ISO 27108:2010

Overview

ISO 27108:2010 specifies a laboratory method to determine selected plant treatment agents and biocide products in drinking water, ground water and surface water. The procedure uses solid‑phase microextraction (SPME) for sample enrichment followed by gas chromatography‑mass spectrometry (GC‑MS) (electron‑impact ionisation). For most target compounds covered by the standard the limit of determination is at least 0.05 µg/L, and validation data from an interlaboratory trial cover the 0.05–0.3 µg/L range. The method is designed for small sample volumes (typically 8–16 mL) and requires verification if applied to other compounds or different water matrices.

Key topics and technical requirements

• Principle: Adsorption of dissolved analytes onto an SPME fused‑silica fibre with a coated adsorbent polymer; thermal desorption into the GC injector; separation by capillary GC and detection by MS.
• Analytical performance: Limit of determination dependent on matrix, compound and MS sensitivity; validated low‑µg/L performance for many pesticides/biocides.
• Sample handling: Follow recommended sampling and preservation practices; small sample volumes are used and consistent salt addition (near saturation) can improve extraction yield for many analytes.
• SPME operation:
  • Precondition new fibres and monitor fibre sensitivity during a sequence (reference solution measurements).
  • Keep extraction time and temperature constant (example: 60 min and ~30 °C).
  • Minimise salt encrustation on SPME needle and injector.
  • Automated samplers with an SPME option are recommended for reproducibility.
• Reagents & standards: Use high‑purity solvents (e.g. ethyl acetate, acetone, acetonitrile), internal standards (preferably deuterated or 13C‑labelled analogues such as atrazine‑d), and lab water meeting ISO 3696.
• Interferences & QC: Fibre batch variability, matrix effects and GC/MS system stability must be monitored; use blanks, calibration and quality controls.

Applications and users

• Environmental laboratories performing trace analysis of pesticides, herbicides and biocides in surface, ground and drinking waters.
• Regulatory monitoring programs for water quality and contaminant surveillance.
• Research groups studying pesticide fate and transport or evaluating treatment efficacy.
• Useful where rapid, solvent‑saving enrichment (SPME) and sensitive GC‑MS detection are required.

Related standards

• ISO 3696 - Water for analytical laboratory use
• ISO 5667-1 - Sampling: programme design and techniques
• ISO 5667-3 - Sampling: preservation and handling

Keywords: ISO 27108, water quality, SPME, GC‑MS, pesticide analysis, biocide detection, drinking water monitoring, limit of determination, method validation.