Application of Adsorptive Cathodic Stripping Voltammetry for Determination of Trace Amounts of Zinc Using Nalidixic Acid As a Chelating Agent



Gholivand MB¹ ; Pourhossein A² ; Shahlaei M³
Source: Chemia Analityczna Published:2009

Abstract

A sensitive method for determination of trace zinc based on adsorptive preconcentration of zinc-nalidixic acid (NAL) complex onto the surface of a hanging mercury drop electrode (HMDE) has been described. Optimum conditions of determination were as follows: pH 8.7, 90 μmol L-1 NAL, accumulation potential -800 mV, and accumulation time 120 s. Under optimal conditions, a linear calibration graph in Zn range 15-2500 nmol L-1 and detection limit of 5 nmol L-1 were obtained. Relative standard deviation for 80 nmol L-1 concentration was 2.3% (n = 10). The effect of positively and negatively charged ions on the peak height of Zn-NAL complex was evaluated. The method was applied to the determination of zinc in: spring water, tap water, seawater, dry tea, Tab. Sanatogen gold A-Z, and NIST certified reference material with satisfactory results.