Square wave stripping voltammetry of titanium based on adsorptive accumulation of its hydroxynaphthol blue (HNB) complex at the static mercury drop electrode
Ics. Fraga et al., Square wave stripping voltammetry of titanium based on adsorptive accumulation of its hydroxynaphthol blue (HNB) complex at the static mercury drop electrode, ANAL LETTER, 34(1), 2001, pp. 125-135
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.