Use of ¹H NMR and chemometrics to detect additives present in the Brazilian commercial gasoline

Abstract

In Brazil, gasoline is classified as type C, where the addition of oxygenates occurs as anhydrous ethanol at a concentration determined by law. The gasoline can be marketed as common (CG) or additive gasoline (AG), which differs by the addition of packages of multifunctional additives that confer beneficial properties to the fuel. However, there are no methods for the identification of additives in gasoline. This paper describes the use of Nuclear Magnetic Resonance spectroscopy of hydrogen (1H NMR) along with principal component analysis (PCA) and Soft Independent Modelling of Class Analogies (SIMCA) to differentiate between CG and AG. All AG samples were correctly classified, including thirty-three CG samples intentionally additive with 500, 1000 and 2500 ppm of seven different commercial additives. The methodology allows to detect the presence of additives used in commercial gasolines and can be an important tool for quality control of the product.