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The asymmetric logistic peak is tested as a new function for the parametric signal fitting (PSF) of highly asymmetric electrochemical signals in non-bilinear datasets, such as those obtained in linear sweep voltammetry (LSV) or in the presence of irreversible electrochemical processes. This new multivariate curve resolution strategy (PSF-ALPA) is successfully applied to LS voltammograms measured for the Cd(II)-glutathione system with a hanging mercury drop electrode, where Cd(II) is reversibly reduced, and to differential pulse voltammograms (DPV) measured at a glassy carbon electrode, where Cd(II) reduction becomes irreversible. Matrix augmentation by using LS voltammograms measured at different scan rates provides good results and encourages the development of ALPA methodology for third order data.

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Multivariate curve resolution by alternating least squares (MCR-ALS) with the aim of achieving the electrochemical second order advantage has been applied to potential-time second-order data. In this work a simple way is reported as a first approach towards generation of the instrumental electrochemical second-order data by differential pulse voltammetry (DPV). A linear dependency exists in the pulse duration profiles of the electroactive species in the mixture samples. Rank deficiency of the mixture data matrix is broken by matrix augmentation. Due to existence of potential shift in the obtained data, MCR-ALS could not be achieved the convergence on the augmented data. So this shift was corrected with potential shift correction algorithm. Results of MCR-ALS after shift correction show that the proposed method could be efficiently used for determination of Pb 2 + in the presence of unexpected interferents in the river water sample.