Adsorptive Cathodic Stripping Voltammetry Determination of Ultra Trace of Lead in Different Real Samples

Abstract

In the present work, an adsorptive cathodic stripping voltammetric method using a hanging mercury drop electrode (HMDE) was described in order to determine the ultra trace of lead ions with carbidopa in different real samples. The method is based on accumulation of lead metal ion on mercury electrode using carbidopa as a suitable complexing agent. The potential was scanned to the negative direction and the differential pulse stripping voltammograms were recorded. The instrumental and chemical parameters were optimized. The optimized conditions were obtained in pH of 8.4, carbidopa amount of 1.0×10⁻⁶ M, accumulation potential of 0. 0 V, accumulation time of 100 s, scan rate of 100 mV/s and pulse height of 50 mV. The relationship between the peak current versus concentration was linear over the range of 2.4×10⁻¹⁰–4.8×10⁻⁷ M. The limits of detection were 5.8×10⁻¹¹ M and the relative standard deviation at 4.8×10⁻¹⁰, 2.1×10⁻⁸, and 2.4×10⁻⁷ M of lead ion were obtained 3.2, 2.9, and 2.7%, respectively (n=7).