Pharmaceutical Grade Methylparaben Methylparaben Bacteriostatic Powder High Content

Pharmaceutical Grade Methylparaben Methylparaben Bacteriostatic Agent Powder The main function of methylparaben is to act as organic synthetic food, as well as antibacterial preservatives for cosmetics, and can also be used as feed preservatives
.

Methylparaben usually refers to methylparaben, also known as methylparaben, which is an organic substance, white crystal or colorless crystal, easily soluble in alcohol, ether and acetone, and very slightly soluble in water.

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【Check】Acidity: Take 2.
0ml of the solution under the clarity and color of the solution, add 2ml of ethanol and 5ml of water, shake well, add 2 drops of bromocresol green indicator solution, and titrate with sodium hydroxide titration solution (0.
1mol/L) When it turns blue, the volume of sodium hydroxide titration solution (0.
1mol/L) should not exceed 0.
1ml
.

The clarity and color of the solution take 1.
0g of this product, add 10ml of ethanol to dissolve it, and check it according to the law (general rule 0901 and general rule 0902), the solution should be clear and colorless; General Principle 0901 The first method) comparison shall not be deeper
.

For chloride, take 2.
0g of this product, add 50.
0ml of water, heat it in a water bath at 80°C for 5 minutes, let it cool, and filter; Liquid comparison should not be more concentrated (0.
035%)
.

　　Sulfate Take 25.
0ml of the continuous filtrate under the chloride item and check according to the law (General Rule 0802).
Compared with the control solution made of 2.
4ml of standard potassium sulfate solution, it should not be more concentrated (0.
024%)
.

　　Take an appropriate amount of this product for related substances, accurately weigh it, add mobile phase to dissolve and quantitatively dilute to make a solution containing about 1mg per 1ml, as the test solution; accurately measure 1ml, put it in a 100ml measuring bottle, and dilute it with mobile phase to the mark, shake well, and use it as a control solution; take an appropriate amount of the reference substance of p-hydroxybenzoic acid, accurately weigh it, add mobile phase to dissolve and quantitatively dilute to make a solution containing about 3 µg per 1ml, as a reference solution; accurately measure the control Put 5ml of the product solution in a 50ml volumetric flask, dilute to the mark with mobile phase, shake well, and use it as a sensitivity solution
.

According to the chromatographic conditions under the content determination item, inject 20µl of the sensitivity solution into the liquid chromatograph, and the signal-to-noise ratio of the p-hydroxybenzoic acid peak should be greater than 20
.

Then precisely measure 20µl each of the test solution, the reference solution and the reference solution, inject them into the liquid chromatograph, and record the chromatogram to 4 times the retention time of the main peak
.

If there is a peak consistent with the retention time of the p-hydroxybenzoic acid peak in the chromatogram of the test solution, the peak area should not exceed 0.
3% according to the external standard method, and the peak area of ​​other single impurities should not be greater than 0.
4 times the main peak area of ​​the control solution ( 0.
4%), the sum of the peak areas of each impurity shall not be greater than 0.
8 times (0.
8%) of the main peak area of ​​the control solution
.