EN ISO 13646:2025 PDF

Overview

EN ISO 13646:2025, developed by CEN and ISO, provides validated methods for the determination of selected estrogens in whole water samples. Utilizing solid-phase extraction (SPE) paired with liquid chromatography (LC) or gas chromatography (GC) coupled to mass spectrometry (MS), this standard enables trace-level analysis of five key estrogens. The methodologies are suitable for drinking water, groundwater, and surface water-including samples with elevated levels of suspended particulate matter (SPM) and dissolved organic carbon (DOC). The standard applies strict quality procedures and calibration recommendations, supporting environmental monitoring and compliance with water quality regulations regarding pharmaceutical residues and endocrine-disrupting compounds.

Key Topics

• Target Analytes: The standard focuses on five selected estrogens: 17alpha-ethinylestradiol (EE2), 17alpha-estradiol, 17beta-estradiol, estriol, and estrone, all of which have significant relevance as endocrine disruptors in aquatic environments.
• Analytical Workflow:
  • Sample Preparation: Water samples, potentially containing up to 500 mg/l SPM and up to 14 mg/l DOC, are spiked with isotopically labeled standards.
  • Solid-Phase Extraction (SPE): Extraction is performed using cartridges or disks, with protocols tailored to matrix complexity and target levels.
  • Detection: Following purification and reconcentration, analytes are separated via LC or GC and quantified using tandem mass spectrometry (MS/MS) or high-resolution mass spectrometry (HRMS).
• Sensitivity and Range: The typical quantification range is as low as 0.006 ng/l for EE2 and 0.038 ng/l for the other estrogens, extending up to tens of ng/l, depending on instrument capability and sample matrix.
• Interference Controls: Stringent protocols minimize contamination and cross-interference from solvents, glassware, and sampling materials, critical for ultra-trace analysis.
• Quality Assurance: Calibration by isotope dilution, comprehensive quality control procedures (blanks, recovery checks), and explicit calculation methods for accuracy, recovery, and measurement uncertainty are specified.

Applications

The EN ISO 13646:2025 standard has clear practical value for a range of stakeholders:

• Environmental Monitoring Authorities: Enables regulatory agencies and laboratories to monitor and report trace estrogen concentrations in waterbodies, supporting the implementation of environmental quality standards (EQS) and compliance with directives addressing pharmaceutical contaminants.
• Water Utilities and Treatment Plants: Assists in tracking contamination in potable and raw water sources, as well as assessing treatment efficiency for estrogenic compounds.
• Research and Academia: Provides a robust protocol for scientific studies of hormone transport, removal, and ecological impacts in the water cycle.
• Method Validation in New Matrices: While focused on natural waters, the procedures can be adapted for other water types (e.g., treated wastewater, industrial effluents) provided appropriate verification of accuracy and stability.
• Traceability and Compliance: Detailed methodological requirements establish traceability and support defensible laboratory results for regulatory reporting and accreditation.

Related Standards

To ensure harmonization and facilitate comprehensive water quality assessment, users should be aware of these associated standards:

• ISO 8466-1: Water quality - Calibration and evaluation of analytical methods - Part 1: Linear calibration function
• ISO 21253-1: Water quality - Multi-compound class methods - Criteria for the identification of target compounds by gas and liquid chromatography and mass spectrometry
• ISO 11352: Water quality - Estimation of measurement uncertainty based on validation and quality control data

Additional sampling, quality assurance, and terminology standards such as ISO 5667-1 and ISO 5667-3 complement EN ISO 13646:2025 for comprehensive procedural coverage.

By implementing EN ISO 13646:2025, laboratories and environmental authorities can reliably quantify estrogenic micropollutants, improving water quality surveillance and helping safeguard aquatic ecosystems and human health. For more information or access to the full standard, consult your national standardization body or visit the CEN or ISO websites.