1.1 本指南涵盖了对聚合物样品进行µ-XRF分析的法医实验室人员使用的推荐技术和程序。 1.2 本指南介绍了聚合物µ-XRF分析中使用的各种技术和程序，包括样品处理和制备、仪器操作条件以及光谱数据收集、评估和解释。 1.3 本指南介绍了配备单毛细管或多毛细管光学器件和能量色散X的µ-XRF系统的应用- 射线探测器（EDS）。 1.4 本指南旨在在更广泛的分析方案范围内应用（例如，指南 E1610 指导 E3260 )用于聚合物样品的法医学分析 ( 1- 6. ) 。 2. µ-XRF分析可以提供有关聚合物材料来源之间潜在关系的额外信息。 1.5 聚合物材料的组成和制造或X射线荧光理论的基本方面可以在各种文本中找到 ( 7- 18 ) 。 1. 6. 本标准适用于受过必要的正规教育和特定学科培训的合格法医学从业者（见实践 E2917 ， E3233 ， E3234 )，并表现出执行法医案件工作的熟练程度。 1.7 单位-- 以国际单位制表示的数值应视为标准。本标准中不包括其他计量单位。 1.8 本标准并非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制定适当的安全、健康和环境实践，并确定监管限制的适用性。 1.9 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====== 4.1 µ-XRF是一种用于聚合物的无损定性元素分析技术。它涉及X射线源对样品的激发，从而产生特征X的发射- 使用能量色散X射线检测器检测的射线。结果同时显示为原子序数为11或更大的元素的作为能量函数的强度谱。 4.2 µ-XRF能够确定样品的元素组成，并可用于比较聚合物材料的成分（例如，胶带衬垫、胶带粘合剂、油漆层）。 4.3 对从聚合物样品获得的X射线光谱进行比较，以进行源判别或潜在关联。 4.4 µ-XRF分析的定量方法可用，但由于缺乏制备的聚合物标准参考样品，因此不用于聚合物分析。 4.5 一般来说，异质样本的可用信息会随着其尺寸的减小或其状况的恶化而减少，这降低了其代表源材料的可能性。 4.6 从聚合物中收集的µ-XRF数据仅限于特定信息（例如，检测到的元素、相对元素丰度）； 需要额外的分析程序来进一步表征和鉴定聚合物样品的化学成分。 4.7 µ-XRF的局限性包括无法检测微量浓度的某些元素，无法分析单个颗粒，与光束穿透深度相对于样品厚度有关的潜在干扰，无法分辨某些元素的峰值（例如，Ba Lα/Ti Kα），以及一些材料由于暴露于辐射而变色的可能性。

1.1 This guide covers recommended techniques and procedures intended for use by forensic laboratory personnel that perform µ-XRF analysis of polymer samples. 1.2 This guide describes various techniques and procedures used in the µ-XRF analysis of polymers that include sample handling and preparation, instrument operating conditions, and spectral data collection, evaluation and interpretation. 1.3 This guide describes the application of µ-XRF systems equipped with either mono- or poly- capillary optics and an energy dispersive X-ray detector (EDS). 1.4 This guide is intended to be applied within the scope of a broader analytical scheme (for example, Guide E1610 , Guide E3260 ) for the forensic analysis of a polymer sample ( 1- 6 ) . 2 A µ-XRF analysis can provide additional information regarding the potential relationships between the sources of polymeric materials. 1.5 The fundamental aspects of the composition and manufacture of polymeric materials or theory of X-ray fluorescence can be found in various texts ( 7- 18 ) . 1.6 This standard is intended for use by competent forensic science practitioners with the requisite formal education, discipline-specific training (see Practices E2917 , E3233 , E3234 ), and demonstrated proficiency to perform forensic casework. 1.7 Units— The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.8 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. 1.9 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 ====== 4.1 µ-XRF is a nondestructive qualitative elemental analysis technique used for polymers. It involves excitation of a sample by an X-ray source resulting in the emission of characteristic X-rays detected using an energy dispersive X-ray detector. Results are displayed simultaneously as a spectrum of intensity as a function of energy for elements of atomic number 11 or greater. 4.2 µ-XRF enables the determination of the elemental composition of a specimen and can be utilized for comparisons of components of polymeric materials (for example, tape backings, tape adhesives, paint layers). 4.3 Comparisons of X-ray spectra acquired from polymer samples are conducted for source discrimination or potential association. 4.4 Quantitative processes for µ-XRF analysis are available but are not used for polymer analyses because of the lack of prepared polymer standard reference samples. 4.5 In general, information available from a heterogeneous specimen diminishes as its size is reduced or its condition degrades, which lessens its likelihood of being representative of the source material. 4.6 µ-XRF data collected from polymers is limited to specific information (for example, elements detected, relative elemental abundance); additional analytical procedures are required to further characterize and identify the chemical composition of the polymer sample. 4.7 Limitations of µ-XRF include the inability to detect some elements in trace concentrations, the inability to analyze individual particles, the potential interference related to the penetration depth of the beam relative to the sample thickness, the inability to resolve the peaks of some elements (for example, Ba Lα / Ti Kα), and the potential for discoloration of some materials due to exposure to radiation.