Simultaneous Voltammetric Determination of Zn(II), Pb(II), Cu(II), and Hg(II) in Ethanol Fuel Using an Organofunctionalized Modified Graphite‐Polyurethane Composite Disposable Screen‐Printed Device |
| |
| Authors: | Thalita R Saciloto Priscila Cervini Éder T G Cavalheiro |
| |
| Affiliation: | Institute of Chemistry of S?o Carlos, University of S?o Paulo, Av. Trabalhador S?o‐carlense 400, 13566‐590, S?o Carlos, SP, Brazil |
| |
| Abstract: | A disposable screen‐printed device containing working, auxiliary, and reference electrodes is proposed for the simultaneous voltammetric determination of Zn(II), Pb(II), Cu(II), and Hg(II) in ethanol fuel. The working electrode was printed using an ink modified with 2‐benzothiazole‐2‐thiol organofunctionalized SBA‐15 silica, in order to increase sensitivity. The performance of this electrode was compared with that of bare and SBA‐15‐modified electrodes. After optimizing the experimental parameters, the device was applied in determination of the analytes in commercial ethanol fuel samples, using 0.10 mol L?1 KCl/ethanol ratios of 30 : 70 (v/v), with H+]=10?5 mol L?1. After 5 min of preconcentration at ? 1.3 V (vs. pseudo‐Ag/AgCl), four well‐resolved signals were obtained, enabling simultaneous determination of the four analytes using a differential pulse anodic stripping voltammetry (DPASV) procedure. The limits of detection were 0.30, 0.065, 0.030, and 0.046 µmol L?1 for Zn(II), Pb(II), Cu(II), and Hg(II), respectively. The results of these analyses were in agreement with those obtained using graphite furnace atomic absorption spectroscopy (GFAAS) for Pb(II), Cu(II), and Hg(II), and high‐resolution continuum source flame atomic absorption spectrometry (HR‐CS‐FAAS) for Zn2+, at a 95 % confidence level. Analytes originally present in the samples could be detected, and the interference of some cations and anions was evaluated. |
| |
| Keywords: | Ethanol fuel Metallic contaminants Voltammetric stripping analysis Modified composite screen‐printed electrode |
|
|
