Non-linear four-way kinetic-excitation-emission fluorescence data processed by a variant of parallel factor analysis and by a neural network model achieving the second-order advantage: malonaldehyde determination in olive oil samples

GARCIA REIRIZ, A.; DAMIANI, P. C.; OLIVIERI, A. C.; CAÑADA CAÑADA, F.; MUÑOZ DE LA PEÑA, A.

ANALYTICAL CHEMISTRY

American Chemical Society

Año: 2008 vol. 80 p. 7248 - 7256

0003-2700

Four-way data were obtained by recording the kinetic evolution of excitation-emission fluorescence matrices for the product of the Hantzsch reaction between the analyte malonaldehyde and methylamine. The reaction product, 1,4-disubstituted-1,4-dihydropyridine-3,5-dicarbaldehyde, is a highly fluorescent compound. The non-linear nature of the kinetic fluorescence data has been demonstrated, and therefore the four-way data were processed with parallel factor analysis combined with a non-linear pseudo-univariate regression, based on a quadratic polynomial fit, and also with a recently introduced neural network methodology, based on the combination of unfolded principal component analysis, residual trilinearization and radial basis functions. The applied chemometric strategies are not only able to adequately model the non-linear data, but also to successfully determine malonaldehyde in olive oil samples. This is possible since the experimentally recorded four-way data, modelled with the above mentioned advanced chemometric approaches, permit the achievement of the second-order advantage. This allows us to predict the analyte concentration in a complex background, in spite of the non-linear behaviour and in the presence of uncalibrated interferents. The present work is a new example of the use of higher-order data for the resolution of a complex non-linear system, successfully employed in the context of food chemical analysis.