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: 3.5). 06/2008; 75(4):973-7. DOI: 10.1016/j.talanta.2007.12.038
Source: PubMed

ABSTRACT 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.

1 Bookmark
  • [Show abstract] [Hide abstract]
    ABSTRACT: In this article, the decade of electroanalysis with bismuth-based electrodes is reviewed (with 222 refs.). Emphasis is put on the environmentally friendly (“green”) character of bismuth electrodes, their versatility and variability in use, as well as the actual classification of the individual types of electrodes, sensors, and detectors that utilize the unique properties of metallic bismuth. Of particular interest is the genesis of the field, when the respective activities and achievements are monitored year by year over the whole period of 2000–2009, including the circumstances of the introduction of bismuth-coated electrodes into electrochemical stripping analysis. The review highlights all the significant milestones and break-points that had directed the experimental work around the globe, outlining the present day's position of this lively, inspiring, and still highly prospective area. Finally, it provides a special insight into electroanalysis with bismuth electrodes through numerous surveys, summaries, and detailed statistical data obtained by analyzing the accessible literature database.
    Electroanalysis 06/2010; 22(13):1405 - 1420. · 2.82 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: A simple and sensitive spectrophotometric method to the simultaneous determination of Mn(2+) and Fe(3+) in foods, vegetable and water sample with the aid of artificial neural networks (ANNs) is described. It relies on the complexation of analytes with recently synthesised bis pyrazol base ligand as 4,4'[(4-cholorophenyl)methylene] bis(3-methyl-1-phenyl-1H-pyrazol-5-ol)(CMBPP). The analytical data show that the ratio of ligand to metal in metal complexes is 1:1 and 1:2 for Fe(3+) and Mn(2+), respectively. It was found that the complexation reactions are completed at pH 6.7 and 5min after mixing. The results showed that Mn(2+) and Fe(3+) could be determined simultaneously in the range of 0.20-7.5 and 0.30-9.0mgl(-1), respectively. The analytical characteristics of the method such as the detection limit and the relative standard error predictions were calculated. The data obtained from synthetic mixtures of the metal ions were processed by radial basis function networks (RBFNs) and feed forward neural networks (FFNNs). The optimal conditions of the neural networks were obtained by adjusting various parameters by trial-and-error. Under the working conditions, the proposed methods were successfully applied to the simultaneous determination of elements in different water, tablet, rice, tea leaves, tomato, cabbage and lettuce samples.
    Food Chemistry 06/2013; 138(2-3):991-7. · 3.33 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: BACKGROUNDA simple, selective and sensitive multi-component method for the simultaneous determination of Zn2+, Mn2+ and Fe3+ based on complex formation with 2-benzylspiro[isoindoline-1,5′-oxazolidine]-2′,3,4′-trione using artificial neural networks is proposed.RESULTSThe analytical data showed that metal-to-ligand ratios in Zn2+ and Fe3+ complexes was 1:1 and for Mn2+ complex was 1:2. It was found at pH 6.5 and 5 min after mixing, the complexation reactions were completed. The coloured complexes exhibited absorption bands in the wavelength range 200–400 nm. The results showed that Zn2+, Mn2+ and Fe3+ could be determined in the range 0.1–18.0, 0.3–10.0 and 0.5–20.0 mg L−1, respectively.CONCLUSION The data obtained from synthetic mixtures of metal ions were processed by radial basis function networks (RBFNs) and back-propagation neural network. The optimal conditions of the neural networks were obtained by adjusting various parameters. Satisfactory precision and accuracy were obtained with all networks, although, because of surprisingly lower root mean square error (%) values, RBFNs were the preferred approach. The proposed approach was tested by analysing the composition of the different mixtures containing Zn2+, Mn2+ and Fe3+. The proposed method was successfully applied to the simultaneous determination of Zn2+, Mn2+ and Fe3+ ions in milk and vegetable samples. © 2013 Society of Chemical Industry
    Journal of the Science of Food and Agriculture 06/2014; 94(8). · 1.76 Impact Factor

Full-text (2 Sources)

Available from
Jun 4, 2014