Electrodeposition as a Preconcentration and Sample Preparation Technique for Trace Selenium and Tellurium Determination by X-Ray Fluorescence Spectrometry

Abstract

Electrodeposition is as an attractive technique for sample preparation in X-ray fluorescence spectrometry with advantages of low cost, high sensitivity, and minimal interferences. A simple and efficient electrolysis process for the preconcentration of selenium(IV) and tellurium(IV) is reported. The analytes were electrodeposited on a polished substrate of high purity copper, which was rinsed with deionized water, dried, and directly analyzed by x-ray fluorescence. The influence of concomitant metal ions, electrodeposition voltage, pH, and electrolyte concentration on the deposition efficiency was investigated. The presence of lead(II) was shown to improve the efficiency and reproducibility of the deposition of selenium(IV). Moreover, the results showed that the method provided superior tolerance to various coexisting ions. The reproducibility of determination was 2.4% for selenium(IV) and 1.9% for tellurium(IV) (n = 7). The detection limits for the measurement of selenium(IV) and tellurium(IV) were 0.44 and 0.57 µg L−1, respectively. The method was validated by analyzing certified reference materials and applied to the determination of trace selenium and tellurium in environmental water samples with satisfactory results.