Diagnostic assay of chromium (VI) in the ex vivo fluid of the urine of a smoker using a fluorine‐doped handmade sensor

Abstract

A voltammetric diagnosis of a chromium (VI) ion was investigated using a fluorine-doped graphite pencil electrode. Square wave (SW) stripping working conditions were attained at a high range of 0.051–0.45 mg L⁻¹ and a microrange of 0.05–0.4 µg L⁻¹ in a 0.1 M NH₄H₂PO₄ electrolyte solution, at a relative standard deviation of 1.68% (RSD, n=15), using 10.0 µg L⁻¹ Cr(VI). A fast experimental time was used only for the 120 sec SW accumulation time. An analytical detection-limit (DL) of 0.008 µg L⁻¹ was attained. DL appeared to be more sensitive than common voltammetric and spectrophotometric assays. The developed sensor was applied to tap water and the urine of a smoker. It was found that the methods can be applicable for in vivo fluid or medicinal diagnosis. J. Clin. Lab. Anal. 23:82–87, 2009.