Résumé
AIM: To estahlish a RP-HPLC method of determining two caffeic acid derivatives in Echinacea extract and to determine 5 Echinacea purpurea root extracts. METHODS: RP-HPLC was applied to determine 2 caffeic acid derivatives in E.purpurea extract:caftaric acid and chicoric acid.HPLC conditions were as follows: Agilent ZORBAX StableBond C_(18) column(5 ?m,4.6 mm?250 mm) was used,with A(acetonitrile) —B(0.1% H_3PO_4) gradient elution as a mobile phase.The flow rate was 1.2 mL/min.The detection wavelenth was set at 330 nm. RESULTS: 2 caffeic acid derivatives were separated well.The linear range for caftaric acid and chicoric acid were 0.064-0.416 ?g and 0.1-0.7 ?g,respectively.Its average recoveries were 99.37% with RSD of(1.50%) and 100.44% with RSD of 1.71%,respectively. CONCLUSION: The method is simple,accurate,strong specificity and can be used to control the quality of E.purpurea extract and new medicine development.