Abstract
In Japan, regular gasoline and premium gasoline are used as fuel for motor vehicles. Sometimes an accident will occur in which regular gasoline was filled by mistake instead of premium gasoline and discrimination between regular and premium gasoline is required in the investigation process. According to the standards, regular and premium gasolines are different only in octane value. Since measuring octane value requires a special device, an alternative method for determining a gasoline sample as a regular or premium one is desired. In this paper a new method for discriminating between regular and premium gasoline utilizing gas chromatography/mass spectrometry (GC/MS) is proposed. Analyzation of regular and premium gasoline collected in December 2007, March, June and September 2008 from gas stations of 15 different brands in northwestern Chiba and eastern Saitama prefecture revealed that, compared to regular gasoline, premium gasoline was rich in alkylate while smaller in 2- and 3-methylhexane concentration. All 120 gasoline samples were correctly classified as either regular or premium gasoline by measuring the ratio of alkylate to methylhexane fractions.
