Abstract: A pre-column derivatization-HPLC method was developed for the simultaneous determination of the 13 kinds of free amino acids in Dendrobium huoshanense. A Waters XBridge C₁₈ column（250 mm×4.6 mm,5 μm）was used with 0.1 mol/L sodium acetate buffer (A) and acetonitrile-water（4∶1）(B) as mobile phases in gradient elution mode.The flow rate was 1.0 mL/min and the column temperature was 35 ℃.The DAD detection wavelength was set at 254 nm.The results showed that,adopted the established HPLC method,the 13 kinds of free amino acids were separated well and the average recoveries were between 92.7%-104.3% with RSD＜2.5%.Our study suggested that the developed HPLC method was simple,accurate and reproductive.It is suitable for the simultaneous determination of the 13 kinds of free amino acids in D.huoshanense.

Key words: Dendrobium huoshanense, pre-column derivatization, free amino acids, HPLC