The separation of flavonoids in medicinal plants and raw cosmetics was described by high performance liquid chromatography with a photodiode array detector. The influence of wavelength, mobile phase component, sample treatment including solvent selection and extraction and other conditions affecting the separation were optimized. Elution with methanol/phosphoric acid (pH 2.0) in a Phenomenex C18 (25 cm * 4.6 mm i.d.) column allowed us to separate twelve flavonoids in medicinal plants and raw cosmetics with high resolution and short analysis time.
