5.1 The quantitative determination of olefins in spark-ignition engine fuels is required to comply with government regulations.

5.2 Knowledge of the total olefin content provides a means to monitor the efficiency of catalytic cracking processes.

5.3 This test method provides better precision for olefin content than Test Method D1319. It also provides data in a much shorter time, approximately 20 min following calibration, and maximizes automation to reduce operator labor.

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

1.1 This test method provides for the quantitative determination of total olefins in the C₄ to C₁₀ range in spark-ignition engine fuels or related hydrocarbon streams, such as naphthas and cracked naphthas. Olefin concentrations in the range from 0.2 % by liquid-volume or mass to 5.0 % by liquid-volume or mass, or both, can be determined directly on the as-received sample whereas olefins in samples containing higher concentrations are determined after appropriate sample dilution prior to analysis.

1.2 This test method is applicable to samples containing alcohols and ethers; however, samples containing greater than 15 % alcohol must be diluted. Samples containing greater than 5.0 % ether must also be diluted to the 5.0 % or less level, prior to analysis. When ethyl-tert-butylether is present, only olefins in the C₄ to C₉ range can be determined.

1.3 This test method can not be used to determine individual olefin components.

1.4 This test method can not be used to determine olefins having higher carbon numbers than C₁₀.

Note 1: Precision was determined only on samples containing MTBE and ethanol.

1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.

1.7 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.