1.1 合成和二次采样是采样和分析事件链中的关键环节，必须按照项目目标和说明进行，以确保生成的数据具有代表性。本指南讨论了复合采样的优点和适当使用，混合复合样本的现场程序和技术，以及从较大样本中收集无偏和精确子样本的程序。它讨论了在设计用于表征废物（主要是固体）和潜在污染介质的采样计划时使用复合样品的优点和局限性。 本指南假设选择了适当的采样设备来采集无偏样本。 1.2 该指南未涉及:应在何处采集样本（取决于目标）（见指南 第6044页 )，取样设备的选择，因选择不合适的取样设备而产生的偏差，样品收集程序或从样品中收集代表性样品，或对所得数据的统计解释，以及设计用于动态取样工艺废物流的设备。它也没有提供足够的信息来统计设计优化的抽样计划，或确定要收集的样本数量，或计算要合成的最佳样本数量，以实现指定的数据质量目标（见实践 D5792型 ). 《指南》阐述了规划废物取样活动的标准程序 第4687页 . 1.3 本指南中描述的样品混合和二次取样程序被认为不适合分析挥发性有机化合物的样品。挥发性有机物通常在样品收集、处理、运输和实验室样品制备过程中因挥发而损失，除非使用专门的程序。本指南中描述的增强混合预计会导致挥发性成分的显著损失。应使用专门的程序合成样品以测定挥发物，例如直接合成甲醇（见指南 第4547天 ). 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 本指南为管理或负责设计采样和分析计划的人员提供了指导，以确定样本组合是否有助于更有效地实现研究目标。样本必须正确组合，否则可能会丢失有关污染分布和样本差异的有用信息。 5.2 所述的混合样品和获得代表性子样品的程序广泛适用于需要将少量材料运输到实验室的废物取样。混合和二次取样部分为准备取样和分析计划的人员以及现场人员提供指导。 5.3 虽然本指南通常侧重于固体材料，但复合取样的属性和限制同样适用于静态液体样品。

1.1 Compositing and subsampling are key links in the chain of sampling and analytical events that must be performed in compliance with project objectives and instructions to ensure that the resulting data are representative. This guide discusses the advantages and appropriate use of composite sampling, field procedures and techniques to mix the composite sample, and procedures to collect an unbiased and precise subsample(s) from a larger sample. It discusses the advantages and limitations of using composite samples in designing sampling plans for characterization of wastes (mainly solid) and potentially contaminated media. This guide assumes that an appropriate sampling device is selected to collect an unbiased sample. 1.2 The guide does not address: where samples should be collected (depends on the objectives) (see Guide D6044 ), selection of sampling equipment, bias introduced by selection of inappropriate sampling equipment, sample collection procedures or collection of a representative specimen from a sample, or statistical interpretation of resultant data and devices designed to dynamically sample process waste streams. It also does not provide sufficient information to statistically design an optimized sampling plan, or determine the number of samples to collect or calculate the optimum number of samples to composite to achieve specified data quality objectives (see Practice D5792 ). Standard procedures for planning waste sampling activities are addressed in Guide D4687 . 1.3 The sample mixing and subsampling procedures described in this guide are considered inappropriate for samples to be analyzed for volatile organic compounds. Volatile organics are typically lost through volatilization during sample collection, handling, shipping, and laboratory sample preparation unless specialized procedures are used. The enhanced mixing described in this guide is expected to cause significant losses of volatile constituents. Specialized procedures should be used for compositing samples for determination of volatiles such as combining directly into methanol (see Guide D4547 ). 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 This guide provides guidance to persons managing or responsible for designing sampling and analytical plans for determining whether sample compositing may assist in more efficiently meeting study objectives. Samples must be composited properly, or useful information on contamination distribution and sample variance may be lost. 5.2 The procedures described for mixing samples and obtaining a representative subsample are broadly applicable to waste sampling where it is desired to transport a reduced amount of material to the laboratory. The mixing and subsampling sections provide guidance to persons preparing sampling and analytical plans and field personnel. 5.3 While this guide generally focuses on solid materials, the attributes and limitations of composite sampling apply equally to static liquid samples.