1.1 本指南旨在概述染色纤维中存在的纤维着色剂（或单个染料成分）的薄层色谱法（TLC）。它旨在应用于纤维样品法医分析的更广泛的分析方案范围内。TLC可以提供无法通过其他颜色分析（如显微分光光度法（MSP））获得的信息 ( 1. ) 。 2. 1.2 本标准旨在供受过必要正规教育和特定学科培训的合格法医学从业者使用（见实践 917年2月 )，并表现出执行法医案件工作的熟练程度（见实践 E3255 )。 1.3 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。 1.4 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。 1.5 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 薄层色谱法是一种廉价而简单的技术，可用于补充与法医纤维检查相关的一般分析方案中的其他分析技术。 5.2 只有在样本量足够（即可以提取足够的着色剂进行分析）且无法使用其他技术（如比较显微镜和MSP）区分感兴趣的纤维时，才考虑使用TLC对纤维着色剂进行法医学分析，以进行单纤维比较。如果确定较大的纤维单元（例如，线或簇）是均匀的，则可以将其作为单独的样品进行处理。不要将不能直接相关的纤维作为TLC的集体样品处理。 5.3 在TLC分析之前进行的提取程序可以提供关于染料分类的有用信息。TLC可以提供有关染料成分的定性信息。使用这种技术可以区分由不同染料成分组成的相似颜色。 TLC的应用可以用于区分纤维，或者可以支持纤维共享共同来源的可能性。 5.4 TLC在某些情况下可能非常困难或不可取。短纤维或浅色纤维可能缺乏通过TLC检查所需的足够量的着色剂。从某些纤维中提取染料是不可能的 ( 2. ， 3. ) 。有些纤维类型不能真正提取，但会改变或失去颜色。活性染料与纤维共价结合，通常不能通过传统的提取方法去除，但可以通过分别通过酶促或化学消化破坏纤维而从棉花和羊毛中释放出来 ( 1. ) 为了保护证据不受有害变化的影响，或者为了另一个审查员可能进行的分析，可以排除去除颜色或采用破坏性方法进行分析。

1.1 This guide is intended as an overview of the Thin-Layer Chromatography (TLC) of fiber colorants (or individual dye components) present in dyed fibers. It is intended to be applied within the scope of a broader analytical scheme for the forensic analysis of fiber samples. TLC could provide information that cannot be obtained through other color analyses (such as microspectrophotometry (MSP)) ( 1 ) . 2 1.2 This standard is intended for use by competent forensic science practitioners with the requisite formal education, discipline-specific training (see Practice E2917 ), and demonstrated proficiency to perform forensic casework (see Practice E3255 ). 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 TLC is an inexpensive and simple technique that could be used to complement other analytical techniques within a general analytical scheme related to forensic fiber examination. 5.2 Consider the forensic analysis of fiber colorants using TLC for single fiber comparisons only when the sample size is adequate (that is, enough colorant can be extracted for analysis) and it is not possible to discriminate between the fibers of interest using other techniques, such as comparison microscopy and MSP. Larger fibrous units (for example, thread or tuft) can be treated as an individual sample if determined to be homogeneous. Do not treat fibers that cannot be directly related to each other as a collective sample for the purposes of TLC. 5.3 The extraction procedures carried out prior to TLC analysis can provide useful information about dye classification. TLC can provide qualitative information about dye components. Similar colors made up of different dye components can be differentiated using this technique. The application of TLC may serve to discriminate between fibers or it may support the possibility of fibers sharing a common source. 5.4 TLC can be prohibitively difficult or undesirable in some circumstances. Short lengths of fibers or pale-colored fibers can lack adequate amounts of colorant necessary to be examined by TLC. Dye extraction from some fibers can be impossible ( 2 , 3 ) . Some fiber types do not truly extract, but change or lose color. Reactive dyes are covalently bonded to the fiber and typically cannot be removed by conventional extraction methods, but can be released from cotton and wool by disrupting the fiber by enzymatic or chemical digestion, respectively ( 1 ) . The desire to preserve evidence from deleterious change or for possible analysis by another examiner can preclude removing the color or employing a destructive method for analysis.