4.1 Knowledge of the concentration of benzene may be required for regulatory use, control of gasoline blending, and/or process optimizations.

1.1 This test method covers the determination of benzene and toluene in finished motor and aviation spark ignition fuels by gas chromatography. This test method has two procedures: Procedure A uses capillary column gas chromatography and Procedure B uses packed gas chromatography columns. Procedures A and B have separate precisions.

1.2 Benzene can be determined between the levels of: (1) Procedure A 0.1 % and 5.0 % by volume and toluene can be determined between the levels 0.4 % and 20 % by volume, and (2) Procedure B benzene can be determined between the levels of 0.1 % and 5 % by volume and toluene can be determined between the levels of 2 % and 20 % by volume.

1.3 The precision for this test method was determined using conventional spark ignition fuel (motor ‘gasolines’) as well as those containing blended ethanol and such ethers as MTBE, ETBE, TAME, and other alcohols such as methanol and butanols. This method may be used for finished motor and aviation gasolines that contain ethanol blend up to 20 % and butanols blend up to 20 %.

1.4 M85 and E85 fuels were not included in the precision for Procedure A. M85 and E85 fuels cause interference with Procedure B.

1.5 Procedure A uses MIBK as the internal standard. Procedure B uses sec-butanol as the internal standard. The use of Procedure B for fuels containing blended butanols requires that sec-butanol be below the detection limit in the fuels.

1.6 The values stated in SI units are to be regarded as standard. The values given in parentheses are for information only.

1.7 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.

1.8 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.