Abstract

Ateesa Yazdanipour, Ali Niazi*, Samira Kamel Foladi and Roya Tajik

Bismuth forms the complexes with xylenol orange in the weak acidic solution. An adsorptive differential pulse stripping method for the determination of bismuth is proposed. The procedure involves an adsorptive accumulation of bismuth on a hanging mercury drop electrode (HMDE) in the presence of xylenol orange, followed by reduction of adsorbed bismuth by voltammetric scan using differential pulse modulation. The optimum experimental conditions are: xylenol orange concentration of 0.20 µg mL^-1, pH 5.0, accumulation potential of -600 mV versus Ag/AgCl, accumulation time of 100 s, scan rate of 20 mV s^-1 and pulse height of 100 mV. The peak current is proportional to the concentration of bismuth over range of 0.004-0.170 µg mL^-1, and the detection limit is 2.0 ng mL^-1. The relative standard deviations (n=3) for 0.08 µg mL^-1 bismuth is 0.67%, respectively. The proposed method was applied to the determination of bismuth in pharmaceutical formulations and tap water with satisfactory results.

Bismuth; Determination; Water; Pharmaceutical; Voltammetry

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