1.1 本指南涵盖了通过放射化学分离和α光谱法测定土壤中的镎-237。本指南提供了选择样品制备、分离和测量的选项。尽管镎-237不是全球沉降物的组成部分，但它是生产反应堆和乏燃料处理的产物。本指南旨在分析之前根据实践收集和处理的10克土壤 C998 和 C999 . 只要铀和钍等干扰物的浓度等于或接近环境浓度，也可以分析较大尺寸的环境土壤样品。 根据样品溶解方法的选择，所有化学形式的镎可能都不能完全溶解。本指南应允许根据计数时间、样本量、检测器效率、背景和示踪剂产量，从每克亚贝克勒尔水平到适用标准测定镎-237浓度。 1.2 以国际单位制表示的数值应视为标准值。本标准不包括其他计量单位。 1.3 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和健康实践，并确定监管限制的适用性。 第节给出了具体的预防说明 9 . 1.4 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 土壤采样和分析程序提供了确定土壤中放射性核素浓度和分布的直接方法。镎-237的存在和范围特别令人感兴趣，因为它是迁移和植物吸收方面更具流动性的超铀物质之一。 由于土壤是长寿命放射性核素的集成商和蓄水池，并在对人类具有潜在重要性的几种途径中起中介作用，因此了解土壤中镎-237的浓度至关重要。

1.1 This guide covers the determination of neptunium-237 in soil by means of radiochemical separations and alpha spectrometry. This guide provides options in the selection of sample preparation, separation, and measurement. Although neptunium-237 is not a component of global fallout, it is a product of production reactors and spent fuel processing. This guide is designed for analysis of ten grams of soil previously collected and treated in accordance with Practices C998 and C999 . Larger-size samples of environmental soil may also be analyzed, as long as the concentrations of interferences such as uranium and thorium are at or near environmental concentrations. Depending on the choice of a sample dissolution method, all chemical forms of neptunium may not be completely solubilized. This guide should allow the determination of neptunium-237 concentrations from sub becquerel per gram levels to applicable standards depending on count time, sample size, detector efficiency, background, and tracer yield. 1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.3 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 and health practices and determine the applicability of regulatory limitations prior to use. Specific precautionary statements are given in Section 9 . 1.4 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 A soil sampling and analysis program provides a direct means of determining the concentration and distribution of radionuclides in soil. The presence and extent of neptunium-237 is of particular interest because it is one of the more mobile transuranics in terms of migration and plant uptake. Since soil is an integrator and a reservoir on long-lived radionuclides, and serves as an intermediary in several pathways of potential importance to humans, knowledge of the concentration of neptunium-237 in soil is essential.