Overview
ISO 24293:2009 specifies a validated analytical method for the determination of individual isomers of nonylphenol in non-filtered water samples using solid phase extraction (SPE) followed by gas chromatography/mass spectrometry (GC/MS). The standard covers drinking water, ground water, surface water and waste water and defines practical concentration ranges: 0.001–0.1 µg/L for individual isomers, 0.01–0.2 µg/L for the sum of 4‑nonylphenol isomers, and, depending on matrix, 0.1–50 µg/L for some waste water samples.
Key topics and requirements
- Target analytes: Thirteen 4‑nonylphenol isomers (eleven identified and two tentatively identified) that make up the majority of environmentally relevant isomers.
- Sampling & preservation: Non-filtered sampling per ISO 5667‑1; acidify to about pH 3.5 and quench residual chlorine (e.g., sodium thiosulfate) to avoid analyte degradation.
- SPE extraction: Conditioning and extraction using styrene‑divinylbenzene polymer SPE cartridges (typical packing ≥200 mg); extraction flow rates and procedures for high‑suspended‑solids samples are specified.
- Clean‑up & concentration: Solvent elution, drying (nitrogen), and concentration steps prior to GC/MS analysis.
- GC/MS analysis: Temperature‑programmed capillary GC coupled with MS, with quantification based on selected ions; operating conditions and suitable columns are described in informative annexes.
- Standards & calibration: Use of internal standard (example: 4‑n‑nonylphenol solution, 1 ng/µL) and calibration over the total procedure; procedures for blank determination, response factor calculation and recovery checks are provided.
- Documentation: Calculation methods, expression of results, performance data, and test report requirements (including limits of quantification and method performance) are included.
Applications and users
ISO 24293:2009 is intended for:
- Environmental and public‑health laboratories performing water quality monitoring for endocrine‑disrupting compounds.
- Regulatory bodies assessing compliance and contamination of drinking water, surface water, groundwater and waste water.
- Wastewater treatment operators, environmental consultants and research labs conducting source apportionment, trend monitoring or risk assessments for nonylphenol isomers.
Practical benefits include isomer‑specific detection (important for toxicity profiling), low detection limits suitable for regulatory monitoring, and a reproducible SPE–GC/MS workflow.
Related standards
- ISO 3696 - Water for analytical laboratory use
- ISO 5667‑1 - Water sampling guidance
- ISO 8466‑1 - Calibration and evaluation of analytical methods
Keywords: ISO 24293:2009, nonylphenol, 4-nonylphenol, SPE, GC/MS, water quality, isomers, environmental monitoring, drinking water, waste water.
