What Are the Best Methods for Glucose Determination?

Glucose, organic compound, molecular formula C ₆ H ₁₂ O _6. It is the most widely distributed and most important monosaccharide in nature, and it is a polyhydroxy aldehyde. Pure glucose is colorless crystal with sweet taste but not as sweet as sucrose, easily soluble in water, slightly soluble in ethanol, and insoluble in ether. The natural glucose aqueous solution rotates to the right, so it belongs to "dextrose".

German chemist Margrave S. Marggraf in Berlin in 1747 ^[2]

1. A sugar aqueous solution obtained by partially hydrolyzing edible corn starch with food-grade acids and / or enzymes, purified and concentrated. Due to the different degree of hydrolysis, the amount of D-glucose contained can vary widely. Produced from corn starch, known as "corn syrup".

2. Glucose can be prepared from starch by hydrolysis with hydrochloric acid or dilute sulfuric acid. It can also be made from starch as raw material under the action of starch saccharifying enzyme.

The central nervous system depends almost entirely on the supply of blood glucose as an energy source, and diabetes may occur once blood glucose rises to 80 mg%.

Industrially, glucose is produced by hydrolysis of starch. In the 1960s, microbial enzymes were used to produce glucose. This is a major innovation and has significant advantages over acid hydrolysis. In the production, the raw materials do not need to be refined, no acid and pressure resistant equipment is needed, and the sugar solution has no bitter taste and high sugar yield.

Glucose is mainly used in medicine as a nutrient for injection (glucose injection).

"Chinese Pharmacopoeia" 2015 edition two pages 1268

This product is D-(+)-glucopyranose monohydrate.

[ Properties ] This product is colorless crystal or white crystalline or granular powder; odorless and sweet.

This product is soluble in water and slightly soluble in ethanol.

The specific rotation is about 10g of this product, accurately weighed, put in a 100ml measuring bottle, add an appropriate amount of water and 0.2ml of ammonia test solution, after dissolving, dilute to the mark with water, shake well, leave it for 10 minutes, and measure at 25 according to law (General Rule 0621), the specific rotation is + 52.6 ° to + 53.2 °.

[ Identification ] (1) Take about 0.2g of this product, add 5ml of water to dissolve it, and slowly drop it into the lukewarm alkaline tartrate test solution to form a red precipitate of cuprous oxide.

(2) Take an appropriate amount of this product under the item of loss on drying and measure it according to law. The infrared light absorption spectrum of this product should be consistent with the control spectrum (spectrum set 702).

[ Check ] Acidity Take 2.0g of this product, add 20ml of water to dissolve, add 3 drops of phenolphthalein indicator solution and 0.20ml of sodium hydroxide titration solution (0.02mol / L), it should show pink.

Clarity and color of the solution: Take 5.0g of this product. After dissolving in heated water, let cool and dilute to 10ml with water. The solution should be clear and colorless. If it is turbid, compare with No. 1 turbidity standard solution (General Rule 0902 first method) , Must not be more concentrated; such as color development, and the control solution (take 3.0ml cobalt chloride solution for colorimetry, 3.0ml potassium dichromate solution for colorimetry and 6.0ml copper sulfate solution for colorimetry, diluted with water to 50ml) 1.0 Dilute to 10ml with water and not deeper.

Clarity of ethanol solution Take 1.0g of this product, add 20ml of ethanol, and place on a water bath and heat to reflux for about 40 minutes. The solution should be clear.

Chloride Take 0.60g of this product and check it according to law (General Rule 0801). Compared with the control solution made from 6.0ml of standard sodium chloride solution, it must not be more concentrated (0.01%).

Sulfate Take 2.0g of this product and check it according to law (General Rule 0802). Compared with the control solution made from 2.0ml of standard potassium sulfate solution, it must not be more concentrated (0.01%).

Sulfite and soluble starch Take 1.0g of this product, add 10ml of water to dissolve, add 1 drop of iodine test solution, it should be yellow immediately.

Loss on drying Take this product and dry to constant weight at 105 ° C. Lose weight is 7.5% ~ 9.5% (General rule 0831).

Ignition residue shall not exceed 0.1% (General Rule 0841).

Protein Take 1.0g of this product, add 10ml of water to dissolve, add 3ml of sulfosalicylic acid solution (1 5), no precipitation should occur.

Barium salt Take 2.0g of this product, add 20ml of water to dissolve, the solution is divided into two equal parts, one part is added with dilute sulfuric acid 1ml, the other part is added with 1ml water, shake well, and let stand for 15 minutes.

