ISO 13163 specifies the determination of lead-210 (Pb) activity concentration in samples of all types of water using liquid scintillation counting (LSC). For raw and drinking water, the sample should be degassed in order to minimize the ingrowth of Pb from radon-222 (Rn).
ISO 13163:2013 Referenced Document
ISO 11929 Determination of the characteristic limits (decision threshold, detection limit and limits of the confidence interval) for measurements of ionizing radiation - Fundamentals and application
ISO/IEC 17025 General requirements for the competence of testing and calibration laboratories [Standard in French]*, 2017-11-01 Update
ISO/IEC Guide 98-3 Uncertainty of measurement - Guide to the expression of uncertainty in measurement (GUM:1995). Extension to any number of output quantities