Overview
ISO 5667-23:2011 - Water quality - Sampling - Part 23: Guidance on passive sampling in surface waters - provides standardized guidance for using passive sampling to determine time‑weighted average and equilibrium concentrations of the free dissolved fraction of organic, organometallic and inorganic substances (including metals) in surface waters. The standard explains principles, device types and modes (integrative/kinetic and equilibrium), and the full sampling-to-analysis workflow: deployment, retrieval, extraction and calculation of concentrations.
Keywords: ISO 5667-23, passive sampling, surface waters, water quality, time-weighted average, equilibrium concentrations, passive sampling devices, free dissolved fraction, metals, organic compounds, sampling protocols.
Key topics and technical requirements
ISO 5667-23 covers practical and technical aspects needed for reliable passive sampling and includes:
- Principle and modes of operation: differences between equilibrium and integrative (kinetic) sampling; membrane-controlled vs water boundary layer control.
- Passive sampling device characteristics: receiving phase, membranes, polymers and sorbents; device types summarized in Annex A.
- Device handling and preparation: assembly, storage and pre-deployment preparation to avoid contamination.
- Field deployment procedures: selection of sites, safety precautions, transport, deployment and retrieval protocols (including recommended materials - Annex B).
- Deployment time estimation: guidance on selecting appropriate exposure durations to capture time‑weighted averages or equilibrium concentrations.
- Quality assurance and quality control: replicate devices, field controls, reagent blanks, recovery spikes, analytical recovery standards and performance reference compounds (PRCs) where applicable; Annex C provides QC measures.
- Extraction and laboratory analysis: extraction of analytes from the receiving phase and preparation for instrumental analysis.
- Calculations and reporting: converting accumulated mass to concentrations (time‑weighted or equilibrium) and minimum contents of the test report.
The standard emphasizes that passive samplers measure the free dissolved (and for some metal samplers, small molecular mass bound) fractions - not necessarily the same fractions obtained by a grab (bottle) sample.
Practical applications and users
ISO 5667-23 is intended for organizations involved in aquatic chemical monitoring, including:
- Environmental regulators and compliance monitoring programs
- Water utilities and catchment managers
- Environmental consultancies and field sampling teams
- Accredited testing laboratories performing passive sampler analysis
- Academic and applied researchers studying contaminant dynamics (pesticides, pharmaceuticals, PAHs, PCBs, metals)
Use cases: long‑term monitoring of fluctuating pollutant concentrations, source identification, screening for trace organic and inorganic contaminants, support for risk assessment and trend analysis.
Related standards
ISO 5667-23 is part of the ISO 5667 series on water sampling. Relevant related documents include:
For implementers, following ISO 5667-23 alongside these related parts ensures consistent, defensible passive sampling and water-quality data.