Take 1.0g of calcium salt , add 10ml of water to dissolve, add 1ml of ammonia test solution and 5ml of ammonium oxalate test solution, shake well and let stand for 1 hour, if turbidity occurs, and standard calcium solution [precisely weigh 0.1250g of calcium carbonate, In a 500ml measuring flask, add 5ml of water and 0.5ml of hydrochloric acid to dissolve, dilute to the mark with water, and shake well. Each 1ml is equivalent to 0.1mg of calcium (Ca)] 1.0ml comparison solution made of must not be more concentrated (0.01%).

Take 2.0g of iron salt , add 20ml of water to dissolve, add 3 drops of nitric acid, slowly boil for 5 minutes, let cool, dilute with water to make 45ml, add 3.0ml of ammonium thiocyanate solution (30 100), shake well, such as Compared with the control solution made by the same method with 2.0ml of standard iron solution, the color must not be deeper (0.001%).

Heavy metal Take 4.0g of this product, add 23ml of water to dissolve, add 2ml of acetate buffer solution (pH 3.5), and check according to law (general rule 0821 first method), containing no more than five parts per million of heavy metals.

Take 2.0g of arsenic salt , add 5ml of water to dissolve, add 5ml of dilute sulfuric acid and 0.5ml of potassium bromide bromine test solution, heat in a water bath for about 20 minutes to keep a slight excess of bromine, and add bromine if necessary. Appropriate amount of potassium bromide test solution, and replenish evapotranspiration at any time, let cool, add 5ml of hydrochloric acid and appropriate amount of water to 28ml, check according to law (General Law 0822 first method), should meet the requirements (0.0001%).

Microbial limit Take 10g of this product and make a 1:10 test solution with sterile sodium chloride-peptone buffer pH 7.0.

The total number of aerobic bacteria, molds and yeasts shall be 1ml for the test solution, and shall be checked according to law (General 1105 plate method). The total number of aerobic bacteria in 1g of the test product shall not exceed 1000cfu, and the total number of molds and yeasts shall not exceed 100cfu.

Take 10ml of the test solution of 1:10 E. coli and check it according to law (General Rule 1106). 1g of the test solution shall not be detected.

[ Category ] Nutritional medicine.

[ Storage ] Keep sealed.

[ Preparation ] (1) glucose injection (2) glucose powder (3) glucose sodium chloride injection (4) compound sodium lactate glucose injection ^[6]

Hypertonic glucose, potassium and insulin (30 to 40 mmol of potassium is required for each 1000 calories of glucose). From a nutritional point of view, the part of the heat energy needed by the critically ill patients under stress should be provided by the fat emulsion and simultaneously supplied with the compound amino acid preparation. ^[2]

(I) Fermentation Industry

The growth of microorganisms requires a suitable carbon-to-nitrogen ratio. As the carbon source of the microorganisms, glucose is the main material of the fermentation medium. For example, antibiotics, monosodium glutamate, vitamins, amino acids, organic acids, enzyme preparations, etc. require a large amount of glucose, and can also be used. As raw materials for microbial polysaccharides and organic solvents.

(Two) food industry

At present, crystalline glucose is mainly used in the food industry. With the improvement of living standards and the continuous development of science and technology in the food industry, the application of glucose in the food industry is becoming more and more widespread. The food industry will remain the largest market for a long time to come.

(Three) the chemical industry

Glucose is also widely used in industry. It is used as a reducing agent in the printing and dyeing and tanning industries. It is also commonly used as a reducing agent in chemical silver plating industries such as the mirror making industry, thermos gallbladder silver plating and glass fiber silver plating.

The application of glucose in the tanning industry for the tanning industry: chrome tanning agent is the best tanning agent for manufacturing light leather (shoe upper, clothing leather). Tanning with chrome salts has a history of 100 years. The produced leather has the characteristics of high shrinkage temperature, good elasticity, resistance to flexion, washing resistance, solid and durable. The chrome tanning agent is mainly basic chromium sulfate (basic chromium chloride can also be used, but its tanning agent is less effective than chromium sulfate). Its manufacturing method uses glucose or sulfur dioxide as a reducing agent, and dichromate is reduced to basic chromium sulfate in a sulfuric acid solution to form a chrome tanning solution. After the tanning solution is concentrated and dried, a powdery chrome tanning agent can be obtained. .

(4) Synthesis and transformation

Glucose can be synthesized or converted into other products by hydrogenation, oxidation, isomerization, alkaline degradation, esterification, acetalization, etc. Such as hydrogenation to sorbitol; oxidation to glucuronic acid, diacid, etc., and can be further made into calcium acid, sodium, zinc acid and gluconolactone lactone; isomerization to F42, F55, F90 fructose syrup and crystals Fructose; also isomerized to mannose (raw material for the production of mannitol), of which sorbitol can further generate vitamin C, which is widely used in clinical treatment, and 15% of mannitol is clinically safe and effective to reduce intracranial Pressure medication to treat brain edema and glaucoma. ^[2]