ASTM D6839-02

A knowledge of spark-ignition engine fuel composition is useful for regulatory compliance, process control, and quality assurance.

The quantitative determination of olefins and other hydrocarbon types in spark-ignition engine fuels is required to comply with government regulations.

This test method is not applicable to M85 and E85 fuels, which contain 85 % methanol and ethanol, respectively.

1.1 This test method provides for the quantitative determination of saturates, olefins, aromatics and oxygenates in spark-ignition engine fuels by multidimensional gas chromatography. Each hydrocarbon type can be reported either by carbon number (see Note 1) or as a total.

Note 1—There can be an overlap between the C₉ and C₁₀ aromatics; however, the total is accurate. Isopropyl benzene is resolved from the C₈ aromatics and is included with the other C₉ aromatics.

1.2 This test method is applicable to spark-ignition engine fuel with total aromatic content up to 50 % (V/V), total olefinic content up to 30 % (V/V) and oxygen compounds up to 15 % (V/V).

1.3 This test method is not intended to determine individual hydrocarbon components except benzene.

1.4 Oxygenates as specified in Test Method D 4815 have been verified not to interfere with hydrocarbons. Within the round robin sample set, the following oxygenates have been tested: MTBE, ethanol, ETBE, and TAME. Other oxygenates can be determined and quantified using Test Method D 4815 or D 5599.

1.5 The values stated in SI units are to be regarded as the standard.

1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.