an examination
Moisture moisture measurement method (Appendix IX H first method) determination, not more than 10.0%.
Total ash must not exceed 5.0% (Appendix IX K).
The acid-insoluble ash must not exceed 1.0% (Appendix IX K).
Leaching
According to the cold soaking method (Appendix XA) under the alcohol-soluble extract determination method,
Alcohol as solvent, not less than 15.0%.
Determination of content
According to high performance liquid chromatography (Appendix VI D) determination.
Chromatographic conditions and system suitability tests were carried out with octadecylsilane-bonded silica gel as the filler; acetonitrile was used as the mobile phase A, and 0.04% phosphoric acid solution (containing 2% isopropyl alcohol) was used as the mobile phase B. The gradient was as shown in the following table. Elution; detection wavelength is 325 nm. The number of theoretical plates should not be less than 3,000 based on the caffeic acid peak.
Time (minutes) Mobile Phase A (%) Mobile Phase B (%)
0 to 12 13 87
12-13 13→54 87→46
13～19 54 46 Preparation of reference solution Weigh precisely the amount of caffeic acid reference substance and ethyl caffeic acid reference substance and add methanol to make a mixed solution containing 10 μg per 1 ml. The test solution was prepared by taking about 2 g of the product powder (passing the No. 4 sieve), accurately weighed, and setting it in the Soxhlet extractor, and extracting it with petroleum ether (60-90° C.) for 2 hours, and discarding the petroleum ether solution. The residue dries the solvent, adds the chloroform-methanol (3:1) mixed solution and extracts for 6 hours. The extract recovers at least the amount of solvent, transfers to a 10 ml volumetric flask, and the container is washed with the same solvent into the same volumetric flask and diluted. To the scale, shake, that is, too.
Assay
5 μl of each of the reference solution and the test solution were accurately taken and injected into the liquid chromatograph to determine the result. Calculated on dry products, the total amount of caffeic acid (C9H8O4) and caffeic acid ethyl ester (C11H12O4) should not be less than 0.20%.
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