ISO 17852:2006

Overview - ISO 17852:2006 (Water quality - Mercury by AFS)

ISO 17852:2006 defines a validated laboratory method for the determination of total mercury in drinking, surface, ground and rain water using atomic fluorescence spectrometry (AFS). The standard covers sample pre‑treatment (including chemical digestion), reagent and standard preparation, instrumental setup, interferences, precision and reporting. It can be extended to industrial and municipal waste waters after appropriate additional digestion.

Key topics and technical requirements

• Analytical principle: Mercury atoms are detected by atomic fluorescence after generation of elemental mercury vapour (reduction with Sn(II)) and purging into an AFS detector.
• Sample digestion / preservation: Organic mercury species are decomposed with chemically generated bromine/bromine chloride (potassium bromide / potassium bromate reagent). Excess oxidant is removed with ascorbic acid prior to analysis.
• Reagents & standards: High‑purity water (ISO 3696 grade 1) and low‑mercury reagents are required. The standard specifies preparation of stock and calibration standards and recommends matched matrix reagent blanks.
• Range & detection limits: Potential linear dynamic range ≈ 1 ng/l to 100 µg/l; practical working range often 10 ng/l to 10 µg/l. With careful reagent selection, method detection limits < 1 ng/l are obtainable. Precision is typically < 5% relative standard deviation for concentrations > 20× the method detection limit.
• Instrumentation & accessories: Continuous‑flow vapour generator, gas–liquid separator, moisture removal (hygroscopic membrane), AFS detector and high‑purity argon gas supply are detailed. Clean labware and sample handling procedures are emphasized to avoid contamination and mercury loss.
• Interferences & controls: Notes on adsorption/desorption, tubing material (avoid permeable plastics such as silicone), quenching by water vapour, complexing anions (sulfide, iodide, bromide), and amalgamation by noble metals.

Applications - who uses ISO 17852:2006

• Environmental and public‑health laboratories performing water quality monitoring for regulatory compliance.
• Municipal and industrial laboratories monitoring effluent and process waters (with additional digestion).
• Research institutes studying mercury cycling, contamination incidents, and remediation effectiveness.
• Instrument manufacturers and service providers validating AFS systems and training analytical staff.

Related standards and references

• ISO 3696 - Water for analytical laboratory use (grade 1)
• ISO 5667-1, -2, -3 - Water sampling guidance (design, techniques, preservation/handling)

Keywords: ISO 17852:2006, water quality, mercury determination, atomic fluorescence spectrometry, AFS, detection limit, mercury in water, mercury monitoring, environmental laboratory.