Rubescens A test standard - Huaqiang Electronic Network

Properties: This product is a white crystalline powder with no odor and a special scent.

It dissolves well in solvents like methanol, ethanol, and acetone, but is only slightly soluble in petroleum ether and almost insoluble in water.

Test Procedure: Take 10 mg of the sample and dissolve it in 10 ml of methanol. The resulting solution should be clear, colorless, or slightly yellow.

Melting Point: Dry the product under reduced pressure using phosphorus pentoxide as a desiccant until constant weight. Then measure the melting point range using the capillary method. The melting point is between 248°C and 250°C according to the Chinese Pharmacopoeia, 2005 edition, Appendix VII C.

Loss on Drying: After drying with phosphorus pentoxide under reduced pressure, the weight loss should not exceed 3% (Chinese Pharmacopoeia 2005 edition, Appendix IX G).

Purity Determination: Using high-performance liquid chromatography (HPLC), as specified in the Chinese Pharmacopoeia 2005 edition, Appendix VI D, the normalization method must show a purity of at least 98%, while the external standard method should not be less than 95%.

Chromatographic Conditions:

Column: Hypersil C18, 5 μm, 4.6 mm × 250 mm

Mobile Phase: Methanol:Water = 60:40

Flow Rate: 0.8 ml/min

Detection Wavelength: 238 nm

Preparation of Standard Solution: Accurately weigh 8 mg of Rubescens A reference substance and dissolve it in 15 ml of methanol in a 25 ml volumetric flask. Sonicate, cool to room temperature, and dilute to volume. Mix thoroughly.

Preparation of Test Solution: Accurately weigh an equivalent amount of the test sample (8 mg) and follow the same procedure as the standard solution.

Determination: Inject 15 μL of methanol into the HPLC for blank measurement. Then inject 15 μL of both the reference and test solutions. Record the peak areas of both samples.

Calculation: Use the formula Wx = (A1 × C2 × ws) / (A2 × C1), where:

Wx = Content of the test sample

C1 = Concentration of the test solution

C2 = Concentration of the reference solution

A1 = Peak area of the test sample

A2 = Peak area of the reference solution

Ws = Reference content (98%)

(Provided by our company)

About Qingyun:

Nanjing Qingyun Biotechnology Co., Ltd. is located in Nanjing, the ancient capital of the Six Dynasties. The company specializes in the production, sales, and service of plant extracts, active ingredient monomers, and plant raw powders. With a team of experts in phytochemistry, traditional Chinese medicine, biotechnology, and modern analytical techniques, we are committed to research and development of high-quality natural products.

Qingyun Ordering Instructions:

1. Orders can be placed via phone, QQ, or other methods. When placing an order, please inform the sales representative about the product name, quantity, and specifications.

2. Same-day payment processing is available. In special cases, invoices can be issued for reimbursement purposes.

3. Our product advantages include efficient technology, stable quality, a complete inventory system, and a professional sales team.

4. Packaging is standard, but customized packaging is available upon request.

5. We ensure strict quality control. If any quality issues are confirmed through our company, we offer unconditional returns.

6. Storage conditions: Keep sealed and away from light.

Qingyun Biological Service:

1. Custom R&D and production of chemical active ingredients and TCM standard products.

2. Development of industrial-scale separation and purification processes for herbal medicine compounds and high-concentration extracts.

3. Production of natural product APIs and intermediates, including synthetic and semi-synthetic options.

4. Customized research and development and production of traditional Chinese medicine extracts.