本文件规定了使用液体闪烁计数（LSC）或比例计数（PC）测定环境水样中90Sr和89Sr放射性浓度的条件。 本方法适用于饮用水、雨水、地表水和地下水、海水以及冷却水、工业用水、生活污水和工业废水经适当取样和处理，并制备试样后的试样。需要对试样进行过滤和化学分离，以从试样的试验部分分离和纯化锶。 检测限取决于样品体积、使用的仪器、样品计数时间、背景计数率、检测效率和化学产率。本文件中描述的方法使用当前可用的LSC计数器，检测限约为10 mBq l−1和2MBq l−89Sr和90Sr分别为1，低于世卫组织安全饮用水标准（100 Bq·l）−89Sr和10Bq·l各1个−1代表90Sr）[3]。 对于2L的样品体积，这些值可以通过1000分钟的计数时间实现。 本文件中描述的方法适用于紧急情况。当核事故后发生沉降物时，89Sr对放射性锶总量的贡献不容忽视。本文件提供了测定89Sr存在时90Sr活性浓度的试验方法。 该方法不包括90Sr和89Sr吸附在悬浮物上的分析。 用户有责任确保所选水样试验方法的有效性。

This document specifies conditions for the determination of 90Sr and 89Sr activity concentration in samples of environmental water using liquid scintillation counting (LSC) or proportional counting (PC). The method is applicable to test samples of drinking water, rainwater, surface and ground water, marine water, as well as cooling water, industrial water, domestic, and industrial wastewater after proper sampling and handling, and test sample preparation. Filtration of the test sample and a chemical separation are required to separate and purify strontium from a test portion of the sample. The detection limit depends on the sample volume, the instrument used, the sample count time, the background count rate, the detection efficiency and the chemical yield. The method described in this document, using currently available LSC counters, has a detection limit of approximately 10 mBq l−1 and 2 mBq l−1 for 89Sr and 90Sr, respectively, which is lower than the WHO criteria for safe consumption of drinking water (100 Bq·l−1 for 89Sr and 10 Bq·l−1 for 90Sr)[3]. These values can be achieved with a counting time of 1 000 min for a sample volume of 2 l. The methods described in this document are applicable in the event of an emergency situation. When fallout occurs following a nuclear accident, the contribution of 89Sr to the total amount of radioactive strontium is not negligible. This document provides test methods to determine the activity concentration of 90Sr in presence of 89Sr. The analysis of 90Sr and 89Sr adsorbed to suspended matter is not covered by this method. It is the user’s responsibility to ensure the validity of this test method selected for the water samples tested.