1.1 本指南旨在作为希望执行的实验室的参考 99 土壤中的Tc分析。对于示踪剂的选择和从土壤基质中提取Tc的方法，给出了几个选项。使用提取色谱树脂从样品基质中分离Tc。然后给出了确定 99 原始样品中的Tc活性。由用户决定哪些选项适合使用，并生成验收数据以支持所选程序。 1.2 由于可用的各种提取方法、使用的各种示踪剂、使用的可变检测方法以及缺乏经认证的参考材料 99 Tc在土壤中，没有足够的数据来支持作为标准方法编写的单一方法。 1.3 以国际单位制表示的数值应视为标准，除非非国际单位制的摩尔单位， M ，用于化学品和试剂的浓缩。国际单位制后括号中给出的值仅供参考，不被视为标准值。 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 本指南提供了几个选项，用于确定 99 土壤样品中的Tc。根据从土壤基质中提取Tc的方法，样品大小可能高达200 g。由用户决定是否适合最终数据的预期用途。

1.1 This guide is intended to serve as a reference for laboratories wishing to perform 99 Tc analyses in soil. Several options are given for selection of a tracer and for the method of extracting the Tc from the soil matrix. Separation of Tc from the sample matrix is performed using an extraction chromatography resin. Options are then given for the determination of the 99 Tc activity in the original sample. It is up to the user to determine which options are appropriate for use, and to generate acceptance data to support the chosen procedure. 1.2 Due to the various extraction methods available, various tracers used, variable detection methods used, and lack of certified reference materials for 99 Tc in soil, there is insufficient data to support a single method written as a standard method. 1.3 The values stated in SI units are to be regarded as standard, except where the non-SI unit of molar, M , is used for the concentration of chemicals and reagents. The values given in parentheses after SI units are provided for information only and are not considered 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 This guide offers several options for the determination of 99 Tc in soil samples. Sample sizes of up to 200 g are possible, depending on the method chosen to extract Tc from the soil matrix. It is up to the user to determine if it is appropriate for the intended use of the final data.