Determination of methanol ratio in methanol-doped biogasoline by a fiber Raman sensing system

A novel Raman spectral method is reported to determine the methanol ratio in methanol-doped biogasoline quantitatively and quickly. The Raman spectrum information for different ratio biogasoline has been obtained and recorded. The relative intensity ratio of two typical Raman peaks for methanol and gasoline satisfied a linear relation versus their volume ratio in the certain range which could be used as a quantitative measurement. This method, compared with the direct intensity measurement of Raman peak, may not only eliminate the random measurement error due to dark current, but also confirm the accurate ratio of methanol and gasoline.