Terahertz quantitatively distinguishing gasoline mixtures using multiparameter-combined analysis.

Refined oil mixtures can be quantified using terahertz-absorption-coefficient spectra and dualistic linear regression fitting. However, when this method was used to quantify mixtures of 90# and 97# gasolines, the absolute error between the real and fitted value was large (25%), and this was due to the component similarity between 90# and 97# gasolines. To solve this problem, the present research addresses the possibility of developing a method that would allow direct, simple, and accurate determination of the 97# gasoline content in gasoline mixtures using a terahertz time-domain pulse coupled to a multiparameter-combined analysis.

Terahertz spectroscopy for quantifying refined oil mixtures.

In this paper, the absorption coefficient spectra of samples prepared as mixtures of gasoline and diesel in different proportions are obtained by terahertz time-domain spectroscopy. To quantify the components of refined oil mixtures, a method is proposed to evaluate the best frequency band for regression analysis. With the data in this frequency band, dualistic linear regression fitting is used to determine the volume fraction of gasoline and diesel in the mixture based on the Beer-Lambert law.