Overview
EN ISO 6468:1996 specifies a laboratory method for the determination of certain organochlorine insecticides, polychlorinated biphenyls (PCBs) and chlorobenzenes (excluding mono- and dichlorobenzenes) in drinking water, groundwater, surface water and wastewater. The procedure uses liquid–liquid extraction followed by gas chromatography with an electron-capture detector (GC‑ECD). It is applicable to samples containing up to 0.05 g/L suspended solids and is intended for trace-level analysis where contamination control is critical.
Key topics and requirements
- Scope and matrix limits: Applies to various water types; samples should be extracted preferably within 24 hours and stored in the dark at about 4 °C. Endosulfan and heptachlor require special handling due to stability concerns.
- Extraction: Liquid–liquid extraction using non-polar solvents such as hexane, petroleum ether or heptane; sample volumes typically around 1 L.
- Cleanup and concentration: Uses techniques such as alumina/silica gel cleanup, alumina/silver nitrate, and concentration devices (e.g., Kuderna‑Danish evaporator).
- Chromatography: Analysis by GC with ECD; use of capillary columns (different polarities recommended) for compound separation and identification.
- Detection capability: Detection limits depend on compound and matrix; typical reported limits range from about 1 ng/L to 50 ng/L for individual compounds under low‑organic conditions.
- Quality control: Emphasizes blank determinations, solvent and reagent purity, standard stock and intermediate solutions, and evaluation of recoveries. Preventing contamination is critical at low ng/L levels.
- Safety: Method uses flammable/toxic solvents and ECDs that contain radionuclides - follow applicable safety and legal requirements.
Applications and users
This standard is used for:
- Environmental monitoring of pesticides, PCBs and chlorobenzenes in surface and ground waters
- Drinking water compliance testing and risk assessment
- Wastewater investigations and pollution source identification
- Research labs, contract analytical laboratories, water utilities, and regulatory agencies requiring a validated GC‑ECD method for organochlorine contaminants
Related standards
- ISO 5667-1 and ISO 5667-2 (water sampling guidance) - referenced for sampling design and techniques.
- Other ISO/CEN water quality and chemical analysis standards for complementary sampling, preservation and alternate analytical methods.
Keywords: EN ISO 6468:1996, water quality, organochlorine insecticides, PCBs, chlorobenzenes, gas chromatographic method, liquid–liquid extraction, GC‑ECD, environmental monitoring, water testing.