First Seminar of Medicinal & Natural Products Chemistry Shiraz, Iran. May 10-11, 2005 A36 Application of Potentiometric Titration in Drugs Analysis Mohammad hassan amini Chemistry and chemical engineering research center of iran , P.O.Box 14335-186 Potentiometric titrations involve following the changes in the cell emf brought about by the addition of a titrant of an accurately known concentration to the test solution. The method is applicable to any titrimetric reaction for which an indicator electrode is available to follow the concentration of at least one of the substances involved. Because of easy operation , precise results and wide kind of material that can be measured in this method , Potentiometric titration is an important method in analytical chemistry . Drug chemicals usually have an electroactive agent and also because of above mentioned reasons , Potentiometric titration is widely applicable in drug analysis that contain assay determination of initial material and measurment of effective chemical in end used drug. Potentiometric titration can be made as acid – base titration ( aqueous phase or non-aqueous phase ) , oxidation – reduction titration , precipitation titration and complexometric titration. Most important point in the Potentiometric titration is the choice of adequate working electrode , registration of emf changes against concentration of titrant and finding of end point. In this paper , at first we describe different methods of Potentiometric titration and then describe our experiences about analysis of some drugs by different methods of Potentiometric titration and finally the result of every analysis will be shown.