Objective: To develop an HPLC method for determination of ferulic acid concentrated in the serum of SD rats treated by Yangyin Tongnao Granules(YTG)decoction. Methods: SD rats serum containing Chinese herbal formula by intragastric administrating YTG was prepared. The determination was carried out with HPLC

using phenomenex GEMINI-C18 column

methanol

and3% acetic acid (32∶68) was used as mobile phase with a flow rate of 1.0 mL·min-1

and at the detection wave length of 323 nm. Results: The calibration curve showed a good linearity over the range of 0.33~10.56 μg·mL-1 (r=0.999 2). and the average recovery for 96.41%

RSD=2.36% (n=6)

RSD=2.04% was less within day and RSD=5.04% was less than 10% day-to-day. and the minimum detection amount was 2.6ng and the minimum detection concentrations in serum was 0.075 μg·mL-1

when the signal-to-noise ratio S/N=3. Conclusion: This method was rapid

sensitive

stable and exact

It was appropriate for the quantitative determination of ferulic acid in the rat serum.