Abstract No single isocratic chromatographic technique allows the complete separation of common organic aliphatic and alicyclic acids of plants. In order to obtain a better isocratic separation with a single HPLC method we combined in one chromatography assay the Ion Exchange and Reverse Phase technics in building a twin phase column. The first attempts are promising. This double chromatography based on the polarity of molecule (Reverse Phase) and on its acidic characteristics (Ion Exchange) has the advantages of both methods and allows good separations of the acids.