Determination of iron in water samples by adsorptive stripping voltammetry with a bismuth film electrode in the presence of 1-(2-piridylazo)-2-naphthol

Departamento de Química Analítica, Facultad de Química, Universidad de Chile, Las Palmeras 3425, Casilla 653, Santiago, Chile.
Talanta (Impact Factor: 3.55). 06/2008; 75(4):973-7. DOI: 10.1016/j.talanta.2007.12.038
Source: PubMed


An adsorptive stripping voltammetry method for the determination of iron has been developed. The procedure is based on the adsorptive collection of a complex of iron with 1-(2-piridylazo)-2-naphthol (PAN) on a bismuth-coated glassy carbon electrode (BiFE). Factors affecting the stripping performance, such as pH, PAN concentration (C(PAN)), potential, accumulation time (E(ads), t(ads)), and interference by other ions were also studied. The optimum conditions were obtained in a 0.1 mol L(-1) acetate buffer at pH 4.0, C(PAN) 5.0 micromol L(-1), t(ads) 60 s, E(ads) -400 mV, pulse height 4.0 mV, pulse amplitude 25 mV, and frequency 15 Hz. The detection limit was found to be 0.1 microg L(-1) when a t(ads) of 60 s was used, and the linear range was from 0.4 to 60.0 microg L(-1). The proposed procedure was validated by determining of Fe(III) in CRM-MFD, QCS-19 and CRM-SW certified reference materials and applied in seawater samples with satisfactory results.

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Available from: Rodrigo Segura, Dec 19, 2013
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    • "In order to solve these problems, great efforts have been taken to develop mercury-free solid electrodes. For example, solid-state gold-amalgamation [14], ion-selective membranes [15], ionomercoatings [16] [17] [18] [19], carbon paste [20], glassy carbon [21] electrodes and gold microelectrode ensembles [22] as new solid electrodes have been developed for iron determination. However, the continuous improvements of functional electrodes are still urgently required for achieving simple, rapid and sensitive detection of trace iron, especially in coastal waters. "
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