Extractive Spectrophotometric Determination of Tungsten(VI) in Alloy Steels Using Ethopropazine Hydrochloride

Ethopropazine hydrochloride (EPH) has been proposed as a sensitive reagent for the spectrophotometric determination of tungsten(VI). The method is based on the formation of a chloroform-soluble yellow-colored ternary complex by the interaction of EPH and thiocyanate with tungsten(V). The complex exhibits the absorption maximum at 404 nm with Sandell’s sensitivity value of 20.03 ng cm–2. The complex obeyed Beer’s law in the concentration range of 1–15 µg ml–1 with an optimum concentration range of 2.3–12.9 µg ml–1. The effects of foreign ions in the determination of tungsten(VI) were investigated. The method has also been successfully applied to the analysis of alloy steels.