Overview
EN ISO 11206:2013 (ISO 11206:2011) specifies a validated analytical method for the determination of dissolved bromate in water using ion chromatography (IC) combined with a post column reaction (PCR). The method applies to a range of water types (drinking water, mineral water, raw and surface waters, partially treated water, swimming pool water). With appropriate sample pretreatment (e.g. dilution, removal of oxidants and solids) the method can detect bromate down to about 0.5 µg/L. The working range is ultimately limited by the ion‑exchange capacity of the separator column; dilution may be required to bring samples into range.
Key topics and technical requirements
- Analytical principle: separation of bromate by anion-exchange IC, followed by a PCR where bromate oxidizes iodide (catalysed by molybdenum(VI)) to tri-iodide, measured by UV absorbance at 352 nm.
- Detection limit and working range: practical detection ~0.5 µg/L; working range depends on column capacity and eluent/gradient selection.
- Reagents and PCR reagent: high-purity water (ISO 3696), eluents (carbonate or sulfuric acid examples), and a PCR reagent composed of potassium iodide with catalytic ammonium heptamolybdate (prepared fresh, deoxygenated and protected from light).
- Sample pretreatment: remove ozone, chlorine dioxide, chlorite, metals and solids as required; dilution and filtration may be necessary.
- Interferences: metal ions, organic matter, particulate matter and especially chlorite can interfere; procedures for chlorite removal and use of cation-exchange cleanup are specified.
- Quality and calibration: separator column resolution and PCR conditions must meet defined performance checks. Calibration and evaluation follow ISO 8466‑1 / ISO 8466‑2 procedures; regular checks and possible use of standard addition are recommended when matrix effects are suspected.
- Apparatus and operation: choice of column, eluent composition (isocratic or gradient) and degassing/helium sparging are important to maintain resolution and detector stability.
Applications and users
- Routine monitoring of drinking water safety and compliance testing where bromate is a regulated disinfection by-product.
- Water utilities, environmental and public health laboratories, bottled water producers, pool operators and contract testing laboratories.
- Method useful for process control in water treatment plants and research on formation and removal of bromate.
Related standards
Keywords: EN ISO 11206:2013, ISO 11206, bromate determination, ion chromatography (IC), post column reaction (PCR), water quality, bromate 0.5 µg/L, water monitoring.