High-performance liquid chromatographic determination of the biologically active principle hypericin in phytotherapeutic vegetable extracts and alcoholic beverages

Hypericin was determined using an RP C-18 (3 mu m) column (8.3 x 0.4 cm I.D.), thermostated at 50 degrees C. The separation was achieved with programmed elution using phosphate buffer (pH 7)-methanol (3:7) and water-methanol (3:7) as eluents. Fluorimetric detection was carried out with excitation at 470 nm and emission at 590 nm. The analytical sample was prepared by simple dilution in methanol of the phytotherapeutic extract or of the alcoholic beverage. Hypericin can be rapidly and accurately determined at concentrations down to 0.1 mg/kg without any interferences.