DETERMINATION OF BENZENE, TOLUENE, ETHYLBENZENE, AND XYLENES IN GASOLINES BY GAS-CHROMATOGRAPHY DEUTERIUM-ISOTOPE DILUTION FOURIER-TRANSFORM INFRARED-SPECTROSCOPY

Benzene, toluene, ethylbenzene, and xylenes (BTEX) in gasolines were determined by isotope dilution GC/FTIR with the perdeuterated analogs of the analytes as internal standards (ISTD). Careful selection of frequencies for selective absorbance reconstructions provided good selectivity of the analytes over their respective ISTDs as well as coeluting hydrocarbons such as 1-methyl-1-cyclopentene in the case of benzene. Detection limits were less than 0.1 wt %, and calibration curves were linear and stable for several months. An average relative standard deviation of 0.8 % and an average percentage accuracy of 0.5 % were found.