Stopped-flow kinetic spectrophotometric method for the simultaneous determination of iron, titanium and vanadium

Abstract

A kinetic method for the simultaneous determination of iron, titanium and vanadium is proposed based on their inductive effects on the chromium(VI)-iodide-starch reaction in weakly acidic medium. The reaction was monitored with the stopped-flow spectrophotometric technique. The calibration graphs are linear in the ranges 0–2.2, 0–3.1 and 0–1.8 μg ml −1 for Fe(II), Ti(III) and V(IV), respectively, and the detection limits are 0.012, 0.020 and 0.018 μg ml −1, respectively. It was found that 100–1000 times higher concentrations of Co 2+, Ni 2+, Zr 4+, Mn 2+, Cd 2+, Cu 2+, Pb 2+ and tervalent rare earths ions do not interfere with the determination. The method was applied to the determination of Fe, Ti and V in an aluminium alloy and a synthetic sample.