One of the most common types of complexometric titrations involves using EDTA as the testing reagent. Other chelating agents such as EGTA and CDTA can be used. A specific metal ion titrant and indicator can be used in some titrations when a specific ion is tested for.
Complexometric titrations are performed to test for specific ions involved in complexation reactions. Because every reaction only occurs when the appropriate ions are present, the titrant used is adjusted as needed. An example of this is using Ag+ to test for cyanides or Hg2+ to determine the presence of chlorine ions. Complexometric titrations can also be performed with color indicators to test for the presence of free metal ions or metal complexes.