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

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 microg L(-1) in a 0.1 M NH(4)H(2)PO(4) electrolyte solution, at a relative standard deviation of 1.68% (RSD, n=15), using 10.0 microg 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 microg 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. (c) 2009 Wiley-Liss, Inc.