1.1 本指南涵盖了从取样点到实验室接收地下水样品的现场保存方法。本指南未描述实验室保存方法。本标准未涉及吹扫和取样技术，但在指南中进行了说明 D6564/D6564米 ， D6634/D6634米 ， D7929 ，和实践 D6771 。 1.2 由于样品采集过程中暴露在环境条件下，地下水样品相对于地表原位条件会发生化学、物理和生物变化。样品的物理和化学保存最大限度地减少了从取回地下水样品到将其从样品容器中取出进行提取或分析时可能发生的样品化学性质的进一步变化。 1.3 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。 1.4 本指南提供了有组织的信息收集或一系列选项，不建议采取具体行动。本文件不能取代教育或经验，应与专业判断结合使用。并非本指南的所有方面都适用于所有情况。本ASTM标准并不代表或取代必须判断特定专业服务是否充分的护理标准，也不应在不考虑项目许多独特方面的情况下应用本文件。本文件标题中的“标准”一词仅表示该文件已通过ASTM共识程序批准。 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。 1.6 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====== 4.1 地下水样品相对于年会发生化学、物理和生物变化- 样品采集过程中暴露于环境条件（例如压力、温度、紫外线辐射、大气氧气和污染物）导致的地面原位条件 ( 1. )( 2. ) 。 6. 样品的物理和化学保存最大限度地减少了从取回地下水样品到将其从样品容器中取出进行提取或分析，或两者兼而有之的样品化学性质的进一步变化。还应采取措施保护样品容器的物理完整性。 4.2 特定分析物的样品保存需求应在采样事件之前确定，并根据指南记录在特定地点的采样和分析计划中 D5903 保存样品的决定应根据个别分析方法定义的特定参数做出。 4.3 本指南包括美国政府文件中的示例。当工作在其他国家或地区时，应咨询当地管理或监管机构。 注1: 本标准产生的结果的质量取决于执行该标准的人员的能力以及所用设备和设施的适用性。符合实践标准的机构 D3740 通常被认为能够胜任和客观的测试/取样/检查等。本标准的使用者应注意遵守实践 D3740 其本身不能保证可靠的结果。可靠的结果取决于许多因素；实践 D3740 提供了评估其中一些因素的方法。

1.1 This guide covers methods for field preservation of ground water samples from the point of sampling through receipt at the laboratory. Laboratory preservation methods are not described in this guide. Purging and sampling techniques are not addressed in this standard but are addressed in Guides D6564/D6564M , D6634/D6634M , D7929 , and Practice D6771 . 1.2 Ground water samples are subject to chemical, physical, and biological change relative to in situ conditions at the ground surfaces due to exposure to ambient conditions during sample collection. Physical and chemical preservation of samples minimize further changes in sample chemistry that can occur from the moment the ground water sample is retrieved, to the time it is removed from the sample container for extraction or analysis. 1.3 Units— 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 offers an organized collection of information or a series of options and does not recommend a specific course of action. This document cannot replace education or experience and should be used in conjunction with professional judgment. Not all aspects of this guide may be applicable in all circumstances. This ASTM standard is not intended to represent or replace the standard of care by which the adequacy of a given professional service must be judged, nor should this document be applied without consideration of a project's many unique aspects. The word“ Standard” in the title of this document means only that the document has been approved through the ASTM consensus process. 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 ====== 4.1 Ground water samples are subject to chemical, physical, and biological change relative to in- situ conditions at the ground surfaces as a result of exposure to ambient conditions during sample collection (for example, pressure, temperature, ultraviolet radiation, atmospheric oxygen, and contaminants) ( 1 ) ( 2 ) . 6 Physical and chemical preservation of samples minimize further changes in sample chemistry that can occur from the moment the ground water sample is retrieved, to the time it is removed from the sample container for extraction or analysis, or both. Measures also should be taken to preserve the physical integrity of the sample container. 4.2 The need for sample preservation for specific analytes should be defined prior to the sampling event and documented in the site-specific sampling and analysis plan in accordance with Guide D5903 . The decision to preserve a sample should be made on a parameter-specific basis as defined by individual analytical methods. 4.3 This guide includes examples from government documents in the United States. When work is in other countries or regions, the local governing or regulating agencies should be consulted. Note 1: The quality of the result produced by this standard is dependent on the competence of the personnel performing it, and the suitability of the equipment and facilities used. Agencies that meet the criteria of Practice D3740 are generally considered capable of competent and objective testing/sampling/inspection/etc. Users of this standard are cautioned that compliance with Practice D3740 does not in itself assure reliable results. Reliable results depend on many factors; Practice D3740 provides a means of evaluating some of those factors.