1.1 本试验方法包括通过单色、波长色散X射线荧光（MWDXRF）光谱法测定萘、汽油、汽油-乙醇混合物、重新配制汽油（RFG）、乙醇和乙醇燃料混合物以及浓度为3 mg/kg至100 毫克/千克。该试验方法的精度通过实验室间研究确定，该研究使用了表1中所述的液体代表性样品 1.1和 1.2 估计合并定量限（PLOQ）为3 毫克/千克。 注1: 挥发性样品，如高蒸气压汽油或轻烃，由于分析过程中轻组分的蒸发，可能无法达到规定的精度。 注2: 芳香化合物如甲苯属于D16芳香烃和相关化学品委员会的管辖范围。然而，甲苯可能导致汽油中的硅污染（参见 5.4 )，因此将其包含在本测试方法中。 1.2 如果校准标准的矩阵与样本矩阵或中所述的矩阵校正相匹配，则可使用该测试方法分析含有乙醇和其他含氧化合物的汽油样本 附件A1 应用于结果。第节提供了矩阵匹配和矩阵校正的条件 6. ，干扰。 1.3 硅浓度高于100的样品 mg/kg可在用适当溶剂稀释后进行分析。稀释样品的硅测定精度和偏差尚未确定，且可能与纯样品所示不相同（第节 17 ). 1.4 该测试方法中的一个基本假设是标准矩阵和样本矩阵匹配良好，或者考虑了矩阵差异（参见 14.5 ). 基质失配可由样品和标准品之间的C/H比差异或其他干扰杂原子的存在引起；遵守第节中的注意事项和建议 6. . 1.5 以国际单位制表示的值应视为标准值。本标准不包括其他测量单位。 1.6 本标准并不旨在解决与其使用相关的所有安全问题（如有）。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，并确定监管限制的适用性。 1.7 本国际标准是根据世界贸易组织技术性贸易壁垒（TBT）委员会发布的《国际标准、指南和建议制定原则决定》中确立的国际公认标准化原则制定的。 =====意义和用途====== 5.1 本试验方法可快速准确地测量石脑油、汽油、汽油-乙醇混合物、RFG、乙醇和乙醇燃料混合物以及甲苯中的总硅含量，且样品制备最少。 典型分析时间为5 最小值至10 每个样品的最小值。 5.2 与传统WDXRF技术中使用的多色激发相比，单色X射线激发减少了背景，简化了矩阵校正，并提高了信号/背景比。 3. 5.3 硅油消泡剂可添加到焦化原料中，以尽量减少焦化过程中的泡沫。焦化石脑油中的残留硅会对石脑油的下游催化处理产生不利影响。该试验方法提供了测定石脑油中硅含量的方法。 5.4 汽油、汽油-乙醇混合物、变性乙醇及其混合物的硅污染导致车辆部件（例如火花塞、排气氧传感器、催化转化器）污染，需要更换和修理零件。成品汽油、汽油乙醇混合物和乙醇燃料混合物可以通过多种方式与硅接触。废烃溶剂如甲苯可添加到汽油中。 这种溶剂可以含有可溶性硅化合物。硅基消泡剂可用于乙醇工厂，然后将硅传递到成品乙醇燃料混合物中。该测试方法可用于确定汽油、汽油-乙醇混合物和乙醇-燃料混合物是否符合燃料硅含量的规范，以及解决客户问题。 5.5 本试验方法涵盖的一些硅化合物比通常用于制备校准标准品的硅化合物挥发性更高。由于分析过程中轻物质的选择性损失，挥发性化合物可能不符合本试验方法规定的精度。

1.1 This test method covers the determination of total silicon by monochromatic, wavelength-dispersive X-ray fluorescence (MWDXRF) spectrometry in naphthas, gasoline, gasoline-ethanol blends, reformulated gasoline (RFG), ethanol and ethanol-fuel blends, and toluene at concentrations of 3 mg/kg to 100 mg/kg. The precision of this test method was determined by an interlaboratory study using representative samples of the liquids described in 1.1 and 1.2 . The pooled limit of quantitation (PLOQ) was estimated to be 3 mg/kg. Note 1: Volatile samples such as high-vapor-pressure gasolines or light hydrocarbons might not meet the stated precision because of the evaporation of light components during the analysis. Note 2: Aromatic compounds such as toluene are under the jurisdiction of Committee D16 on Aromatic Hydrocarbons and Related Chemicals. However, toluene can be a contributor to silicon contamination in gasoline (see 5.4 ), thus its inclusion in this test method. 1.2 Gasoline samples containing ethanol and other oxygenates may be analyzed with this test method provided the matrix of the calibration standards is either matched to the sample matrices or the matrix correction described in Annex A1 is applied to the results. The conditions for matrix matching and matrix correction are provided Section 6 , Interferences. 1.3 Samples with silicon concentrations above 100 mg/kg can be analyzed after dilution with appropriate solvent. The precision and bias of silicon determinations on diluted samples have not been determined and may not be the same as shown for neat samples (Section 17 ). 1.4 A fundamental assumption in this test method is that the standard and sample matrices are well matched, or that the matrix differences are accounted for (see 14.5 ). Matrix mismatch can be caused by C/H ratio differences between samples and standards or by the presence of other interfering heteroatoms; observe the cautions and recommendations in Section 6 . 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. 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 provides rapid and precise measurement of total silicon in naphthas, gasoline, gasoline-ethanol blends, RFG, ethanol and ethanol-fuel blends, and toluene with minimum sample preparation. Typical analysis time is 5 min to 10 min per sample. 5.2 Excitation by monochromatic X-rays reduces background, simplifies matrix correction, and increases the signal/background ratio compared to polychromatic excitation used in conventional WDXRF techniques. 3 5.3 Silicone oil defoamer can be added to coker feedstocks to minimize foaming in the coker. Residual silicon in the coker naphtha can adversely affect downstream catalytic processing of the naphtha. This test method provides a means to determine the silicon content of the naphtha. 5.4 Silicon contamination of gasoline, gasoline-ethanol blends, denatured ethanol, and their blends has led to fouled vehicle components (for example, spark plugs, exhaust oxygen sensors, catalytic converters) requiring parts replacement and repairs. Finished gasoline, gasoline-ethanol blends, and ethanol-fuel blends can come into contact with silicon a number of ways. Waste hydrocarbon solvents such as toluene can be added to gasoline. Such solvents can contain soluble silicon compounds. Silicon-based antifoam agents can be used in ethanol plants, which then pass silicon on to the finished ethanol-fuel blend. This test method can be used to determine if gasoline, gasoline-ethanol blends, and ethanol-fuel blends meet specifications with respect to silicon content of the fuel, and for resolution of customer problems. 5.5 Some silicon compounds covered by this test method are significantly more volatile than the silicon compounds typically used for the preparation of the calibration standards. Volatile compounds may not meet the stated precision from this test method because of selective loss of light materials during the analysis.