Determination of rosmarinic acid and caffeic acid in aromatic herbs by HPLC

An HPLC method for the determination of rosmarinic and caffeic acids in several aromatic herbs, namely, rosemary, sage, thyme, spearmint, balm, and lavender, has been developed and validated. The separation system consisted of a C18 reversed-phase column, a gradient elution system of methanol/water containing orthophosphoric acid, and a photodiode array detector. The content of rosmarinic and caffeic acids was found to be 2.0–27.4, and 0–0.4 mg/g, respectively, in the aromatic herbs analysed. The described method is simple, sensitive, reproducible and ideally suited for rapid routine analysis.