Resolution (and quantitation) of mixtures with overlapped spectra by orthogonal projection approach and alternating least squares Original Research Article

Resolution and quantitative determination of a mixture of overlapped pesticides, carbendazim, fuberidazole and thiabendazole, in fluorescence spectroscopy by multivariate curve resolution–orthogonal projection approach (MCR–OPA) and by multivariate curve resolution–alternating least squares (MCR–ALS) is shown. Both approaches have been tested using a single matrix (two-way data) or an augmented matrix containing several data matrices simultaneously (three-way data). Augmented matrix data analysis showed an improvement in the recovery of the spectral profiles in both MCR methods. On the other hand, the influence of the pesticide concentrations in the MCR–ALS resolution power was evaluated using measures of dissimilarity between the real and the estimated excitation spectra, and correlations >0.96 were obtained at concentration levels higher than the quantitation limit.