New Screen-Printed Carbon Sensor for Trace Analysis of Thallium(I)

Abstract

Thallium is an element classified as a heavy metal. In chemical compounds it occurs on +1 and +3 oxidation levels. In the context of the toxicity of this element, Tl(I) is most often referred to. The similarity of Tl+ ions to K+ ions is the basis of the mechanism of toxic action of Tl(I) on the human body. The main features of thallium poisoning in humans are gastroenteritis, polyneuropathy and alopecia Thallium in the environment comes from both natural and anthropogenic sources. Due to the high toxicity of thallium and its easy absorption by the human and animal organisms, it is extremely important to monitor the amount of this element, including in water. The purpose of this work is to present a new method for determination of thallium in water samples using a screen-printed sensor with carbon working electrode modified with multiwalled carbon nanotubes and in-situ plated bismuth film. The measurements were carried out using square wave anodic stripping voltammetry (SWASV) method. Simultaneous deposition of bismuth and thallium took place at a potential of -0.9 V for 180 s. Under optimized conditions a linear calibration curve was obtained in the range of Tl(I) concentrations from 1·10-8 to 1·10-6 mol L-1. The procedure allows to achieve the limits of detection and quantification of Tl(I), 2.8 × 10-9 and 9.3 × 10-9 mol L-1 respectively. The method was applied for determination of Tl(I) in spiked water samples from Vistula river. [1] Kozak, J., Tyszczuk-Rotko, K., Rotko, M. Physicochemical Problems of Mineral Processing 2019 , 55(6), 1422-1428.