ISO 19361:2017

Overview

ISO 19361:2017 - Measurement of radioactivity: Determination of beta emitters activities - Test method using liquid scintillation counting (LSC) is a generic international standard that defines requirements and procedures for measuring beta-emitting radionuclides using liquid scintillation counting. It covers preparation of a scintillation source by mixing the test sample with a scintillation cocktail and specifies metrological controls needed to produce reliable, comparable activity concentrations across laboratories.

Key SEO keywords: ISO 19361:2017, liquid scintillation counting, beta emitters, measurement of radioactivity, scintillation cocktail, activity concentration.

Key Topics and Requirements

• Scope and sample types
  • Applies to liquid (aqueous or organic) and solid samples (particles, filters, planchets) prepared as a scintillation source.
  • Measurement range typically spans from a few Bq·L−1 up to 10^6 Bq·L−1, depending on sample preparation and instrumentation.
• Instrumentation and reagents
  • Requirements for liquid scintillation counters, counting vials, scintillation cocktails and calibration source solutions.
• Metrological controls
  • Determination of background, detection efficiency, quench correction, and calibration procedures.
  • Guidance on counting conditions, control of interferences and calibration checks.
• Sample preparation limits
  • Generic LSC procedures are provided; specific pre-treatments (e.g., distillation for 3H or benzene synthesis for 14C) are outside the scope and described in dedicated test methods.
• Data treatment and reporting
  • Calculation of activity concentration, decision threshold, detection limit, confidence intervals and expression of results.
• Annexes
  • Informative guidance on internal standard method, TDCR (triple-to-double coincidence ratio) LSC, and Cerenkov measurement options.

Practical Applications

• Environmental monitoring of water, air and soil for beta-emitting radionuclides.
• Monitoring of effluents and discharges from nuclear facilities, industry and NORM operations.
• Laboratory screening and quantification of beta activity in food, biological and waste samples.
• Regulatory compliance, accreditation, interlaboratory comparisons and proficiency testing.

Who Would Use This Standard

• Radioanalytical laboratories (environmental, clinical, research).
• Regulatory and public health agencies performing radionuclide monitoring.
• Nuclear industry and waste management organizations.
• Accreditation bodies and laboratory quality managers.

Related Standards

• Specific ISO/technical methods for sample-specific pretreatments (e.g., 3H and 14C preparation) and other ISO standards on radioactivity measurement. Annexes in ISO 19361 reference TDCR and Cerenkov LSC techniques for advanced measurement options.

ISO 19361:2017 provides a robust, traceable framework for LSC-based beta emitter measurements, ensuring reproducible activity concentrations and sound uncertainty evaluation for routine and compliance testing.