1.1 使用化学类似物铼作为示踪剂，通过萃取色谱法从水样中分离和浓缩锝。通过电感耦合等离子体质谱（ICP-MS）测量锝与铼的比率，然后量化 99 Tc浓度。 1.1.1 本规程作为试验方法的替代方法提供 D7168 它提供了不同的分离介质几何形状和液体闪烁光谱测量。该方法应能达到类似的检测限。 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。 ====意义和用途====== 5.1 锝-99是由铀和钚裂变产生的，并通过核武器试验和核材料加工释放到环境中。 在氧化环境中，它以极易移动的高技术离子TcO的形式存在 4. – ，它是硝酸盐的类似物，可以被生物体吸收。监测 99 核处理设施周围水域中的Tc是完整环境监测计划的一部分。 5.2 锝-99是一种长寿命（半衰期2.1E+5年）、弱β（最大β能量293kev）发射放射性同位素。Tc没有稳定同位素。因此，其活性浓度的测定对传统的放射化学测定方法提出了独特的挑战。 该方法为方法的加标/非加标复制方法提供了一种替代方法 D7168 并使用指南中提供的选项 C1387 用于确定 99 土壤中的Tc。

1.1 Technetium is separated and concentrated from a water sample by extraction chromatography using its chemical analog, rhenium, as a tracer. The ratio of technetium to rhenium is measured by inductively coupled plasma mass spectrometry (ICP-MS) to then quantify the 99 Tc concentration. 1.1.1 This practice is provided as an alternative to Test Method D7168 which provides for a different separation media geometry and measurement by liquid scintillation spectrometry. Similar detection limits should be attainable by this method. 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. ====== Significance And Use ====== 5.1 Technetium-99 is produced by the fission of uranium and plutonium, and has been released to the environment via nuclear weapons testing and nuclear materials processing. In an oxidizing environment, it exists as the very mobile pertechnetate ion, TcO 4 – , which is an analog to nitrate and can be taken up by living organisms. Monitoring of 99 Tc in waters around nuclear processing facilities is part of a complete environmental monitoring program. 5.2 Technetium-99 is a long-lived (half-life 2.1E+5years), weak beta (maximum beta energy of 293 keV) emitting radioisotope. There are no stable isotopes of Tc. Thus the determination of its activity concentration presents unique challenges to traditional radiochemical determination methods. This method provides an alternative to the spiked/unspiked replicate method of Method D7168 and uses options presented in Guide C1387 for the determination of 99 Tc in soil.