ASTM D6379 Standard Test Method for Determination of Aromatic Hydrocarbon Types
ASTM D6379 Standard Test Method for Determination of Aromatic Hydrocarbon Types in Aviation Fuels and Petroleum Distillates - High Performance Liquid Chromatography Method with Refractive Index Detection
4. Summary of Test Method
4.1 The test portion is diluted 1:1 with the mobile phase, such as heptane, and a fixed volume of this solution injected into a high performance liquid chromatograph fitted with a polar column. This column has little affinity for the non-aromatic hydrocarbons and exhibits a pronounced selectivity for aromatic hydrocarbons. As a result of this selectivity, the aromatic hydrocarbons are separated from the non-aromatic hydrocarbons into distinct bands in accordance with their ring structure, that is, MAHs and DAHs.
4.2 The column is connected to a refractive index detector that detects the components as they elute from the column. The electronic signal from the detector is continually monitored by a data processor. The amplitudes of the signals (peak areas) from the sample aromatics are compared with those obtained from previously-run calibration standards in order to calculate the percent m/m MAHs and DAHs in the sample. The sum of the MAHs and DAHs is reported as the total aromatic content (percent m/m) of the sample.
5. Significance and Use
5.1 Accurate quantitative information on aromatic hydrocarbon types can be useful in determining the effects of petroleum processes on production of various finished fuels. This information can also be useful for indicating the quality of fuels and for assessing the relative combustion properties of finished fuels.
