Rapid and quantitative detection of ethanol proportion in ethanol–gasoline mixtures by Raman spectroscopy

The paper reports a Raman spectral in-situ detection technique to measure the ethanol proportion in an ethanol–gasoline mixture rapidly and quantitatively. The transformed information of Raman spectra for different mixtures of gasoline and ethanol have been observed and recorded. The relative intensity ratio of two typical Raman peaks for ethanol and gasoline satisfies a linear relation with a variation in volume ratio which could be used as a quantitative measure. This method, compared with the direct intensity measurement of a Raman peak, may not only eliminate the random measurement error due to dark current, but also confirm the accurate the proportion of ethanol and gasoline.