Obelisc N column are used for separation of weak and strong organic acids in mixed-mode HILIC. Benzoic and naphthalenesulfonic acids are retained based on polar interaction mode and anion-exchange mode. Order of elution and retention pattern can be changed by modifying mobile phase. PH of the mobile phase changes ionization state of stationary phase and analytes. Fast quantitation method for benzoic and naphthalenesulfonic acid can be developed using UV, ELSD or LC/MS detection. HPLC Method can be used for mixture of organic and inorganic strong and weak acids.