Complexometric titration is defined as a form of volumetric analysis in which the formation of a colored complex is used to indicate the end point of the titration (1). Complexometric titrations are based on the formation of complexes between metal ions and compounds capable of donating electrons to form a stable and soluble complex (2). The complex is formed as a result of titration of metal ions with a complexing agent or ligand. The principle of complexometric titrations is based on the transformation of a simple ion into a complete ion and the use of a metal indicator to determine the end point (3) and the displacement of water from the sphere of solvation of metal ions by the ligands (5). Different indicators are used in complexometric titrations because they have different pH ranges and detect different metals in those ranges (1). Therefore complexometric titrations are useful for determining a mixture of different metals (1). There are 4 types of complexometric titrations, namely direct titration, back titration, substitution titration and indirect titration (3). Direct titration is similar to acid-base titration, in which a standard chelon solution is added to the metal ion until the end point is detected (3). Although this method is the most convenient, it is limited by the slow complexation reaction and interference due to the presence of other ions (3). In the titration an excess of EDTA standard solution is added to the metal solution to be analyzed and the excess is titrated with a standard solution of a second metal ion (3). In substitution titration, the metal to be analyzed quantitatively moves away from the complex (3). When the first 2 methods do not provide a clear end point, the metal can be determined by displacement... at the center of the paper... evaluated relative to a known volume of EDTAReferenceswww.srmuniv.ac.in/downloads /Complexometric_Titration.pdfCairns, D. (2008). Essential elements of pharmaceutical chemistry. Third edition. Pharmaceutical press. London. Great Britain. p152 – 154Husain, A. (2007). Pharmaceutical analysis: theoretical basis of the analysis. Complexometric titrations. Department of Pharmaceutical Chemistry, Faculty of Pharmacy. Jamia Hamdard. Hamdard Nagar New Delhi. Indiawww.pharma-board.com/fop-drs/drawady/3rd_partII.pdfTandlich, R. (2014). Pharmaceutical chemistry. Complexometric titrations. Rhodes University. Grahamstown. South Africa. Slide 59-82www.bionmr.un/edu/courses/chem221/lectures/chapter-12.pptChemlab.truman.edu/CHEM222manual/pdf/edta.pdfFuria, T. E. (1980). CRC Handbook of Food Additives, Second Edition, Volume 2. CRC Press. Florida. United States of America. P274