HPLC determination of 4 phenolic acids in Yangxue Qingnao granules

Objective:To establish an HPLC method for determination of gallic acid,protocatechuic acid,caffeic acid and ferulic acid in Yangxue Qingnao granules.Method:HPLC with electrochemical detection (HPLC-ECD) was used.The separation was performed on Hypersil ODS(250mm×4.0mm,5.0μm)column.The mobile phase consisted of methanol(A)-4% acetic acid(B)using a linear gradient elution of 0%→49% A at 0→42 min.The flow-rate was 0.8mL min~(-1).The detection was done at 0.7V and column temperature was 30℃.Results:The linear ranges are 18.06-90.30μg·mL~(-1)(r=0.9997)for gallic acid,0.51-2.53μg·mL~(-1)(r=0.9994)for protocatechuic acid,1.48-7.39μg·mL~(-1)(r=0.9997)for caffeic acid and 1.31-6.55μg·mL~(-1)(r=0.9996) for ferulic acid respectively.The average recoveries(n=6)were 98.7% (RSD=2.1%)for gallic acid,98.9% (RSD=2.1%)for protocatechuic acid,98.7%(RSD=2.4%)for caffeic acid and 99.3%(RSD=2.0%)for feru- lic acid respectively.Conclusion:A rapid,sensitive and accurate method for the determination of gallic acid,proto- catechuic acid,caffeic acid and ferulic acid is found.The study may provide a scientific basis for the quality control of Yangxue Qingnao granules.