How many ways can you determine the glucose content? What are their principles?

The first is determined by membrane reagent, and the principle is as follows:

CH2OH(CHOH)4CHO+2[Ag(NH3)2OH] (water bath heating) → CH2OH (CHOH) 4COONH4+2AG ↓+3HN3+H2O

Note: (1) The inner wall of the test tube must be clean.

(2) The silver ammonia solution cannot be placed for a long time after use;

(3) Water bath heating, not alcohol lamp direct heating;

(4) Sodium hydroxide can be added to promote the reaction;

5] The silver mirror can be removed by soaking and washing with dilute HNO3.

The silver produced by heating reduction adheres to the test tube wall to form a silver mirror, so this reaction is also called silver mirror reaction.

The second method is determined by the newly prepared copper hydroxide solution, and the principle is as follows:

The glucose solution reacts with the newly generated copper oxide suspension to produce brick red precipitate. (Yellow precipitate will be formed at high concentration)

CH2OH(CHOH)4CHO+2Cu(OH)2- Heating →CH2OH(CHOH)4COOH+Cu2O↓+2H2O

Precautions: (1) The newly prepared 2Cu(OH)2 suspension should be prepared as required and should not be left for a long time.

⑵ When preparing a new suspension of copper hydroxide, the sodium hydroxide solution used must be excessive.

(3) The reaction solution must be directly heated to boiling.

(4) Although glucose molecules contain aldehyde groups, d- glucose contains no aldehyde groups.

Glucose is the most widely distributed and important monosaccharide in nature, and it is a polyhydroxy aldehyde.

Pure glucose is colorless crystal, sweet but not as sweet as sucrose (most people can't taste sweetness), soluble in water, slightly soluble in ethanol and insoluble in ether. Natural glucose aqueous solution rotates to the right, so it belongs to dextrose.

Glucose plays an important role in biology. It is the energy source of living cells and the intermediate product of metabolism, that is, the main energy-supplying substance of organisms. Plants can produce glucose through photosynthesis. It is widely used in candy manufacturing and medicine.

chemical property

It is the most widely distributed monosaccharide in nature. Glucose contains five hydroxyl groups and one aldehyde group, which has the properties of polyol and aldehyde.

Use:

Biological culture medium. Metal reducing agent. Complexing agent for boric acid titration. Microanalysis. Determination of whole blood glucose. Can be directly absorbed by the human body.

The ability of normal human body to utilize glucose per minute is 6 mg per kilogram of body weight. It is a carbohydrate that can be directly absorbed and utilized to supplement heat energy, and it is the main source of energy needed by human body. It is oxidized into carbon dioxide and water in the body, while providing heat or storing it in the form of glycogen. Can promote the detoxification function of the liver and protect the liver. It is the most common energy substance in organisms.