1.1 本试验方法涵盖了精苯中噻吩的测定。 1.2 本试验方法适用于噻吩浓度范围为0.80 mg/kg至1.80 mg/kg的火焰光度检测器（FPD）和0.14 mg/kg至2.61 mg/kg的脉冲火焰光度检测器（PFPD）。对于PFPD，最低定量水平（LOQ）为0.14 mg/kg，最低检测水平（LOD）为0.04 mg/kg。通过仔细的分析技术和/或重复，该方法可用于成功分析低于当前LOD的浓度。可以通过改变样品进样体积、分流比、校准范围或用不含噻吩的溶剂稀释样品来扩展测试方法的范围。 附注1: 见 附录X1 有关LOD计算的其他信息。附注2: 使用ASTM研究报告RR:D16-1038中的数据计算LOD和LOQ。 2 1.3 本试验方法适用于质量标准中描述的苯特性 D2359 和 D4734 并且只有在用户证明该方法可以从样品中包含的其他有机污染物中完全分离噻吩之后，才可适用于其他类型或等级的苯。 1.4 以下内容适用于使用本试验方法确定是否符合适用质量标准，结果应按照惯例的四舍五入方法进行四舍五入 E29 . 1.5 以SI单位表示的值将被视为标准值。本标准不包括其他计量单位。 1.6 本标准并不旨在解决与其使用相关的所有安全性问题（如果有）。本标准的使用者有责任在使用前建立适当的安全、健康和环境实践并确定法规限制的适用性。 有关具体危害陈述，请参见章节 8 . 1.7 本国际标准是根据世界贸易组织技术性贸易壁垒委员会发布的《关于制定国际标准、指南和建议的原则的决定》中确立的国际公认的标准化原则制定的。 ======意义和用途====== 5.1 本试验方法适用于设定苯的质量标准，并用作生产或生产过程中使用苯的内部质量控制工具。 5.2 本试验方法适用于精制苯中噻吩的测定，符合质量标准中描述的质量标准 D2359 并且如果用户已经采取了文中所述的必要预防措施，则可以适用于其他等级的苯。

1.1 This test method covers the determination of thiophene in refined benzene. 1.2 This test method is applicable to samples with thiophene concentrations in the range from 0.80 mg/kg to 1.80 mg/kg for the Flame Photometric Detector (FPD), and from 0.14 mg/kg to 2.61 mg/kg for the Pulsed Flame Photometric Detector (PFPD). For the PFPD, the minimum level of quantitation (LOQ) is 0.14 mg/kg and the minimum level of detection (LOD) is 0.04 mg/kg. With careful analytical technique, and/or replicates, this method can be used to successfully analyze concentrations below the current LOD. The range of the test method may be extended by modifying the sample injection volume, split ratios, calibration range, or sample dilution with thiophene-free solvent. Note 1: See Appendix X1 for additional information on calculation of LOD. Note 2: LOD and LOQ were calculated using data from ASTM Research Report RR:D16-1038. 2 1.3 This test method has been found applicable to benzene characteristic of the type described in Specifications D2359 and D4734 and may be applicable to other types or grades of benzene only after the user has demonstrated that the procedure can completely resolve thiophene from the other organic contaminants contained in the sample. 1.4 The following applies for the purposes of determining the conformance to applicable specifications using this test method, results shall be rounded off in accordance the rounding-off method of Practice E29 . 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. For specific hazard statements, see Section 8 . 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. ====== Significance And Use ====== 5.1 This test method is suitable for setting specifications on benzene and for use as an internal quality control tool where benzene is either produced or used in a manufacturing process. 5.2 This test method was found applicable for determining thiophene in refined benzene conforming to the specifications described in Specification D2359 and may be applicable toward other grades of benzene if the user has taken the necessary precautions as described in the text.