水质.铁-55.使用液体闪烁计数的试验方法

[中文适用范围]： 本文件规定了使用液体闪烁计数（LSC）测定所有类型水样中铁 55 (55Fe) 活度浓度的测试方法。 使用目前可用的液体闪烁计数器，该测试方法可以测量从检测限到120 mBq l-1范围内的55Fe活度浓度。 对于 0.5 l 至 1.5 l 的样品体积，可以通过 7200 s 至 10800 s 的计数时间实现这些值。 较高的活性浓度可以通过稀释样品或使用较小的样品等分试样或同时使用两者来测量。 注：这些性能指标完全取决于各个实验室的测量制度；特别是，检测限受存在的稳定铁含量的影响。 应用范围取决于水中溶解物质的量以及测量设备的性能特征（背景计数率和计数效率）。 实验室有责任确保该测试方法对于测试的水样的适用性。 [外文原描述]： This document specifies a test method for the determination of iron-55 ( 55 Fe) activity concentration in samples of all types of water using liquid scintillation counting (LSC). Using currently available liquid scintillation counters, this test method can measure the 55 Fe activity concentrations in the range from the limit of detection up to 120 mBq l -1 . These values can be achieved with a counting time between 7 200 s and 10 800 s for a sample volume from 0,5 l to 1,5 l. Higher activity concentrations can be measured by either diluting the sample or using smaller sample aliquots or both. NOTE These performance indicators are wholly dependent on the measurement regimes in individual laboratories; in particular, the detection limits are influenced by amount of stable iron present. The range of application depends on the amount of dissolved material in the water and on the performance characteristics of the measurement equipment (background count rate and counting efficiency). It is the laboratory’s responsibility to ensure the suitability of this test method for the water samples tested.