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

Resolution and quantitative determination of a mixture of overlapped pestic ides, carbendazim, fuberidazole and thiabendazole, in fluorescence spectros copy by multivariate curve resolution-orthogonal projection approach (MCR-O PA) 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 simultaneous ly (three-way data). Augmented matrix data analysis showed an improvement i n the recovery of the spectral profiles in both MCR methods. On the other h and, the influence of the pesticide concentrations in the MCR-ALS resolutio n power was evaluated using measures of dissimilarity between the real and the estimated excitation spectra, and correlations >0.96 were obtained at c oncentration levels higher than the quantitation limit. (C) 2001 Elsevier S cience B.V. All rights reserved.