ISO 11206:2011

Overview

ISO 11206:2011 defines a validated laboratory method for the determination of dissolved bromate in water using ion chromatography (IC) combined with a post‑column reaction (PCR) and UV detection. The standard applies to drinking water, mineral water, raw and surface water, partially treated water and swimming‑pool water. With appropriate sample pretreatment (e.g., dilution, removal of oxidants or solids) the method determines bromate at concentrations ≥ 0,5 µg/l; the working range is limited by the ion‑exchange capacity of the separator column.

Key topics and technical requirements

• Principle: Anion separation by IC followed by a PCR where bromate oxidizes iodide (in the presence of catalytic molybdenum(VI)) to tri‑iodide, detected by UV absorbance (typical measurement around 352 nm).
• Sensitivity & range: Method allows detection from 0,5 µg/l upward; sample dilution may be needed to fit the column working range.
• Reagents and PCR mix: Uses degassed eluents (carbonate or sulfuric acid eluents are given as examples) and a PCR reagent typically containing potassium iodide and a small amount of ammonium heptamolybdate (document provides preparation details).
• Apparatus: Complete IC system with degasser, pump, sample injector/autosampler, separator column, in‑line PCR module (reaction coil ≈500 µl, heater ~80 °C) and UV detector (190–400 nm).
• Quality criteria: Chromatographic resolution requirement - peak resolution between bromate and nearest peak must be ≥ 1.3; method performance is verified by calibration and validity checks.
• Interferences & pretreatment: Remove ozone, chlorine dioxide, chlorite, metals and solids as necessary. Chlorite can specifically interfere and has a recommended removal step. Cation cartridge treatment may be required to protect columns.
• Calibration and evaluation: Calibration of the overall procedure per ISO 8466‑1 (or ISO 8466‑2 for non‑linear cases) and control experiments to verify calibration validity; method of standard additions recommended where matrix effects are expected.

Practical applications and who uses it

• Water utilities and laboratories monitoring bromate in drinking water and distribution systems where ozone or bromide oxidation may generate bromate.
• Bottled/mineral water producers, environmental monitoring labs, pool water testing facilities and regulatory agencies enforcing water quality standards.
• Method developers and instrument vendors validating IC/PCR systems for low‑level bromate analysis.

Related standards

• ISO 3696 (water for analytical use)
• ISO 8466‑1 / ISO 8466‑2 (calibration and evaluation)
• Related IC standards: ISO 10304‑1, ISO 10304‑4 and ISO 15061 (method compatibility noted in the standard)

Keywords: ISO 11206, bromate determination, ion chromatography (IC), post‑column reaction (PCR), water quality, drinking water testing, bromate analysis.