A novel gradient elution was efficiently utilized for the separation of the chemical components with a wide range of polarity from the mixed extract of the Chinese medicinal herb Apocynum venetum or mixed standards by high-speed counter-current chromatography. Three sets of solvent systems,
High-performance counter-current chromatography (HPCCC) and high performance liquid chromatography coupled with mass spectrometry (HPLC-MS) was efficiently utilized for the separation and identification of the chemical components with a wide range of polarity from the mixed extract of Chinese