EN ISO 21253-1:2019 PDF

Overview

EN ISO 21253-1:2019 - Water quality: Multi-compound class methods (Part 1) defines the criteria for identifying target compounds in water and environmental samples using gas chromatography (GC) and liquid chromatography (LC) coupled with mass spectrometry (MS). Published by CEN/ISO, this standard sets out a harmonized approach for confirming the presence, indicating, or reporting absence of compounds when used together with compound‑specific analytical methods.

Key topics and requirements

• Scope and intent: Applies to environmental and water-quality analyses; intended to be used alongside specific analytical standards (where those exist, their identification criteria take precedence).
• Three-step identification procedure:
  • Chromatographic separation - use of retention time and relative retention time referenced to a retention-time standard.
  • Mass spectrometric evaluation - selection and measurement of diagnostic ions, use of acquisition modes (e.g., full scan, SIM, MRM/SRM) and high-resolution MS (HRMS) where applicable.
  • Additional confirmation - orthogonal evidence or supplementary analyses when required to meet identification criteria.
• Identification points and diagnostic ions: The standard details how to select diagnostic ions and how MS results contribute identification points toward a confident identification.
• Reporting rules: Defines how to report a compound as identified, indicated, or **absent (