Determination of oleuropein in herbal preparation and Olea europaea L. extracts by HPLC

Oleuropein is a secoiridoide monoterpene. It is found primarily in all parts of the Olea europaea L. tree, mostly in its unripe fruit and leaves. It has a number of beneficial effects on the human body, being readily absorbed from the gastrointestinal tract due to its hydrophilic properties. The paper presents a simple, rapid and precise method for the assay of oleuropein in herbal formulations and the European Olive leaf extract. Chromatographic separation was performed using a C-18 column with an acetonitrile/water 20/80% vol. mixture as the mobile phase. The method has a wide range of linearity between 0.05 and 1.5 mg/mL, very good repeatability of retention time, and accuracies between 95.8 and 103.3%. Its limit of detection is 0.04 mg/mL. The developed method was tested on two herbal formulations which are commercially available in Poland.