Summary of “Determination of Iron in Natural and Drinking Waters by Stripping Voltammetry”
This article discusses a process to determine iron in water sources. Among methods to determine how much iron is in the water, stripping voltammetry is one of the most simplistic and inexpensive methods, but was a health risk due to the toxic mercury in the electrode. An ecologically safe electrode, a thick-film graphite- containing electrode modified with calomel, was proposed as an eco-friendly electrode that could determine Iron (III) in water sources. For the experiment, solutions of Iron(III) was diluted with triply distilled water, then additional electrolytes for each scenario were added. An IVA-5 stripping voltammetric analyzer with cyclic and linear potential sweeps and three-electrode cell was used for the voltammetric measurements, pH measurements were done by a pH-150 pH-meter/millivolt meter, and a 705 UV-Digester was used for UV irradiation. Results from the experiment show that stripping voltammetry and the electrode are effective. A series of variables had to be determined to have the most optimized conditions for use of the analytical signal. Of the 6 supporting electrolytes and organic reagents chosen, the best supporting electrolyte was the Iron(III)-pyrocatechol complex, for it was high voltage and well reproducible. The chosen pH level 7.5 was based on the strength of the analytical signal, which was at its greatest at 7.5 – 8.0. The concentration of pyroctchhol chosen was 5 x 10-4 M for the greatest signal strength. The preconcentration time chosen was 30 seconds. The analytical signal’s highest potential was at 0.1 Volts. The experiment also had to determine and eliminate the highest interfering elements, which were Cu(II), As(III), and Sb(III), by UV irradiation and additional polarization of the electrode, and UV irradiation also was used to decompose organic substances and oxidize Fe(II) to Fe(III). The results of the trials all had a near 100%...
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