In analytical chemistry, titration is used to determine the amount or concentration of a substance known as an analyte. In a titration, one reagent (the titrant) is slowly added to a solution containing the species being measured (the analyte). As it is added, a chemical reaction occurs between the titrant and analyte. The point at which the reaction is complete and an equivalent quantity of titrant and analyte are present (a stoichiometric equivalent) is called the equivalence point.
The equivalence point can be determined by a chemical indicator that is also present in the solution, or by a measurable physical change in the solution, like pH, electrode potential, or light absorption (color). In practice, an abrupt change of this physical property signals the end of titration, called the endpoint. The purpose of titration is to determine the quantity or concentration of an analyte with a known concentration and volume of a titrant.
Automatic titration is done with instrumentation that delivers the titrant precisely, stops at the endpoint, and calculates the concentration of the analyte automatically. Titration systems include both potentiometric and Karl Fischer titrators. Potentiometric systems include application specific mini-titrators for basic analysis and advanced titrators that can accept pH, ORP, ISE and photometric probes. The advanced titration systems offer the ability to connect to an autosampler for high throughput testing. For water content analysis Hanna offers Karl Fischer titrators including both volumetric and coulometric versions.