Square wave stripping voltammetry of titanium based on adsorptive accumulation of its hydroxynaphthol blue (HNB) complex at the static mercury drop electrode

A new method is described for the determination of titanium based on the sq uare wave adsorptive stripping voltammetry of Ti(IV) complexed with Hydroxy naphthol blue (HNB) at the static mercury drop electrode. Optimal condition s were found to be: preconcentration potential, -0.140 V vs. Ag/AgCl (KCl 3 M); preconcentration time, 30 s (with stirring solution); pulse height, 75 mV; frequency, 100 Hz; scan increment, 4 mV; step time, 0.010 s; supporting electrolyte, acetate buffer (0.1 M, pH 3.2), and concentration of hydroxyn aphthol blue, 1.0 x 10(-5) M. The response of the system was found to be li near in a range of Ti(IV) concentrations from 5.0 to 20.0 mug/L. The limit of detection was found to be 0.18 mug/L and the limit of determination to b e 1.09 mug/L, both using 30 s of preconcentration time. The effects of vari ous potential interferences were also studied including a variety of cation s, anions, and organic surfactants. The merits of the procedure were demons trated in the analysis of certified NIST SRM 1633b and 1646a samples.