This test method is designed to obtain benzene purity on the basis of impurities normally present in benzene and may be used for final product inspections and process control.

This test method will detect the following impurities: toluene, methylcyclopentane, n-hexane, 2-methylhexane, cyclohexane, cyclopentane, 2-methylpentane, 2,3-dimethylpentane, 3-methylhexane, n-heptane, methylcyclohexane, ethylcyclopentane, 2,4-dimethylhexane, trimethylpentane, and others where specific impurity standards are available. Absolute purity cannot be accurately determined if unknown impurities are present.

1.1 This test method covers the determination of specific impurities in, and the purity of benzene for cyclohexane feedstock by gas chromatography.

1.2 This test method has been found applicable to benzene in the range from 99 to 100 % purity and to impurities at concentrations of 2 to 10 000 mg/kg.

1.3 In determining the conformance of the test results using this method to applicable specifications, results shall be rounded off in accordance with the rounding-off method of Practice E 29.

1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.

1.5 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. For a specific hazard statement, see 7.1 and Section 8.