Benzene Monitoring

Spectra of regular and premium gasoline comparing the benzene concentrations. The benzene peak is observed at ~ 992 cm-1 and the regular gasoline has more benzene (2.13%) compared to the premium (1.1%). The spectra also show the 1003 cm-1toluene peak which is at a higher concentration in the premium blend.

Spectra of regular and premium gasoline comparing the benzene concentrations. The benzene peak is observed at ~ 992 cm-1 and the regular gasoline has more benzene (2.13%) compared to the premium (1.1%). The spectra also show the 1003 cm-1toluene peak which is at a higher concentration in the premium blend.

A histogram of the distribution of differences between the laboratory and Raman predictions for an independent validation set of spectra that are not included in the PLS model. The standard error of prediction for the validation set (966 samples) with 4 outliers removed was 0.061%.

Typical online PLSanalysis of the percent aromatics concentration (ARO). The plot shows Raman predicted values vs. the measured laboratory values. The standard error of prediction for the PLS model with outliers removed was 0.38%.

A histogram of the distribution of differences between the laboratory and Raman predictions for an independent validation set of spectra that are not included in the PLS model. The standard error of prediction for the validation set (939 samples) with 5 outliers removed was 0.58%.