1.1 本试验方法涵盖了使用可见光谱法测定市售柴油和燃烧器燃料中染料溶剂红164浓度的程序。 注1: 本试验方法适用于规范中的所有1号和2号等级 D396 和 D975 规范中DMA和DMB等级 D2069 . 1.2 为校准标准规定的浓度范围是根据美国国税局的染色要求确定的，该要求规定，免税柴油只有在含有染料溶剂红164（不含其他染料）的情况下才能满足染色要求，其光谱浓度相当于每千桶3.9磅固体染料标准溶剂红26（11）。 1mg/L）柴油。 1.3 以国际单位制表示的值应被视为标准值。本标准不包括其他计量单位。 1.4 本标准并不旨在解决与其使用相关的所有安全问题（如果有的话）。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，并确定监管限制的适用性。 1.5 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 制定本试验方法是为了执行《美国联邦法规》第26篇第48.4082-1（b）条，该条规定，所有免税柴油都必须用一定量的溶剂红164染色，其浓度在光谱上相当于3.9 lb/10 3. bbl（11.1mg/L）溶剂红26。它用于验证在销售前，在码头或炼油厂将正确数量的溶剂红164添加到免税产品中，并检测用于道路使用的征税产品中是否存在溶剂红164。 5.1.1 溶剂红26是偶氮染料，如图所示 图1 它是测量溶剂红164浓度的标准，因为它以经过认证的纯形式提供。 溶剂红164在结构上与溶剂红26相同，除了它含有碳氢化合物（烷基）链以增加其在柴油和燃烧器燃料中的溶解度。溶剂红164的确切成分因制造商和批次而异，具体取决于生产过程中发生的烷基化程度；其可见光谱几乎与溶剂红26的光谱相同。溶剂红164（代替溶剂红26）用于现场染色免税柴油和燃烧器燃料，因为其溶解度更高，成本相对较低。 图1 溶剂红26的结构

1.1 This test method covers the procedure for determining the concentration of dye Solvent Red 164 in commercially available diesel and burner fuels using visible spectroscopy. Note 1: This test method is suitable for all No. 1 and No. 2 grades in Specifications D396 and D975 and for grades DMA and DMB in Specification D2069 . 1.2 The concentration ranges specified for the calibration standards are established in response to the Internal Revenue Service dyeing requirements which state that tax-exempt diesel fuel satisfies the dyeing requirement only if it contains the dye Solvent Red 164 (and no other dye) at a concentration spectrally equivalent to 3.9 lb of the solid dye standard Solvent Red 26 per thousand bbl (11.1 mg/L) of diesel fuel. 1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.4 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. 1.5 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 was developed to provide for the enforcement of 26 CFR 48.4082-1(b), which mandates that all tax-exempt diesel fuels be dyed with an amount of Solvent Red 164 at a concentration that is spectrally equivalent to 3.9 lb/10 3 bbl (11.1 mg/L) of Solvent Red 26. It is employed to verify that the correct amount of Solvent Red 164 is being added to tax-exempt product at terminals or refineries prior to sale, and to detect the presence of Solvent Red 164 in taxed product intended for on-road use. 5.1.1 Solvent Red 26 is the azo dye shown in Fig. 1 . It is the standard against which the concentration of Solvent Red 164 is measured because it is available in a certified pure form. Solvent Red 164 is identical in structure to Solvent Red 26 except that it has hydrocarbon (alkyl) chains incorporated to increase its solubility in diesel and burner fuels. The exact composition of Solvent Red 164 will vary from manufacturer to manufacturer and lot to lot depending upon the extent of alkylation that occurs during production; however, its visible spectrum is virtually identical to the spectrum of Solvent Red 26. Solvent Red 164 is employed in the field (instead of Solvent Red 26) to dye tax-exempt diesel and burner fuels because of its higher solubility and relatively low cost. FIG. 1 Structure of Solvent Red 26