system
Medical AI Inquiry: You was designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.  Labels: OBJECTIVE, METHODS, RESULTS. Meshes: Astragalus Plant, Chromatography, High Pressure Liquid, Drugs, Chinese Herbal, Linear Models, Reference Standards, Saponins, Triterpenes.
user
Is [ Determination of astragaloside IV of eight area in Astragali Radix by HPLC-ELSD internal standard method ]? Context: To establish an HPLC-ELSD internal standard method for determination of astragaloside IV in Astragali Radix. With Ginsenoside Rb2 as internal standard, the separation were carried out on an Agilent TC-C18 (4.6 mm x 150 mm, 3.5 microm) column with methanol-water (72: 28) as mobile phase. The flow rate was 1.0 mL x min(-1) and the drift tube temperature of the ELSD was 75 degrees C. The gas pressure was set at 172.4 kPa using the clean and dry compressed air as spray gas. There was good linearity in the range of 0.5624-5.624 microg of astragaloside IV (r = 0.9999); The average recovery was 98.06% with RSD of 0. 98%.
assistant
The internal standard method is accurate and reproducible, and suitable for quality control of radix astragali. Final Decision: yes