Brazilian gasoline quality: study of adulteration by statistical analysis and gas chromatography

Abstract

A adição de solventes orgânicos (hidrocarbonetos alifáticos pesados, alifáticos leves e hidrocarbonetos aromáticos) na gasolina brasileira é muito freqüente, e esta prática ilícita prejudica a qualidade da gasolina. Neste trabalho, as adulterações por solventes orgânicos de amostras de gasolina foram analisadas. Para a caracterização e comparação destas amostras, alguns parâmetros físico-químicos foram selecionados como fator para análise estatística hierárquica multivariada (Cluster Analysis). Entretanto estes parâmetros não foram eficientes para detectar todos os tipos de adulteração, em particular a adulteração por hidrocarbonetos alifáticos leves e mistura dos mesmos com hidrocarbonetos aromáticos. Este tipo de adulteração é melhor detectada através da análise do perfil cromatográfico destas amostras. A Cromatografia Gasosa (CG) deve ser usada para uma melhor detecção de gasolinas adulteradas. O uso das propriedades físico-químicas de amostras de gasolina na análise estatística multivariada juntamente com os perfis cromatográficos é um método eficiente e viável à detecção da adulteração.The addition of organic solvents (heavy aliphatic, light aliphatic and aromatic hydrocarbons) in Brazilian gasoline is unfortunately very frequent, and this illicit practice does not guarantee gasoline quality. Organic solvent adulterations of gasoline samples have been investigated. For characterization and comparison of these samples, physico-chemical parameters were selected as the factor for hierarchic multivariate analysis (Cluster Analysis). However, these parameters are not efficient to detected all kinds of adulteration. Gas Chromatographic (GC) analysis can be used as a procedure to improve the detection of adulterated gasoline. More detailed information of their compositions was revealed. The use of physico-chemical properties of gasoline samples for hierarchic multivariate analysis and gas chromatographic fingerprints is a practicable method to adulteration detection.

Diesel-Like Fuel Obtained by Catalytic Pyrolysis of Waste Engine Oil

“…Gasoline is a complex mixture of several hundred of liquid, volatile and inflammable petroleum derived compounds, ranging from C4 to C12 carbon atoms [43] and boiling points in the range of 312-454 K (Table 3). Octane number a measure of the gasoline quality for prevention of early ignition which leads to cylinder knocks.…”

Ototoxicity of hydrocarbons present in gasoline: a literature review

“…In general, they are volatile and toxic organic compounds that have a high vapor pressure under normal conditions, to the point of volatizing significantly and entering the atmosphere. Some, known as aromatic hydrocarbons, have a pronounced odor due to delocalization of electrons in their cyclic structures 5,6 .…”

Multivariate calibrations on 1H NMR profiles for prediction of physicochemical parameters of Brazilian commercial gasoline

“…Usually, amongst all analytical techniques, gas chromatographic and infrared spectroscopic methods are employed for establishing adulteration and predict physicochemical parameters in gasoline [10][11][12][13][14][15][16][17][18][19][20]. However, chromatographic techniques are generally slow, time-consuming and expensive for the analysis of a large number of samples, making impracticable its in routine application.…”