Dispersive liquid-liquid microextraction followed by high-performance liquid chromatography for determination of benzoate and sorbate in yogurt drinks and method optimization by central composite design

► A new method was proposed to determine benzoate and sorbate salts in yogurt drinks. ► The method is based on DLLME combined with HPLC. ► The effective parameters in DLLME were optimized using RSM based on CCD. ► The decrease of matrix effect using the DLLME has been demonstrated. ► The increased sensitivity in using DLLME has been demonstrated.