Resumo

PARDI, H. et al. Differential Pulse Adsorptive Cathodic Stripping Voltammetry for the Simultaneous Determination of Pb and Zn in Seawater Using Calcon. Port. Electrochim. Acta [online]. 2021, vol.39, n.1, pp.45-57.  Epub 01-Fev-2021. ISSN 0872-1904.  https://doi.org/10.4152/pea.202101045.

A selective method is presented for the simultaneous determination of Pb and Zn in seawater samples, using Differential Pulse Adsorptive Cathodic Stripping Voltammetry (DPAdCSV). In preliminary studies, it has been proven that Pb and Zn react with calcon, giving rise to the formation of complexes which have adsorptive characteristics with a hanging mercury drop electrode (HMDE) and undergo reduction. The optimum parameters and conditions for determination are investigated. The optimal parameters for DPAdCSV of calcon were found to be 0.3 mol L-1 of acetate buffer, with pH 5, 0.02 mmol L-1 of calcon, adsorptive accumulation potential (Eads) of -0.1 V and adsorptive accumulation duration (tads) of 70 s. Ten replicates were performed, giving RSD values of 1.2% for Pb and 0.4% for Zn. Recovery values were in the range from 98% to 105% for both Pb and Zn. The calibration graphs were linear in the range from 5 to 210 ng mL-1 and 5 to 200 ng mL-1 for Pb and Zn, respectively. The limit of detection (LOD) was 0.01 ng mL-1 for Pb and 0.05 ng mL-1 for Zn. The interference of some common ions was studied and it was concluded that the method could be successfully used to determine the concentration of Pb and Zn in seawater samples.

Palavras-chave : selective method; Pb and Zn; seawater; DPAdCSV method; calcon..

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