Cathodic Stripping Voltammetry Determination of Trace Iron with a Chemically Modified Electrode

✍ Scribed by S.X. Yang; L.H. Du; B.X. Ye

• Publisher: Elsevier Science
• Year: 1995
• Tongue: English
• Weight: 257 KB
• Volume: 52
• Category: Article
• ISSN: 0026-265X
• DOI: 10.1006/mchj.1995.1089

✦ Synopsis

The utility of glass carbon electrode modified with Nafion for the cathodic stripping voltammetric determination of iron (III) is demonstrated. The method is based on the formation of the (\mathrm{Fe}) (III) and (\alpha \alpha)-bipyridine complex, which is preconcentrated by a Nafion-modified electrode at (+0.75 \mathrm{~V}) (vs (\mathrm{Ag}-\mathrm{AgCl})). A stripping scan is carried out from +0.75 to (-0.10 \mathrm{~V}) at (100 \mathrm{mV} / \mathrm{s}) scan rate. The favorable concentration of the base solution contains (0.02 \mathrm{~mol} /) liter (\mathrm{LiCl}, 0.03 \mathrm{~mol} / \mathrm{liter} \mathrm{HCL}), and 1.0 (\times 10^{-5} \mathrm{~mol} /) liter (\alpha \alpha)-bipyridine ( (\mathrm{pH} 2.5) ). Under the optimal conditions, the peak current is proportional to (\mathrm{Fe}(111)) concentration in the range of (0.05-2.0 \mathrm{ng} / \mathrm{ml}) ( (2 \mathrm{~min}) preconcentration time). The method has been used to determine iron in fountain water and longan with satisfactory results. (1995 Academic Press. Inc.