Automated spectrophotometric determination of titanium(IV) in water and brines by flow injection based on its reaction with hydrogen peroxide

An automated spectrophotometric method for the determination of titanium(IV) is described based on the reaction between titanium(IV) and hydrogen peroxide in a flow injection system. The system was optimised by a suitable numerical treatment of the different variables using the simplex algorithm. A wide linear range up to 1000 p.p.m. can be achieved at a sampling rate of 240 samples h-1. The method was applied to the determination of low titanium(IV) concentrations in the presence of high concentrations of salts. Under these conditions, the calibration is linear up to 30 p.p.m. and a sampling rate of up to 120 samples h-1 can be achieved. A study of possible interferences demonstrated that the method has good selectivity, but vanadium(V) and molybdenum(VI) interfere.