Electrochemical Determination of Boric Acid Using the Boric Acid-Tiron Complexation System

For monitoring the boron concentration in reverse osmosis (RU) water produced by desalination plants, a voltammetric determination method for the amount of electrochemically inactive boron has been developed by using the complexation with 4,5-dihydroxybenzene-1,3-disulfonic acid (Tiron). Cyclic voltammetric measurements showed the oxidation peak of boric acid-Tiron 1:1 complex at 920 mV. This peak was successfully applied to the determination of boron in RU water with the LOD of 0.1 mg B dm(-3) by using differential pulse voltammetry. The redox and acid-dissociation behaviors of Tiron and its boron complex are found to depend on the properties of pH buffer reagent.