La espectroscopia infrarroja y el método de calibración multivariada de mínimos cuadrados parciales en la predicción del índice de octano experimental de gasolinas

Abstract

One of the essential tests for the quality control of automotive gasolines is the determination of their knock characteristics by the research octane number (RON). The RON is traditionally determined by a widely used ASTM standard procedure, for which standard expensive equipment is needed, and which is also expensive to run and maintain under optimal conditions. Moreover, it requires intensive attention by the analyst (time consuming) and uses large amounts of sample and reagents. Current guides specify that tests for certifying the end product have to be carried out using standard method, but everyday tests which are used to monitor production units could be performed using alternative methods. Mid-band Fourier transform infrared spectroscopy (FT-MIR) combined with multivariate calibration analysis is a versatile efficient and accurate technique for RON estimation of gasolines and naphthas. This paper focusing on developing an alternative method for predicting the research octane number of regular gasolines by using FT-MIR spectroscopy combined with partial least-squares (PLS) multivariate calibration analysis. 35 gasolines samples with varied composition were taken for calibration. They were subject to the classical RON determinations by using standard ASTM procedure. An FT-MIR spectrum was collected from each sample and these spectra were correlated to the RON obtained by standard method.