Nuclear magnetic resonance (NMR) spectroscopy is sensitive to the connection of the carbon atoms in hydrocarbons, and is one of the most helpful tools for quick quantification and structural elucidation of chemical compounds in fuel analysis . It provides information on all carbon bonding environments within a single experiment. Quantitative 13 C NMR spectrum is an effective and direct method for measuring aromaticity and unsaturated C=C bonds from saturated C-C bonds ---relative percentage of aromatic carbon atoms in hydrocarbons .