ABSTRACT
<p><b>OBJECTIVE</b>To establish an HPLC-ELSD internal standard method for determination of astragaloside IV in Astragali Radix.</p><p><b>METHOD</b>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.</p><p><b>RESULT</b>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%.</p><p><b>CONCLUSION</b>The internal standard method is accurate and reproducible, and suitable for quality control of radix astragali.</p>