Express method for total content assessment of aromatic hydrocarbons and oxygen in finished gasolines by refractometry and densimetry

Study of the refractive index of gasoline+alcohol pseudo-binary mixtures

“…The uncertainty of refractive index data was of 10 -4 and the accuracy of the temperature of the thermostated bath was of ±0.05 K. The refractometer was calibrated using doubly distilled water at atmospheric pressure according to the instrument operating instructions. All the measurements for each binary mixture at working temperature were repeated three times, and the minimum value of the three measurements was selected in order to eliminate bias caused from evaporation [12].…”

“…Refractive index of gasoline components, as hydrocarbons from paraffins, naphtenes, olefins and aromatics groups, together with other hydrocarbons properties, can be used to predict the octane number of the gasoline. Also, it can be used to develop blending recipes for commercial gasoline that meet quality standards requirements [11] and to assess the quality of this petroleum product [12]. The experimental determination of refractive index can be easily and rapidly done with a proper accuracy using small amounts of sample.…”

Quality assessment of gasoline using comprehensive two‐dimensional gas chromatography combined with unfolded partial least squares: A reliable approach for the detection of gasoline adulteration

“…Among these compounds, benzene, toluene, xylenes, hexane, complex hydrocarbon mixtures, mineral spirits, kerosene, rubber solvent, petrochemical naphtha, diesel and thinner have been recognized as frequently used adulterants [6,[10][11][12][13][14][15][16]. The low cost, lower tax rates and similar chemical composition between solvents and gasoline are factors that contribute to their use in adulteration [12].…”

“…The excessive amount of these solvents in gasoline may lead to engine damage, rubber degradation and environmental hazards, as well as tax evasion [1]. Different analytical methods including the spectroscopic and chromatographic techniques combined with chemometric methods have been developed for the study of gasoline adulteration [2,6,11,13,[15][16][17][18][19][20][21]. Among these methods, GC coupled with various detection methods has been widely used to evaluate the quality of gasoline [22][23][24].…”

“…Gasoline adulteration involves addition of organic solvents, such as light aliphatic (C 4 –C 8 ), heavy aliphatic (C 13 –C 15 ) and aromatic hydrocarbons to gasoline. Among these compounds, benzene, toluene, xylenes, hexane, complex hydrocarbon mixtures, mineral spirits, kerosene, rubber solvent, petrochemical naphtha, diesel and thinner have been recognized as frequently used adulterants . The low cost, lower tax rates and similar chemical composition between solvents and gasoline are factors that contribute to their use in adulteration .…”