Infrared Spectroscopy and the Multivariate Least Squares Calibration Method of multivariate least-squares calibration method in the prediction of the experimental octane number of gasolines of gasoline

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.