REVERSED-PHASE HPLC DETERMINATION OF TITANIUM(IV) AND IRON(III) WITH SODIUM 1,2-DIHYDROXYBENZENE-3,5-DISULFONIC ACID

A highly sensitive method has been developed for the determination of titanium(IV) and iron(III) by ion-pair reversed phase liquid chromatog raphy using sodium 1,2-dihydroxybenzene-3,5-disulfonic acid (Tiron) as a precolumn chelating reagent. The metal - Tiron chelates were separa ted on a C-18 (ODS) column; the mobile phase was a 2:8 (v/v) mixture o f acetonitrile and acetate buffer (0.04 mol/L, pH 6.2) containing 2.0 x 10(-3) mol/L Tiron, 0.04 mol/L tetrabutylammonium bromide, and 0.1 m ol/L potassium nitrate. The detection limits for titanium(IV) and iron (III) are 0.5 and 2.0 mu g/L, respectively. The method has been applie d to the simultaneous determination of titanium(IV) and iron(III) in r iver water samples and has furnished highly precise results.