Determination of Cadmium and Zinc in Water and Alloys by Adsorption Stripping Voltammetry

Abstract

A selective and sensitive method to determine of cadmium and zinc in water and alloy samples is proposed by adsorption stripping differential pulse cathodic voltammetry. The complexes of cadmium and zinc ions with xylenol orange (XO) are analyzed based on the adsorption collection onto a hanging mercury drop electrode (HMDE). The variation of peak currents with pH, XO concentration, potential and time of adsorption plus the instrumental parameters such as scan rate and pulse height were optimized. The relationship between peak currents for cadmium(II) and zinc(II) concentration is linear up to 580 and 260 ng/mL, respectively, with a detection limit of 1.7 ng/mL Cd(II) and 1.8 ng/mL Zn(II). The applicability of the method to analysis of water and standard alloy samples was assessed by the determination of Cd(II) and Zn(II) in real samples.

Keywords:

• Cathodic stripping voltammetry
• Xylenol orange
• Cadmium
• Zinc

Acknowledgment

The authors are thankful to the Isfahan University of Technology Research Council and Center of Excellency in Chemistry (IUT) for the support of this work.