Introduction Gasoline is produced by fractional distillation of petroleum at a boi領(lǐng) point between 30°C and 200°C. It contains hydrocarbons such as paraffin, olefin, and aromatics, carbon numbers of which are between 4 and 10. Characterization of gasoline requires the determination of the contents of those hydrocarbons. American Society for Testing and Materials (ASTM) announced a method, D6550-00: Standard Test Method for Determination of Olefin Content of Gasolines by Supercritical-Fluid Chromatography. We have established an analysis system in accordance with this method. JASCO SFC4000超臨界流體