1.1 这种做法与实践类似 E1644 并涵盖了从同一空间内大小相同的区域收集的多达四个单独的沉降粉尘擦拭样品的合成样品中对铅（Pb）的热硝酸消解。 1.2 本规程包含注释，这些注释是解释性的，不是本规程强制性要求的一部分。 1.3 在消化技术（如热块）方面有经验的分析员应采用这种做法。与分析实验室中使用的所有程序一样，在应用于客户样品之前，需要验证该做法的使用并证明其产生可接受的结果。 1.4 以国际单位制或英寸-磅单位表示的数值应单独视为标准值。每个系统中规定的值不一定是精确的等价物；因此，为确保符合本标准，每个系统应独立使用，且两个系统的值不得组合。 1.5 本标准并非旨在解决与其使用相关的所有安全问题（如有）。本标准的用户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。 1.6 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《关于制定国际标准、指南和建议的原则的决定》中确立的国际公认标准化原则制定的。 ====意义和用途====== 5.1 本规程用于制备不超过四个擦拭样品，组合成复合样品，用于随后测定铅含量。 5.2 本实践假设使用符合规范的擦拭布 E1792 除非湿巾符合规格，否则不得使用 E1792 . 5.3 本规程能够制备用于测定油漆粉尘中结合铅的样品。 5.4 本规程可能无法制备样品以测定二氧化硅或硅酸盐基质内或不溶于硝酸的基质内结合的铅。 5.5 为了与用于铅定量的仪器分析方法兼容，可能需要调整最终提取液的硝酸浓度或酸强度，或两者兼而有之。 5.6 该样品制备规程尚未验证是否可用，用户必须在将该规程用于客户样品之前进行验证。 注1: 每次刮水组合（两次刮水、三次刮水和四次刮水）构成不同的矩阵，必须单独验证。

1.1 This practice is similar to Practice E1644 and covers the hot, nitric acid digestion of lead (Pb) from a composited sample of up to four individual wipe samples of settled dust collected from equally-sized areas in the same space. 1.2 This practice contains notes which are explanatory and not part of mandatory requirements of the practice. 1.3 This practice should be used by analysts experienced in digestion techniques such as hot blocks. Like all procedures used in an analytical laboratory, this practice needs to be validated for use and shown to produce acceptable results before being applied to client samples. 1.4 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system are not necessarily exact equivalents; therefore, to ensure conformance with the standard, each system shall be used independently of the other, and values from the two systems shall not be combined. 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 This practice is for use in the preparation of no more than four wipe samples combined to form a composited sample for subsequent determination of lead content. 5.2 This practice assumes use of wipes that meet Specification E1792 and should not be used unless the wipes meet Specification E1792 . 5.3 This practice is capable of preparing samples for determination of lead bound within paint dust. 5.4 This practice may not be capable of preparing samples for determination of lead bound within silica or silicate matrices, or within matrices not soluble in nitric acid. 5.5 Adjustment of the nitric acid concentration or acid strength, or both, of the final extract solution may be necessary for compatibility with the instrumental analysis method to be used for lead quantification. 5.6 This sample preparation practice has not been validated for use and must be validated by the user prior to using the practice for client samples. Note 1: Each combination of wipes (two wipes, three wipes, and four wipes) constitutes a different matrix and must be separately validated.