EXPLANATION
To assess product quality and meet new fuel regulations, it is necessary to have methods to determine oxygenates, benzene, and aromatic content of gasoline. This method can be used for gasolines that contain oxygenates such as alcohols and ethers as additives. They do not interfere with the benzene and other aromatics by this method. It is applicable in the following concentration range in volume %: 0.1 to 20 per component for ethers and alcohols; 0.1 to 2 for benzene; 1 to 15 for toluene; 10 to 40 for total C6 to C12 aromatics. The method has not been tested for refinery individual process streams such as reformates, fluid catalytic cracking napthas, etc., used in blending of gasolines.
TEST SUMMARY
The sample is injected through a cool on-column injector into a gas chromatograph equipped with a methylsilicone WCOT column interfaced to a FT-IR instrument. Mixtures of specified pure oxygenates and aromatic hydrocarbons are used for calibration. Multipoint calibrations consisting of at least five levels and bracketing the concentration of the specified individual aromatics is required. Unidentified aromatic hydrocarbons present that have not been specifically calibrated for, are quantitated using the response factor of 1,2,3,5-tetramethylbenzene.
TEST PRECISION
