NONDESTRUCTIVE ANALYTICAL PROCEDURE FOR SIMULTANEOUS ESTIMATION OF THE MAJOR CLASSES OF HYDROCARBON CONSTITUENTS OF FINISHED GASOLINES

Near-infrared (NIR) spectroscopy in both the short-wave-length (700–1200 nm) region (SW-NIR) and the long-wave-length (1100–2500 nm) region (LW-NIR) is used for the simultaneous estimation of the major classes of hydrocarbon constituents (aliphatics, aromatics, and olefinics) of finished gasolines. The test requires 1–3 cm3 of gasoline, is nondestructive, and takes only a few minutes to perform. Two multivariate calibration approaches have been employed for data reduction: stagewise multilinear regression and partial least squares. Both methods yield comparable results. Success is critically dependent upon training sets of well-characterized samples for which both NIR spectra and constituent values by reference methods are available. Accordingly, the use of near-Infrared spectroscopy is suggested as a rapid method for the estimation of quality parameters of finished gasolines. © 1990, American Chemical Society. All rights reserved.