Any of a number of methods for determining volumetrically the concentration of a desired substance in solution by adding a standard solution of known volume and strength until the reaction is completed, usually as indicated by a change in color due to an indicator. Organic solvents are used in titrating water-insoluble substances (nonaqueous titration). Several types of electrical measurement techniques are used, among which are amperometric, conductometric, and coulometric titration methods, and spectrophotometry is another possible procedure. Titration has been successfully automated, the extent depending on the type of measurement used.