous oxide by aliphatic aldehydes or reducing sugars.

3.The Filin reagent is a dark blue solution, and when it is coheated with fatty aldehydes or reducing sugars, the blue color disappears, and a red cuprous oxide precipitate is precipitated.

4.During the precipitation of cuprous oxide, the color of the reaction solution may gradually change from blue, green, yellow, and red precipitates, and the red precipitate is directly observed when the reaction is fast.

Filin reagent is a common chemical reagent, the main component of which is phthalocyanine or iron salt (phenanthrolineferrous), also known as Fira reagent. It can be used to detect the amount of iron in water and can also be used for quantitative analysis.

The working principle of the Filin reagent is that after adding the Filin reagent to the water sample, the lead leaks, and the iron ions will complexe with the reagent to produce an organic substance, which will show a reddish color. Due to the widespread presence of iron ions in nature and life, the application of Feilin reagent is very wide. For example, it can be used to detect iron in drinking water and sewage, iron content in soil and plants, food, etc., and can also be used as one of the important reagents commonly used in chemical analysis.

In addition, the preservation of Filin reagent needs to pay attention to the following points:

1) The storage temperature should be lower than room temperature and avoid direct sunlight.

2) Avoid contact with other chemicals to prevent unnecessary chemical reactions affecting the quality of the reagent.

3) Clean the used reagent bottles, and try to avoid residual water traps and other sundries.

4) Check whether there is any abnormality such as color change or crystallization of Feilin reagent before use. Abnormal reagents should not be used to ensure the accuracy of the experiment.

Overall, proper storage of Filin reagents can extend their lifetime, ensure accurate results, and reduce the cost of failure.