Epoxy curing agent Knowledge [Sorbitol supply] Sorbitol inspection methods and result standards

[Sorbitol supply] Sorbitol inspection methods and result standards

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Sorbitol is a white hygroscopic powder or crystalline powder or flake Or granules, odorless. Depending on the crystallization conditions, the melting point changes in the range of 88 to 102°C, and the relative density is about 1.49. Easily soluble in water (1g dissolves in about 0.45mL water), slightly soluble in ethanol and acetic acid. It has a refreshing sweetness, the sweetness is about half that of sucrose, and its caloric value is similar to that of sucrose. Sorbitol liquid is a clear, colorless, syrupy liquid with a sweet taste, neutral to litmus, and miscible with water, glycerin and propylene glycol.

Sorbitol inspection methods and result standards:

Acidity:

Take 5.0g of this product, add fresh boiling water After dissolving in 50ml of cold water, add 3 drops of phenolphthalein indicator solution and 0.30ml of sodium hydroxide titration solution (0.02mol/L), it should appear light red.

Clarity and color of the solution:

Take 3.0g of this product, add 20ml of water to dissolve it, the solution should be clear and colorless.

Chloride:

Take 1.4g of this product and check it according to the law (General Rule 0801). Compared with the control solution made of 7.0ml of standard sodium vapor solution, it must not be more concentrated ( 0.005%).

Sulfate:

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

Reducing sugar:

Take 10.0g of this product, place it in a 400ml beaker, add 35ml of water to dissolve, add 50ml of alkaline copper tartrate test solution, cover the glass dish, and heat. Boil within 4 to 6 minutes, continue boiling for 2 minutes, immediately add 100ml of newly boiled water and let it cool, filter it with a 105°C constant weight vertical melting glass crucible, wash the container and sediment in batches with 30ml of hot water, and then continue in sequence Wash the precipitate with 10 ml each of ethanol and diethyl ether, and dry to constant weight at 105°C. The weight of the obtained cuprous oxide shall not exceed 67 mg.

Total sugar:

Take 2.1g of this product, place it in a 250ml ground-mouth flask, add about 40ml of hydrochloric acid solution (9-1000), heat and reflux for 4 hours, and let cool. Transfer the hydrochloric acid solution into a 400ml beaker, wash the container with 10ml of water and put it into the beaker. Neutralize with 24% sodium hydroxide solution. Operate according to the method of “adding 50ml of alkaline copper tartrate test solution” under reducing sugar. The resulting oxidation The weight of cuprous must not exceed 50mg.

Relevant substances:

Take about 0.5g of this product, put it in a 10ml measuring bottle, add water to dissolve and dilute to the mark, shake well, and use it as the test solution; accurately measure 2ml , put in a 100ml measuring flask, dilute to the mark with water, shake well, and use it as a control solution. Take about 0.5g each of mannitol reference substance and sorbitol reference substance respectively, put them in a 10ml measuring bottle, add water to dissolve and dilute to the mark, shake well, and use it as a system suitability solution. According to the test of high performance liquid chromatography (General Chapter 0512), a strong cationic calcium type exchange column (or a chromatographic column with equivalent separation efficiency) using sulfonated cross-linked styrene divinylbenzene copolymer as filler; using water as the flow phase; the flow rate is 0.5ml per minute, the column temperature is 72-85°C, and the differential refractive index detector is used. Take 20u1 of the system suitability solution and inject it into the liquid chromatograph. The separation between the mannitol peak and the sorbitol peak should be greater than 2.0. Precisely measure 20u1 of each of the control solution and the test solution and inject them into the liquid chromatograph, and record the chromatogram to 3 times the retention time of the main component peak. If there is an impurity peak in the chromatogram of the test solution, the area of ​​a single impurity peak shall not be greater than the main peak area of ​​the control solution (2.0%), and the sum of the areas of each impurity peak shall not be greater than 1.5 times (3.0%) of the main peak area of ​​the control solution.

Weight loss on drying:

Take this product, place it in a phosphorus pentoxide dryer, and dry it under reduced pressure at 60°C to constant weight. The weight loss shall not exceed 1.0% (General Rules 0831).

Ignition residue:

Must not exceed 0.1% (General Rule 0841).

Heavy metals:

Take 2.0g of this product, add 2ml of acetate buffer (pH3.5) and an appropriate amount of water to dissolve it into 25ml, and check according to law (General Chapter 0821) Method 1), the content of heavy metals shall not exceed 10 parts per million.

Arsenic salt:

Take 1.0g of this product, add 10ml of water to dissolve, add 5ml of dilute sulfuric acid and 0.5ml of potassium bromide bromine test solution, and heat on a water bath for 20 minutes. Keep a slight excess of bromine (if necessary, potassium bromide bromine test solution can be added dropwise), and replenish the evaporated water at any time, let it cool, add 5 ml of hydrochloric acid and an appropriate amount of water to make 28 ml, and check according to the law (General Rules 0822 No. 1 Law), should comply with regulations (0.0002%)�

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