Energy & Fuels, Vol.18, No.1, 30-36, 2004
H-1 NMR spectroscopic-based method for the estimation of total aromatic content of aviation turbine fuels (ATF): Comparison with liquid chromatographic methods
This work describes the development of a direct and quick method based on H-1 NMR spectroscopy for the determination of total aromatic content of jet and aviation turbine fuels (ATF). The method is based on the calculation of the average group molecular weight of aromatics from the integral intensities of characteristic regions of aromatics 6.5-8.0 ppm and alpha-subsituents (2.1-3.0 ppm). The average chain length of the alkyl subsituents on aromatic rings (other than methyl groups) has been determined from the 1H NMR spectrum of pure aromatic fractions of a few aviation fuels. The NMR results have been compared, and have been found to be well correlated with the other standard methods based on liquid chromatography (LC) (ASTM-D1319 FIA) and IP-436 (HPLC). The results obtained from the three investigated methods- NMR, FIA, and HPLC-have been statistically evaluated and found to give equivalent results. The developed H-1 NMR method is quite fast and reliable, and offers an alternative to long and tedious LC-based methods in routine quality control.