[Hydrocarbon group analysis of gasoline by Raman spectroscopy with outlier detection].

Hydrocarbon group of gasoline not only determines the quality of gasoline, but also directly relates to the impact of exhaust air on the environment. The present paper successfully applied Raman spectroscopy to the quantitative analysis of hydrocarbon group in gasoline. Contaminated samples were removed from calibration set by outlier detection, which effectively improved the partial least squares (PLS) prediction accuracy. The standard prediction errors of aromatics, olefin and oxygen content are 0.23, 0.52 and 0.143 respectively, and the corresponding multiple correlation coefficients of prediction (R2) are 0.987, 0.927 and 0.971. Experimental results show that the effectiveness of Raman spectroscopy for hydrocarbon group analysis in gasoline, and that the prediction accuracy is much better than near infrared spectroscopy or multidimensional gas chromatography. Quantitative calibrations based on Raman spectroscopy can also be used in the on-line analysis of gasoline production processes.