ISO 22478:2006

Overview

ISO 22478:2006 specifies a validated laboratory method for the determination of certain explosives and related compounds in drinking water, groundwater and surface water. The method uses solid-phase extraction (SPE) followed by high-performance liquid chromatography (HPLC) with UV photodiode array (PDA) detection to identify and quantify nitrotoluenes, nitroamines, nitrate esters and related by‑products and degradation products (e.g., TNT, RDX, HMX, PETN).

Key topics and technical requirements

• Principle: Concentration of analytes by SPE on a polystyrene/divinylbenzene adsorbent, solvent elution, concentration of eluate and separation by HPLC with UV-PDA detection.
• Target analytes: Nitroaromatics, nitramines, nitrate esters and selected related compounds (see Table 1 of the standard).
• Working range / sensitivity:
  • Nitroaromatics and nitramines: lower limits typically 0.1–0.5 µg/L (in some cases down to 0.05 µg/L).
  • Nitrate esters: typically ≥ 0.5 µg/L.
• Sampling and storage: Use brown glass bottles, protect samples from light, store at ≤ 4 °C and extract preferably within three days.
• SPE and conditioning: Example practice - use ≥ 0.2 g polystyrene/divinylbenzene adsorbent per 1 L sample; condition cartridges with methanol, acetonitrile then water.
• Reagents and apparatus: Grade‑1 water, HPLC‑grade methanol and acetonitrile, NaCl, phosphate buffer (pH ~3.2), and an HPLC system with PDA detector (typical wavelength range 200–400 nm).
• Interferences & precautions:
  • Light-sensitive compounds (e.g., tetryl) can degrade - protect extracts from light.
  • Humic substances and co-eluting compounds may cause peak overlap; verify peak purity and UV spectra.
  • Mononitrotoluenes may be lost during evaporation - evaluate recoveries.

Applications and users

ISO 22478 is intended for:

• Environmental testing laboratories monitoring contamination near munitions sites.
• Water utilities and regulators assessing drinking-water safety where explosives contamination is suspected.
• Remediation and site‑assessment consultants performing groundwater and surface-water screening.
• Forensic and defense-related analytical labs requiring standardized HPLC/UV methods for explosive residues.

Practical benefits include reproducible quantification of common explosive residues in aqueous matrices and guidance on sampling, SPE conditioning, chromatographic separation and quality control.

Related standards

• ISO 3696 - Water for analytical laboratory use (grade 1)
• ISO 5667-1, -2, -3 - Water quality - Sampling guidance on programme design, techniques and preservation

Keywords: ISO 22478, water quality, explosives determination, HPLC UV detection, nitrotoluenes, nitroamines, nitrate esters, solid-phase extraction, groundwater monitoring.