Quantificação dos teores de biodiesel de crambe e mafurra em misturas com diesel utilizando espectroscopia mir e ferramentas quimiométricas

Abstract

Mid-Infrared absorption spectroscopy associed with the least squares regression is the official method to monitor Brazilian commercial diesel quality. his method, however, uses solvents and a large number of samples for the construction of the calibration curves, which generates waste and increases the time needed for the analysis. In order to develop a non-destructive method, being possible to recover the sample after its quantification, decrease the quantity of samples and make use of a single calibration curve, in this study we used the oilseeds crambe and mafurra, which are not used in human food, for the methyl biodiesel production and PLS analysis for their content determination in mixtures with diesel at a concentration range of 1.00 to 30.00 (% v/v). The global model for crambe methyl biodiesel obatined RMSEC = 0.26 (% v/v), RMSECV = 0.35 (% v/v) and RMSEP = 0.41 (% v/v), and the global model for mafurra methyl biodiesel obtained RMSEC = 0.47 (% v/v), RMSECV = 0.83 (% v/v) and RMSEP = 0.69 (% v/v). Complementary, variables selection methods iPLS, biPLS and siPLS were applied in the global models in order to reduce the spectral range required to regressions construction and to improve the RMSEP, RMSECV and RMSEC values.