title: Crown ether-modified electrodes for the simultaneous stripping voltammetric determination of Cd(II), Pb(II) and Cu(II).
abstract: This work describes the immobilization of 4-carboxybenzo-18-crown-6 (CB-18-crown-6) and 4-carboxybenzo-15-crown-5 (CB-15-crown-5) assisted by lysine on aryl diazonium salt monolayers anchored to the surface of graphite-epoxy composite electrodes (GEC), and their use for the simultaneous determination of Cd(II), Pb(II) and Cu(II) by differential pulse anodic stripping voltammetry (DPASV). These modified electrodes display a good repeatability and reproducibility with detection and quantification limits at levels of µg L(-1) (ppb), confirming their suitability for the determination of Cd(II), Pb(II) and Cu(II) ions in environmental samples. The overlapped nature of the multimetal stripping measurements was resolved by employing the two-sensor array CB-15-crown-5-GEC and CB-18-crown-6-GEC, since the metal complex selectivity exhibited by the considered ligands could add some discrimination power. For the processing of the voltammograms, Discrete Wavelet Transform and Causal Index were selected as preprocessing tools for data compression coupled with an artificial neural network for the modeling of the obtained responses, allowing the resolution of mixtures of these metals with good prediction of their concentrations (correlation with expected values for an external test subset better than 0.942).
authors: Department of Analytical Chemistry, Faculty of Chemistry, Universitat de Barcelona, Martí i Franquès 1-11, 08028 Barcelona, Spain; Sensors & Biosensors Group, Department of Chemistry, Universitat Autònoma de Barcelona, Edifici Cn, 08193 Bellaterra, Spain.
authors: Núria
authors: N
authors: Serrano
authors: Sensors & Biosensors Group, Department of Chemistry, Universitat Autònoma de Barcelona, Edifici Cn, 08193 Bellaterra, Spain.
authors: Andreu
authors: A
authors: González-Calabuig
authors: Sensors & Biosensors Group, Department of Chemistry, Universitat Autònoma de Barcelona, Edifici Cn, 08193 Bellaterra, Spain. Electronic address: manel.delvalle@uab.es.
authors: Manel
authors: M
authors: Del Valle
mesh_terms: D002104:Cadmium / Q000032:analysis*; D003300:Copper / Q000032:analysis*; D043844:Crown Ethers / Q000737:chemistry*; D004563:Electrochemistry / Q000379:methods*; D004566:Electrodes; D006108:Graphite / Q000737:chemistry; D007854:Lead / Q000032:analysis*; D016571:Neural Networks, Computer; D015203:Reproducibility of Results
chemical_list: D043844:Crown Ethers; D002104:Cadmium; D007854:Lead; C042148:15-crown-5; C015762:18-crown-6; D006108:Graphite; D003300:Copper
keywords: Artificial neural network; Crown ether-modified sensors; Electrochemical grafting; Metal determination; Stripping voltammetry