Determination of Rehmannioside A in Rehmannia Glutinosa Oligosaccharide by HPLC-ELSD

OBJECTIVE To establish an HPLC method to determine the content of rehmannioside A in Rehmannia glutinosa oligosaccharide. METHODS The HPLC-ELSD was used with Agilent TC C₁₈ column (4.6 mm×250 mm, 5 μm) at 35 ℃. The mobile phase was methanol and water(10∶90) with a flow rate 1.0 mL·min^-1; The temperature of the drift tube in ELSD was 110 ℃ and the flow rate of dry air was 3.2 L·min^-1. RESULTS The rehmannioside A had a good linear relationship between 0.2-1.2 mg·mL^-1. CONCLUSION The method is accurate, simple with good specificity，and it could be used to determine the content of rehmannioside A in Rehmannia glutinosa oligosaccharide, which may be providing a evidence for the quality control of Rehmannia glutinosa oligosaccharide.