Meaning and use

5.1 This test method is intended to determine the concentration of known impurities in finished benzene and to be used as an overall quality control tool for the production or use of benzene in the manufacturing process. It is commonly applied to impurities such as non-aromatic compounds containing 9 or fewer carbons, toluene, C8 aromatic compounds, and 1, 4-dioxane.

5.2 If undetected impurities are present, absolute purity cannot be determined.

ASTM D7360-2016 Standard Test Method for Analysis of Benzene by Externally Calibrated Gas Chromatography

Step 1: Scope

1.1 This test method includes the determination of normal trace impurities and purity of benzene in finished products by gas chromatography and external calibration. A similar test method using the internal standard calibration technique is test method D4492.

1.2 This test method is suitable for non-aromatic impurities with a content of 5 to 2000 mg/kg and a benzene purity of 99.80% (by weight) or higher.

1.3 This test method is suitable for 5~2000 mg/kg of aromatic impurities in benzene.

1.4 The test method has been found to be suitable for heteroatomic species such as 1, 4-dioxane, 10 to 2000 mg/kg in benzene.

1.5 The detection limits for aromatic impurities are 0.9 mg/kg, 2.7 mg/kg for 1, 4-dioxane, and 1.1 mg/kg for cyclohexane.

ASTM D7360-2016 Standard Test Method for Analysis of Benzene by Externally Calibrated Gas Chromatography

1.6 When using this method to determine the consistency of test results with applicable specifications, the results should be rounded according to the rounding method of Practice E29.

1.7 Values expressed in SI units shall be regarded as standard values. No other units of measurement are included in this standard.

1.8 This standard is not intended to address all safety concerns, if any, associated with its use. It is the responsibility of users of this standard to establish appropriate safety and health practices and to determine the applicability of regulatory restrictions prior to use. See Section 9 for specific hazard descriptions.