1.1 本指南旨在为法医科学从业人员（FSP）提供程序建议，以使用紫外线（UV）、可见光（VIS）、近红外（NIR）或荧光发射分析对单纤维样品进行颜色光谱测量，并在这些测量的基础上比较样品。通过显微分光光度法对颜色进行光谱测量（本指南中称为颜色测量）是更广泛的分析方案的一部分。 1.2 本指南主要关注可见光谱范围内的颜色测量，但也包括一些关于紫外和近红外光谱范围内测量的细节。每个FSP采用的特定方法取决于可用设备、FSP培训、样本适用性和样本量。 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 本指南旨在供具有必要正规教育和特定学科培训的合格法医学从业人员使用（请参阅实践 E2917 )，并展示了执行法医案件的熟练程度。 1.5 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。 1.6 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 颜色比较是纤维比较中的关键步骤之一，因为颜色是纤维最重要的鉴别特征之一。显微分光光度计允许对小样品的颜色进行客观测量（基于选择性光吸收），这可以补充显微镜颜色比较，并且比显微镜颜色比较更具辨别力。 5.2 显微分光光度光谱比较是多分析比较方法的一部分。它与鉴定纤维成分的技术结合使用，如偏振光显微镜（PLM）和傅里叶变换红外光谱（FTIR）。为了鉴定染料成分，其他技术，如薄层色谱法（TLC）、拉曼光谱法或液相色谱质谱法（LC- MS）可以被采用，并且是对显微分光光度法提供的信息的补充。有关PLM、FTIR和TLC的更多详细信息，请参阅指南 E2228 , E2224 ，以及 E2227 分别。 5.3 本指南旨在帮助FSP选择合适的样品制备方法和仪器参数，用于纤维的显微分光光度分析和比较。当用于比较目的时，目标是确定样本之间是否存在任何排除性差异 ( 1. 9 ) . 4. 5.4 MSP数据和比较值的局限性包括: 5.4.1 吸收可能受到环境因素、物理损伤或样品处理的影响。例如，暴露于不规则改变颜色的环境因素（例如光褪色）的纤维或纺织品可能会与没有类似暴露的纤维或织物表现出光谱差异。 5.4.2 从非常暗或非常亮的光纤在可见光区域收集的光谱数据可能价值有限。 5.4.3 某些纤维类型在紫外线区域自然吸收（例如羊毛、聚酯纤维），限制了数据收集和解释。 5.4.4 MSP不是识别纤维中单个染料的实用技术。 5.5 使用透射光谱法测量光纤样品光谱。光纤样品的荧光发射也可以使用具有微光谱荧光测定能力的MSP进行测量 ( 9- 12 ) .

1.1 This guide is intended to assist forensic science practitioners (FSPs) with procedural recommendations for conducting spectral measurements of color on single fiber samples using ultraviolet (UV), visible (VIS), near infrared (NIR), or fluorescence emission analyses, and on comparing samples on the basis of these measurements. Spectral measurement of color (referred to as color measurement in this guide) by microspectrophotometry is part of a broader analytical scheme. 1.2 This guide primarily focuses on color measurements within the visible spectral range, but includes some details concerning measurements in the UV and NIR spectral ranges. The particular method(s) employed by each FSP depends upon available equipment, FSP training, sample suitability, and sample size. 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 guide is intended for use by competent forensic science practitioners with the requisite formal education, discipline-specific training (refer to Practice E2917 ), and demonstrated proficiency to perform forensic casework. 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. 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. ====== Significance And Use ====== 5.1 The comparison of color is one of the key steps taken in a fiber comparison, as color is one of the most important discriminating characteristics of fibers. Microspectrophotometers allow for an objective measurement of the color (based upon selective light absorption) of small samples, which can be complementary to, and more discriminating than, microscopical color comparisons. 5.2 Microspectrophotometric spectral comparison is one part of a multi-analytical comparative approach. It is used in conjunction with techniques that identify the fiber composition, such as polarized light microscopy (PLM) and Fourier transform infrared spectroscopy (FTIR). For the identification of the dye components, other techniques such as thin layer chromatography (TLC), Raman spectroscopy, or liquid chromatography mass spectrometry (LC-MS) can be employed and are complementary to the information provided by microspectrophotometry. For more detailed information regarding PLM, FTIR, and TLC refer to Guides E2228 , E2224 , and E2227 respectively. 5.3 This guide is designed to assist a FSP in the selection of appropriate sample preparation methods and instrumental parameters for the microspectrophotometric analysis and comparison of fibers. When used for comparison purposes, the goal is to determine whether any exclusionary differences exist between the samples ( 1- 9 ) . 4 5.4 Limitations to the value of MSP data and comparisons include: 5.4.1 Absorption can be impacted by environmental factors, physical damage, or sample handling. For example, a fiber or textile that has been exposed to environmental factors that irregularly alter the color (for example, photofading) can exhibit spectral differences to a fiber or textile that has not been similarly exposed. 5.4.2 Spectral data collected in the visible region from very dark or very light fibers could be of limited value. 5.4.3 Certain fiber types naturally absorb in the UV region (for example, wool, polyester), limiting data collection and interpretation. 5.4.4 MSP is not a practical technique to identify the individual dyes in a fiber. 5.5 Fiber sample spectra are measured using transmittance spectroscopy. The emission of fluorescence by fiber samples is also measurable using an MSP with microspectrofluorimetry capability ( 9- 12 ) .