Simultaneous determination of Cu, Pb, Cd, Ni, Co and Zn in bioethanol fuel by adsorptive stripping voltammetry and multivariate linear regression

In this work it is proposed the one-voltammogram simultaneous determination of Cu(II), Pb(II), Cd(II), Ni(II), Co(II), and Zn(II) at ppb and sub-ppb levels in bioethanol fuel samples by adsorptive stripping voltammetry. Mixed ligands were employed providing stripping peaks for all analytes at the same voltammetric scan under optimized conditions. To perform the determination, multivariate linear regression aided by successive projections algorithm (SPA-MLR) was evaluated. The voltammograms were preprocessed with the asymmetric least squares (AsLS) baseline correction algorithm and the icoshift peak alignment tool. An excellent analytical performance was obtained, despite the inherent complexity of the simultaneous determination, with average apparent recovery = 96% +/- 16%, and better prediction results in comparison with the benchmark method of partial least squares (PLS). (C) 2014 Elsevier Ltd. All rights reserved.