Overview
ISO 22032:2006 specifies a laboratory method for the determination of selected polybrominated diphenyl ethers (PBDEs) in sediment and sewage sludge using extraction followed by gas chromatography/mass spectrometry (GC‑MS). The standard covers sample pre‑treatment (freeze‑drying, grinding), extraction (Soxhlet or comparable methods), clean‑up, and instrumental analysis using GC‑MS in either electron impact (EI) or negative ion chemical ionization (NCI) modes. It lists target congeners (including BDE‑47, BDE‑99, BDE‑100, BDE‑153, BDE‑154, BDE‑181, BDE‑183 and BDE‑209) and gives applicable quantitative ranges for GC‑EI‑MS and improved sensitivity for GC‑NCI‑MS.
Key topics and technical requirements
- Target analytes: Selected PBDE congeners (tetra‑ to decabromo diphenyl ethers); Table of congeners provided.
- Detection modes: GC‑MS using EI (higher specificity) or NCI (≈10× greater sensitivity for low levels).
- Quantification ranges: For GC‑EI‑MS, approx. 0.05–25 µg/kg for tetra‑ to octabromo congeners and 0.3–100 µg/kg for BDE‑209; lower limits achievable with NCI.
- Sample preparation: Homogenization, freeze‑drying, grinding and sieving; addition of internal standards prior to extraction.
- Extraction and clean‑up: Soxhlet extraction (typically 16 h) or validated alternative extraction techniques; multi‑layer silica gel chromatographic clean‑up (Annex A examples).
- Calibration and QA: Internal standard calibration over the full procedure, injection standards for recovery checks, blank controls to monitor contamination.
- Interferences & contamination control: Potential co‑eluting compounds (e.g., brominated biphenyls, tetrabromobisphenol A) and environmental/batch contamination from flame‑retardant polymers; avoid contact with polymeric materials and airborne dust.
- Instrumentation & materials: Low‑bleed non‑polar fused‑silica GC columns, high‑purity operating gases, amber vials, baked sand and solvent choices (toluene, acetone/hexane mixtures, dichloromethane).
Applications and users
ISO 22032:2006 is used by:
- Environmental and analytical laboratories monitoring PBDE contamination in sediments and sewage sludge
- Regulatory agencies and compliance testing programs assessing environmental quality or waste management limits
- Research institutions studying fate, transport and bioaccumulation of flame retardant PBDEs
- Consultants performing site investigations and baseline contaminant surveys
Typical applications include routine monitoring, trend analysis, impact assessments around wastewater treatment works, and supporting regulatory enforcement.
Related standards
- ISO 5667‑13 - Guidance on sampling of sludges from sewage and water‑treatment works (sampling best practice referenced by ISO 22032).
- ISO 8466‑1 - Calibration and evaluation of analytical methods (statistical evaluation of calibration used for quantitation).
Keywords: ISO 22032:2006, PBDE, BDE‑209, GC‑MS, electron impact (EI), negative ion chemical ionization (NCI), sediment analysis, sewage sludge, Soxhlet extraction, analytical method.