Overview
EN ISO 15913:2003 (ISO 15913:2000 adopted by CEN) defines an analytical method for determining selected phenoxyalkanoic herbicides (and related compounds such as bentazones and hydroxybenzonitriles) in groundwater and drinking water. The procedure combines solid phase extraction (SPE), derivatization (methylation with diazomethane), and analysis by gas chromatography–mass spectrometry (GC–MS). The method is suitable for low-level quantification - mass concentrations on the order of 50 ng/L (see Annex A for details) - and lists example target compounds (e.g., 2,4‑D, MCPP, MCPA, dichlorprop, bentazone, bromoxynil).
Key Topics and Requirements
- Scope and applicability: Validated for phenoxyalkanoic acids in ground and drinking water; applicability to other compounds or water types must be verified (Annex B).
- Sampling guidance: References ISO 5667 series for sampling, preservation and handling to avoid contamination or loss.
- Enrichment (SPE): Acidify sample and enrich analytes on reversed‑phase adsorbent (commonly RP‑C18 cartridges or glass columns). The standard notes batch-to-batch variability of commercial sorbents and recommends performance checks and consistent use of the same batch.
- Derivatization: Convert acids to methyl esters using diazomethane prior to GC–MS. (WARNING: diazomethane is explosive and highly toxic; strict safety precautions required.)
- Instrumental analysis: Separation and detection by GC–MS with internal standards (preferably deuterated or 13C-labelled). Calibration and blank control are mandatory; the standard addresses interferences and instrument maintenance.
- Quality control: Use of reference solutions (methyl ester and free‑acid standards), internal standards, recovery checks at various concentrations, and interlaboratory trial data (Annex A).
- Supporting material: Annex C on hydrolysis of esterified forms; Annex D includes example mass spectra.
Practical Applications and Users
This standard is designed for:
- Environmental and water quality laboratories performing pesticide and herbicide monitoring
- Regulatory and public‑health authorities assessing drinking water compliance
- Contract analytical labs offering trace-level pesticide analysis in groundwater
- Research groups studying environmental fate of phenoxyalkanoic herbicides
Typical uses include routine monitoring, compliance testing, trend analysis, and validation of remediation efforts.
Related Standards
- ISO 5667‑1, ISO 5667‑2, ISO 5667‑3 - guidance on sampling programmes, sampling techniques and sample preservation
- Adopted as EN ISO 15913:2003 by CEN (European adoption)
Keywords: EN ISO 15913:2003, water quality, phenoxyalkanoic herbicides, SPE, derivatization, diazomethane, GC–MS, drinking water, groundwater, analytical method.