ISO 18073:2004

Overview

ISO 18073:2004 (identical to ISO 18073:2004) is a water quality standard that specifies a method for determination of tetra- to octa‑chlorinated dibenzo‑p‑dioxins (PCDDs) and dibenzofurans (PCDFs) in waters and waste waters (samples containing less than 1% by mass solids). The method uses isotope dilution high‑resolution gas chromatography / high‑resolution mass spectrometry (HRGC/HRMS) and covers the seventeen 2,3,7,8‑substituted PCDD/PCDF congeners. It is a performance‑based method: analysts may adapt procedures to address interferences or reduce costs provided all performance criteria and equivalency requirements are met. The standard also specifies minimum levels (MLs) for interference‑free determination and reports a method detection limit (MDL) for 2,3,7,8‑TCDD of 4.4 pg/L using a 1 L sample.

Key Topics and Requirements

• Analytes and scope: tetra‑ to octa‑chlorinated PCDDs/PCDFs; 17 congeners of regulatory interest.
• Analytical principle: isotope dilution HRGC/HRMS for robust identification and quantification.
• Sample types: surface water, effluent and waste water with <1% suspended solids.
• Sample preparation: spiking with labeled standards, extraction (including Soxhlet for filters), filtration and concentration steps.
• Extract clean‑up: gel‑permeation chromatography (GPC), silica, alumina, carbon and florisil options to remove matrix interferences.
• Calibration and quantification: isotope dilution calibration, internal standards, and combined calibration approaches.
• Quality assurance / quality control (QA/QC): initial precision and recovery (IPR), method blanks, QC check samples, control limits, and performance criteria for method equivalency.
• Performance metrics: specified minimum levels (MLs) and instrument/system performance (MS and GC resolution, ion ratios, retention time requirements).
• Reporting: concentration calculations, internal standard recoveries, and calculation of toxicity equivalents (TEQs).
• Safety: strong warnings on handling highly toxic 2,3,7,8‑substituted congeners and adherence to laboratory safety protocols.

Practical Applications and Users

This standard is intended for:

• Environmental and commercial analytical laboratories performing dioxin and furan monitoring in water and wastewater.
• Regulatory agencies and compliance laboratories assessing discharges, environmental surveillance and enforcement.
• Water utilities, industrial facilities, environmental consultants, and research institutions conducting high‑sensitivity contaminant analysis. Use cases include effluent compliance testing, environmental impact assessments, and monitoring of remediation effectiveness where PCDD/PCDF contamination is a concern.

Related Standards

• ISO 3696 - Water for analytical laboratory use
• ISO 5667‑1 / ISO 5667‑2 - Water quality sampling guidance
• ISO 6879 - Performance characteristics for measurement methods

Keywords: ISO 18073:2004, water quality, dioxins, furans, PCDDs, PCDFs, isotope dilution, HRGC/HRMS, method detection limit, minimum levels, performance‑based method.