Overview
EN ISO 10695:2000 / ISO 10695:2000 defines gas chromatographic methods for the determination of selected organic nitrogen and phosphorus compounds in water. It specifies two validated extraction approaches (liquid/liquid and liquid/solid) and describes chromatographic analysis using capillary columns and a nitrogen–phosphorus (N–P) detector. The standard addresses sample handling, reagents, calibration, identification, calculation, and reporting, and includes informative annexes with detection limits, example chromatograms and precision data.
Key topics and technical requirements
- Two extraction methods
- Liquid/liquid extraction (dichloromethane) - suitable for drinking, ground, surface and wastewater (applicable when suspended solids ≤ 0.05 g/L).
- Liquid/solid extraction - suitable for very low analyte concentrations (order of 0.05 μg/L) in ground, surface and drinking waters; used where higher preconcentration is needed.
- Chromatography and detection
- Capillary GC with at least two columns of different polarity recommended; N–P detector is primary. Mass spectrometry may be used for confirmation.
- Reagents and standards
- High-purity solvents (e.g., dichloromethane, acetone), prepared stock/intermediate/working standards, procedures for solvent quality checks and storage conditions.
- Calibration and QA
- External and internal standard calibration procedures, blank controls, and analytical quality control guidance (referencing ISO/TR 13530).
- Sampling and sample stability
- Sampling per ISO 5667 series; protect samples from light, use glass containers, and limit extraction delay (phosphorus: within ~1 day; nitrogen: within ~2 days).
- Safety and contamination control
- Use of flammable/toxic solvents and potentially toxic analytes - follow laboratory safety regulations and strict contamination-prevention practices.
- Analytes and auxiliary information
- Table of example analytes includes atrazine, simazine, cyanazine, parathion (ethyl/methyl), trifluralin, vinclozolin, terbuthylazine, etc. Annexes provide detection limits, chromatogram examples and MS ions.
Applications and practical value
- Environmental monitoring of rivers, lakes and groundwaters for pesticides and organophosphorus/nitrogen compounds.
- Drinking water quality testing and regulatory compliance assessments.
- Wastewater and effluent surveillance where low-level organic nutrient contaminants must be quantified.
- Method transfer and validation in accredited analytical laboratories performing GC-based trace analysis.
Who should use this standard
- Environmental and water testing laboratories
- Regulatory agencies and public health authorities
- Manufacturers of analytical instrumentation and consumables
- Laboratories seeking ISO-consistent procedures for trace organic N/P compound analysis
Related standards
Keywords: water quality, organic nitrogen, organic phosphorus, gas chromatography, EN ISO 10695, liquid/liquid extraction, liquid/solid extraction, nitrogen-phosphorus detector, pesticide analysis, environmental monitoring.
