Determination of Pb(II) and Cd(II) via anodic stripping voltammetry using an in-situ bismuth film electrode. Increasing the sensitivity of the method by the presence of Alizarin Red S

• Published in: Microchemical journal 2020-12, Vol.159, p.105373, Article 105373
• Main Authors: Rojas-Romo, Carlos, Aliaga, Margarita E., Arancibia, Verónica, Gomez, Marisol
• Format: Article
• Language: English
• Subjects: Alizarin Red S; Anodic stripping voltammetry; Cadmium; In-situ bismuth film electrode; Lead
• ISSN: 0026-265X
• DOI: 10.1016/j.microc.2020.105373

[Display omitted] •A stable in-situ bismuth film electrode is used for Pb(II) and Cd(II) determination.•The presence of Alizarin Red S increases the sensitivity of the method.•A short accumulation time is applied (60 s).•The detection limits are 0.16 and 0.09 µg L−1 for Pb(II) and Cd(II), respectively.•The method is applied in the analysis of four natural water samples. Using the differential pulse anodic stripping voltammetry technique and an in-situ bismuth film deposited on a glassy carbon electrode, a simple and sensitive method for rapid Pb(II) and Cd(II) quantification was developed. The effect of the presence of Alizarin Red S (ARS) was studied, and an increase in the sensitivity of the method was obtained. The developed method was compared to another reported method that uses a 0.1 mol L−1 acetate buffer medium (pH 4.5). The optimal experimental conditions are listed as follows: [CH3COOH]: 30.0 mmol L−1; [Bi(III)]: 0.75 mg L−1; [ARS]: 40.0 µmol L−1; [Fe(CN)64−]: 50.0 µmol L−1; Edep: −1.40 V; tdep: 60 s. Under these conditions, the detection limits were 0.16 and 0.09 µg L−1 and the linearity was maintained at values as great as 30.0 and 15.0 µg L−1 for Pb(II) and Cd(II), respectively. The effect of 35 foreign ions as possible interferents was studied. The method was validated using two certified reference materials (TMDW and TMDA-61.3) with satisfactory results. Finally, the method was applied for the analysis of four natural water samples.