Multivariate curve resolution of overlapping voltammetric peaks: quantitative analysis of binary and quaternary metal mixtures

The application of multivariate curve resolution-alternating least squares (MCR-ALS) to the quantitative analysis of different metal ion mixtures using voltammetric data is described. The performance of MCR-ALS was evaluated in the resolution and quantitation of overlapped voltammetric peaks obtained in the analysis of binary and quaternary mixtures of Cd(II), In(III), Pb(II) and TI(I) metal ions by anodic stripping voltammetry. Quality assessment of qualitative and quantitative determinations was evaluated considering the effects of different constraints and of initial estimations. MCR-ALS results were validated and compared with those obtained by applying other well-established multivariate calibration methods, such as partial least squares (PLS) and direct classical least squares (DCLS) methods.