【国外标准】 Standard Test Method for Analysis of Cyclohexane by Gas Chromatography (External Standard)

5.1 This test method is suitable for setting specifications on the materials referenced in Table 1 and for use as an internal quality control tool where cyclohexane is produced or is used in a manufacturing process. It may also be used in development or research work involving cyclohexane.5.2 This test method is useful in determining the purity of cyclohexane with normal impurities present. If extremely high boiling or unusual impurities are present in the cyclohexane, this test method would not necessarily detect them and the purity calculation would be erroneous.1.1 This test method covers the determination of the purity of cyclohexane by gas chromatography.1.2 This test method is applicable to the measurement of impurities in Table 1. This test method is applicable to samples with concentrations to 400 mg/kg, but may be applicable to a wider range. The limit of detection (LOD) is 1 mg/kg and the limit of quantitation (LOQ) is 3 mg/kg for benzene.NOTE 1: The LOD and LOQ were calculated from the ILS data for benzene.1.3 The following applies for the purposes of determining the conformance of the test results using this test method to applicable specifications, results shall be rounded off in accordance with the rounding-off method of Practice E29.1.4 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use. For specific hazard statements, see Section 8.1.6 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.