The Principle of Water-Content Determination by Karl Fischer Titration

Abstract

In 1935, Karl Fischer (KF) proposed a titration method for water content determination. Since then, KF titration has been extensively applied in the determination of water in various samples, including liquids, solids, and gases. The present article describes the reaction mechanism, the two different methods (i.e., volumetry and coulometry), and their instruments and advantages/disadvantages. As an example, an application of KF titration is described in the study of the coextraction of water with hydrophilic ions to water-immiscible organic solvents (e.g., nitrobenzene).