Overview - SIST ISO 16308:2018 (Water quality - Glyphosate and AMPA by HPLC–MS/MS)
SIST ISO 16308:2018 specifies a validated analytical method for the determination of dissolved glyphosate and its main metabolite, aminomethylphosphonic acid (AMPA), in drinking water, groundwater and surface water. The standard describes an HPLC method coupled with tandem mass spectrometric detection (HPLC–ESI–MS/MS) with a practical working range of 0.03 µg/L to 1.5 µg/L (limits of quantification around 30 ng/L). It is not applicable to marine or salty water unless separately validated.
Key topics and technical requirements
- Analytes addressed: glyphosate (N‑(phosphonomethyl)glycine) and AMPA; gluphosinate can be included if no matrix interference.
- Analytical principle: pre‑column derivatization with 9‑fluorenylmethyl chloroformate (FMOC‑Cl) to reduce polarity and improve chromatographic retention and MS detection; analysis by HPLC coupled to triple‑quadrupole MS with electrospray ionization (ESI–MS/MS).
- Sample preparation: filtration for dissolved fraction, optional liquid–liquid extraction and solid‑phase extraction (SPE) for pre‑concentration; direct injection is permitted if instrument sensitivity allows.
- Calibration and quantification: matrix‑matched calibration and the use of isotopically labelled internal (surrogate) standards (13C,15N labelled glyphosate and AMPA) are specified to correct matrix effects.
- Interferences & matrix effects: treatment of hard water (Ca/Mg) may require increased EDTA or acidification (Annex D). Free chlorine can oxidize analytes-sodium thiosulfate is required for dechlorination.
- Quality control: blank monitoring, identification/confirmation criteria using MS/MS transitions, and performance data (Annex A) are included.
- Instrumentation and reagents: guidance on HPLC columns (alkali‑stable C18 recommended), SPE cartridges, mobile phase buffers, and high‑purity solvents is provided.
Practical applications and users
ISO 16308 is intended for environmental and regulatory laboratories performing pesticide monitoring and water quality control. Typical applications include:
- Regulatory compliance testing for drinking water and groundwater monitoring programs
- Surface‑water monitoring for agricultural runoff and watershed contamination studies
- Routine laboratory surveillance by water utilities and public health agencies
- Research on pesticide fate, transport and degradation (AMPA formation)
Laboratories adopting this method benefit from sensitive, specific detection of glyphosate and AMPA with robust matrix compensation using isotopic surrogates.
Related standards (normative references)
- ISO 3696 - Water for analytical laboratory use
- ISO 5667‑3 - Water quality - Sampling: preservation and handling
- ISO 8466‑1 - Calibration and evaluation of analytical methods (statistical evaluation)
Keywords: SIST ISO 16308:2018, glyphosate, AMPA, HPLC–MS/MS, water quality, derivatization FMOC‑Cl, SPE, matrix‑matched calibration, drinking water testing.